/* ─────────────────────────────
   活体档案 Living Archive · 共享基础
   纸墨档案 · Editorial
   ───────────────────────────── */
:root {
  --paper:      oklch(0.955 0.014 85);
  --paper-2:    oklch(0.898 0.018 87);
  --paper-3:    oklch(0.865 0.02 88);
  --ink:        oklch(0.22 0.015 80);
  --ink-2:      oklch(0.27 0.015 80);
  --ink-3:      oklch(0.19 0.012 78);
  --vellum:     oklch(0.93 0.012 85);
  --text-soft:  oklch(0.235 0.016 80);
  --text-mute:  oklch(0.235 0.012 80);
  --moss:       oklch(0.44 0.08 155);
  --verdigris:  oklch(0.42 0.06 190);
  --cinnabar:   oklch(0.45 0.13 30);
  --cinnabar-deep: oklch(0.36 0.11 30);
  --hairline:   oklch(0.24 0.02 80 / 0.24);
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body:    "Noto Serif SC", "Songti SC", serif;
  --font-latin:   "Fraunces", "Noto Serif SC", serif;
  --font-mono:    "IBM Plex Mono", ui-monospace, monospace;

  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-expo:  cubic-bezier(0.7, 0, 0.84, 0);
  --ease-spring:   cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-in-out-quart: cubic-bezier(0.76, 0, 0.24, 1);

  --z-sticky: 100;
  --z-overlay: 150;
  --z-modal: 200;

  --duration-enter: 450ms;
  --duration-exit:  250ms;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

::selection { background: var(--cinnabar); color: var(--vellum); }

/* ── 纸墨质感：宣纸噪点 + 纸边墨晕（装饰层，opacity ≤0.05 不影响对比度） ── */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 0.22 0 0 0 0 0.13 0 0 0 0 0.1 0 0 0 0.55 0'/%3E%3C/filter%3E%3Crect width='240' height='240' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 240px 240px;
  opacity: 0.045;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(115% 88% at 50% 28%, transparent 58%, oklch(0.24 0.02 80 / 0.05) 100%);
}

:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 3px;
  border-radius: 2px;
}

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

.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.mono--dim { color: var(--text-mute); }

.hairline { height: 1px; background: var(--hairline); margin: 0 clamp(24px, 5vw, 72px); }

/* ── 顶栏 ── */
.masthead {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: var(--z-sticky);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 20px clamp(24px, 5vw, 72px);
  background: linear-gradient(var(--paper) 62%, transparent);
}

.wordmark {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 500;
  letter-spacing: 0.02em;
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.wordmark .zh { font-weight: 460; }
.wordmark .en {
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--text-soft);
  letter-spacing: 0.22em;
}

.masthead nav {
  display: flex;
  align-items: center;
  gap: clamp(16px, 3vw, 36px);
}

.masthead nav a {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-soft);
  position: relative;
  padding: 4px 0;
  transition: color 0.25s var(--ease-out-expo);
}

.masthead nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 100%; height: 2px;
  background: linear-gradient(90deg, var(--cinnabar) 72%, transparent 100%);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease-out-expo);
}

.masthead nav a:hover { color: var(--ink); }
.masthead nav a:hover::after { transform: scaleX(1); }

.masthead nav a[aria-current="page"] { color: var(--ink); }
.masthead nav a[aria-current="page"]::after { transform: scaleX(1); }

.search-trigger {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-soft);
  background: transparent;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  padding: 7px 16px;
  cursor: pointer;
  transition: border-color 0.25s var(--ease-out-expo), color 0.25s;
}

.search-trigger:hover { border-color: var(--cinnabar); color: var(--ink); }

.search-trigger kbd {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-soft);
  border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 1px 6px;
}

/* ── 页脚 ── */
.footer {
  border-top: 1px solid var(--hairline);
  padding: 56px clamp(24px, 5vw, 72px) 40px;
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 40px;
}

.footer .col h4 {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--ink);
  letter-spacing: 0.14em;
  margin-bottom: 16px;
}

.footer .col p, .footer .col li {
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-soft);
  list-style: none;
}

.footer .col li { margin-bottom: 6px; }
.footer .col a:hover { color: var(--ink); }

.footer .colophon {
  margin-top: 44px;
  align-items: center;
  padding-top: 20px;
  border-top: 1px solid var(--hairline);
  grid-column: 1 / -1;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-mute);
  letter-spacing: 0.06em;
}

.footer .seal {
  width: 46px;
  height: 46px;
  border: 2px solid oklch(0.45 0.13 30 / 0.75);
  border-radius: 4px;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.1em;
  line-height: 1.5;
  color: oklch(0.45 0.13 30 / 0.85);
  text-align: center;
  transform: rotate(-7deg);
  flex-shrink: 0;
}

@media (max-width: 1023px) {
  .footer { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 767px) {
  .masthead nav a:not(:first-child) { display: none; }
  .search-trigger kbd { display: none; }
  .footer { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-delay: 0s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}