/* Hallmark · macrostructure: Workbench (pinned player) + Marquee Hero · tone: kinetic-technical · anchor hue: lime 128°
 * genre: atmospheric · theme: custom "光譜實驗室 Spectrum Lab" · nav: N5 floating pill (hide-on-scroll) · footer: Ft5 statement
 * enrichment: Tier-A WebGL light-field (hero) + live demo card · motion: maximal by user request — GSAP/ScrollTrigger + Lenis,
 *   transform/opacity only, paused offscreen, full prefers-reduced-motion fallback
 * differs from v2 (Marquee · dark / classical-serif / warm) on: display style · accent hue · macrostructure
 * Hallmark · pre-emit critique: P5 H5 E5 S4 R4 V5
 */
@import url("tokens.css");

/* =========================================================
 * Base
 * ========================================================= */
*,
*::before,
*::after { box-sizing: border-box; }

html,
body { overflow-x: clip; }

html { -webkit-text-size-adjust: 100%; }
html:not(.lenis) { scroll-behavior: smooth; }
html.lenis, html.lenis body { height: auto; }
.lenis.lenis-smooth { scroll-behavior: auto !important; }
.lenis.lenis-stopped { overflow: hidden; }

[id] { scroll-margin-top: var(--nav-offset); }

body {
  margin: 0;
  background: var(--color-paper);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg, video, canvas { display: block; max-width: 100%; }
a { color: inherit; }
button, input { font: inherit; color: inherit; }
h1, h2, h3 { margin: 0; font-style: normal; }
p, ul, ol, figure { margin: 0; }
::selection { background: var(--color-accent); color: var(--color-on-accent); }

:focus-visible { outline: var(--rule-bold) solid var(--color-focus); outline-offset: 3px; }

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--space-sm);
}
@media (min-width: 768px) { .wrap { padding-inline: var(--space-xl); } }

.skip {
  position: fixed;
  left: var(--space-sm);
  top: -100px;
  z-index: calc(var(--z-loader) + 1);
  padding: var(--space-2xs) var(--space-sm);
  border-radius: var(--radius-sm);
  background: var(--color-accent);
  color: var(--color-on-accent);
}
.skip:focus { top: var(--space-sm); }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.section-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-4xl);
  line-height: 1.08;
  letter-spacing: -0.02em;
  overflow-wrap: anywhere;
  min-width: 0;
}
.lead { margin-top: var(--space-md); max-width: 34rem; color: var(--color-ink-2); font-size: var(--text-lg); }

/* split text (JS wraps characters in .ch) */
.ch-wrap { display: inline-block; vertical-align: top; padding-bottom: 0.08em; margin-bottom: -0.08em; }
.ch { display: inline-block; will-change: transform; }
.ch-word { display: inline-block; white-space: nowrap; }
/* decode headings: scrambling glyphs use the accent */
.ch.is-scramble { color: var(--color-accent); }

.spark {
  display: inline-block;
  width: 10px;
  height: 10px;
  flex: none;
  background: var(--color-accent);
  clip-path: polygon(50% 0, 62% 38%, 100% 50%, 62% 62%, 50% 100%, 38% 62%, 0 50%, 38% 38%);
}

/* =========================================================
 * Loader · progress · cursor
 * ========================================================= */
.loader {
  position: fixed;
  inset: 0;
  z-index: var(--z-loader);
  display: none;
  place-items: center;
  align-content: center;
  gap: var(--space-lg);
  background: var(--color-paper);
}
.js .loader { display: grid; animation: loader-fallback 400ms var(--ease-out) 3s forwards; }
.loader.is-done { pointer-events: none; }
@keyframes loader-fallback { to { opacity: 0; visibility: hidden; } }
.loader__mark { position: relative; display: grid; place-items: center; width: 112px; height: 112px; }
.loader__mark span {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: var(--rule-bold) solid transparent;
  border-top-color: var(--color-accent);
  animation: spin 1.1s var(--ease-in-out) infinite;
}
.loader__mark span:nth-child(2) { inset: 10px; border-top-color: var(--color-cyan); animation-duration: 1.4s; animation-direction: reverse; }
.loader__logo { width: 44px; height: auto; }
.loader__bar { width: 160px; height: 2px; border-radius: var(--radius-pill); background: var(--color-rule); overflow: hidden; }
.loader__bar span { display: block; height: 100%; background: var(--color-accent); transform-origin: left; transform: scaleX(0); }
@keyframes spin { to { transform: rotate(360deg); } }

.progress {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: calc(var(--z-sticky-nav) + 1);
  height: 2px;
  pointer-events: none;
}
.progress span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-accent));
  transform-origin: left;
  transform: scaleX(0);
}

.cursor { display: none; }
@media (hover: hover) and (pointer: fine) {
  .has-cursor .cursor { display: block; }
  .has-cursor, .has-cursor a, .has-cursor button { cursor: none; }
  .has-cursor input { cursor: text; }
}
.cursor__dot, .cursor__ring {
  position: fixed;
  top: 0;
  left: 0;
  z-index: var(--z-cursor);
  pointer-events: none;
  border-radius: 50%;
}
.cursor__dot { width: 6px; height: 6px; margin: -3px 0 0 -3px; background: var(--color-accent); }
.cursor__ring {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  margin: -18px 0 0 -18px;
  border: var(--rule-hair) solid var(--color-ink-3);
}
.cursor__ring::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: var(--color-accent);
  transform: scale(0);
  transition: transform var(--dur-base) var(--ease-out);
}
.cursor__label {
  position: relative;
  max-width: 46px;
  font-size: 0.625rem;
  font-weight: 700;
  line-height: 1.1;
  text-align: center;
  color: var(--color-on-accent);
  opacity: 0;
  transition: opacity var(--dur-fast) var(--ease-out);
}
.cursor.is-hover .cursor__ring { border-color: var(--color-accent); }
.cursor.is-label .cursor__ring::before { transform: scale(1.44); } /* 52px (was 86px) */
.cursor.is-label .cursor__label { opacity: 1; }
.cursor.is-label .cursor__dot { opacity: 0; }

/* =========================================================
 * Buttons
 * ========================================================= */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2xs);
  min-height: var(--control-h);
  padding: 0 var(--space-md);
  border: var(--rule-hair) solid transparent;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: var(--text-sm);
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  isolation: isolate;
  overflow: hidden;
  transition:
    color var(--dur-fast) var(--ease-out),
    border-color var(--dur-fast) var(--ease-out),
    box-shadow var(--dur-base) var(--ease-out);
}
.btn--sm { min-height: 38px; padding-inline: var(--space-sm); }
.btn--lg { min-height: 54px; padding-inline: var(--space-lg); font-size: var(--text-base); }
.btn:disabled, .btn[aria-disabled="true"] { opacity: 0.55; cursor: not-allowed; }
.btn:active { box-shadow: none; }

.btn--accent { background: var(--color-accent); color: var(--color-on-accent); }
.btn--accent::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: var(--color-accent-hover);
  transform: translateY(101%);
  border-radius: inherit;
  transition: transform var(--dur-base) var(--ease-out);
}
.btn--accent:hover { box-shadow: 0 0 40px -6px var(--color-glow); }
.btn--accent:hover::after { transform: translateY(0); }

.btn--ghost { border-color: var(--color-rule-strong); color: var(--color-ink); background: var(--color-glass); }
.btn--ghost:hover { border-color: var(--color-ink-3); }

.btn[data-state="loading"] { cursor: progress; opacity: 0.8; }
.btn[data-state="success"] { background: var(--color-success); color: var(--color-on-accent); }
.btn[data-state="error"] { background: var(--color-danger); color: var(--color-on-accent); }

.play-ic {
  width: 0;
  height: 0;
  border-left: 9px solid currentColor;
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
}

/* =========================================================
 * Nav · N5 floating pill, hides on scroll down
 * ========================================================= */
.nav {
  position: fixed;
  top: calc(var(--space-sm) + env(safe-area-inset-top, 0px));
  left: 50%;
  z-index: var(--z-sticky-nav);
  width: calc(100% - var(--space-lg));
  max-width: 960px;
  transform: translateX(-50%);
  transition: transform var(--dur-slow) var(--ease-out), opacity var(--dur-base) var(--ease-out);
}
.nav.is-hidden { transform: translate(-50%, calc(-100% - var(--space-lg))); }
.nav__pill {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-2xs) var(--space-2xs) var(--space-2xs) var(--space-sm);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-pill);
  background: var(--color-glass);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  box-shadow: 0 20px 40px -24px var(--color-shade);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-sm);
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
}
.brand__logo { display: block; width: auto; height: 28px; }
.brand__ai {
  display: inline-grid;
  place-items: center;
  min-height: 20px;
  padding: 0 var(--space-2xs);
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  color: var(--color-on-accent);
  font-family: var(--font-display);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.02em;
}
.nav__links {
  display: none;
  gap: var(--space-3xs);
  margin: 0 0 0 auto;
  padding: 0;
  list-style: none;
}
.nav__links a, .nav__login {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 var(--space-xs);
  border-radius: var(--radius-pill);
  color: var(--color-ink-2);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur-fast) var(--ease-out), background-color var(--dur-fast) var(--ease-out);
}
.nav__links a:hover, .nav__login:hover { color: var(--color-ink); background: var(--color-paper-4); }
.nav__links a.is-active, .nav__links a[aria-current="page"], .nav__login[aria-current="page"] { color: var(--color-ink); background: var(--color-paper-4); }
.nav__login, .nav__cta { display: none; }
.nav__toggle {
  position: relative;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-left: auto;
  border: 0;
  border-radius: 50%;
  background: var(--color-paper-4);
  cursor: pointer;
}
.nav__burger { position: relative; width: 18px; height: 10px; }
.nav__burger span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur-base) var(--ease-out), top var(--dur-base) var(--ease-out);
}
.nav__burger span:first-child { top: 0; }
.nav__burger span:last-child { top: 8px; }
.nav__toggle[aria-expanded="true"] .nav__burger span:first-child { top: 4px; transform: rotate(45deg); }
.nav__toggle[aria-expanded="true"] .nav__burger span:last-child { top: 4px; transform: rotate(-45deg); }
@media (min-width: 900px) {
  .nav__links, .nav__login, .nav__cta { display: inline-flex; }
  .nav__links { margin-left: 0; }
  .nav__toggle { display: none; }
  .menu { display: none !important; }
}

.menu {
  position: fixed;
  inset: 0;
  z-index: calc(var(--z-sticky-nav) - 1);
  display: grid;
  align-content: center;
  gap: var(--space-xl);
  padding: var(--space-4xl) var(--space-md) var(--space-xl);
  background: var(--color-scrim);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
}
.menu[hidden] { display: none; }
.menu__links { list-style: none; margin: 0; padding: 0; }
.menu__links a {
  display: flex;
  align-items: baseline;
  gap: var(--space-sm);
  padding-block: var(--space-2xs);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-3xl);
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
}
.menu__links a span { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-accent); }
.menu__foot { display: grid; gap: var(--space-2xs); }

/* =========================================================
 * Hero
 * ========================================================= */
.hero {
  position: relative;
  display: grid;
  align-items: center;
  min-height: 100svh;
  padding-block: calc(var(--nav-offset) + var(--space-lg)) var(--space-4xl);
  overflow: clip;
  isolation: isolate;
}
.hero__gl, .hero__veil {
  position: absolute;
  inset: 0;
  z-index: -2;
  width: 100%;
  height: 100%;
}
.hero__gl {
  background:
    radial-gradient(60% 60% at 80% 30%, var(--color-cyan-soft), transparent 70%),
    radial-gradient(50% 50% at 20% 80%, var(--color-accent-soft), transparent 70%),
    var(--color-paper);
}
.hero__veil {
  z-index: -1;
  background:
    linear-gradient(to bottom, transparent 55%, var(--color-paper)),
    radial-gradient(70% 90% at 25% 50%, var(--color-scrim), transparent 75%);
  pointer-events: none;
}
.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-2xl);
  align-items: center;
}
@media (min-width: 1100px) { .hero__grid { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); } }

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  min-height: 34px;
  padding: 0 var(--space-sm);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-pill);
  background: var(--color-glass);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-ink-2);
}
.badge__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 0 var(--color-glow);
  animation: ping 2s var(--ease-out) infinite;
}
@keyframes ping {
  0% { box-shadow: 0 0 0 0 var(--color-glow); }
  100% { box-shadow: 0 0 0 10px transparent; }
}

.hero__title {
  margin-top: var(--space-md);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.6rem, 0.4rem + 5.6vw, 6rem);
  line-height: 1.06;
  letter-spacing: -0.03em;
  overflow-wrap: anywhere;
  min-width: 0;
}
.hero__title :lang(zh-Hant), .hero__title { font-feature-settings: "palt"; }
.hero__line { display: block; padding-bottom: 0.06em; } /* no mask: the intro fades whole letters in */
.hero__in { display: inline-block; }
.hero__line--accent { color: var(--color-accent); }

.rotator { position: relative; display: inline-grid; vertical-align: top; }
.rotator__item {
  grid-area: 1 / 1;
  white-space: nowrap;
  opacity: 0;
}
.rotator__item.is-on { opacity: 1; }
.no-motion .rotator__item { transition: none; }

.hero__lede { margin-top: var(--space-lg); max-width: 32rem; font-size: var(--text-lg); color: var(--color-ink-2); }
.hero__actions { display: flex; flex-wrap: wrap; gap: var(--space-xs); margin-top: var(--space-xl); }

.hero__demo { position: relative; justify-self: center; width: 100%; max-width: 480px; perspective: 1200px; }
.live {
  position: relative;
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-lg);
  background: var(--color-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 40px 80px -40px var(--color-shade), 0 0 0 1px var(--color-paper-2) inset;
  overflow: hidden;
  transform-style: preserve-3d;
}
.live__head, .live__foot {
  display: flex;
  align-items: center;
  gap: var(--space-2xs);
  padding: var(--space-sm) var(--space-md);
  font-size: var(--text-sm);
  color: var(--color-ink-2);
}
.live__head { border-bottom: var(--rule-hair) solid var(--color-rule); }
.live__rec { width: 8px; height: 8px; border-radius: 50%; background: var(--color-coral); animation: blink 1.4s steps(2) infinite; }
@keyframes blink { 50% { opacity: 0.2; } }
.live__time { margin-left: auto; font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-ink-3); }
.live__body { display: grid; gap: var(--space-sm); padding: var(--space-md); align-content: start; }
.bubble { border-radius: var(--radius-md); padding: var(--space-sm) var(--space-md); font-size: var(--text-sm); line-height: 1.6; }
.bubble--user { display: grid; justify-self: end; max-width: 88%; background: var(--color-paper-4); border-bottom-right-radius: var(--space-3xs); }
.live__ghost, .live__typing { grid-area: 1 / 1; }
.live__ghost { visibility: hidden; }
.bubble--ai { background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-rule); border-bottom-left-radius: var(--space-3xs); opacity: 0; }
.bubble--ai.is-on { opacity: 1; transition: opacity var(--dur-base) var(--ease-out); }
.bubble__who { display: flex; align-items: center; gap: var(--space-2xs); font-size: var(--text-xs); font-weight: 700; color: var(--color-accent); margin-bottom: var(--space-2xs); }
.caret { display: inline-block; width: 2px; height: 1.1em; margin-left: 2px; vertical-align: text-bottom; background: var(--color-accent); animation: blink 1s steps(2) infinite; }
.live__list { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--space-2xs); }
.live__list li { display: flex; gap: var(--space-2xs); align-items: flex-start; opacity: 0; transform: translateY(8px); transition: opacity var(--dur-base) var(--ease-out), transform var(--dur-base) var(--ease-out); }
.live__list li.is-on { opacity: 1; transform: none; }
.live__list li::before { content: ""; flex: none; width: 14px; height: 14px; margin-top: 4px; border: var(--rule-bold) solid var(--color-accent); border-radius: 4px; }
.live__foot { border-top: var(--rule-hair) solid var(--color-rule); font-size: var(--text-xs); }
.live__chapter { white-space: nowrap; }
.live__track { flex: 1; height: 4px; border-radius: var(--radius-pill); background: var(--color-paper-4); overflow: hidden; }
.live__track span { display: block; height: 100%; background: var(--color-accent); transform-origin: left; transform: scaleX(0.1); }

.float-chip {
  position: absolute;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  padding: var(--space-2xs) var(--space-sm);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-pill);
  background: var(--color-paper-3);
  box-shadow: 0 20px 40px -20px var(--color-shade);
  font-size: var(--text-xs);
  font-weight: 700;
  white-space: nowrap;
  pointer-events: none;
}
.float-chip--a { top: -18px; left: -12px; color: var(--color-accent); }
.float-chip--b { bottom: 64px; right: -20px; }
.float-chip--c { bottom: -16px; left: 18%; color: var(--color-cyan); }
@media (max-width: 599px) { .float-chip--b { right: 0; } .float-chip--a { left: 0; } }
.kbd { font-family: var(--font-mono); padding: 0 var(--space-3xs); border: var(--rule-hair) solid var(--color-rule-strong); border-radius: 4px; }

.hero__scroll {
  position: absolute;
  bottom: var(--space-lg);
  left: 50%;
  translate: -50% 0;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
}
.hero__mouse { position: relative; width: 22px; height: 34px; border: var(--rule-bold) solid var(--color-ink-3); border-radius: 12px; }
.hero__mouse span { position: absolute; top: 6px; left: 50%; width: 3px; height: 7px; margin-left: -1.5px; border-radius: 2px; background: var(--color-accent); animation: wheel 1.6s var(--ease-in-out) infinite; }
@keyframes wheel { 0% { transform: translateY(0); opacity: 1; } 80% { transform: translateY(10px); opacity: 0; } 100% { opacity: 0; } }

/* =========================================================
 * Ticker
 * ========================================================= */
.ticker {
  display: grid;
  gap: var(--space-2xs);
  padding-block: var(--space-lg);
  border-block: var(--rule-hair) solid var(--color-rule);
  overflow: clip;
  -webkit-mask: linear-gradient(90deg, transparent, var(--color-ink) 10%, var(--color-ink) 90%, transparent);
  mask: linear-gradient(90deg, transparent, var(--color-ink) 10%, var(--color-ink) 90%, transparent);
}
.ticker__row { display: flex; width: max-content; will-change: transform; }
.ticker__track {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  padding-right: var(--space-lg);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-3xl);
  line-height: 1.2;
  white-space: nowrap;
}
.ticker__track i { font-style: normal; font-size: var(--text-lg); color: var(--color-accent); }
.ticker__row--alt .ticker__track { color: var(--color-ink-3); font-family: var(--font-body); font-weight: 700; font-size: var(--text-xl); }
.ticker__row--alt .ticker__track i { color: var(--color-cyan); font-size: var(--text-xs); }

/* =========================================================
 * Method · pinned player
 * ========================================================= */
.method { padding-block: var(--space-4xl); }
.method__pin {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-xl);
  align-items: center;
}
@media (min-width: 960px) {
  .method__pin { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: var(--space-3xl); }
}
.steps { list-style: none; margin: var(--space-lg) 0 0; padding: 0; display: grid; gap: var(--space-3xs); }
.step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-sm);
  width: 100%;
  padding: var(--space-xs) var(--space-sm);
  border: var(--rule-hair) solid transparent;
  border-radius: var(--radius-md);
  background: transparent;
  text-align: left;
  cursor: pointer;
  opacity: 0.55;
  transition: opacity var(--dur-base) var(--ease-out), background-color var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out);
}
.step:hover { opacity: 0.85; }
.step.is-on { opacity: 1; background: var(--color-paper-2); border-color: var(--color-rule-strong); }
.step__no { font-family: var(--font-mono); font-size: var(--text-sm); color: var(--color-ink-3); padding-top: 2px; }
.step.is-on .step__no { color: var(--color-accent); }
.step__txt { display: grid; grid-template-rows: auto 0fr; transition: grid-template-rows var(--dur-slow) var(--ease-out); }
.step.is-on .step__txt { grid-template-rows: auto 1fr; }
.step__txt strong { font-size: var(--text-lg); line-height: 1.4; }
.step__txt span { min-height: 0; overflow: hidden; font-size: var(--text-sm); color: var(--color-ink-2); }
.step__txt span::before { content: ""; display: block; height: var(--space-3xs); }

.stage {
  position: relative;
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(80% 60% at 100% 0%, var(--color-cyan-soft), transparent 60%),
    radial-gradient(60% 50% at 0% 100%, var(--color-accent-soft), transparent 60%),
    var(--color-paper-2);
  box-shadow: 0 60px 120px -60px var(--color-shade);
  overflow: hidden;
  transform-style: preserve-3d;
}
.stage__top { display: flex; align-items: center; justify-content: space-between; padding: var(--space-sm) var(--space-md); border-bottom: var(--rule-hair) solid var(--color-rule); font-size: var(--text-xs); color: var(--color-ink-3); }
.stage__dotline { display: flex; gap: var(--space-3xs); }
.stage__dotline span { width: 6px; height: 6px; border-radius: 50%; background: var(--color-rule-strong); }
.stage__dotline span:first-child { background: var(--color-accent); }
.stage__label b { color: var(--color-ink); font-family: var(--font-mono); }
.stage__screen { position: relative; min-height: 400px; padding: var(--space-lg); }
@media (min-width: 768px) { .stage__screen { min-height: 440px; padding: var(--space-xl); } }
.scene {
  position: absolute;
  inset: var(--space-lg);
  display: grid;
  align-content: center;
  gap: var(--space-md);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-slow) var(--ease-out), visibility 0s linear var(--dur-slow);
}
@media (min-width: 768px) { .scene { inset: var(--space-xl); } }
.scene.is-on { opacity: 1; visibility: visible; transition: opacity var(--dur-slow) var(--ease-out), visibility 0s; }
.scene__cap { font-size: var(--text-sm); color: var(--color-ink-3); }
.stage__bar { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-2xs); padding: 0 var(--space-md) var(--space-md); }
.seg { height: 3px; border-radius: var(--radius-pill); background: var(--color-rule-strong); overflow: hidden; }
.seg i { display: block; height: 100%; background: var(--color-accent); transform-origin: left; transform: scaleX(0); }

/* scene 1 · prompt parts */
.parts { display: flex; flex-wrap: wrap; gap: var(--space-2xs); }
.part {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  padding: var(--space-2xs) var(--space-sm);
  border-radius: var(--radius-pill);
  border: var(--rule-hair) solid var(--color-rule-strong);
  background: var(--color-paper-3);
  font-size: var(--text-sm);
}
.part em { font-style: normal; font-size: var(--text-xs); font-weight: 700; padding: 2px var(--space-2xs); border-radius: var(--radius-pill); }
.part--role em { background: var(--color-accent-soft); color: var(--color-accent); }
.part--task em { background: var(--color-cyan-soft); color: var(--color-cyan); }
.part--fmt em { background: var(--color-coral-soft); color: var(--color-coral); }
.part--ex em { background: var(--color-paper-4); color: var(--color-ink-2); }
.prompt-out { padding: var(--space-md); border-radius: var(--radius-md); background: var(--color-paper); border: var(--rule-hair) solid var(--color-accent-deep); box-shadow: 0 0 40px -20px var(--color-glow); }
.prompt-out__label { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-accent); }
.prompt-out p { margin-top: var(--space-2xs); font-family: var(--font-mono); font-size: var(--text-sm); line-height: 1.7; color: var(--color-ink-2); }

/* scene 2 · generation */
.gen { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--space-xs); }
.gen li {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  background: var(--color-paper-3);
  font-size: var(--text-sm);
}
.gen b { margin-left: auto; font-weight: 600; color: var(--color-ink-3); white-space: nowrap; }
.tick { position: relative; width: 20px; height: 20px; flex: none; border-radius: 6px; background: var(--color-accent); }
.tick::after { content: ""; position: absolute; left: 7px; top: 3px; width: 5px; height: 10px; border: solid var(--color-on-accent); border-width: 0 2px 2px 0; transform: rotate(45deg); }
.gen__hint { display: flex; align-items: center; gap: var(--space-2xs); font-size: var(--text-sm); color: var(--color-ink-2); }

/* scene 3 · flow svg */
.flow { width: 100%; height: auto; overflow: visible; }
.flow__path { fill: none; stroke: var(--color-accent-deep); stroke-width: 2; stroke-dasharray: 6 8; }
.flow__node rect { fill: var(--color-paper-3); stroke: var(--color-rule-strong); stroke-width: 1; }
.flow__node text { fill: var(--color-ink); font-family: var(--font-body); font-size: 15px; font-weight: 700; text-anchor: middle; }
.flow__node--ai rect { fill: var(--color-accent); stroke: var(--color-accent); }
.flow__node--ai text { fill: var(--color-on-accent); }
.flow__pulse { fill: var(--color-accent); filter: drop-shadow(0 0 6px var(--color-accent)); }
.flow__pulse--2 { fill: var(--color-cyan); filter: drop-shadow(0 0 6px var(--color-cyan)); }

/* scene 4 · result */
.result { position: relative; display: grid; }
.result__bars { display: flex; align-items: flex-end; gap: var(--space-sm); height: 240px; padding: var(--space-md); border-radius: var(--radius-md); background: var(--color-paper); border: var(--rule-hair) solid var(--color-rule); }
.result__bars span {
  position: relative;
  flex: 1;
  height: var(--h);
  border-radius: var(--space-2xs) var(--space-2xs) 4px 4px;
  background: linear-gradient(to top, var(--color-accent-deep), var(--color-accent));
  transform-origin: bottom;
}
.result__bars span:nth-child(1) { --h: 42%; }
.result__bars span:nth-child(2) { --h: 68%; }
.result__bars span:nth-child(3) { --h: 55%; }
.result__bars span:nth-child(4) { --h: 86%; }
.result__bars span:nth-child(5) { --h: 74%; }
.result__bars span:nth-child(even) { background: linear-gradient(to top, var(--color-cyan-soft), var(--color-cyan)); }
.result__bars i { position: absolute; bottom: calc(var(--space-md) * -1 - 2px); left: 50%; translate: -50% 100%; font-style: normal; font-size: var(--text-xs); color: var(--color-ink-3); }
.result__stamp {
  position: absolute;
  top: calc(var(--space-sm) * -1);
  right: var(--space-sm);
  display: grid;
  place-items: center;
  width: 92px;
  height: 92px;
  border-radius: 50%;
  border: var(--rule-bold) solid var(--color-accent);
  color: var(--color-accent);
  font-family: var(--font-display);
  font-weight: 700;
  transform: rotate(-12deg);
  box-shadow: 0 0 40px -10px var(--color-glow);
  background: var(--color-paper-2);
}

/* =========================================================
 * Courses · rail
 * ========================================================= */
.courses { padding-block: var(--space-4xl); }
.courses__head { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-lg); align-items: end; margin-bottom: var(--space-xl); }
@media (min-width: 1100px) { .courses__head { grid-template-columns: minmax(0, 1fr) auto; } }
.courses__ctrl { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-sm); min-width: 0; }
.filters { display: flex; gap: var(--space-2xs); overflow-x: auto; scrollbar-width: none; padding-block: var(--space-3xs); max-width: 100%; }
.filters::-webkit-scrollbar { display: none; }
.filter, .task {
  flex: none;
  min-height: 40px;
  padding: 0 var(--space-sm);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--color-ink-2);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out);
}
.filter:hover, .task:hover { border-color: var(--color-ink-3); color: var(--color-ink); }
.filter:active, .task:active { transform: translateY(1px); }
.filter:disabled, .task:disabled { opacity: 0.55; cursor: not-allowed; }
.filter[aria-pressed="true"], .task[aria-pressed="true"] { background: var(--color-accent); border-color: var(--color-accent); color: var(--color-on-accent); }
.arrows { display: flex; gap: var(--space-2xs); }
.arrow {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: 50%;
  background: transparent;
  font-size: var(--text-lg);
  cursor: pointer;
  transition: background-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.arrow:hover { background: var(--color-ink); color: var(--color-paper); }
.arrow:active { transform: scale(0.96); }
.arrow:disabled { opacity: 0.35; cursor: not-allowed; }

.rail {
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  scroll-padding-inline: max(var(--space-xl), calc((100vw - var(--wrap)) / 2 + var(--space-xl)));
  scrollbar-width: none;
  cursor: grab;
}
@media (max-width: 767px) { .rail { scroll-padding-inline: var(--space-sm); } }
.rail::-webkit-scrollbar { display: none; }
.rail.is-drag { cursor: grabbing; scroll-snap-type: none; }
.rail.is-drag .card__link { pointer-events: none; }
.rail .card__link, .rail img, .rail svg { -webkit-user-drag: none; user-select: none; -webkit-user-select: none; }
.rail__track {
  display: flex;
  gap: var(--space-md);
  width: max-content;
  margin: 0;
  padding: var(--space-md) max(var(--space-xl), calc((100vw - var(--wrap)) / 2 + var(--space-xl))) var(--space-xl);
  list-style: none;
}
@media (max-width: 767px) { .rail__track { padding-inline: var(--space-sm); } }
.card { width: min(78vw, 360px); flex: none; scroll-snap-align: start; }
.card.is-out { display: none; }
.card__link {
  display: flex;
  flex-direction: column;
  height: 100%;
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-lg);
  background: var(--color-paper-2);
  text-decoration: none;
  overflow: hidden;
  transform-style: preserve-3d;
  transition: border-color var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out);
}
.card__link:hover { border-color: var(--color-accent-deep); box-shadow: 0 30px 60px -30px var(--color-glow); }
.card__link:active { border-color: var(--color-accent); }
.card__body { display: flex; flex-direction: column; gap: var(--space-2xs); padding: var(--space-md); flex: 1; }
.card__series { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-ink-3); }
.card__title { font-family: var(--font-display); font-weight: 600; font-size: var(--text-xl); line-height: 1.3; overflow-wrap: anywhere; }
.card__body p { font-size: var(--text-sm); color: var(--color-ink-2); }
.card__go { margin-top: auto; padding-top: var(--space-sm); /* pinned to the card bottom so every card lines up */ font-size: var(--text-sm); font-weight: 700; color: var(--color-accent); }
.card__go span { display: inline-block; transition: transform var(--dur-base) var(--ease-out); }
.card__link:hover .card__go span { transform: translateX(4px); }

/* generative covers */
.cover {
  --c: var(--color-accent);
  --c-soft: var(--color-accent-soft);
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background:
    radial-gradient(70% 80% at 70% 20%, var(--c-soft), transparent 70%),
    var(--color-paper-3);
  isolation: isolate;
}
.cover--cyan { --c: var(--color-cyan); --c-soft: var(--color-cyan-soft); }
.cover--coral { --c: var(--color-coral); --c-soft: var(--color-coral-soft); }
.cover b {
  position: absolute;
  left: var(--space-md);
  bottom: var(--space-sm);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-2xl);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--color-ink);
  z-index: 2;
}
.cover--orbit span {
  position: absolute;
  width: 70%;
  aspect-ratio: 2.4;
  border: var(--rule-hair) solid var(--c);
  border-radius: 50%;
  opacity: 0.8;
  animation: spin 14s linear infinite;
}
.cover--orbit span:nth-child(2) { width: 50%; animation-duration: 9s; animation-direction: reverse; opacity: 0.6; }
.cover--orbit span:nth-child(3) { width: 18px; aspect-ratio: 1; border: 0; background: var(--c); box-shadow: 0 0 30px 6px var(--c-soft); animation: pulse-dot 2.4s var(--ease-in-out) infinite; }
@keyframes pulse-dot { 50% { transform: scale(1.5); } }
.cover--grid {
  background:
    radial-gradient(circle at center, var(--color-rule-strong) 1.5px, transparent 1.6px) 0 0 / 22px 22px,
    radial-gradient(70% 80% at 70% 20%, var(--c-soft), transparent 70%),
    var(--color-paper-3);
}
.cover--grid span {
  position: absolute;
  top: 22%;
  left: 12%;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--c);
  box-shadow: 0 0 40px 4px var(--c-soft);
  animation: hop 6s var(--ease-in-out) infinite;
}
@keyframes hop {
  0%, 100% { transform: translate(0, 0); }
  25% { transform: translate(220%, 0) rotate(90deg); }
  50% { transform: translate(220%, 110%) rotate(180deg); }
  75% { transform: translate(0, 110%) rotate(270deg); }
}
.cover--wave svg { position: absolute; inset: 0; width: 200%; height: 100%; animation: drift 8s linear infinite; }
.cover--wave path { fill: none; stroke: var(--c); stroke-width: 2; opacity: 0.8; }
.cover--wave path:nth-child(2) { opacity: 0.45; }
.cover--wave path:nth-child(3) { opacity: 0.25; }
@keyframes drift { to { transform: translateX(-50%); } }
.cover--nodes svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.cover--nodes path { fill: none; stroke: var(--color-rule-strong); stroke-width: 2; stroke-dasharray: 5 7; animation: dash 1.6s linear infinite; }
.cover--nodes circle { fill: var(--color-paper-4); stroke: var(--c); stroke-width: 2; }
.cover--nodes .cover__pulse { fill: var(--c); stroke: none; offset-path: path("M60 110 L 200 50 L 340 110"); animation: travel 3s var(--ease-in-out) infinite; filter: drop-shadow(0 0 6px var(--c)); }
@keyframes dash { to { stroke-dashoffset: -24; } }
@keyframes travel { from { offset-distance: 0%; } to { offset-distance: 100%; } }

.rail__meter { margin-top: calc(var(--space-sm) * -1); }
.rail__progress { display: block; height: 2px; border-radius: var(--radius-pill); background: var(--color-rule); overflow: hidden; }
.rail__progress i { display: block; height: 100%; width: 100%; background: var(--color-accent); transform-origin: left; transform: scaleX(0.2); }

/* =========================================================
 * Playground
 * ========================================================= */
.play { padding-block: var(--space-4xl); }
.play__head { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-md); align-items: end; margin-bottom: var(--space-xl); }
@media (min-width: 960px) { .play__head { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); } .play__head .lead { margin-top: 0; } }
.play__box {
  display: grid;
  gap: var(--space-md);
  padding: var(--space-md);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-lg);
  background: var(--color-paper-2);
}
@media (min-width: 768px) { .play__box { padding: var(--space-lg); } }
.play__controls { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: var(--space-sm); }
.tasks { display: flex; flex-wrap: wrap; gap: var(--space-2xs); }
.mode {
  position: relative;
  display: inline-grid;
  grid-template-columns: 1fr 1fr;
  padding: var(--space-3xs);
  border-radius: var(--radius-pill);
  background: var(--color-paper);
  border: var(--rule-hair) solid var(--color-rule-strong);
  isolation: isolate;
}
.mode__opt {
  min-height: 38px;
  padding: 0 var(--space-md);
  border: 0;
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--color-ink-2);
  font-size: var(--text-sm);
  font-weight: 700;
  white-space: nowrap;
  cursor: pointer;
  transition: color var(--dur-base) var(--ease-out);
}
.mode__opt[aria-checked="true"] { color: var(--color-on-accent); }
.mode__opt:hover:not([aria-checked="true"]) { color: var(--color-ink); }
.mode__thumb {
  position: absolute;
  z-index: -1;
  top: var(--space-3xs);
  bottom: var(--space-3xs);
  left: var(--space-3xs);
  width: calc(50% - var(--space-3xs));
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  transition: transform var(--dur-base) var(--ease-out);
}
.mode.is-pro .mode__thumb { transform: translateX(100%); }
.play__panes { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-md); }
@media (min-width: 960px) { .play__panes { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); } }
.pane { position: relative; padding: var(--space-md); border-radius: var(--radius-md); background: var(--color-paper); border: var(--rule-hair) solid var(--color-rule); min-height: 220px; }
.pane__label { display: inline-flex; align-items: center; gap: var(--space-2xs); font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-ink-3); }
.play__prompt { margin-top: var(--space-sm); font-family: var(--font-mono); font-size: var(--text-sm); line-height: 1.8; color: var(--color-ink); white-space: pre-wrap; }
.play__answer { margin-top: var(--space-sm); font-size: var(--text-sm); line-height: 1.8; color: var(--color-ink-2); white-space: pre-wrap; min-height: 8em; }
.play__verdict {
  display: inline-flex;
  margin-top: var(--space-sm);
  padding: var(--space-3xs) var(--space-xs);
  border-radius: var(--radius-pill);
  font-size: var(--text-xs);
  font-weight: 700;
  opacity: 0;
  transition: opacity var(--dur-base) var(--ease-out);
}
.play__verdict.is-on { opacity: 1; }
.play__verdict[data-tone="meh"] { background: var(--color-coral-soft); color: var(--color-coral); }
.play__verdict[data-tone="good"] { background: var(--color-accent-soft); color: var(--color-accent); }
.play__run { justify-self: start; }

/* =========================================================
 * Learning path
 * ========================================================= */
.path { padding-block: var(--space-4xl); }
.path__map { position: relative; margin-top: var(--space-2xl); }
.path__svg { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.path__base, .path__line { fill: none; stroke-width: 3; vector-effect: non-scaling-stroke; }
.path__base { stroke: var(--color-rule); stroke-dasharray: 2 10; stroke-linecap: round; }
.path__line { stroke: var(--color-accent); stroke-linecap: round; filter: drop-shadow(0 0 8px var(--color-glow)); }
.path__stops { position: relative; list-style: none; margin: 0; padding: 0; display: grid; gap: var(--space-3xl); }
.stop {
  position: relative;
  max-width: 24rem;
  padding: var(--space-md) var(--space-md) var(--space-md) var(--space-xl);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-lg);
  background: var(--color-paper-2);
}
@media (min-width: 768px) { .stop--right { justify-self: end; } .stop { margin-left: var(--space-xl); } .stop--right { margin-right: var(--space-xl); } }
.stop__dot {
  position: absolute;
  left: var(--space-md);
  top: calc(var(--space-md) + 6px);
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 6px var(--color-accent-soft);
}
.stop__lv { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-accent); }
.stop h3 { margin-top: var(--space-2xs); font-family: var(--font-display); font-weight: 600; font-size: var(--text-xl); line-height: 1.3; }
.stop p { margin-top: var(--space-2xs); font-size: var(--text-sm); color: var(--color-ink-2); }

/* =========================================================
 * FAQ · animated accordion (grid-rows 0fr → 1fr)
 * ========================================================= */
.faq { padding-block: var(--space-4xl); }
.faq__grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-xl); }
@media (min-width: 960px) { .faq__grid { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: var(--space-3xl); } }
.acc__item { border-bottom: var(--rule-hair) solid var(--color-rule); }
.acc__item:first-child { border-top: var(--rule-hair) solid var(--color-rule); }
.acc__btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  width: 100%;
  padding: var(--space-md) 0;
  border: 0;
  background: transparent;
  font-size: var(--text-lg);
  font-weight: 700;
  text-align: left;
  cursor: pointer;
  transition: color var(--dur-fast) var(--ease-out);
}
.acc__btn:hover { color: var(--color-accent); }
.acc__ic { position: relative; width: 36px; height: 36px; flex: none; border-radius: 50%; border: var(--rule-hair) solid var(--color-rule-strong); transition: transform var(--dur-base) var(--ease-out), background-color var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out); }
.acc__ic::before, .acc__ic::after { content: ""; position: absolute; top: 50%; left: 50%; width: 12px; height: 2px; background: currentColor; translate: -50% -50%; }
.acc__ic::after { rotate: 90deg; transition: opacity var(--dur-fast) var(--ease-out); }
.acc__btn[aria-expanded="true"] .acc__ic { transform: rotate(180deg); background: var(--color-accent); border-color: var(--color-accent); color: var(--color-on-accent); }
.acc__btn[aria-expanded="true"] .acc__ic::after { opacity: 0; }
.acc__panel { display: grid; grid-template-rows: 0fr; transition: grid-template-rows var(--dur-slow) var(--ease-out); }
.acc__panel > div { overflow: hidden; }
.acc__panel p { padding-bottom: var(--space-md); max-width: 40rem; color: var(--color-ink-2); }
.acc__panel a { color: var(--color-accent); text-underline-offset: 0.2em; }
.acc__item.is-open .acc__panel { grid-template-rows: 1fr; }

/* =========================================================
 * CTA · rotating conic border
 * ========================================================= */
@property --angle { syntax: "<angle>"; initial-value: 0deg; inherits: false; }
.cta { padding-block: var(--space-2xl); }
.cta__card {
  position: relative;
  padding: var(--space-2xl) var(--space-md);
  border-radius: var(--radius-lg);
  background: var(--color-paper-2);
  text-align: center;
  overflow: hidden;
  isolation: isolate;
}
.cta__card::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  padding: 1.5px;
  border-radius: inherit;
  background: conic-gradient(from var(--angle), transparent 0 60%, var(--color-cyan) 75%, var(--color-accent) 90%, transparent 100%);
  -webkit-mask: linear-gradient(var(--color-ink) 0 0) content-box, linear-gradient(var(--color-ink) 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(var(--color-ink) 0 0) content-box exclude, linear-gradient(var(--color-ink) 0 0);
  animation: angle 5s linear infinite;
}
@keyframes angle { to { --angle: 360deg; } }
@media (min-width: 768px) { .cta__card { padding: var(--space-4xl) var(--space-2xl); } }
.cta__glow {
  position: absolute;
  z-index: -1;
  left: 50%;
  top: 100%;
  width: 80%;
  aspect-ratio: 2;
  translate: -50% -50%;
  border-radius: 50%;
  background: radial-gradient(closest-side, var(--color-glow), transparent);
  filter: blur(30px);
  opacity: 0.6;
}
.cta__title { font-family: var(--font-display); font-weight: 700; font-size: var(--text-4xl); line-height: 1.1; letter-spacing: -0.02em; overflow-wrap: anywhere; min-width: 0; }
.cta .lead { margin-inline: auto; }
.cta__form { display: flex; flex-wrap: wrap; justify-content: center; gap: var(--space-2xs); max-width: 34rem; margin: var(--space-xl) auto 0; }
.input {
  flex: 1 1 14rem;
  min-width: 0;
  min-height: 54px;
  padding: 0 var(--space-md);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-pill);
  background: var(--color-paper);
  color: var(--color-ink);
  outline: var(--rule-bold) solid transparent;
  outline-offset: 1px;
  transition: border-color var(--dur-fast) var(--ease-out);
}
.input::placeholder { color: var(--color-ink-3); }
.input:hover { border-color: var(--color-ink-3); }
.input:focus-visible { outline-color: var(--color-focus); }
.input[aria-invalid="true"] { border-color: var(--color-danger); }
.input:disabled { opacity: 0.55; cursor: not-allowed; }
.form-msg { flex-basis: 100%; min-height: 1.5em; font-size: var(--text-sm); color: var(--color-ink-3); }
.form-msg[data-tone="error"] { color: var(--color-danger); }

/* =========================================================
 * Footer · Ft5 statement
 * ========================================================= */
.footer { padding-block: var(--space-2xl); border-top: var(--rule-hair) solid var(--color-rule); }
.footer .wrap { max-width: 1040px; }
.footer__faq { margin-top: var(--space-2xl); }
.footer__faq .faq__grid { padding-top: var(--space-2xl); border-top: var(--rule-hair) solid var(--color-rule); }
.footer__faq .section-title { font-size: var(--text-3xl); }
.footer__faq .lead { font-size: var(--text-base); }
@media (min-width: 960px) { .footer__faq .faq__grid { grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: var(--space-2xl); } }
.footer__grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-lg); align-items: start; }
@media (min-width: 768px) { .footer__grid { grid-template-columns: auto minmax(0, 1fr); gap: var(--space-xl); } }
.footer__brand { display: grid; gap: var(--space-sm); justify-items: start; }
.footer__logo { width: clamp(180px, 20vw, 260px); height: auto; max-width: 100%; }
.footer__meta { display: grid; gap: var(--space-sm); min-width: 0; }
@media (min-width: 768px) { .footer__meta { justify-items: end; padding-top: var(--space-2xs); } }
.footer__links { display: flex; flex-wrap: wrap; gap: var(--space-2xs) var(--space-md); margin: 0; padding: 0; list-style: none; font-size: var(--text-sm); }
@media (min-width: 768px) { .footer__links { justify-content: flex-end; } }
.footer__links a { color: var(--color-ink-2); text-decoration: none; white-space: nowrap; transition: color var(--dur-fast) var(--ease-out); }
.footer__links a:hover, .footer__links a[aria-current="page"] { color: var(--color-accent); }
.footer__base { display: flex; flex-wrap: wrap; gap: var(--space-2xs) var(--space-md); font-size: var(--text-sm); color: var(--color-ink-3); }
.footer__top-link { color: var(--color-ink-2); text-decoration: none; white-space: nowrap; }
.footer__top-link:hover { color: var(--color-accent); }

/* =========================================================
 * Sub-pages
 * ========================================================= */
.page-top { padding-top: calc(var(--nav-offset) + var(--space-lg)); }
.crumbs { font-size: var(--text-sm); color: var(--color-ink-3); }
.crumbs ol { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-2xs); margin: 0; padding: 0; list-style: none; }
.crumbs li { display: inline-flex; align-items: center; gap: var(--space-2xs); white-space: nowrap; }
.crumbs li + li::before { content: "/"; color: var(--color-rule-strong); }
.crumbs a { text-decoration: none; transition: color var(--dur-fast) var(--ease-out); }
.crumbs a:hover { color: var(--color-accent); }
.crumbs [aria-current] { color: var(--color-ink-2); }

.tag { display: inline-flex; align-items: center; min-height: 28px; padding: 0 var(--space-xs); border: var(--rule-hair) solid var(--color-rule-strong); border-radius: var(--radius-pill); font-size: var(--text-xs); font-weight: 700; line-height: 1; color: var(--color-ink-2); white-space: nowrap; }
.tag--accent { border-color: var(--color-accent-deep); color: var(--color-accent); }

.course-hero { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-xl); align-items: center; padding-block: var(--space-xl) var(--space-3xl); }
@media (min-width: 1024px) { .course-hero { grid-template-columns: minmax(0, 6fr) minmax(0, 6fr); } }
.course-hero__tags { display: flex; flex-wrap: wrap; gap: var(--space-2xs); margin-top: var(--space-lg); }
.course-hero__title { margin-top: var(--space-md); font-family: var(--font-display); font-weight: 700; font-size: var(--text-4xl); line-height: 1.08; letter-spacing: -0.02em; overflow-wrap: anywhere; min-width: 0; }
.course-hero__sub { display: block; margin-top: var(--space-sm); font-family: var(--font-body); font-weight: 700; font-size: var(--text-2xl); letter-spacing: 0; color: var(--color-ink-2); text-wrap: balance; }
.facts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-sm); margin: var(--space-xl) 0 0; padding-top: var(--space-md); border-top: var(--rule-hair) solid var(--color-rule); }
.facts dt { font-size: var(--text-xs); color: var(--color-ink-3); }
.facts dd { margin: var(--space-3xs) 0 0; font-family: var(--font-display); font-weight: 600; font-size: var(--text-xl); }
.course-hero .cover { aspect-ratio: 4 / 3; border-radius: var(--radius-lg); border: var(--rule-hair) solid var(--color-rule-strong); }
.course-hero .cover b { font-size: var(--text-4xl); }

.course-body { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-xl); padding-bottom: var(--space-4xl); }
@media (min-width: 1024px) {
  .course-body { grid-template-columns: minmax(0, 1fr) minmax(0, 22rem); gap: var(--space-3xl); }
  .buy { position: sticky; top: calc(var(--nav-offset) + var(--space-md)); align-self: start; z-index: var(--z-sticky); }
}
@media (max-width: 1023px) { .course-body__aside { order: -1; } }
.block { padding-block: var(--space-xl); border-top: var(--rule-hair) solid var(--color-rule); }
.block:first-child { border-top: 0; padding-top: 0; }
.block__title { font-family: var(--font-display); font-weight: 600; font-size: var(--text-2xl); line-height: 1.25; margin-bottom: var(--space-md); }
.outcomes { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-sm); }
@media (min-width: 640px) { .outcomes { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.outcomes li { display: flex; gap: var(--space-xs); padding: var(--space-md); border-radius: var(--radius-md); background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-rule); color: var(--color-ink-2); }
.outcomes .tick { margin-top: 2px; }
.syllabus { counter-reset: mod; }
.syllabus .acc__btn { font-size: var(--text-base); }
.mod__no { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-accent); margin-right: var(--space-sm); }
.mod__name { flex: 1; }
.lessons { list-style: none; margin: 0; padding: 0 0 var(--space-md); display: grid; gap: var(--space-3xs); }
.lessons li { display: grid; grid-template-columns: 3rem minmax(0, 1fr); gap: var(--space-sm); padding: var(--space-2xs) 0; color: var(--color-ink-2); font-size: var(--text-sm); }
.lessons li span:first-child { color: var(--color-ink-3); font-family: var(--font-mono); }
.fit { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-md); }
@media (min-width: 640px) { .fit { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.fit__col { padding: var(--space-md); border-radius: var(--radius-md); background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-rule); }
.fit__col h3 { font-size: var(--text-sm); color: var(--color-ink-3); margin-bottom: var(--space-2xs); }
.fit__col--yes h3 { color: var(--color-accent); }
.fit__col ul { margin: 0; padding-left: var(--space-md); display: grid; gap: var(--space-3xs); color: var(--color-ink-2); }
.teacher { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: var(--space-md); align-items: center; }
.teacher__photo { width: 72px; height: 72px; border-radius: 50%; background: conic-gradient(from 0deg, var(--color-accent), var(--color-cyan), var(--color-coral), var(--color-accent)); padding: 2px; }
.teacher__photo span { display: block; width: 100%; height: 100%; border-radius: 50%; background: var(--color-paper-3); overflow: hidden; }
.teacher__photo img { width: 100%; height: 100%; object-fit: cover; }
.teacher__name { font-family: var(--font-display); font-weight: 600; font-size: var(--text-xl); }
.muted { color: var(--color-ink-3); }
.buy__card { padding: var(--space-lg); border-radius: var(--radius-lg); background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-rule-strong); box-shadow: 0 40px 80px -40px var(--color-shade); }
.buy__label { font-size: var(--text-xs); color: var(--color-ink-3); }
.buy__price { margin-top: var(--space-3xs); font-family: var(--font-display); font-weight: 700; font-size: var(--text-3xl); line-height: 1.1; }
.buy__actions { display: grid; gap: var(--space-2xs); margin-top: var(--space-md); }
.buy__actions .btn { width: 100%; }
.buy__note { margin-top: var(--space-md); font-size: var(--text-xs); color: var(--color-ink-3); }
.buy__note a { color: var(--color-ink-2); text-underline-offset: 0.2em; }

.auth { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-xl); min-height: 100svh; padding-block: calc(var(--nav-offset) + var(--space-lg)) var(--space-2xl); align-items: center; position: relative; isolation: isolate; }
@media (min-width: 960px) { .auth { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: var(--space-3xl); } }
.auth .hero__gl, .auth .hero__veil { position: fixed; }
.auth__side { display: none; }
@media (min-width: 960px) { .auth__side { display: block; } }
.auth__side .section-title { font-size: var(--text-display); }
.auth__main { width: 100%; max-width: 26rem; justify-self: center; padding: var(--space-lg); border-radius: var(--radius-lg); background: var(--color-glass); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); border: var(--rule-hair) solid var(--color-rule-strong); }
.auth__title { font-family: var(--font-display); font-weight: 700; font-size: var(--text-3xl); line-height: 1.1; }
.auth__main .lead { margin-top: var(--space-2xs); font-size: var(--text-base); }
.auth__form { display: grid; gap: var(--space-md); margin-top: var(--space-lg); }
.auth__alt { margin-top: var(--space-lg); font-size: var(--text-sm); color: var(--color-ink-3); }
.auth__alt a { color: var(--color-accent); font-weight: 700; text-underline-offset: 0.2em; }
.field { display: grid; gap: var(--space-2xs); }
.field__row { display: flex; align-items: center; justify-content: space-between; gap: var(--space-sm); }
.field label { font-size: var(--text-sm); font-weight: 700; }
.field__link { font-size: var(--text-sm); color: var(--color-ink-3); white-space: nowrap; text-underline-offset: 0.2em; }
.field__link:hover { color: var(--color-ink); }
.field .input { width: 100%; border-radius: var(--radius-md); }
.pw { position: relative; }
.pw .input { padding-right: 5rem; }
.pw__toggle { position: absolute; top: 50%; right: var(--space-2xs); translate: 0 -50%; min-height: 38px; padding: 0 var(--space-xs); border: 0; border-radius: var(--radius-sm); background: transparent; color: var(--color-ink-2); font-size: var(--text-sm); font-weight: 700; cursor: pointer; white-space: nowrap; transition: background-color var(--dur-fast) var(--ease-out); }
.pw__toggle:hover { background: var(--color-paper-4); color: var(--color-ink); }
.auth .btn--accent { width: 100%; }
.auth .form-msg { margin-top: calc(var(--space-sm) * -1); }

.legal__head { padding-block: var(--space-xl); }
.legal__title { font-family: var(--font-display); font-weight: 700; font-size: var(--text-4xl); line-height: 1.1; overflow-wrap: anywhere; min-width: 0; }
.legal__date { margin-top: var(--space-sm); font-size: var(--text-sm); color: var(--color-ink-3); }
.legal__grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-xl); padding-bottom: var(--space-4xl); }
@media (min-width: 960px) {
  .legal__grid { grid-template-columns: minmax(0, 15rem) minmax(0, 1fr); gap: var(--space-3xl); }
  .toc { position: sticky; top: calc(var(--nav-offset) + var(--space-md)); align-self: start; z-index: var(--z-sticky); }
}
.toc { padding: var(--space-md); border-radius: var(--radius-lg); background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-rule); }
.toc__title { font-size: var(--text-xs); color: var(--color-ink-3); margin-bottom: var(--space-2xs); }
.toc ol { margin: 0; padding-left: var(--space-md); display: grid; gap: var(--space-3xs); font-size: var(--text-sm); }
.toc a { color: var(--color-ink-2); text-decoration: none; transition: color var(--dur-fast) var(--ease-out); }
.toc a:hover { color: var(--color-accent); }
.legal__section + .legal__section { margin-top: var(--space-xl); padding-top: var(--space-xl); border-top: var(--rule-hair) solid var(--color-rule); }
.legal__section h2 { font-family: var(--font-display); font-weight: 600; font-size: var(--text-xl); line-height: 1.35; margin-bottom: var(--space-sm); }
.legal__section p { max-width: 42rem; color: var(--color-ink-3); }

/* =========================================================
 * Player scenes share one grid cell: the screen grows to the
 * tallest scene, so content can never spill over the top bar.
 * ========================================================= */
.stage__screen { display: grid; }
.stage__screen > .scene { position: relative; inset: auto; grid-area: 1 / 1; }

/* =========================================================
 * Mobile action bar (index: start learning · course: enrol)
 * ========================================================= */
.mbar {
  position: fixed;
  inset: auto 0 0 0;
  z-index: calc(var(--z-sticky-nav) - 2);
  padding: var(--space-xs) var(--space-sm) calc(var(--space-xs) + env(safe-area-inset-bottom, 0px));
  border-top: var(--rule-hair) solid var(--color-rule-strong);
  background: var(--color-glass);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  transform: translateY(110%);
  transition: transform var(--dur-slow) var(--ease-out);
}
.mbar.is-on { transform: none; }
.mbar__inner { display: flex; align-items: center; justify-content: space-between; gap: var(--space-sm); max-width: 560px; margin-inline: auto; }
.mbar__text { display: grid; min-width: 0; line-height: 1.35; }
.mbar__text b { font-size: var(--text-sm); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.mbar__text span { font-size: var(--text-xs); color: var(--color-ink-3); }
.mbar .btn { flex: none; }
@media (min-width: 768px) { .mbar { display: none; } }

/* =========================================================
 * Mobile & tablet design (below 960 / 768 px)
 * ========================================================= */
@media (hover: none) {
  a, button { -webkit-tap-highlight-color: transparent; }
  .arrows { display: none; }
  .btn:active, .filter:active, .task:active, .step:active { transform: scale(0.97); }
}

@media (max-width: 959px) {
  /* method: four steps become a compact tab bar right above the player */
  .steps { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-3xs); margin-top: var(--space-lg); }
  .steps li { display: flex; }
  .step {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
    padding: var(--space-xs) var(--space-3xs);
    text-align: center;
    justify-items: center;
    opacity: 0.6;
  }
  .step__txt { grid-template-rows: auto; }
  .step__txt strong { font-size: var(--text-sm); line-height: 1.3; }
  .step__txt span { display: none; }
  .method__pin { gap: var(--space-md); }
}

@media (max-width: 767px) {
  .method, .courses, .play, .path { padding-block: var(--space-2xl); }
  .cta { padding-block: var(--space-md) var(--space-2xl); }
  .lead { font-size: var(--text-base); }

  /* hero */
  .hero { min-height: auto; padding-bottom: var(--space-2xl); }
  .hero__grid { gap: var(--space-xl); }
  .hero__lede { font-size: var(--text-base); margin-top: var(--space-md); }
  .hero__actions { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); margin-top: var(--space-lg); }
  .hero__actions .btn { padding-inline: var(--space-sm); }
  .hero__scroll, .float-chip { display: none; }
  .live__body { padding: var(--space-sm); gap: var(--space-xs); }
  .live__head, .live__foot { padding-inline: var(--space-sm); }

  /* player */
  .stage__screen { padding: var(--space-md); min-height: 0; }
  .stage__top { padding-inline: var(--space-sm); }
  .stage__bar { padding-inline: var(--space-sm); }
  .prompt-out { padding: var(--space-sm); }
  .gen li { padding: var(--space-xs) var(--space-sm); }
  .result__bars { height: 180px; gap: var(--space-2xs); padding: var(--space-sm); }
  .result__stamp { width: 72px; height: 72px; font-size: var(--text-sm); }

  /* courses */
  .courses__head { margin-bottom: var(--space-md); }
  .filters { margin-inline: calc(var(--space-sm) * -1); padding-inline: var(--space-sm); }
  .rail__track { gap: var(--space-sm); padding-bottom: var(--space-lg); }
  .card { width: min(80vw, 340px); }

  /* playground */
  .play__head { margin-bottom: var(--space-lg); }
  .play__box { padding: var(--space-sm); gap: var(--space-sm); }
  .play__controls { display: grid; gap: var(--space-sm); }
  .tasks { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; margin-inline: calc(var(--space-sm) * -1); padding-inline: var(--space-sm); }
  .tasks::-webkit-scrollbar { display: none; }
  .mode { width: 100%; }
  .pane { min-height: 0; padding: var(--space-sm); }
  .play__answer { min-height: 6em; }
  .play__run { width: 100%; min-height: 52px; }

  /* learning path: a vertical timeline on the left edge */
  .path__map { margin-top: var(--space-xl); }
  .path__stops { gap: var(--space-md); padding-left: var(--space-lg); }
  .stop, .stop--right { margin: 0; max-width: none; padding: var(--space-md); }
  .stop__dot { left: calc(var(--space-sm) * -1 - 10px); top: calc(var(--space-md) + 4px); }

  /* subscribe */
  .cta__card { padding: var(--space-xl) var(--space-md); }
  .cta__form { display: grid; justify-content: stretch; width: 100%; }
  .cta__form .btn { width: 100%; }

  /* footer clears the action bar and the home indicator */
  .footer { padding-bottom: calc(var(--space-2xl) + env(safe-area-inset-bottom, 0px)); }
  .footer__faq { margin-top: var(--space-xl); }
  .footer__faq .faq__grid { padding-top: var(--space-xl); }
  .acc__btn { font-size: var(--text-base); padding-block: var(--space-sm); }

  /* course page */
  .course-hero { padding-block: var(--space-lg) var(--space-xl); }
  .course-hero__sub { font-size: var(--text-xl); }
  .course-hero .cover { aspect-ratio: 16 / 10; }
  .course-hero .cover b { font-size: var(--text-3xl); }
  .facts dd { font-size: var(--text-lg); }
  .block { padding-block: var(--space-lg); }
}

/* =========================================================
 * In-page editor (owner / editors only)
 * ========================================================= */
.editor__open {
  position: fixed;
  left: var(--space-sm);
  bottom: calc(var(--space-sm) + env(safe-area-inset-bottom, 0px));
  z-index: calc(var(--z-sticky-nav) + 5);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  min-height: var(--control-h);
  padding: 0 var(--space-md);
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-pill);
  background: var(--color-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 16px 32px -16px var(--color-shade);
  color: var(--color-ink);
  font-size: var(--text-sm);
  font-weight: 700;
  cursor: pointer;
  transition: border-color var(--dur-fast) var(--ease-out), background-color var(--dur-fast) var(--ease-out);
}
.editor__open:hover { border-color: var(--color-accent); }
.editor__open[hidden], .editor__bar[hidden] { display: none; }
@media (max-width: 767px) { .editor__open { bottom: calc(84px + env(safe-area-inset-bottom, 0px)); } }

.editor__bar {
  position: fixed;
  inset: auto 0 0 0;
  z-index: calc(var(--z-sticky-nav) + 5);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2xs) var(--space-md);
  padding: var(--space-sm) var(--space-md) calc(var(--space-sm) + env(safe-area-inset-bottom, 0px));
  border-top: var(--rule-bold) solid var(--color-accent);
  background: var(--color-paper-2);
  box-shadow: 0 -20px 40px -20px var(--color-shade);
}
.editor__hint { font-size: var(--text-sm); font-weight: 700; color: var(--color-accent); }
.editor__status { flex: 1 1 12rem; min-height: 1.5em; font-size: var(--text-sm); color: var(--color-ink-2); }
.editor__status[data-tone="error"] { color: var(--color-danger); }
.editor__actions { display: flex; gap: var(--space-2xs); margin-left: auto; }
.editor__toast {
  position: fixed;
  left: 50%;
  bottom: calc(var(--space-xl) + env(safe-area-inset-bottom, 0px));
  z-index: calc(var(--z-sticky-nav) + 6);
  translate: -50% 0;
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-pill);
  background: var(--color-success);
  color: var(--color-on-accent);
  font-size: var(--text-sm);
  font-weight: 700;
  white-space: nowrap;
}
.is-editing [data-ek] {
  outline: var(--rule-hair) dashed var(--color-accent-deep);
  outline-offset: 3px;
  border-radius: 4px;
  cursor: text;
}
.is-editing [data-ek]:hover { outline-color: var(--color-accent); }
.is-editing [data-ek]:focus { outline: var(--rule-bold) solid var(--color-accent); background: var(--color-accent-soft); }
.is-editing, .is-editing a, .is-editing button { cursor: auto; }
.is-editing .cursor { display: none; }
.is-editing .mbar { transform: translateY(110%); }
.is-editing .rotator { display: flex; flex-wrap: wrap; gap: 0 0.4em; }
.is-editing .rotator__item { grid-area: auto; opacity: 1 !important; transform: none !important; }
.is-editing .footer { padding-bottom: calc(var(--space-4xl) + env(safe-area-inset-bottom, 0px)); }

/* =========================================================
 * Reduced motion — everything static, content fully visible
 * ========================================================= */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 120ms !important;
    transition-property: opacity, color, background-color, border-color !important;
  }
  .js .loader { display: none; }
  .scene { transition: none; }
}

/* =========================================================
 * 課程內容(AI 應用初級班)· 堂色 / 講師 / 收費 / 報名 / 學員頁
 * ========================================================= */
.tone-orange { --tone: var(--lesson-orange); }
.tone-teal { --tone: var(--lesson-teal); }
.tone-blue { --tone: var(--lesson-blue); }
.tone-green { --tone: var(--lesson-green); }
.tone-purple { --tone: var(--lesson-purple); }
.tone-magenta { --tone: var(--lesson-magenta); }
.cover[class*="tone-"] { --c: var(--tone); --c-soft: color-mix(in oklab, var(--tone) 18%, transparent); }
.card[class*="tone-"] .card__series::before { content: ""; display: inline-block; width: 8px; height: 8px; margin-right: var(--space-2xs); border-radius: 50%; background: var(--tone); vertical-align: 0.05em; }
.card[class*="tone-"] .card__link:hover { border-color: var(--tone); box-shadow: 0 30px 60px -30px color-mix(in oklab, var(--tone) 45%, transparent); }
.card[class*="tone-"] .card__go { color: var(--tone); }
.lead a { color: var(--color-accent); text-underline-offset: 0.2em; }

.syllabus .acc__item[class*="tone-"] .mod__no { color: var(--tone); }
.syllabus__note { margin: calc(var(--space-xs) * -1) 0 var(--space-md); font-size: var(--text-sm); }
.acc__panel .mod__hook { padding-bottom: var(--space-xs); color: var(--color-ink); font-weight: 700; }
.facts--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
@media (min-width: 640px) { .facts--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); } }

/* 講師 */
.teach { padding-block: var(--space-4xl) var(--space-2xl); }
.teach__grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-xl); align-items: center; }
@media (min-width: 960px) { .teach__grid { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: var(--space-3xl); } }
.teach__photo { width: 100%; max-width: 520px; margin: 0; aspect-ratio: 1; overflow: hidden; border-radius: var(--radius-lg); border: var(--rule-hair) solid var(--color-rule-strong); background: var(--color-paper-3); box-shadow: 0 40px 80px -40px var(--color-shade); }
.teach__photo img { display: block; width: 100%; height: 100%; object-fit: cover; }
.teach__eyebrow { margin-bottom: var(--space-xs); font-family: var(--font-mono); font-size: var(--text-xs); letter-spacing: 0.1em; color: var(--color-accent); }
.teach__role { margin-top: var(--space-xs); font-weight: 700; color: var(--color-ink-2); }
.teach__ig { margin-top: var(--space-lg); }

/* 收費 */
.price { padding-block: var(--space-2xl); }
.price__head { margin-bottom: var(--space-xl); }
.plans { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-sm); margin: 0; padding: 0; list-style: none; }
@media (min-width: 900px) { .plans { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.plan { position: relative; display: flex; flex-direction: column; gap: var(--space-2xs); padding: var(--space-lg); border-radius: var(--radius-lg); background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-rule); }
.plan--best { border-color: var(--color-accent-deep); box-shadow: 0 40px 80px -40px var(--color-glow); }
.plan__tag { position: absolute; top: var(--space-md); right: var(--space-md); padding: var(--space-3xs) var(--space-xs); border-radius: var(--radius-pill); background: var(--color-accent); color: var(--color-on-accent); font-size: var(--text-xs); font-weight: 700; }
.plan__name { font-weight: 700; color: var(--color-ink-2); }
.plan__price { font-family: var(--font-display); font-weight: 700; font-size: var(--text-4xl); line-height: 1; letter-spacing: -0.02em; }
.plan__cur { font-family: var(--font-mono); font-size: var(--text-sm); font-weight: 500; letter-spacing: 0; color: var(--color-ink-3); vertical-align: middle; }
.plan__price small { font-family: var(--font-body); font-size: var(--text-base); font-weight: 500; letter-spacing: 0; color: var(--color-ink-3); }
.plan__for { font-size: var(--text-sm); color: var(--color-ink-3); }
.plan__list { flex: 1; display: grid; align-content: start; gap: var(--space-2xs); margin: var(--space-sm) 0 var(--space-md); padding: var(--space-sm) 0 0; border-top: var(--rule-hair) solid var(--color-rule); list-style: none; font-size: var(--text-sm); color: var(--color-ink-2); }
.plan__list li { display: flex; gap: var(--space-2xs); }
.plan__list li::before { content: "✓"; flex: none; font-weight: 700; color: var(--color-accent); }
.plan .btn { width: 100%; }
.intake { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-sm); margin: var(--space-md) 0 0; padding: var(--space-md) var(--space-lg); border-radius: var(--radius-lg); border: var(--rule-hair) dashed var(--color-rule-strong); }
@media (min-width: 900px) { .intake { grid-template-columns: repeat(4, minmax(0, 1fr)); } }
.intake dt { font-size: var(--text-xs); color: var(--color-ink-3); }
.intake dd { margin: var(--space-3xs) 0 0; font-weight: 700; }

/* 報名按鈕 */
.contact { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--space-2xs); margin-top: var(--space-md); }
.contact--center { max-width: 44rem; margin: var(--space-xl) auto 0; }
@media (min-width: 768px) { .contact--center { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.contact__btn { flex-direction: column; gap: var(--space-3xs); min-height: 64px; padding-block: var(--space-2xs); line-height: 1.2; }
.contact__k { font-weight: 700; }
.contact__v { font-size: var(--text-xs); font-weight: 500; opacity: 0.8; }
.contact__btn.is-off { opacity: 0.55; }
.contact__btn.is-off::after { display: none; }
.contact__msg { grid-column: 1 / -1; min-height: 1.5em; font-size: var(--text-sm); color: var(--color-ink-2); }
.buy__opts { display: grid; gap: var(--space-3xs); margin: var(--space-sm) 0 0; padding: 0; list-style: none; font-size: var(--text-sm); }
.buy__opts li { display: flex; justify-content: space-between; gap: var(--space-sm); padding-block: var(--space-3xs); border-bottom: var(--rule-hair) solid var(--color-rule); color: var(--color-ink-2); }
.buy__opts b { color: var(--color-ink); }
.teacher__photo span img { display: block; }

/* 學員頁 */
.dash[hidden] { display: none; }
.dash { padding-bottom: var(--space-4xl); }
.dash__head { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: flex-end; gap: var(--space-md); padding-block: var(--space-xl) var(--space-lg); }
.dash__hi { margin-bottom: var(--space-2xs); font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-ink-3); }
.dash__plan { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-xs); margin-top: var(--space-sm); font-size: var(--text-sm); }
.dash__next { margin-bottom: var(--space-xl); padding: var(--space-lg); border-radius: var(--radius-lg); background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-accent-deep); }
.dash__label { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-accent); }
.dash__next-title { margin-top: var(--space-2xs); font-family: var(--font-display); font-weight: 600; font-size: var(--text-2xl); line-height: 1.25; overflow-wrap: anywhere; }
.dash__hint { margin-top: var(--space-sm); font-size: var(--text-sm); color: var(--color-ink-3); }
.dash__foot { margin-top: var(--space-lg); font-size: var(--text-sm); }
.lrows { display: grid; gap: var(--space-2xs); margin: 0; padding: 0; list-style: none; }
.lrow { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; gap: var(--space-sm); align-items: center; padding: var(--space-sm) var(--space-md); border-radius: var(--radius-md); background: var(--color-paper-2); border: var(--rule-hair) solid var(--color-rule); border-left: 3px solid var(--tone, var(--color-accent)); }
.lrow__no { font-family: var(--font-mono); color: var(--tone, var(--color-accent)); }
.lrow__main { display: grid; gap: var(--space-3xs); min-width: 0; }
.lrow__main b { overflow-wrap: anywhere; }
.lrow__main span { font-size: var(--text-xs); color: var(--color-ink-3); }
.lrow__state { padding: var(--space-3xs) var(--space-xs); border-radius: var(--radius-pill); border: var(--rule-hair) solid var(--color-rule-strong); font-size: var(--text-xs); font-weight: 700; white-space: nowrap; }
.lrow.is-locked { opacity: 0.55; }
@media (max-width: 479px) {
  .lrow { grid-template-columns: auto minmax(0, 1fr); }
  .lrow__state { grid-column: 2; justify-self: start; }
  .plan { padding: var(--space-md); }
  .intake { padding: var(--space-md); }
}

/* =========================================================
 * Language switcher · Redbooth-style
 * Closed: "English 🌐". Open: the globe slides left and the
 * languages roll out in one row. White globe on the dark UI.
 * ≥1280px it sits in the top-right corner; below that, in the nav.
 * ========================================================= */
.lang { position: relative; display: flex; align-items: center; }
.lang--pill { margin-left: auto; }
.nav__toggle { margin-left: 0; }
.lang--corner { display: none; }
@media (min-width: 1280px) {
  .lang--pill { display: none; }
  .nav__links { margin-left: auto; }
  .lang--corner {
    position: fixed;
    top: calc(var(--space-sm) + env(safe-area-inset-top, 0px));
    right: var(--space-md);
    z-index: calc(var(--z-sticky-nav) + 1);
    display: flex;
    padding: calc(var(--space-2xs) - 1px);
    border: var(--rule-hair) solid var(--color-rule-strong);
    border-radius: var(--radius-pill);
    background: var(--color-glass);
    backdrop-filter: blur(18px) saturate(140%);
    -webkit-backdrop-filter: blur(18px) saturate(140%);
    box-shadow: 0 20px 40px -24px var(--color-shade);
    transition: transform var(--dur-slow) var(--ease-out);
  }
  .nav.is-hidden + .lang--corner { transform: translateY(calc(-100% - var(--space-lg))); }
}

.lang__btn {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 var(--space-xs);
  border: 0;
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--color-ink);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color var(--dur-fast) var(--ease-out);
}
.lang__btn:hover { background: var(--color-paper-4); }
.lang__btn:active .lang__globe { transform: scale(0.9); }
.lang__btn:focus-visible { outline: var(--rule-bold) solid var(--color-focus); outline-offset: 2px; }
.lang__cur {
  display: inline-block;
  max-width: 8em;
  margin-right: var(--space-2xs);
  padding-block: 0.15em; /* room for descenders (g, p) — overflow is hidden for the fold animation */
  line-height: 1.2;
  overflow: hidden;
  transition: max-width var(--dur-slow) var(--ease-out), margin var(--dur-slow) var(--ease-out), opacity var(--dur-base) var(--ease-out);
}
.lang__globe {
  flex: none;
  width: 20px;
  height: 20px;
  fill: none;
  stroke: var(--color-ink);
  stroke-width: 1.5;
  transition: transform var(--dur-slow) var(--ease-out);
}
.lang__btn:hover .lang__globe { transform: rotate(-20deg); }
.lang.is-open .lang__globe { transform: rotate(-180deg); }

.lang__list {
  display: flex;
  align-items: center;
  gap: var(--space-3xs);
  max-width: 0;
  margin: 0;
  padding: 0;
  overflow: hidden;
  list-style: none;
  visibility: hidden;
  opacity: 0;
  transition: max-width var(--dur-slow) var(--ease-out), opacity var(--dur-base) var(--ease-out), visibility 0s linear var(--dur-slow);
}
.lang.is-open .lang__list {
  max-width: 26rem;
  visibility: visible;
  opacity: 1;
  transition: max-width var(--dur-slow) var(--ease-out), opacity var(--dur-base) var(--ease-out), visibility 0s;
}
.lang.is-open .lang__list li { animation: lang-roll var(--dur-slow) var(--ease-out) both; }
.lang.is-open .lang__list li:nth-child(2) { animation-delay: 60ms; }
.lang.is-open .lang__list li:nth-child(3) { animation-delay: 120ms; }
@keyframes lang-roll { from { opacity: 0; transform: translateX(14px); } }
.lang__opt {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 var(--space-xs);
  border-radius: var(--radius-pill);
  color: var(--color-ink-2);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur-fast) var(--ease-out), background-color var(--dur-fast) var(--ease-out);
}
.lang__opt:hover { color: var(--color-ink); background: var(--color-paper-4); }
.lang__opt:focus-visible { outline: var(--rule-bold) solid var(--color-focus); outline-offset: -2px; color: var(--color-ink); }
.lang__opt[aria-current="true"] { color: var(--color-accent); }

/* corner: the label folds away so the globe slides left as the row opens */
.lang--corner.is-open .lang__cur { max-width: 0; margin-right: 0; opacity: 0; }

/* inside the nav there's no room to grow sideways, so the row drops below */
.lang--pill .lang__list {
  position: absolute;
  top: calc(100% + var(--space-xs));
  right: 0;
  z-index: 2;
  max-width: none;
  padding: var(--space-3xs);
  overflow: visible;
  border: var(--rule-hair) solid var(--color-rule-strong);
  border-radius: var(--radius-pill);
  background: var(--color-paper-2);
  box-shadow: 0 30px 60px -20px var(--color-shade);
  transform: translateY(-6px);
  transition: transform var(--dur-base) var(--ease-out), opacity var(--dur-base) var(--ease-out), visibility 0s linear var(--dur-base);
}
.lang--pill.is-open .lang__list { transform: none; transition: transform var(--dur-base) var(--ease-out), opacity var(--dur-base) var(--ease-out), visibility 0s; }
@media (max-width: 379px) { .lang--pill .lang__btn { padding: 0 var(--space-2xs); } }
/* phones: anchor the row to the nav's right edge so it never runs off-screen */
@media (max-width: 899px) {
  .lang--pill { position: static; }
  .lang--pill .lang__list { right: var(--space-2xs); }
}

@media (prefers-reduced-motion: reduce) {
  .lang__cur, .lang__globe, .lang__list, .lang--corner { transition: none; }
  .lang.is-open .lang__list li { animation: none; }
}

/* per-language fonts */
:root:lang(zh-Hans) {
  --font-display: "Unbounded", "Noto Sans SC", system-ui, sans-serif;
  --font-body: "Manrope", "Noto Sans SC", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Noto Sans SC", ui-monospace, monospace;
}
/* English: Unbounded runs wide, so headings step down a size */
:root:lang(en) .section-title { font-size: clamp(2rem, 1.1rem + 3vw, 3.75rem); letter-spacing: -0.03em; }
:root:lang(en) .cta__title { font-size: clamp(1.75rem, 1rem + 3vw, 3.5rem); letter-spacing: -0.03em; }
@media (max-width: 379px) {
  .brand__logo { height: 22px; }
}
/* English labels are longer: stack the hero buttons on small phones */
@media (max-width: 419px) {
  :root:lang(en) .hero__actions { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 359px) { .hero__actions { grid-template-columns: minmax(0, 1fr); } }

/* 登入卡:登入 / 註冊 / 註冊完成 三個畫面 */
.auth__view[hidden] { display: none; }
.auth__switch {
  padding: 0 0 0 var(--space-3xs);
  border: 0;
  background: none;
  color: var(--color-accent);
  font: inherit;
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 0.2em;
  cursor: pointer;
}
.auth__switch:hover { color: var(--color-accent-hover); }
.auth__switch:focus-visible { outline: var(--rule-bold) solid var(--color-focus); outline-offset: 2px; border-radius: 4px; }
.field__hint { font-size: var(--text-xs); color: var(--color-ink-3); }
.check { display: flex; align-items: flex-start; gap: var(--space-xs); font-size: var(--text-sm); color: var(--color-ink-2); cursor: pointer; }
.check input { flex: none; width: 18px; height: 18px; margin-top: 2px; accent-color: var(--color-accent); cursor: pointer; }
.check input[aria-invalid="true"] { outline: var(--rule-bold) solid var(--color-danger); outline-offset: 2px; }
.check a { color: var(--color-accent); text-underline-offset: 0.2em; }
.auth__id {
  margin-top: var(--space-lg);
  padding: var(--space-md);
  border: var(--rule-hair) dashed var(--color-accent-deep);
  border-radius: var(--radius-md);
  background: var(--color-accent-soft);
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 500;
  letter-spacing: 0.06em;
  text-align: center;
  color: var(--color-accent);
  user-select: all;
}
.auth__go { width: 100%; margin-top: var(--space-lg); }

/* 收費:早鳥價、實體班預告、創始班說明 */
.plan__early { font-size: var(--text-sm); font-weight: 700; color: var(--color-accent); }
.buy .plan__early { margin-top: var(--space-3xs); }
.soon {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-md);
  margin-top: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-lg);
  border: var(--rule-hair) dashed var(--color-rule-strong);
  background: var(--color-paper-2);
}
.soon__tag { padding: var(--space-3xs) var(--space-xs); border-radius: var(--radius-pill); border: var(--rule-hair) solid var(--color-accent-deep); color: var(--color-accent); font-size: var(--text-xs); font-weight: 700; white-space: nowrap; }
.soon__name { font-weight: 700; }
.soon__text { margin-top: var(--space-3xs); font-size: var(--text-sm); color: var(--color-ink-2); }
.soon__price { font-family: var(--font-display); font-weight: 700; font-size: var(--text-xl); white-space: nowrap; }
.price__note { margin-top: var(--space-sm); font-size: var(--text-sm); color: var(--color-ink-3); }
@media (max-width: 639px) {
  .soon { grid-template-columns: minmax(0, 1fr); gap: var(--space-xs); padding: var(--space-md); }
  .soon__tag { justify-self: start; }
}

/* 登入頁:只有卡片,置中並加大 */
.auth { grid-template-columns: minmax(0, 1fr); justify-items: center; }
.auth__main { max-width: 34rem; padding: var(--space-lg); }
@media (min-width: 768px) { .auth__main { padding: var(--space-xl) var(--space-2xl); } }
.auth__main .auth__title { font-size: var(--text-4xl); }

/* 電郵確認提示 / 註冊完成附註 */
.notice {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-xs) var(--space-md);
  margin-bottom: var(--space-lg);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-lg);
  border: var(--rule-hair) solid var(--color-accent-deep);
  background: var(--color-accent-soft);
}
.notice[hidden] { display: none; }
.notice__title { font-weight: 700; }
.notice__text { margin-top: var(--space-3xs); font-size: var(--text-sm); color: var(--color-ink-2); overflow-wrap: anywhere; }
.notice__msg { grid-column: 1 / -1; font-size: var(--text-sm); color: var(--color-ink-2); }
.notice__msg:empty { display: none; }
.auth__note { margin-top: var(--space-sm); font-size: var(--text-sm); color: var(--color-ink-2); text-align: center; }
.auth__note[hidden] { display: none; }
button.field__link { padding: 0; }
@media (max-width: 559px) { .notice { grid-template-columns: minmax(0, 1fr); } }