:root {
  --accent-start: #C0392B;
  --accent-end:   #E67E22;
  --bg:           #fdf8f6;
  --surface:      #ffffff;
  --text:         #1a1008;
  --text-secondary: #6b7280;
  --border:       rgba(0,0,0,0.07);
  --radius:       16px;
  --shadow:       0 4px 24px rgba(192,57,43,0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:      #1a0f0a;
    --surface: #261510;
    --text:    #f5ede8;
    --text-secondary: #9ca3af;
    --border:  rgba(255,255,255,0.08);
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* NAV */
nav {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 18px 40px;
  position: sticky;
  top: 0;
  background: rgba(253,248,246,0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}
@media (prefers-color-scheme: dark) {
  nav { background: rgba(26,15,10,0.88); }
}
.nav-logo { font-size: 1.25rem; font-weight: 700; margin-right: auto; }
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a { text-decoration: none; color: var(--text-secondary); font-size: 0.9rem; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.lang-switcher { display: flex; gap: 6px; }
.lang-switcher a {
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  text-decoration: none;
  color: var(--text-secondary);
  transition: all .2s;
}
.lang-switcher a:hover, .lang-switcher a.active {
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  color: white;
  border-color: transparent;
}

/* HERO */
.hero {
  max-width: 800px;
  margin: 0 auto;
  padding: 80px 24px 60px;
  text-align: center;
}
.hero-icon {
  width: 100px; height: 100px;
  border-radius: 24px;
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 52px;
  margin-bottom: 28px;
  box-shadow: 0 8px 32px rgba(192,57,43,0.35);
}
.hero h1 { font-size: 3rem; font-weight: 800; line-height: 1.15; margin-bottom: 20px; }
.hero p { font-size: 1.15rem; color: var(--text-secondary); max-width: 540px; margin: 0 auto 36px; line-height: 1.75; }
@media (max-width: 600px) {
  .hero h1 { font-size: 2rem; }
  .hero p  { font-size: 1rem; }
}

/* BUTTONS */
.btn-group { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: all .2s;
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  color: white;
  box-shadow: 0 4px 20px rgba(192,57,43,0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(192,57,43,0.45); }
.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { border-color: var(--accent-start); color: var(--accent-start); }

/* FEATURES */
.features {
  max-width: 1000px;
  margin: 0 auto 80px;
  padding: 0 24px;
}
.features h2 { text-align: center; font-size: 1.75rem; font-weight: 700; margin-bottom: 40px; }
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}
.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
}
.feature-icon { font-size: 2rem; margin-bottom: 14px; }
.feature-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.feature-card p  { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }

/* FOOTER */
footer {
  text-align: center;
  padding: 40px 24px;
  border-top: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.85rem;
}
footer a { color: var(--accent-start); text-decoration: none; }
footer a:hover { text-decoration: underline; }
.footer-links { display: flex; gap: 20px; justify-content: center; margin-bottom: 12px; flex-wrap: wrap; }

/* PRIVACY / PROSE */
.prose {
  max-width: 720px;
  margin: 60px auto 80px;
  padding: 0 24px;
}
.prose h1 { font-size: 2rem; font-weight: 800; margin-bottom: 8px; }
.prose .meta { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 48px; }
.prose h2 { font-size: 1.2rem; font-weight: 700; margin: 36px 0 12px; }
.prose p, .prose li { color: var(--text-secondary); margin-bottom: 12px; font-size: 0.95rem; line-height: 1.75; }
.prose ul { padding-left: 20px; }
.prose a { color: var(--accent-start); text-decoration: none; }
.prose a:hover { text-decoration: underline; }
.prose .highlight {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 24px;
  margin: 24px 0;
  font-size: 0.9rem;
}

.prose .update-date {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-top: 48px;
  opacity: 0.7;
}

/* Per-language formal serif fonts */
html[lang="ja"] body { font-family: "Shippori Mincho", "Yu Mincho", "YuMincho", serif; }
html[lang="en"] body { font-family: "Cormorant Garamond", Georgia, "Times New Roman", serif; }
html[lang="zh-Hans"] body { font-family: "Noto Serif SC", "Source Han Serif SC", "STSong", serif; }
html[lang="zh-Hant"] body { font-family: "Noto Serif TC", "Source Han Serif TC", "Apple LiSung", serif; }
html[lang="ko"] body { font-family: "Nanum Myeongjo", "Batang", serif; }

@media (max-width: 640px) {
  nav { padding: 12px 16px; flex-wrap: wrap; row-gap: 10px; }
  .nav-logo { margin-right: 0; }
  .nav-links { display: none; }
  .lang-switcher { width: 100%; justify-content: center; gap: 6px; }
  .lang-switcher a { padding: 5px 11px; font-size: 0.72rem; }
}