@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=Noto+Sans+SC:wght@400;500;600&family=Noto+Serif+SC:wght@400;500;600&family=Source+Serif+4:opsz,wght@8..60,400;8..60,500;8..60,600&display=swap');

:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --surface-soft: #f1eee8;
  --ink: #181716;
  --ink-soft: #55504a;
  --ink-faint: #928b82;
  --accent: #c44f2e;
  --accent-warm: #c44f2e;
  --accent-soft: #efe0d8;
  --border: #e2ded6;
  --border-strong: #c9c1b5;
  --nav-bg: rgba(251, 250, 247, 0.88);
  --shadow-soft: 0 20px 60px rgba(37, 31, 25, 0.08);
  --serif: 'Source Serif 4', 'Noto Serif SC', 'Songti SC', 'STSong', Georgia, serif;
  --sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
}

html.dark {
  --bg: #121211;
  --surface: #191816;
  --surface-soft: #211f1c;
  --ink: #f4f0ea;
  --ink-soft: #c5beb5;
  --ink-faint: #827970;
  --accent: #e07a56;
  --accent-warm: #e07a56;
  --accent-soft: #2d211c;
  --border: #302d29;
  --border-strong: #51483f;
  --nav-bg: rgba(18, 18, 17, 0.88);
  --shadow-soft: 0 20px 60px rgba(0, 0, 0, 0.32);
}

@media (prefers-color-scheme: dark) {
  html:not(.light):not(.dark) {
    --bg: #121211;
    --surface: #191816;
    --surface-soft: #211f1c;
    --ink: #f4f0ea;
    --ink-soft: #c5beb5;
    --ink-faint: #827970;
    --accent: #e07a56;
    --accent-warm: #e07a56;
    --accent-soft: #2d211c;
    --border: #302d29;
    --border-strong: #51483f;
    --nav-bg: rgba(18, 18, 17, 0.88);
    --shadow-soft: 0 20px 60px rgba(0, 0, 0, 0.32);
  }
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  transition: background-color 0.25s var(--ease), border-color 0.25s var(--ease);
}

html.theme-switching *,
html.theme-switching *::before,
html.theme-switching *::after {
  transition: none !important;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-weight: 400;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 1rem clamp(1.2rem, 4vw, 3rem);
  background: var(--nav-bg);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid transparent;
}

nav.scrolled { border-bottom-color: var(--border); }

.nav-name {
  color: var(--ink);
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: clamp(0.8rem, 2vw, 1.4rem);
}

.nav-links {
  display: flex;
  gap: clamp(1rem, 2.6vw, 2rem);
  list-style: none;
}

.nav-links a {
  color: var(--ink-faint);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  position: relative;
  text-decoration: none;
  text-transform: uppercase;
}

.nav-links a::after {
  background: var(--accent);
  bottom: -0.35rem;
  content: '';
  height: 2px;
  left: 0;
  position: absolute;
  right: 0;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.2s var(--ease);
}

.nav-links a:hover,
.nav-links a.active { color: var(--ink); }

.nav-links a:hover::after,
.nav-links a.active::after { transform: scaleX(1); }

.lang-toggle {
  border: 1px solid var(--border);
  display: flex;
  overflow: hidden;
}

.lang-btn {
  background: transparent;
  border: none;
  color: var(--ink-faint);
  cursor: pointer;
  font-family: var(--sans);
  font-size: 0.68rem;
  font-weight: 600;
  padding: 0.3rem 0.65rem;
}

.lang-btn.active {
  background: var(--ink);
  color: var(--bg);
}

.theme-btn {
  align-items: center;
  background: transparent;
  border: 1px solid var(--border);
  cursor: pointer;
  display: flex;
  height: 2rem;
  justify-content: center;
  padding: 0;
  width: 2rem;
}

.theme-btn:hover {
  background: var(--ink);
  border-color: var(--ink);
}

.theme-btn:hover .theme-icon { color: var(--bg); }

.theme-icon {
  color: var(--ink-faint);
  font-size: 0.85rem;
  font-style: normal;
  line-height: 1;
}

.hamburger {
  background: transparent;
  border: none;
  cursor: pointer;
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}

.hamburger span {
  background: var(--ink);
  display: block;
  height: 1.5px;
  transition: transform 0.25s, opacity 0.25s;
  width: 22px;
}

.hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

.mobile-menu {
  align-items: center;
  background: var(--bg);
  bottom: 0;
  display: none;
  flex-direction: column;
  gap: 2.2rem;
  justify-content: center;
  left: 0;
  position: fixed;
  right: 0;
  top: 0;
  z-index: 99;
}

.mobile-menu.open { display: flex; }

.mobile-menu a {
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.page {
  margin: 0 auto;
  max-width: 1080px;
  padding: 0 clamp(1.2rem, 4vw, 3rem);
}

.section-label {
  color: var(--accent);
  display: block;
  font-size: 0.66rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  margin-bottom: 1rem;
  text-transform: uppercase;
}

.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

footer {
  align-items: center;
  border-top: 1px solid var(--border);
  color: var(--ink-faint);
  display: flex;
  font-size: 0.72rem;
  justify-content: space-between;
  margin: 0 auto;
  max-width: 1080px;
  padding: 2rem clamp(1.2rem, 4vw, 3rem);
}

.footer-name {
  color: var(--ink-soft);
  font-family: var(--sans);
  font-weight: 600;
}

.footer-copy {
  color: var(--ink-faint);
  letter-spacing: 0.04em;
}

.btn-outline {
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--ink);
  cursor: pointer;
  display: inline-flex;
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  gap: 0.5rem;
  letter-spacing: 0.1em;
  min-height: 2.55rem;
  padding: 0.62rem 1.15rem;
  text-decoration: none;
  text-transform: uppercase;
}

.btn-outline:hover {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--bg);
}

.btn-outline svg {
  flex-shrink: 0;
  fill: none;
  height: 13px;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.5;
  width: 13px;
}

hr.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0;
}

html[lang="zh"] em,
html[lang="zh"] i,
html[lang="zh"] cite,
[data-zh] em,
[data-zh] i { font-style: normal !important; }

@media (max-width: 760px) {
  nav { padding: 0.9rem 1.2rem; }
  .nav-links { display: none; }
  .hamburger { display: flex; }
  .nav-right { gap: 0.75rem; }
  footer { align-items: flex-start; flex-direction: column; gap: 0.35rem; }
}