/* 94AI 官網共用樣式：延續課程封面與募資影片「黑曜石＋霓虹綠光切痕」視覺（見 course-promo 交接檔第四節） */
:root {
  --bg: #0a0b0c;
  --bg-2: #111314;
  --card: rgba(255, 255, 255, 0.04);
  --card-strong: rgba(255, 255, 255, 0.07);
  --line: rgba(255, 255, 255, 0.12);
  --text: #f2f3f2;
  --muted: #a9aeaa;
  --neon: #5cff6a;
  --neon-glow: rgba(92, 255, 106, 0.45);
  --neon-soft: rgba(92, 255, 106, 0.12);
  --amber: #f2a93b;
  --danger: #ff6b6b;
  --radius: 14px;
  --wrap: 1120px;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Noto Sans TC", "Microsoft JhengHei", "PingFang TC", sans-serif;
  font-size: 17px;
  line-height: 1.8;
  overflow-x: hidden;
}
img, video { max-width: 100%; height: auto; display: block; }
a { color: var(--neon); text-underline-offset: 3px; }
a:hover { text-shadow: 0 0 12px var(--neon-glow); }
:focus-visible { outline: 2px solid var(--neon); outline-offset: 3px; border-radius: 4px; }
strong { color: #fff; }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 16px; }
.muted { color: var(--muted); }
.small { font-size: 0.88em; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--neon); color: #000; padding: 6px 12px; z-index: 100; }
.skip:focus { left: 8px; }

/* ---------- 頁首 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10, 11, 12, 0.88);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap { display: flex; align-items: center; gap: 16px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: #fff; text-decoration: none; font-weight: 700; white-space: nowrap; }
.brand img { width: 36px; height: 36px; }
.brand span { color: var(--amber); font-weight: 500; letter-spacing: 0.05em; }
.nav { margin-left: auto; display: flex; gap: 4px; align-items: center; }
.nav a { color: var(--text); text-decoration: none; font-size: 15px; padding: 6px 10px; border-radius: 8px; }
.nav a:hover { background: var(--card-strong); text-shadow: none; }
.nav .nav-cta { border: 1px solid var(--neon); color: var(--neon); }
@media (max-width: 880px) {
  .nav a:not(.nav-cta) { display: none; }
  .brand span { display: none; }
}

/* ---------- 主視覺 ---------- */
.hero {
  position: relative;
  background: #050606 url("/media/hero-bg.webp") center / cover no-repeat;
  padding: 72px 0 80px;
  text-align: center;
}
.hero::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, rgba(10,11,12,0.25), rgba(10,11,12,0.55) 70%, var(--bg)); }
.hero > .wrap { position: relative; z-index: 1; }
/* 封面招牌元素：細白線外框，上下緣斷開嵌字 */
.frame {
  position: relative;
  max-width: 680px;
  margin: 0 auto;
  border: 2px solid rgba(255, 255, 255, 0.9);
  padding: 48px 20px 44px;
  background: rgba(5, 6, 6, 0.35);
}
.frame .edge {
  position: absolute; left: 50%; transform: translateX(-50%);
  background: #0b0c0d; padding: 0 18px;
  letter-spacing: 0.35em; font-weight: 500; white-space: nowrap;
  font-size: clamp(14px, 3.6vw, 20px);
}
.frame .edge.top { top: -0.95em; color: var(--amber); }
.frame .edge.bottom { bottom: -0.95em; color: #fff; }
.frame h1 { margin: 0; font-size: clamp(30px, 7.4vw, 60px); line-height: 1.25; font-weight: 900; letter-spacing: 0.02em; }
.frame h1 .glow { color: var(--neon); text-shadow: 0 0 18px var(--neon-glow); }
.hero .tagline { margin: 44px 0 6px; font-size: clamp(20px, 4.4vw, 28px); font-weight: 700; }
.hero .lead { max-width: 640px; margin: 0 auto; color: #d6dad7; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-top: 28px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 48px; padding: 10px 22px; border-radius: 999px;
  font-weight: 700; font-size: 16px; text-decoration: none; cursor: pointer;
  border: 2px solid var(--neon); transition: box-shadow 0.2s, transform 0.2s;
}
.btn-primary { background: var(--neon); color: #041006; }
.btn-primary:hover { box-shadow: 0 0 24px var(--neon-glow); text-shadow: none; transform: translateY(-1px); }
.btn-ghost { background: rgba(0, 0, 0, 0.4); color: var(--neon); }
.btn-ghost:hover { background: var(--neon-soft); text-shadow: none; }

/* ---------- 區塊 ---------- */
section { padding: 72px 0; }
section.alt { background: var(--bg-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.eyebrow { color: var(--amber); letter-spacing: 0.3em; font-size: 14px; font-weight: 500; margin: 0 0 6px; }
h2 { font-size: clamp(26px, 5vw, 38px); line-height: 1.35; margin: 0 0 20px; font-weight: 900; }
h2 .glow, h3 .glow { color: var(--neon); text-shadow: 0 0 14px var(--neon-glow); }
h3 { font-size: clamp(20px, 3.6vw, 24px); line-height: 1.45; margin: 40px 0 14px; }
h4 { font-size: 18px; margin: 0 0 6px; }
p { margin: 0 0 14px; }
.section-lead { max-width: 760px; color: #d6dad7; }

.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}
.card.accent { border-color: var(--neon); box-shadow: 0 0 0 1px var(--neon-soft) inset; }
.card .tag { display: inline-block; font-size: 13px; color: var(--amber); letter-spacing: 0.12em; margin-bottom: 4px; }
.card p:last-child, .card ul:last-child { margin-bottom: 0; }
.num {
  display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 50%;
  border: 2px solid var(--neon); color: var(--neon); font-weight: 700; margin-bottom: 8px;
}
.quote {
  border-left: 3px solid var(--neon);
  padding: 6px 0 6px 18px;
  margin: 24px 0;
  font-size: 1.08em;
  color: #fff;
}
ul.ticks { list-style: none; padding: 0; margin: 0 0 14px; }
ul.ticks li { position: relative; padding-left: 26px; margin-bottom: 6px; }
ul.ticks li::before { content: ""; position: absolute; left: 4px; top: 0.72em; width: 9px; height: 9px; border-radius: 50%; background: var(--neon); box-shadow: 0 0 8px var(--neon-glow); }
ul.crosses li::before { background: var(--danger); box-shadow: none; }

/* 前後對照表 */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 14px 16px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { background: var(--card-strong); color: var(--amber); font-weight: 700; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
@media (max-width: 560px) { th, td { padding: 10px; font-size: 15px; } th { white-space: normal; } }
td.after { color: #fff; }
td.after::before { content: "→ "; color: var(--neon); font-weight: 700; }

/* 學習流程 */
.flow { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 16px 0 0; padding: 0; list-style: none; }
.flow li { background: var(--neon-soft); border: 1px solid rgba(92, 255, 106, 0.4); border-radius: 999px; padding: 6px 14px; font-size: 15px; }
.flow li:not(:last-child)::after { content: "→"; color: var(--neon); margin-left: 12px; }
.flow li { display: inline-flex; align-items: center; }

/* 示範動圖（mp4 循環短片） */
figure { margin: 0; }
.clip {
  border-radius: 12px; overflow: hidden; border: 1px solid var(--line); background: #1a1b1c;
  aspect-ratio: 800 / 408;
}
.clip video, .clip img { width: 100%; height: 100%; object-fit: cover; }
figcaption { font-size: 14px; color: var(--muted); margin-top: 8px; }
.shot { border-radius: 12px; border: 1px solid var(--line); }

/* 章節 */
.chapter { margin-top: 32px; padding: 24px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); }
.chapter > h3 { margin-top: 0; }
.chapter .meta { display: grid; gap: 4px; margin-bottom: 16px; color: #d6dad7; }
.units { list-style: none; margin: 0 0 16px; padding: 0; display: grid; gap: 10px; }
.units li { background: rgba(0,0,0,0.25); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; }
.units .type { color: var(--muted); font-size: 14px; }
.units .win { display: block; margin-top: 4px; color: var(--neon); font-size: 15px; }
.big-win { background: rgba(242, 169, 59, 0.1); border: 1px solid rgba(242, 169, 59, 0.45); border-radius: 10px; padding: 12px 14px; margin-bottom: 16px; }
.clips { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); margin-top: 16px; }

/* 學習地圖 */
.map { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); counter-reset: course; }
.map .card { position: relative; padding-top: 56px; }
.map .card::before {
  counter-increment: course; content: counter(course);
  position: absolute; top: 14px; left: 20px; width: 32px; height: 32px; border-radius: 50%;
  display: grid; place-items: center; border: 2px solid var(--neon); color: var(--neon); font-weight: 700;
}
.map .card.accent::before { background: var(--neon); color: #041006; }
.map .series { color: var(--muted); font-size: 14px; margin: 0; }
.map h4 { font-size: 19px; line-height: 1.45; margin: 2px 0 10px; }

/* 講師 */
.teacher { display: grid; gap: 28px; grid-template-columns: minmax(0, 240px) 1fr; align-items: start; }
.teacher img.portrait { border-radius: 50%; border: 3px solid var(--neon); box-shadow: 0 0 30px var(--neon-soft); width: 100%; max-width: 240px; }
@media (max-width: 720px) { .teacher { grid-template-columns: 1fr; } .teacher img.portrait { max-width: 180px; margin: 0 auto; } }

/* 常見問題 */
details { border: 1px solid var(--line); border-radius: 12px; background: var(--card); margin-bottom: 10px; }
summary { cursor: pointer; padding: 16px 48px 16px 18px; font-weight: 700; position: relative; list-style: none; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 18px; top: 50%; transform: translateY(-50%); color: var(--neon); font-size: 24px; font-weight: 400; }
details[open] summary::after { content: "−"; }
details > div { padding: 0 18px 16px; color: #d6dad7; }

/* 行動呼籲 */
.final { text-align: center; }
.final p { max-width: 700px; margin-left: auto; margin-right: auto; }

/* 頁尾 */
.site-footer { border-top: 1px solid var(--line); padding: 32px 0 40px; color: var(--muted); font-size: 14px; }
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: center; justify-content: space-between; }
.site-footer a { color: var(--text); }

/* ---------- 下載頁 ---------- */
.page-head { padding: 56px 0 24px; }
.download-box { display: grid; gap: 20px; grid-template-columns: 1fr auto; align-items: center; }
@media (max-width: 720px) { .download-box { grid-template-columns: 1fr; } }
.file-meta { display: grid; grid-template-columns: max-content 1fr; gap: 4px 14px; font-size: 15px; margin: 0; }
.file-meta dt { color: var(--muted); }
.file-meta dd { margin: 0; }
code, .mono { font-family: Consolas, "Cascadia Mono", monospace; font-size: 0.9em; }
.hash { word-break: break-all; color: #d6dad7; }
.steps { counter-reset: step; list-style: none; padding: 0; margin: 0; display: grid; gap: 14px; }
.steps > li { counter-increment: step; position: relative; padding: 18px 18px 18px 64px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); }
.steps > li::before {
  content: counter(step); position: absolute; left: 18px; top: 18px; width: 32px; height: 32px; border-radius: 50%;
  display: grid; place-items: center; background: var(--neon); color: #041006; font-weight: 900;
}
.steps h4 { margin-bottom: 6px; }
.ui { display: inline-block; padding: 0 8px; border: 1px solid var(--line); border-radius: 6px; background: var(--card-strong); color: #fff; font-size: 0.92em; white-space: nowrap; }
.note { border-left: 3px solid var(--amber); background: rgba(242, 169, 59, 0.08); padding: 12px 16px; border-radius: 0 10px 10px 0; margin: 14px 0; }
.note.ok { border-left-color: var(--neon); background: var(--neon-soft); }
.verdicts { display: grid; gap: 10px; }
.verdicts div { padding: 10px 14px; border-radius: 10px; border: 1px solid var(--line); background: rgba(0,0,0,0.25); }
.prose h2 { font-size: clamp(22px, 4vw, 28px); margin-top: 36px; }
.prose { max-width: 820px; }

/* 講師作品、同學評價：電腦版兩欄、手機一欄 */
.works { grid-template-columns: repeat(auto-fit, minmax(min(420px, 100%), 1fr)); align-items: start; }