@import url("https://fonts.googleapis.com/css2?family=Klee+One:wght@400;600&family=Noto+Sans+TC:wght@400;500;700;800&display=swap");

:root {
  --teal: #123f4a;
  --teal-2: #246775;
  --sky: #cfe6e6;
  --mist: #e8f1ee;
  --cream: #f6f0df;
  --paper: #fffaf0;
  --coral: #e06b55;
  --coral-dark: #a84638;
  --ink: #173139;
  --soft: #52676b;
  --line: #99b2b3;
  --body: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;
  --hand: "Klee One", "Noto Sans TC", sans-serif;
  --page: min(1320px, calc(100vw - 64px));
  --read: 72ch;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--cream); font-family: var(--body); font-size: 18px; line-height: 1.9; }
a { color: inherit; }
img { display: block; max-width: 100%; }
button { font: inherit; }
:focus-visible { outline: 3px solid var(--coral); outline-offset: 4px; }
.skip-link { position: fixed; z-index: 100; left: 16px; top: -80px; padding: 8px 14px; background: white; }
.skip-link:focus { top: 16px; }

.site-nav { position: sticky; top: 0; z-index: 50; background: rgba(246,240,223,.96); border-bottom: 1px solid var(--teal); backdrop-filter: blur(10px); }
.nav-inner { width: var(--page); min-height: 70px; margin: auto; display: flex; align-items: stretch; gap: 28px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 800; }
.brand-mark { position: relative; width: 44px; height: 19px; border: 2px solid var(--teal); border-radius: 5px; background: var(--paper); }
.brand-mark::after { content: ""; position: absolute; inset: 3px; background: repeating-linear-gradient(90deg, var(--teal) 0 2px, transparent 2px 5px); }
.site-menu { margin-left: auto; display: flex; }
.nav-group { position: relative; }
.nav-group summary { min-height: 70px; display: flex; align-items: center; list-style: none; padding: 0 14px; cursor: pointer; font-size: .84rem; font-weight: 700; }
.nav-group summary::-webkit-details-marker { display: none; }
.nav-group summary::after { content: "↘"; margin-left: 8px; color: var(--coral); }
.nav-group.is-active summary { box-shadow: inset 0 -5px var(--coral); }
.nav-panel { position: absolute; top: 67px; right: 0; width: 260px; padding: 10px; background: var(--paper); border: 1px solid var(--teal); box-shadow: 0 20px 50px rgba(18,63,74,.18); }
.nav-panel a { display: block; padding: 9px 12px; text-decoration: none; font-size: .86rem; }
.nav-panel a:hover, .nav-panel a[aria-current="page"] { background: var(--teal); color: white; }
.nav-toggle { display: none; margin-left: auto; border: 0; background: none; font-weight: 800; color: var(--teal); }

.hero { position: relative; min-height: min(760px, calc(100vh - 70px)); overflow: hidden; background: var(--sky); display: grid; }
.hero-art { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: center; }
.hero::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(232,241,238,.98) 0 35%, rgba(232,241,238,.72) 48%, transparent 67%); }
.hero-copy { position: relative; z-index: 2; width: var(--page); margin: auto; display: grid; align-content: center; justify-items: start; }
.eyebrow { margin: 0 0 20px; color: var(--coral-dark); font: 800 .72rem/1.2 var(--body); letter-spacing: .16em; }
h1, h2, h3 { font-family: var(--hand); letter-spacing: -.04em; }
.hero h1 { max-width: 720px; margin: 0; font-size: clamp(3.3rem, 6.5vw, 7.6rem); line-height: 1.02; text-wrap: balance; }
.hero .lead { max-width: 620px; margin: 26px 0 34px; color: var(--soft); }
.button { display: inline-flex; min-height: 49px; align-items: center; padding: 10px 18px; text-decoration: none; background: var(--teal); color: white; border: 1px solid var(--teal); font-weight: 800; }
.button.secondary { margin-left: 8px; background: transparent; color: var(--teal); }
.track-rule { height: 54px; border-block: 1px solid var(--line); background: linear-gradient(var(--cream),var(--cream)) padding-box, repeating-linear-gradient(90deg, var(--teal) 0 3px, transparent 3px 54px); position: relative; }
.track-rule::before, .track-rule::after { content: ""; position: absolute; left: 0; right: 0; height: 3px; background: var(--teal); }
.track-rule::before { top: 17px; }
.track-rule::after { bottom: 17px; }
.page-shell { width: var(--page); margin: auto; }
.home-section { padding: clamp(72px, 9vw, 128px) 0; }
.section-head { display: grid; grid-template-columns: 100px minmax(0, 850px); gap: 26px; margin-bottom: 50px; }
.section-head small { padding-top: 10px; border-top: 4px solid var(--coral); color: var(--coral-dark); font-weight: 800; letter-spacing: .12em; }
.section-head h2 { margin: 0; font-size: clamp(2.5rem, 4.7vw, 5.3rem); line-height: 1.1; }
.section-head p { grid-column: 2; max-width: var(--read); margin: 0; color: var(--soft); }
.route-choice { display: grid; grid-template-columns: 1.15fr .9fr .9fr; gap: 14px; }
.choice-card { min-height: 290px; padding: 30px; border: 1px solid var(--teal); background: var(--paper); display: flex; flex-direction: column; text-decoration: none; }
.choice-card:first-child { background: var(--teal); color: white; }
.choice-card small { color: var(--coral); font-weight: 800; letter-spacing: .12em; }
.choice-card h3 { margin: auto 0 10px; font-size: 1.75rem; line-height: 1.2; }
.choice-card p { margin: 0; color: inherit; opacity: .82; font-size: .9rem; }
.choice-card span { margin-top: 22px; color: var(--coral); font-weight: 800; }

.breath-map-section { padding: clamp(50px, 7vw, 92px) max(17px, calc((100vw - min(1320px, calc(100vw - 64px))) / 2)); background: var(--teal); color: white; }
.breath-inner { display: grid; grid-template-columns: .72fr 1.28fr; gap: 60px; align-items: center; }
.breath-inner h2 { margin: 0 0 20px; font-size: clamp(2.5rem, 4.6vw, 5rem); line-height: 1.08; }
.breath-inner p { color: #c7dcdd; }
.harp-map { background: var(--paper); color: var(--ink); border: 4px solid #8fb6bb; padding: 22px; overflow-x: auto; }
.harp-row { display: grid; grid-template-columns: 52px repeat(10, minmax(46px,1fr)); gap: 5px; align-items: center; min-width: 650px; margin-bottom: 5px; }
.harp-row strong { font-size: .75rem; color: var(--teal-2); }
.harp-note { min-height: 52px; border: 1px solid var(--line); background: white; color: var(--ink); cursor: pointer; font-weight: 800; }
.harp-note.draw { background: var(--mist); }
.harp-note.is-scale { border: 3px solid var(--coral); }
.harp-note.is-playing { background: var(--coral); color: white; }
.harp-holes { display: grid; grid-template-columns: 52px repeat(10,minmax(46px,1fr)); gap: 5px; min-width: 650px; }
.harp-holes span { text-align: center; font-weight: 800; color: var(--teal); }
.spine-list { border-top: 1px solid var(--line); }
.spine-row { min-height: 112px; display: grid; grid-template-columns: 90px 1fr auto; gap: 22px; align-items: center; border-bottom: 1px solid var(--line); text-decoration: none; }
.spine-row b { width: 54px; height: 28px; display: grid; place-items: center; background: var(--coral); color: white; border-radius: 14px; font-size: .72rem; }
.spine-row h3 { margin: 0; font-size: 1.5rem; }
.spine-row p { margin: 5px 0 0; color: var(--soft); font-size: .9rem; }
.spine-row span { color: var(--coral-dark); font-size: 1.4rem; }

.lesson-hero { background: var(--mist); border-bottom: 12px solid var(--coral); }
.lesson-hero-inner { width: var(--page); min-height: 430px; margin: auto; display: grid; grid-template-columns: minmax(0, 900px) 1fr; gap: 50px; align-items: end; padding: 86px 0 60px; }
.lesson-hero h1 { margin: 0 0 22px; font-size: clamp(3rem, 5.8vw, 6.8rem); line-height: 1.06; text-wrap: balance; }
.lesson-hero .lead { margin: 0; max-width: var(--read); color: var(--soft); }
.lesson-index { align-self: start; justify-self: end; padding-top: 10px; border-top: 4px solid var(--coral); color: var(--coral-dark); font-weight: 800; letter-spacing: .14em; }
.lesson-layout { width: var(--page); margin: auto; padding: 72px 0 120px; display: grid; grid-template-columns: 250px minmax(0, 880px); gap: clamp(48px, 8vw, 120px); align-items: start; }
.lesson-rail { position: sticky; top: 100px; font-size: .84rem; }
.lesson-rail strong { display: block; margin-bottom: 12px; color: var(--coral-dark); font-size: .75rem; letter-spacing: .12em; }
.lesson-rail a { display: block; padding: 9px 0; border-bottom: 1px solid var(--line); text-decoration: none; }
.lesson-rail a[aria-current="page"] { color: var(--coral-dark); font-weight: 800; }
.takeaway { margin: 0 0 60px; padding: 26px 30px; background: var(--paper); border-left: 8px solid var(--coral); font: 600 1.22rem/1.7 var(--hand); }
.lesson-section { padding-bottom: 58px; margin-bottom: 58px; border-bottom: 1px solid var(--line); }
.lesson-section h2 { margin: 0 0 20px; font-size: clamp(1.9rem, 3.2vw, 3.1rem); line-height: 1.2; }
.lesson-section p { margin: 0; max-width: var(--read); color: var(--soft); }
.lesson-section ul { padding: 0; list-style: none; display: grid; gap: 8px; }
.lesson-section li { position: relative; padding-left: 28px; }
.lesson-section li::before { content: "→"; position: absolute; left: 0; color: var(--coral-dark); }
.practice-card { margin-top: 70px; padding: clamp(32px,5vw,58px); background: var(--teal); color: white; position: relative; }
.practice-card::after { content: ""; position: absolute; top: 0; bottom: 0; right: 24px; width: 2px; background: repeating-linear-gradient(var(--coral) 0 12px, transparent 12px 22px); }
.practice-card small { color: var(--coral); font-weight: 800; letter-spacing: .12em; }
.practice-card h2 { margin: 12px 0 20px; font-size: 2rem; }
.practice-card ol { color: #d6e6e6; }
.practice-card .check { margin: 22px 42px 0 0; padding-top: 18px; border-top: 1px solid #4d7780; }
.resource-list { margin-top: 46px; padding: 24px; border: 1px solid var(--line); background: var(--paper); }
.resource-list h2 { margin: 0 0 10px; font-size: 1.2rem; }
.resource-list a { display: block; padding: 7px 0; color: var(--coral-dark); }
.chapter-turn { margin-top: 62px; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.chapter-turn a { min-height: 110px; padding: 20px; background: var(--paper); border: 1px solid var(--line); text-decoration: none; }
.chapter-turn a:last-child { text-align: right; }
.chapter-turn small { display: block; color: var(--coral-dark); font-weight: 800; }
.site-footer { padding: 58px 0; background: var(--teal); color: white; }
.footer-inner { width: var(--page); margin: auto; display: grid; grid-template-columns: 1.3fr 1fr 1fr; gap: 40px; }
.site-footer h2 { margin: 0 0 10px; font-size: 1.6rem; }
.site-footer p, .site-footer a { color: #bad1d2; font-size: .82rem; }
.site-footer a { display: block; padding: 4px 0; }

@media (max-width: 900px) {
  :root { --page: min(100% - 34px, 720px); }
  body { font-size: 17px; }
  .site-nav, .nav-inner { min-height: 64px; }
  .nav-toggle { display: block; min-width: 48px; }
  .site-menu { display: none; position: absolute; top: 64px; left: 0; right: 0; max-height: calc(100vh - 64px); overflow: auto; padding: 10px 17px 24px; background: var(--cream); border-bottom: 1px solid var(--teal); }
  .site-menu[data-open="true"] { display: block; }
  .nav-group summary { min-height: 50px; padding: 0; border-bottom: 1px solid var(--line); }
  .nav-panel { position: static; width: auto; border: 0; box-shadow: none; padding: 6px 0 12px 14px; background: transparent; }
  .hero { min-height: 800px; }
  .hero-art { height: 47%; object-position: 64% center; }
  .hero::after { background: linear-gradient(180deg, transparent 0 30%, rgba(232,241,238,.82) 44%, var(--mist) 56%); }
  .hero-copy { align-content: end; padding-bottom: 56px; }
  .hero h1 { font-size: clamp(3rem, 14vw, 5rem); }
  .hero .lead { font-size: .97rem; }
  .section-head { grid-template-columns: 52px 1fr; gap: 16px; }
  .section-head p { grid-column: 1 / -1; }
  .route-choice { grid-template-columns: 1fr; }
  .choice-card { min-height: 205px; }
  .breath-inner { grid-template-columns: 1fr; gap: 32px; }
  .harp-map { margin-inline: -17px; border-inline: 0; }
  .spine-row { grid-template-columns: 64px 1fr auto; gap: 12px; }
  .lesson-hero-inner { min-height: 410px; grid-template-columns: 1fr; align-content: end; padding: 68px 0 46px; }
  .lesson-index { justify-self: start; }
  .lesson-layout { grid-template-columns: 1fr; padding-top: 28px; }
  .lesson-rail { position: static; display: flex; gap: 8px; overflow-x: auto; padding-bottom: 10px; }
  .lesson-rail strong { display: none; }
  .lesson-rail a { flex: 0 0 auto; padding: 7px 10px; background: var(--paper); border: 1px solid var(--line); }
  .chapter-turn, .footer-inner { grid-template-columns: 1fr; }
  .chapter-turn a:last-child { text-align: left; }
}

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }