/* ============================================
   公開頁面共用樣式 ── site.css
   首頁 / 課程 / 特色 / 講師 / 登入 都引用這個
   ============================================ */

:root {
  --bg: #07091a;
  --bg-1: #0c1130;
  --surface: rgba(255,255,255,0.025);
  --surface-2: rgba(255,255,255,0.05);
  --surface-hover: rgba(255,255,255,0.08);
  --border: rgba(255,255,255,0.08);
  --border-strong: rgba(255,255,255,0.16);
  --text: #f4f6ff;
  --text-2: #c4cbe6;
  --text-3: #8c97bd;
  --text-4: #5b6688;
  --brand: #6f80ff;
  --brand-2: #a855f7;
  --brand-3: #06b6d4;
  --green: #22c55e;
  --orange: #fb923c;
  --rose: #f43f5e;
  --grad-brand: linear-gradient(135deg, #6f80ff 0%, #a855f7 100%);
  --grad-cool: linear-gradient(135deg, #06b6d4 0%, #6f80ff 100%);
  --grad-warm: linear-gradient(135deg, #fb923c 0%, #f43f5e 100%);
  --ff-sans: 'Inter', 'Noto Sans TC', system-ui, -apple-system, sans-serif;
  --ff-mono: 'JetBrains Mono', ui-monospace, monospace;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --ease-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; -webkit-font-smoothing: antialiased; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--ff-sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
  letter-spacing: -0.005em;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(900px circle at 15% 12%,  rgba(111,128,255,.20), transparent 50%),
    radial-gradient(800px circle at 85% 14%, rgba(168,85,247,.16), transparent 55%),
    radial-gradient(1100px circle at 50% 95%, rgba(6,182,212,.10), transparent 60%);
  pointer-events: none;
  z-index: 0;
}
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.5  0 0 0 0 0.5  0 0 0 0 0.7  0 0 0 0.05 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  opacity: .35;
  pointer-events: none;
  z-index: 1;
}
main { position: relative; z-index: 2; }

/* ===== Top Navigation ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(160%) blur(18px);
  -webkit-backdrop-filter: saturate(160%) blur(18px);
  background: rgba(7,9,26,0.55);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 14px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text);
  flex-shrink: 0;
}
.brand-mark {
  width: 36px; height: 36px;
  border-radius: 10px;
  background: var(--grad-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-family: var(--ff-mono);
  font-size: 14px;
  letter-spacing: -0.04em;
  box-shadow: 0 6px 20px rgba(111,128,255,.45);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-name { font-weight: 700; font-size: 14px; letter-spacing: -0.01em; }
.brand-sub { font-size: 11px; color: var(--text-3); font-family: var(--ff-mono); letter-spacing: 0.04em; }

.nav-links {
  display: flex;
  gap: 4px;
  align-items: center;
}
.nav-link {
  padding: 7px 14px;
  color: var(--text-3);
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 500;
  border-radius: 8px;
  transition: color .15s, background .15s;
}
.nav-link:hover { color: var(--text); background: var(--surface-2); }
.nav-link.active { color: var(--text); }
.nav-link.cta {
  margin-left: 8px;
  padding: 7px 18px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
}
.nav-link.cta:hover { background: var(--surface-hover); border-color: var(--border-strong); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 22px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: all .2s var(--ease);
  font-family: inherit;
}
.btn-primary {
  background: var(--grad-brand);
  color: #fff;
  box-shadow: 0 10px 30px rgba(111,128,255,.4), inset 0 1px 0 rgba(255,255,255,.2);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px rgba(111,128,255,.55); }
.btn-ghost {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--surface-hover); border-color: var(--border-strong); }
.btn svg { width: 16px; height: 16px; }

/* ===== Section Header ===== */
section.section {
  max-width: 1280px;
  margin: 0 auto;
  padding: 80px 28px;
}
.section-head {
  text-align: center;
  margin-bottom: 56px;
}
.section-eyebrow {
  display: inline-block;
  font-family: var(--ff-mono);
  font-size: 12px;
  color: var(--brand);
  letter-spacing: 0.12em;
  margin-bottom: 14px;
  text-transform: uppercase;
  font-weight: 700;
}
.section-head h1, .section-head h2 {
  font-size: clamp(34px, 5vw, 56px);
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1.1;
  margin-bottom: 16px;
}
.section-head p {
  font-size: 17px;
  color: var(--text-2);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ===== Footer ===== */
footer.site-footer {
  max-width: 1280px;
  margin: 0 auto;
  padding: 60px 28px 40px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-3);
  font-size: 13px;
  flex-wrap: wrap;
  gap: 16px;
  position: relative;
  z-index: 2;
}
footer.site-footer .copy { color: var(--text-3); }
footer.site-footer .links { display: flex; gap: 18px; }
footer.site-footer .links a { color: var(--text-3); text-decoration: none; transition: color .15s; }
footer.site-footer .links a:hover { color: var(--text); }

/* ===== Reveal ===== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
.reveal.in { opacity: 1; transform: translateY(0); }

/* ===== Eyebrow Tag ===== */
.eyebrow-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 12px;
  color: var(--text-2);
  font-family: var(--ff-mono);
  letter-spacing: 0.04em;
}
.eyebrow-tag .pulse {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 8px var(--green);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse { 0%,100% { opacity: 1 } 50% { opacity: .35 } }

@media (max-width: 720px) {
  .nav-links .nav-link:not(.cta) { display: none; }
  footer.site-footer { flex-direction: column; text-align: center; }
}

:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; border-radius: 6px; }