/* ========================================
   慕月溪 · Design System
   心慕皎月，静听溪声
   ======================================== */

@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@200;300;400;600&family=ZCOOL+XiaoWei&display=swap');

:root {
  /* sky */
  --sky-top: #050a18;
  --sky-mid: #0c1528;
  --sky-deep: #060c1a;
  /* moon */
  --moon-core: #f5e6c8;
  --moon-gold: #d4a45c;
  --moon-warm: rgba(200,175,120,0.35);
  /* text */
  --text-primary: #e4ddd0;
  --text-dim: rgba(232,224,212,0.4);
  --text-faint: rgba(232,224,212,0.18);
  /* accent */
  --accent: rgba(200,175,120,0.45);
  --accent-line: rgba(200,175,120,0.2);
  /* fonts */
  --font-display: 'ZCOOL XiaoWei','Noto Serif SC','Songti SC',serif;
  --font-body: 'Noto Serif SC','Songti SC',serif;
  --font-ui: -apple-system,'PingFang SC','Microsoft YaHei','Helvetica Neue',sans-serif;
}

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

html {
  height:100%;
  scroll-behavior: smooth;
}

body {
  min-height:100%;
  font-family: var(--font-body);
  background: var(--sky-deep);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }

/* ---- NAV ---- */
.site-nav {
  position: fixed; top:0; left:0; right:0;
  z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 clamp(1.2rem, 4vw, 3rem);
  height: 56px;
  background: linear-gradient(180deg, rgba(5,10,24,0.85) 0%, rgba(5,10,24,0.4) 70%, transparent 100%);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  opacity: 0;
  animation: navFadeIn 1.5s ease forwards 2.5s;
  transition: background 0.4s;
}
.site-nav.scrolled {
  background: rgba(5,10,24,0.92);
}
@keyframes navFadeIn {
  to { opacity: 1; }
}

.nav-brand {
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.15em;
  color: var(--text-primary);
  cursor: pointer;
  transition: text-shadow 0.3s;
  user-select: none;
}
.nav-brand:hover {
  text-shadow: 0 0 20px rgba(212,175,100,0.2);
}

.nav-links {
  display: flex; gap: clamp(1rem, 3vw, 2.2rem);
  list-style: none;
}
.nav-links a {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  position: relative;
  padding: 4px 0;
  transition: color 0.3s;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0; left: 50%; right: 50%;
  height: 1px;
  background: var(--moon-gold);
  opacity: 0;
  transition: all 0.35s cubic-bezier(0.22,1,0.36,1);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
}
.nav-links a:hover::after,
.nav-links a.active::after {
  left: 0; right: 0; opacity: 0.5;
}

/* mobile menu */
.nav-toggle {
  display: none;
  background: none; border: none; cursor: pointer;
  width: 24px; height: 18px;
  position: relative;
}
.nav-toggle span {
  display: block; position: absolute;
  left: 0; width: 100%; height: 1px;
  background: var(--text-dim);
  transition: all 0.3s;
}
.nav-toggle span:nth-child(1) { top: 0; }
.nav-toggle span:nth-child(2) { top: 8px; }
.nav-toggle span:nth-child(3) { top: 16px; }
.nav-toggle.open span:nth-child(1) { top:8px; transform:rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity:0; }
.nav-toggle.open span:nth-child(3) { top:8px; transform:rotate(-45deg); }

@media (max-width: 600px) {
  .nav-toggle { display: block; }
  .nav-links {
    position: fixed; top: 56px; left:0; right:0;
    flex-direction: column;
    align-items: center;
    gap: 0;
    background: rgba(5,10,24,0.95);
    backdrop-filter: blur(12px);
    max-height: 0; overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s;
    padding: 0;
  }
  .nav-links.open {
    max-height: 300px;
    padding: 1rem 0;
  }
  .nav-links a {
    display: block;
    padding: 0.8rem 0;
    font-size: 0.85rem;
  }
}

/* ---- PAGE SHELL (for sub-pages) ---- */
.page-shell {
  min-height: 100vh;
  padding-top: 56px;
  background: var(--sky-deep);
}

/* page hero */
.page-hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  text-align: center;
  padding: 4rem 1.5rem;
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 30%, rgba(200,175,120,0.03) 0%, transparent 70%);
}

.page-hero .icon {
  font-size: 2.4rem;
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: fadeUp 1s ease forwards 0.3s;
}
.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 400;
  letter-spacing: 0.3em;
  padding-left: 0.3em;
  opacity: 0;
  animation: fadeUp 1s ease forwards 0.5s;
}
.page-hero .subtitle {
  font-size: clamp(0.8rem, 1.4vw, 0.95rem);
  font-weight: 300;
  color: var(--text-dim);
  letter-spacing: 0.2em;
  margin-top: 1rem;
  opacity: 0;
  animation: fadeUp 1s ease forwards 0.8s;
}

@keyframes fadeUp {
  0% { opacity:0; transform:translateY(14px); }
  100% { opacity:1; transform:translateY(0); }
}

/* coming soon badge */
.coming-soon {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 2.5rem;
  padding: 8px 20px;
  border: 1px solid var(--accent-line);
  border-radius: 20px;
  font-family: var(--font-ui);
  font-size: 0.72rem;
  color: var(--text-faint);
  letter-spacing: 0.12em;
  opacity: 0;
  animation: fadeUp 1s ease forwards 1.1s;
}
.coming-soon .dot {
  width: 4px; height: 4px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 4s ease-in-out infinite;
}
@keyframes pulse { 0%,100%{opacity:.3} 50%{opacity:.7} }

/* decorative line separator */
.sep-line {
  width: 1px; height: 40px;
  background: linear-gradient(180deg, var(--accent-line), transparent);
  margin: 0 auto;
}

/* ---- FOOTER ---- */
.site-footer {
  text-align: center;
  padding: 2rem 1rem;
  font-family: var(--font-ui);
  font-size: 0.65rem;
  color: var(--text-faint);
  letter-spacing: 0.1em;
  border-top: 1px solid rgba(200,175,120,0.06);
}