/* Thiên Cơ Luận — landing styles (cổ phong) */

@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,400;0,500;0,600;0,700;1,400;1,600&family=Be+Vietnam+Pro:wght@400;500;600;700&display=swap');

:root {
  --parchment: #F5EFE0;
  --parchment-light: #FAF5E8;
  --parchment-dark: #E8E0CC;
  --ink-black: #1A1612;
  --ink-sepia: #2B2419;
  --antique-gold: #C9A961;
  --antique-gold-dark: #8B7340;
  --antique-gold-light: #E8C778;
  --lacquer-red: #8B2820;
  --lacquer-red-dark: #5D1810;
  --jade-green-dark: #2D6A4F;
  --silver: #6B6660;
  --silver-light: #9B9690;

  --serif: 'Cormorant Garamond', Georgia, serif;
  --sans: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--parchment);
  color: var(--ink-black);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
}
a { color: var(--lacquer-red); text-decoration: none; transition: opacity 0.2s; }
a:hover { opacity: 0.7; }

.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(245, 239, 224, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 0.5px solid var(--parchment-dark);
  padding: 16px 24px;
}
.nav-inner { max-width: 1080px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; }
.nav-brand { display: flex; align-items: center; gap: 10px; }
.nav-seal {
  width: 36px; height: 36px;
  background: var(--lacquer-red);
  color: var(--parchment-light);
  font-family: var(--serif); font-weight: 700; font-size: 20px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 4px; letter-spacing: -1px;
}
.nav-name { font-family: var(--serif); font-size: 20px; font-weight: 700; color: var(--ink-black); }
.nav-links { display: flex; gap: 24px; font-size: 14px; }
.nav-links a { color: var(--silver); font-weight: 500; }
.nav-links a:hover { color: var(--ink-black); }

.hero {
  padding: 80px 24px 60px;
  text-align: center;
  background: linear-gradient(180deg, var(--parchment-light) 0%, var(--parchment) 100%);
}
.hero-glyph {
  font-family: var(--serif); font-size: 88px; font-weight: 700;
  color: var(--antique-gold);
  text-shadow: 0 0 18px rgba(201, 169, 97, 0.5);
  letter-spacing: 4px; margin-bottom: 16px;
}
.hero-eyebrow {
  font-family: var(--serif); font-style: italic; font-size: 14px;
  color: var(--antique-gold-dark);
  letter-spacing: 3px; text-transform: uppercase; margin-bottom: 12px;
}
.hero-title {
  font-family: var(--serif); font-size: 56px; font-weight: 700;
  color: var(--ink-black); letter-spacing: 0.5px;
  margin-bottom: 20px; line-height: 1.1;
}
.hero-sub {
  font-family: var(--serif); font-style: italic; font-size: 19px;
  color: var(--silver); max-width: 560px; margin: 0 auto 36px;
  line-height: 1.5;
}
.hero-cta {
  display: inline-flex; align-items: center; gap: 10px;
  background: var(--ink-black); color: var(--antique-gold-light);
  padding: 14px 28px; border-radius: 8px;
  font-family: var(--serif); font-weight: 700; font-size: 15px;
  letter-spacing: 2px; text-transform: uppercase;
  border: 1px solid var(--antique-gold-dark);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}
.hero-cta:hover { opacity: 0.9; transform: translateY(-1px); }

.section { padding: 60px 24px; max-width: 1080px; margin: 0 auto; }
.section-eyebrow {
  font-family: var(--serif); font-style: italic; font-size: 13px;
  color: var(--lacquer-red); letter-spacing: 4px; text-transform: uppercase;
  text-align: center; margin-bottom: 8px;
}
.section-title {
  font-family: var(--serif); font-size: 40px; font-weight: 700;
  color: var(--ink-black); text-align: center; margin-bottom: 48px;
}
.divider { width: 80px; height: 1px; background: var(--antique-gold-dark); margin: 0 auto 48px; opacity: 0.4; }

.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; }
.feature {
  background: var(--parchment-light);
  border: 0.6px solid var(--antique-gold-dark);
  border-radius: 12px; padding: 28px 24px;
  transition: transform 0.2s, box-shadow 0.2s;
}
.feature:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08); }
.feature-glyph {
  font-family: var(--serif); font-size: 32px; font-weight: 700;
  color: var(--lacquer-red); margin-bottom: 12px;
  text-shadow: 0 0 8px rgba(139, 40, 32, 0.3);
}
.feature-title { font-family: var(--serif); font-size: 20px; font-weight: 700; color: var(--ink-black); margin-bottom: 8px; }
.feature-desc { font-size: 14px; color: var(--silver); line-height: 1.6; }

.doc { max-width: 720px; margin: 0 auto; padding: 40px 24px 80px; }
.doc-title { font-family: var(--serif); font-size: 40px; font-weight: 700; color: var(--ink-black); margin-bottom: 8px; text-align: center; }
.doc-eyebrow {
  font-family: var(--serif); font-style: italic; font-size: 13px;
  color: var(--antique-gold-dark); letter-spacing: 3px;
  text-transform: uppercase; text-align: center; margin-bottom: 36px;
}
.doc h2 { font-family: var(--serif); font-size: 24px; font-weight: 700; color: var(--ink-black); margin: 32px 0 12px; }
.doc p, .doc li {
  font-family: var(--sans); font-size: 15px; color: var(--ink-black);
  line-height: 1.7; margin-bottom: 10px;
}
.doc ul { padding-left: 20px; margin-bottom: 16px; }
.doc strong { color: var(--lacquer-red); font-weight: 600; }
.doc .meta { font-family: var(--serif); font-style: italic; font-size: 13px; color: var(--silver); text-align: center; margin-bottom: 24px; }

.footer { background: var(--ink-black); color: var(--silver-light); padding: 48px 24px 32px; text-align: center; }
.footer-seal { font-family: var(--serif); font-weight: 700; font-size: 22px; color: var(--antique-gold); letter-spacing: 12px; margin-bottom: 12px; }
.footer-brand { font-family: var(--serif); font-style: italic; font-size: 14px; color: var(--antique-gold-light); margin-bottom: 24px; }
.footer-links { display: flex; gap: 24px; justify-content: center; flex-wrap: wrap; font-size: 13px; margin-bottom: 16px; }
.footer-links a { color: var(--silver-light); }
.footer-links a:hover { color: var(--antique-gold-light); }
.footer-copy { font-size: 12px; color: var(--silver); opacity: 0.8; }

@media (max-width: 640px) {
  .hero { padding: 56px 20px 40px; }
  .hero-glyph { font-size: 64px; }
  .hero-title { font-size: 38px; }
  .hero-sub { font-size: 16px; }
  .section { padding: 40px 20px; }
  .section-title { font-size: 28px; margin-bottom: 32px; }
  .nav-links { gap: 16px; font-size: 13px; }
  .doc-title { font-size: 30px; }
  .doc h2 { font-size: 20px; }
}