/* ===================================================================
   木吉他教學 — "editorial conservatory" design system.
   Refined music-method-book aesthetic: serif display (with CJK 宋體/明體),
   clean sans for reading, warm paper base, tonewood-amber accent, hairline
   rules, chapter-numbered courses/lessons, faint paper grain. CSP-safe
   (system fonts + inline data-URI texture). Served at /courses.css
   =================================================================== */

:root {
  --serif: "Iowan Old Style", "Hoefler Text", "Palatino Linotype", Palatino,
    "Songti TC", "Noto Serif TC", "Source Han Serif TC", "Songti SC", "MingLiU",
    Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC",
    "Noto Sans TC", "Microsoft JhengHei", "Hiragino Sans", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;

  --paper: #f5efe3;
  --paper-2: #fffdf8;
  --panel: #fbf6ec;
  --ink: #241c14;
  --ink-soft: #564a3c;
  --ink-faint: #91836f;
  --line: #e6dcc8;
  --line-soft: #efe7d6;
  --accent: #bb6a25;
  --accent-deep: #8a4715;
  --accent-tint: #f1e3cd;
  --espresso: #211910;
  --espresso-2: #34281a;
  --gold: #c79a54;
  --done: #4a8a52;

  --maxw: 1080px;
  --measure: 40rem;
  --radius: 14px;
  --shadow: 0 18px 40px -24px rgba(40, 28, 14, 0.45);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.72;
  color: var(--ink);
  background-color: var(--paper);
  /* faint paper grain */
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: var(--accent-deep); text-decoration: none; }
a:hover { color: var(--accent); }
h1, h2, h3, h4 { font-family: var(--serif); font-weight: 600; color: var(--ink); letter-spacing: -0.01em; }
.skip-link { position: absolute; left: -999px; }
.skip-link:focus { left: 12px; top: 12px; background: var(--paper-2); padding: 10px 14px; border-radius: 10px; z-index: 50; box-shadow: var(--shadow); }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- header ---------- */
.site-header { position: sticky; top: 0; z-index: 30; background: color-mix(in srgb, var(--paper) 86%, transparent); backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--line); }
.header-inner { max-width: var(--maxw); margin: 0 auto; padding: 13px 24px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { display: inline-flex; align-items: center; gap: 9px; font-family: var(--serif); font-size: 1.16rem; font-weight: 600; color: var(--ink); letter-spacing: 0.01em; }
.brand:hover { color: var(--ink); }
.brand svg { width: 19px; height: 19px; color: var(--accent); flex: none; }
.site-nav { display: flex; align-items: center; gap: 26px; }
.site-nav a { font-family: var(--sans); font-size: 0.95rem; font-weight: 500; color: var(--ink-soft); letter-spacing: 0.01em; }
.site-nav a:hover { color: var(--accent-deep); }
.site-nav a.on { color: var(--ink); }
.site-nav a.on::after { content: ""; display: block; height: 2px; background: var(--accent); border-radius: 2px; margin-top: 3px; }

/* ---------- buttons ---------- */
.btn { display: inline-flex; align-items: center; gap: 8px; font-family: var(--sans); font-weight: 600; font-size: 1rem; padding: 13px 26px; border-radius: 999px; border: 1px solid transparent; transition: transform .14s ease, box-shadow .14s ease, background .14s ease, color .14s; cursor: pointer; }
.btn-primary { background: var(--accent); color: #fff; box-shadow: 0 10px 22px -12px rgba(187, 106, 37, .8); }
.btn-primary:hover { background: var(--accent-deep); color: #fff; transform: translateY(-2px); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { color: var(--accent-deep); border-color: var(--accent); transform: translateY(-2px); }
.btn-light { background: var(--paper-2); color: var(--ink); }
.btn-light:hover { background: #fff; transform: translateY(-2px); color: var(--ink); }

.eyebrow { font-family: var(--sans); font-size: 0.74rem; font-weight: 700; letter-spacing: 0.22em; text-transform: uppercase; color: var(--accent); margin: 0; }
.eyebrow.light { color: var(--gold); }

main { display: block; }

/* ---------- homepage hero ---------- */
.hero { max-width: var(--maxw); margin: 0 auto; padding: 84px 24px 56px; position: relative; }
.hero::before { content: ""; position: absolute; inset: -10% -20% auto -20%; height: 360px; background: radial-gradient(60% 100% at 30% 0%, rgba(187,106,37,.10), transparent 70%); pointer-events: none; z-index: -1; }
.hero .eyebrow { margin-bottom: 18px; }
.hero-title { font-size: clamp(2.6rem, 6.5vw, 4.3rem); line-height: 1.08; margin: 0 0 22px; letter-spacing: -0.02em; }
.hero-lead { font-family: var(--sans); font-size: 1.2rem; line-height: 1.7; color: var(--ink-soft); max-width: 34rem; margin: 0 0 32px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }

/* ---------- academies + course cards ---------- */
.academies { max-width: var(--maxw); margin: 0 auto; padding: 24px 24px 8px; }
.academy { margin-bottom: 60px; }
.academy-head { display: flex; align-items: baseline; gap: 16px; margin-bottom: 26px; }
.academy-kicker { font-family: var(--sans); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.2em; text-transform: uppercase; color: var(--ink-faint); flex: none; }
.academy-head h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin: 0; flex: none; }
.academy-head .rule { flex: 1; height: 1px; background: var(--line); align-self: center; }
.course-grid { display: grid; gap: 18px; grid-template-columns: 1fr; }
@media (min-width: 640px) { .course-grid { grid-template-columns: 1fr 1fr; } }

.course-card { position: relative; display: flex; flex-direction: column; background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 26px 22px; color: inherit; overflow: hidden; transition: transform .16s ease, box-shadow .16s ease, border-color .16s; }
.course-card::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--accent); transform: scaleY(0); transform-origin: top; transition: transform .2s ease; }
a.course-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--line); color: inherit; }
a.course-card:hover::before { transform: scaleY(1); }
.course-num { font-family: var(--serif); font-size: 0.92rem; font-weight: 600; color: var(--accent); letter-spacing: 0.06em; margin-bottom: 8px; }
.course-card h3 { font-size: 1.34rem; line-height: 1.3; margin: 0 0 9px; }
.course-card p { font-family: var(--sans); margin: 0; color: var(--ink-soft); font-size: 0.97rem; line-height: 1.62; }
.course-go { margin-top: 16px; font-family: var(--sans); font-size: 0.9rem; font-weight: 600; color: var(--accent-deep); }
.course-card.soon { opacity: 0.78; }
.course-card.soon .course-num, .course-card.soon h3 { color: var(--ink-faint); }
.soon-tag { margin-top: 16px; display: inline-block; align-self: flex-start; font-family: var(--sans); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.08em; color: var(--ink-faint); background: var(--line-soft); padding: 4px 11px; border-radius: 999px; }

/* per-course identity icon (replaces the old chapter number) */
.course-icon { width: 44px; height: 44px; display: grid; place-items: center; background: var(--accent-tint); color: var(--accent-deep); border-radius: 12px; margin-bottom: 16px; transition: background .16s, color .16s; }
.course-icon svg { width: 24px; height: 24px; }
a.course-card:hover .course-icon { background: var(--accent); color: #fff; }
.course-card.soon .course-icon { background: var(--line-soft); color: var(--ink-faint); }
/* academy description line */
.academy-desc { font-family: var(--sans); color: var(--ink-soft); font-size: 1rem; line-height: 1.62; margin: -12px 0 26px; max-width: 42rem; }

/* ---------- free-tool band (dark) ---------- */
.tools-band { background: var(--espresso); color: #efe6d6; margin-top: 28px; }
.tools-band::after { content: ""; display: block; }
.tools-inner { max-width: var(--maxw); margin: 0 auto; padding: 60px 24px; display: grid; gap: 34px; grid-template-columns: 1fr; align-items: center; }
@media (min-width: 760px) { .tools-inner { grid-template-columns: 1.1fr 0.9fr; } }
.tools-text h2 { color: #fbf3e4; font-size: clamp(1.7rem, 3.4vw, 2.4rem); margin: 14px 0 14px; }
.tools-text p { font-family: var(--sans); color: #c9bca6; margin: 0 0 24px; max-width: 30rem; }
.tools-visual { display: flex; justify-content: center; }
.tools-visual svg { width: 100%; max-width: 360px; height: auto; }

/* ---------- breadcrumbs ---------- */
.crumbs { max-width: var(--maxw); margin: 0 auto; padding: 26px 24px 0; font-family: var(--sans); font-size: 0.86rem; color: var(--ink-faint); }
.crumbs a { color: var(--ink-soft); }
.crumbs a:hover { color: var(--accent-deep); }

/* ---------- course overview ---------- */
.course, .lesson { max-width: var(--maxw); margin: 0 auto; padding: 0 24px 80px; }
.course-hero { display: grid; grid-template-columns: 1fr; gap: 26px; padding: 34px 0; border-bottom: 1px solid var(--line); margin-bottom: 38px; }
@media (min-width: 820px) { .course-hero { grid-template-columns: 1fr auto; align-items: center; gap: 48px; } }
.course-hero .academy-kicker, .course-hero .kicker { display: inline-block; margin-bottom: 14px; }
.course-start { margin-top: 26px; }
.course-hero-art { display: flex; justify-content: center; }
.course-cover { width: 132px; height: 132px; border-radius: 26px; background: linear-gradient(150deg, var(--accent-tint), #fff7ea); color: var(--accent-deep); display: grid; place-items: center; box-shadow: var(--shadow); }
.course-cover svg { width: 60px; height: 60px; }
@media (max-width: 819px) { .course-hero-art { display: none; } }
.course-intro { margin-bottom: 38px; max-width: var(--measure); }
.curriculum h2 { font-size: 1.5rem; margin: 0 0 4px; }
.kicker { font-family: var(--sans); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent); }
.course-hero h1, .lesson-head h1 { font-size: clamp(2rem, 5vw, 3rem); line-height: 1.15; margin: 0 0 18px; letter-spacing: -0.02em; }
.lead { font-family: var(--sans); font-size: 1.16rem; line-height: 1.68; color: var(--ink-soft); margin: 0; max-width: var(--measure); }
.toc h2 { font-size: 1.3rem; margin: 0 0 6px; }
.toc-list { list-style: none; counter-reset: l; padding: 0; margin: 18px 0 0; border-top: 1px solid var(--line); }
.toc-list li { border-bottom: 1px solid var(--line); }
.toc-list a { display: flex; align-items: baseline; gap: 20px; padding: 20px 8px; color: inherit; transition: background .14s, padding .14s; }
.toc-list a:hover { background: var(--panel); padding-left: 16px; color: inherit; }
.toc-num { font-family: var(--serif); font-size: 1.05rem; color: var(--accent); font-weight: 600; flex: none; width: 1.8rem; }
.toc-text { flex: 1; }
.toc-text strong { display: block; font-family: var(--serif); font-size: 1.2rem; font-weight: 600; }
.toc-text em { font-style: normal; font-family: var(--sans); color: var(--ink-soft); font-size: 0.95rem; }
.toc-arrow { color: var(--ink-faint); flex: none; transition: transform .16s, color .16s; }
.toc-list a:hover .toc-arrow { transform: translateX(4px); color: var(--accent); }

/* ---------- lesson reading ---------- */
.lesson-head { padding: 30px 0 26px; }
.lesson .lead { margin-bottom: 4px; }
.prose { max-width: var(--measure); font-family: var(--sans); }
.prose > * { max-width: var(--measure); }
.prose h2 { font-size: 1.62rem; line-height: 1.3; margin: 42px 0 14px; }
.prose h2::before { content: ""; display: block; width: 34px; height: 2px; background: var(--accent); margin-bottom: 16px; border-radius: 2px; }
.prose h3 { font-size: 1.24rem; margin: 30px 0 10px; }
.prose p { margin: 0 0 19px; }
.prose ul, .prose ol { margin: 0 0 19px; padding-left: 1.35em; }
.prose li { margin-bottom: 8px; padding-left: 4px; }
.prose li::marker { color: var(--accent); }
.prose strong { color: var(--ink); font-weight: 700; }
.prose a { text-decoration: underline; text-decoration-color: var(--accent-tint); text-underline-offset: 3px; }
.prose code { font-family: var(--mono); background: var(--accent-tint); color: var(--accent-deep); padding: 2px 7px; border-radius: 6px; font-size: 0.88em; }
.prose pre { background: var(--espresso); color: #f3ead9; padding: 16px 18px; border-radius: 12px; overflow-x: auto; }
.prose pre code { background: none; color: inherit; padding: 0; }
.prose blockquote { margin: 26px 0; padding: 6px 0 6px 24px; border-left: 3px solid var(--accent); font-family: var(--serif); font-size: 1.22rem; line-height: 1.55; color: var(--ink-soft); font-style: italic; }
.prose hr { border: none; border-top: 1px solid var(--line); margin: 34px 0; }

/* embedded tool card */
.embed-tool { margin: 30px 0; padding: 24px 26px; border-radius: var(--radius); background: linear-gradient(135deg, #fff7ec, var(--accent-tint)); border: 1px solid #e8cfa9; }
.embed-tool-link { font-family: var(--serif); font-weight: 600; font-size: 1.16rem; color: var(--accent-deep); }
.embed-tool-link:hover { color: var(--accent); }
.embed-tool p { font-family: var(--sans); margin: 7px 0 0; color: var(--ink-soft); font-size: 0.95rem; }

/* prev / next */
.lesson-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 52px; padding-top: 30px; border-top: 1px solid var(--line); }
.lesson-nav a { display: flex; flex-direction: column; gap: 3px; padding: 16px 18px; border: 1px solid var(--line); border-radius: 12px; background: var(--paper-2); font-family: var(--sans); font-weight: 600; color: var(--ink); font-size: 0.95rem; transition: border-color .14s, transform .14s; }
.lesson-nav a:hover { border-color: var(--accent); transform: translateY(-2px); color: var(--ink); }
.lesson-nav .nav-next { text-align: right; }
.lesson-nav .nav-up { grid-column: 1 / -1; text-align: center; color: var(--ink-soft); font-weight: 500; }
.lesson-nav .nav-dir { font-size: 0.76rem; letter-spacing: 0.04em; color: var(--ink-faint); font-weight: 700; }
.lesson-nav .nav-ttl { font-family: var(--serif); font-weight: 600; font-size: 1.04rem; }
.lesson-nav > span:empty { visibility: hidden; }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--line); background: var(--panel); margin-top: 20px; }
.footer-inner { max-width: var(--maxw); margin: 0 auto; padding: 40px 24px; display: flex; flex-wrap: wrap; align-items: center; gap: 10px 22px; font-family: var(--sans); font-size: 0.88rem; color: var(--ink-soft); }
.footer-inner .foot-brand { font-family: var(--serif); font-size: 1.05rem; color: var(--ink); margin-right: auto; }
.footer-inner a { color: var(--ink-soft); }
.footer-inner a:hover { color: var(--accent-deep); }
.footer-sub { max-width: var(--maxw); margin: 0 auto; padding: 0 24px 40px; font-family: var(--sans); font-size: 0.8rem; color: var(--ink-faint); }

/* ---------- motion ---------- */
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
.hero .eyebrow, .hero-title, .hero-lead, .hero-actions { animation: rise .7s cubic-bezier(.2,.7,.2,1) backwards; }
.hero-title { animation-delay: .06s; }
.hero-lead { animation-delay: .14s; }
.hero-actions { animation-delay: .22s; }
@media (prefers-reduced-motion: reduce) { *, *::before { animation: none !important; transition: none !important; scroll-behavior: auto; } }

/* ---------- optimisation pass ---------- */
/* homepage hero: two columns with rosette art on desktop */
.home .hero { display: grid; grid-template-columns: 1fr; gap: 26px; }
@media (min-width: 900px) {
  .home .hero { grid-template-columns: 1.05fr 0.95fr; align-items: center; gap: 50px; padding-top: 72px; }
}
.hero-art { display: none; }
@media (min-width: 900px) {
  .hero-art { display: flex; justify-content: center; animation: rise .9s cubic-bezier(.2,.7,.2,1) backwards; animation-delay: .18s; }
  .hero-art svg { width: 100%; max-width: 340px; height: auto; }
}
.rosette-ring { transform-box: fill-box; transform-origin: center; animation: spin 70s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* lesson reading progress — CSS scroll-driven (no JS; progressive enhancement) */
.read-progress { position: fixed; top: 0; left: 0; height: 3px; width: 100%; background: var(--accent); transform: scaleX(0); transform-origin: 0 50%; z-index: 60; }
@supports (animation-timeline: scroll()) {
  .read-progress { animation: rp linear both; animation-timeline: scroll(root block); }
}
@keyframes rp { to { transform: scaleX(1); } }

/* tabular numerals for chapter numbers */
.course-num, .toc-num, .kicker { font-variant-numeric: tabular-nums lining-nums; }

/* accessibility + finishing polish */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 3px; }
.btn:focus-visible, .course-card:focus-visible, .toc-list a:focus-visible { outline-offset: 4px; }
::selection { background: var(--accent-tint); color: var(--ink); }
.prose h2, .prose h3 { scroll-margin-top: 84px; }

/* ---------- teaching-platform components ---------- */
/* trust line under hero */
.trust { max-width: var(--maxw); margin: 0 auto; text-align: center; font-family: var(--sans); font-size: 0.84rem; letter-spacing: 0.03em; color: var(--ink-faint); padding: 6px 24px 30px; }

/* value-prop features */
.features { max-width: var(--maxw); margin: 0 auto; padding: 32px 24px 18px; }
.section-h { font-size: clamp(1.5rem, 3vw, 2rem); text-align: center; margin: 0; }
.feature-grid { display: grid; gap: 22px; grid-template-columns: 1fr; margin-top: 32px; }
@media (min-width: 720px) { .feature-grid { grid-template-columns: repeat(3, 1fr); } }
.feature { text-align: center; padding: 6px 14px; }
.f-icon { width: 48px; height: 48px; margin: 0 auto 16px; color: var(--accent); display: grid; place-items: center; background: var(--accent-tint); border-radius: 13px; }
.f-icon svg { width: 25px; height: 25px; }
.feature h3 { font-size: 1.18rem; margin: 0 0 8px; }
.feature p { font-family: var(--sans); color: var(--ink-soft); margin: 0; font-size: 0.96rem; line-height: 1.62; }

/* course-card metadata + tags */
.card-meta, .course-meta { display: flex; align-items: center; gap: 10px; font-family: var(--sans); font-size: 0.84rem; color: var(--ink-soft); }
.card-meta { margin-top: 18px; padding-top: 15px; border-top: 1px solid var(--line-soft); }
.course-meta { margin-top: 22px; }
.tag { display: inline-block; font-weight: 700; font-size: 0.72rem; letter-spacing: 0.03em; padding: 4px 10px; border-radius: 999px; }
.tag-level { background: var(--accent-tint); color: var(--accent-deep); }
.tag-free { background: #e6efe3; color: #3e6a45; margin-left: auto; }
.course-meta .tag-free { margin-left: 0; }
.meta-n { color: var(--ink-faint); }

/* lesson course-player layout: outline sidebar + reading column */
.lesson-layout { display: grid; grid-template-columns: 1fr; gap: 28px; }
@media (min-width: 940px) { .lesson-layout { grid-template-columns: 248px 1fr; gap: 52px; align-items: start; } }
.lesson-main { min-width: 0; }
.course-outline { border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper-2); padding: 18px 18px 12px; }
@media (min-width: 940px) { .course-outline { position: sticky; top: 80px; } }
.outline-back { display: block; font-family: var(--serif); font-weight: 600; font-size: 1.02rem; color: var(--ink); padding-bottom: 13px; margin-bottom: 8px; border-bottom: 1px solid var(--line); }
.outline-back:hover { color: var(--accent-deep); }
.outline-list { list-style: none; padding: 0; margin: 0; }
.outline-list a { display: flex; gap: 11px; padding: 10px 9px; border-radius: 9px; font-family: var(--sans); font-size: 0.92rem; line-height: 1.42; color: var(--ink-soft); font-weight: 500; transition: background .14s, color .14s; }
.outline-list a:hover { background: var(--panel); color: var(--ink); }
.outline-list .o-num { color: var(--ink-faint); font-variant-numeric: tabular-nums lining-nums; flex: none; }
.outline-list li.on a { background: var(--accent-tint); color: var(--accent-deep); font-weight: 700; }
.outline-list li.on .o-num { color: var(--accent); }

/* learning path — 演奏技巧學院 三部曲 (vertical timeline) */
.learn-path { list-style: none; margin: 6px 0 0; padding: 0; }
.path-step { position: relative; display: grid; grid-template-columns: 46px 1fr; gap: 22px; padding-bottom: 20px; }
.path-step:not(:last-child)::before { content: ""; position: absolute; left: 22px; top: 50px; bottom: -2px; width: 2px; background: linear-gradient(var(--accent), var(--accent-tint)); }
.path-node { width: 46px; height: 46px; border-radius: 50%; background: var(--accent); color: #fff; display: grid; place-items: center; font-family: var(--serif); font-weight: 700; font-size: 1.25rem; box-shadow: 0 0 0 5px var(--paper); z-index: 1; }
.path-card { display: block; background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; color: inherit; transition: transform .16s, box-shadow .16s, border-color .16s; }
a.path-card:hover { transform: translateY(-2px); box-shadow: var(--shadow); color: inherit; }
.path-card.soon { opacity: 0.82; }
.path-part { display: block; font-family: var(--sans); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.12em; color: var(--accent); margin-bottom: 7px; }
.path-card.soon .path-part { color: var(--ink-faint); }
.path-card h3 { font-size: 1.26rem; margin: 0 0 8px; }
.path-card p { font-family: var(--sans); color: var(--ink-soft); margin: 0; font-size: 0.96rem; line-height: 1.6; }
.path-card .card-meta { margin-top: 14px; padding-top: 12px; }
.path-card .soon-tag { margin-top: 14px; }

/* ---------- course-info: 你會學到什麼 + 適合誰 ---------- */
.course-info { display: grid; grid-template-columns: 1fr; gap: 30px; margin-bottom: 42px; }
@media (min-width: 760px) { .course-info { grid-template-columns: 1.4fr 1fr; gap: 44px; align-items: start; } }
.course-info h2 { font-size: 1.32rem; margin: 0 0 16px; }
.outcome-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 13px; }
.outcome-list li { position: relative; padding-left: 32px; font-family: var(--sans); color: var(--ink-soft); line-height: 1.55; }
.outcome-list li::before { content: ""; position: absolute; left: 0; top: 3px; width: 20px; height: 20px; border-radius: 50%; background: var(--accent-tint); }
.outcome-list li::after { content: "✓"; position: absolute; left: 0; top: 2px; width: 20px; text-align: center; color: var(--accent-deep); font-size: 0.78rem; font-weight: 700; }
.audience { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; }
.audience p { font-family: var(--sans); color: var(--ink-soft); margin: 0; line-height: 1.62; }

/* ---------- lesson completion ---------- */
.lesson-done { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin: 36px 0 0; padding: 24px 0 0; border-top: 1px solid var(--line); }
#done-btn { font-family: var(--sans); font-weight: 600; font-size: 0.96rem; padding: 11px 22px; border-radius: 999px; border: 1.5px solid var(--accent); background: transparent; color: var(--accent-deep); cursor: pointer; transition: background .14s, color .14s, border-color .14s; }
#done-btn:hover { background: var(--accent-tint); }
#done-btn.is-done { background: var(--done); border-color: var(--done); color: #fff; }
.lesson-done-hint { font-family: var(--sans); font-size: 0.82rem; color: var(--ink-faint); }
/* completed → swap the number for a check, in outline + TOC */
.outline-list li.is-done .o-num, .toc-list li.is-done .toc-num { color: transparent; position: relative; }
.outline-list li.is-done .o-num::after, .toc-list li.is-done .toc-num::after { content: "✓"; position: absolute; inset: 0; display: grid; place-items: center; color: var(--done); font-weight: 700; }
.outline-list li.is-done a { color: var(--ink); }

/* ---------- about ---------- */
.about { max-width: 46rem; margin: 0 auto; padding: 58px 24px 8px; text-align: center; }
.about .eyebrow { margin-bottom: 14px; }
.about-body { font-family: var(--sans); font-size: 1.08rem; line-height: 1.78; color: var(--ink-soft); margin: 18px 0 28px; }

/* ---------- FAQ ---------- */
.faq { max-width: 52rem; margin: 0 auto; padding: 50px 24px 18px; }
.faq .section-h { margin-bottom: 26px; }
.faq-list { display: grid; gap: 12px; }
.faq-item { background: var(--paper-2); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.faq-item summary { cursor: pointer; padding: 18px 22px; font-family: var(--serif); font-weight: 600; font-size: 1.08rem; color: var(--ink); list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-family: var(--sans); font-size: 1.45rem; line-height: 1; color: var(--accent); flex: none; transition: transform .2s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-a { padding: 0 22px 20px; }
.faq-a p { font-family: var(--sans); color: var(--ink-soft); margin: 0; line-height: 1.66; }

/* more prominent next-lesson */
.lesson-nav .nav-next { border-color: var(--accent); }
.lesson-nav .nav-next .nav-dir { color: var(--accent-deep); }
.lesson-nav .nav-next:hover { background: var(--accent-tint); }

/* ---------- student login (Phase 3 scaffold) ---------- */
.login { max-width: 460px; margin: 0 auto; padding: 56px 24px 80px; }
.login-card { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 38px 32px; text-align: center; box-shadow: var(--shadow); }
.login-card h1 { font-size: 1.7rem; margin: 12px 0 12px; }
.login-sub { font-family: var(--sans); color: var(--ink-soft); font-size: 0.98rem; line-height: 1.62; margin: 0 0 28px; }
.login-buttons { display: grid; gap: 12px; }
.login-btn { display: flex; align-items: center; justify-content: center; padding: 13px 20px; border-radius: 12px; font-family: var(--sans); font-weight: 600; font-size: 1rem; border: 1px solid transparent; transition: filter .14s, transform .14s; }
.login-btn:hover { transform: translateY(-1px); filter: brightness(0.97); text-decoration: none; }
.login-line { background: #06C755; color: #fff; }
.login-google { background: #fff; color: #3c4043; border-color: #dadce0; }
.login-facebook { background: #1877F2; color: #fff; }
.login-btn.disabled { opacity: 0.45; cursor: not-allowed; pointer-events: none; }
.login-note { font-family: var(--sans); font-size: 0.84rem; color: var(--ink-faint); margin: 26px 0 0; line-height: 1.5; }
.login-fine { font-family: var(--sans); font-size: 0.78rem; color: var(--ink-faint); margin: 10px 0 0; }

/* ---------- student area (Phase 3 scaffold) ---------- */
.student { max-width: 820px; margin: 0 auto; padding: 36px 24px 80px; }
.student-hero { margin-bottom: 36px; }
.student-hero h1 { font-size: clamp(1.8rem, 4vw, 2.4rem); margin: 0 0 8px; }
.student-hero p { font-family: var(--sans); color: var(--ink-soft); margin: 0; }
.student-section { margin-bottom: 42px; }
.student-section > h2 { font-size: 1.32rem; margin: 0 0 18px; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.progress-cards { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 620px) { .progress-cards { grid-template-columns: 1fr 1fr; } }
.progress-card { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 22px; }
.pc-head { display: flex; justify-content: space-between; align-items: baseline; font-family: var(--sans); margin-bottom: 12px; }
.pc-head strong { font-family: var(--serif); font-size: 1.1rem; }
.pc-head span { color: var(--ink-faint); font-size: 0.86rem; }
.pbar { height: 8px; background: var(--line-soft); border-radius: 999px; overflow: hidden; }
.pbar span { display: block; height: 100%; background: var(--accent); border-radius: 999px; }
.pc-next { display: inline-block; margin-top: 14px; font-family: var(--sans); font-size: 0.9rem; font-weight: 600; color: var(--accent-deep); }
.credit-list { list-style: none; padding: 0; margin: 0 0 18px; display: grid; gap: 10px; }
.credit { display: flex; align-items: center; gap: 14px; background: var(--paper-2); border: 1px solid var(--line); border-radius: 12px; padding: 14px 18px; font-family: var(--sans); }
.credit-state { flex: none; font-size: 0.74rem; font-weight: 700; padding: 4px 11px; border-radius: 999px; }
.credit.done .credit-state { background: #e6efe3; color: var(--done); }
.credit.scheduled .credit-state { background: var(--accent-tint); color: var(--accent-deep); }
.credit.pending .credit-state { background: var(--line-soft); color: var(--ink-faint); }
.credit-main { color: var(--ink-soft); }
.hw-card { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; }
.hw-top { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; font-family: var(--sans); }
.hw-top strong { font-family: var(--serif); font-size: 1.1rem; }
.hw-status { flex: none; font-size: 0.74rem; font-weight: 700; padding: 4px 11px; border-radius: 999px; }
.hw-status.graded { background: #e6efe3; color: var(--done); }
.hw-video { display: inline-block; margin: 14px 0; font-family: var(--sans); font-weight: 600; color: var(--accent-deep); }
.hw-feedback { background: var(--panel); border-radius: 12px; padding: 16px 18px; }
.hw-fb-head { font-family: var(--sans); font-weight: 600; font-size: 0.9rem; margin-bottom: 6px; }
.stars { color: var(--accent); letter-spacing: 2px; }
.hw-feedback p { font-family: var(--sans); color: var(--ink-soft); margin: 0; line-height: 1.6; }
.qa-thread { display: grid; gap: 12px; margin-bottom: 18px; }
.qa-msg { padding: 13px 18px; border-radius: 14px; max-width: 88%; }
.qa-msg p { font-family: var(--sans); margin: 4px 0 0; line-height: 1.6; }
.qa-who { font-family: var(--sans); font-size: 0.74rem; font-weight: 700; color: var(--ink-faint); }
.qa-me { background: var(--accent-tint); justify-self: end; }
.qa-teacher { background: var(--paper-2); border: 1px solid var(--line); justify-self: start; }

/* student dashboard — real identity + localStorage progress + locked 1-on-1 */
.student-eyebrow { font-family: var(--sans); font-size: 0.76rem; letter-spacing: 0.13em; text-transform: uppercase; color: var(--accent-deep); font-weight: 700; margin: 0 0 8px; }
.student-meta { font-family: var(--sans); font-size: 0.9rem; color: var(--ink-faint); margin: 6px 0 14px; }
.student-actions { font-family: var(--sans); font-size: 0.9rem; color: var(--ink-faint); }
.student-actions a { color: var(--accent-deep); font-weight: 600; }
.student-actions a.logout { color: var(--ink-faint); }
.progress-loading, .progress-empty { font-family: var(--sans); color: var(--ink-soft); margin: 0; line-height: 1.6; }
.progress-empty a { color: var(--accent-deep); font-weight: 600; }
.student-section.locked .locked-card { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.locked-badge { display: inline-block; font-family: var(--sans); font-size: 0.74rem; font-weight: 700; color: var(--accent-deep); background: var(--accent-tint); padding: 4px 11px; border-radius: 999px; margin-bottom: 12px; }
.locked-card h2 { font-size: 1.3rem; margin: 0 0 10px; padding: 0; border: 0; }
.locked-card > p { font-family: var(--sans); color: var(--ink-soft); margin: 0 0 14px; line-height: 1.6; }
.locked-feats { list-style: none; padding: 0; margin: 0 0 16px; display: grid; gap: 10px; }
.locked-feats li { font-family: var(--sans); color: var(--ink-soft); background: var(--panel); border-radius: 12px; padding: 12px 16px; }
.locked-note { font-family: var(--sans); font-size: 0.86rem; color: var(--ink-faint); margin: 0; line-height: 1.6; }