:root {
  --color-surface: #f5f5f5;
  --color-surface-alt: #eeeded;
  --color-surface-deep: #e3e3e1;
  --color-ink: #605b52;
  --color-ink-soft: #757066;
  --color-ink-muted: #878278;
  --color-line: #dad9d8;
  --color-primary: #81745b;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e5e3df;
  --color-accent: #9d6b52;
  --color-accent-ink: #ffffff;
  --color-highlight: #e5dcd8;
  --color-focus: #9b5e40;
  --color-contrast-surface: #201f1c;
  --color-contrast-ink: #e7e6e4;
  --color-contrast-line: #4c4b48;
  --color-contrast-accent: #ad7b62;
  --overlay-scrim: linear-gradient(180deg, rgba(32, 31, 28, 0.35) 0%, rgba(32, 31, 28, 0.72) 55%, rgba(32, 31, 28, 0.92) 100%);
  --font-heading: "Songti SC", STSong, "Source Han Serif SC", SimSun, serif;
  --font-body: "Songti SC", STSong, "Source Han Serif SC", SimSun, serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 12.2px;
  --text-sm: 15.2px;
  --text-base: 17px;
  --text-lg: 21.2px;
  --text-xl: 26.6px;
  --text-2xl: 33.2px;
  --text-3xl: 41.5px;
  --text-4xl: 51.9px;
  --text-display: clamp(39px, 8.0vw, 102px);
  --text-figure: clamp(32px, 5.7vw, 73px);
  --weight-heading: 439;
  --weight-body: 400;
  --leading-body: 1.94;
  --leading-heading: 1.22;
  --tracking-heading: 0.024em;
  --radius-sm: 1px;
  --radius-md: 2px;
  --radius-lg: 2px;
  --radius-pill: 2px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1120px;
  --measure: 67ch;
  --gutter: 24px;
  --section-y: 138px;
  --section-y-lg: 193px;
}

/* ---------- reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img { max-width: 100%; height: auto; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-focus); }
button { font: inherit; color: inherit; background: none; border: 0; }
[hidden] { display: none !important; }

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

.mono,
.num,
[data-year],
.entry-num,
.entry-meta,
.status-line,
.scale-rule ~ * { font-variant-numeric: tabular-nums; }

.mono { font-family: var(--font-mono); letter-spacing: 0.06em; }

.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -80px;
  z-index: 200;
  padding: var(--space-1) var(--space-3);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  border-radius: var(--radius-sm);
  transition: top 160ms ease-out;
}
.skip-link:focus { top: var(--space-2); color: var(--color-contrast-ink); }

/* ---------- 布局骨架 ---------- */
.shell {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--alt { background-color: var(--color-surface-alt); }
.section--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--deep h1, .section--deep h2, .section--deep h3 { color: var(--color-contrast-ink); }

.section-head {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-bottom: var(--space-6);
}

.section-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-primary);
}

.section-title {
  font-size: var(--text-2xl);
  letter-spacing: var(--tracking-heading);
}

.kicker {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-ink-muted);
}

.lede {
  max-width: var(--measure);
  font-size: var(--text-lg);
  line-height: 1.8;
  color: var(--color-ink-soft);
}

.prose { max-width: var(--measure); }
.prose p { margin-bottom: var(--space-3); }
.prose p:last-child { margin-bottom: 0; }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }

.scale-rule {
  height: 1px;
  width: 100%;
  background-image: repeating-linear-gradient(
    90deg,
    var(--color-line) 0 22px,
    transparent 22px 32px
  );
}

.note {
  padding: var(--space-3);
  background-color: var(--color-surface-deep);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  line-height: 1.85;
  color: var(--color-ink-soft);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.breadcrumb a { color: var(--color-ink-soft); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb-sep {
  font-family: var(--font-mono);
  color: var(--color-ink-muted);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 9px 18px;
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-primary);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  line-height: 1.6;
  cursor: pointer;
  transition: background-color 200ms ease-out, color 200ms ease-out, border-color 200ms ease-out;
}
.btn:hover {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--solid {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--solid:hover {
  background-color: color-mix(in srgb, var(--color-primary) 78%, var(--color-contrast-surface));
  border-color: color-mix(in srgb, var(--color-primary) 78%, var(--color-contrast-surface));
  color: var(--color-primary-ink);
}
.btn--quiet {
  border-color: transparent;
  color: var(--color-ink-soft);
  padding-inline: 4px;
}
.btn--quiet:hover {
  background-color: transparent;
  color: var(--color-primary);
}

/* ---------- 索引条目 ---------- */
.entry-list { display: block; }

.entry {
  display: grid;
  grid-template-columns: minmax(52px, auto) minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 4px var(--space-4);
  padding-block: var(--space-3);
}

.entry-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-primary);
}

.entry-title {
  font-size: var(--text-lg);
  line-height: 1.5;
}
.entry-title a { color: inherit; }
.entry-title a:hover { color: var(--color-primary); }

.entry-meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

/* ---------- 标签与批次标记 ---------- */
.tag {
  display: inline-block;
  padding: 1px 8px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  line-height: 1.9;
  white-space: nowrap;
}
.tag--accent {
  background-color: var(--color-highlight);
  color: var(--color-accent);
}
.tag--batch {
  font-family: var(--font-mono);
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  letter-spacing: 0.08em;
}

[data-marker] { transition: background-color 420ms ease-out; }
[data-marker].is-marked { background-color: var(--color-highlight); }

/* ---------- 筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  margin-bottom: var(--space-6);
}

.filter-btn {
  padding: 5px 12px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-ink-muted);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: background-color 180ms ease-out, color 180ms ease-out;
}
.filter-btn:hover {
  background-color: var(--color-surface-deep);
  color: var(--color-ink);
}
.filter-btn[aria-pressed="true"] {
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
}

.filter-count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

/* ---------- 图片容器 ---------- */
.figure {
  position: relative;
  margin: 0;
  border-radius: var(--radius-sm);
  background-color: var(--color-surface-deep);
  overflow: hidden;
}
.figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure--wide { aspect-ratio: 16 / 9; }
.figure--card { aspect-ratio: 4 / 3; }
.figure--square { aspect-ratio: 1 / 1; }

.figure-ph {
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 4 / 3;
  background-color: var(--color-surface-deep);
  background-image: repeating-linear-gradient(
    90deg,
    var(--color-line) 0 1px,
    transparent 1px 18px
  );
  color: var(--color-ink-muted);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  padding: var(--space-2);
  text-align: center;
}

.figure-scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
}
.figure-text {
  position: absolute;
  left: var(--space-4);
  right: var(--space-4);
  bottom: var(--space-4);
  color: var(--color-contrast-ink);
  font-size: var(--text-lg);
}

.figure-caption {
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

/* ---------- 命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background-color: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
  transition: background-color 200ms ease-out;
}
.site-header[data-scrolled="true"] { background-color: var(--color-surface-alt); }

.header-shell {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  grid-template-areas: "brand nav status";
  align-items: center;
  gap: var(--space-2) var(--space-6);
  min-height: 78px;
  padding-block: 12px;
}

.brand {
  grid-area: brand;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-ink);
}
.brand:hover { color: var(--color-ink); }

.brand-mark {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.16em;
  color: var(--color-primary);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.brand-name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.08em;
  line-height: 1.3;
}

.brand-line {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  line-height: 1.4;
}

.nav-toggle {
  grid-area: toggle;
  display: none;
  align-items: center;
  gap: var(--space-2);
  padding: 8px 12px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  color: var(--color-ink-soft);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  cursor: pointer;
  transition: color 180ms ease-out, border-color 180ms ease-out;
}
.nav-toggle:hover { color: var(--color-primary); border-color: var(--color-primary); }

.nav-toggle-mark {
  position: relative;
  display: inline-block;
  width: 16px;
  height: 9px;
}
.nav-toggle-mark::before,
.nav-toggle-mark::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 1px;
  background-color: currentColor;
  transition: transform 200ms ease-out, top 200ms ease-out;
}
.nav-toggle-mark::before { top: 0; }
.nav-toggle-mark::after { top: 8px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-mark::before { top: 4px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-mark::after { top: 4px; transform: rotate(-45deg); }

.site-nav {
  grid-area: nav;
  display: flex;
  align-items: center;
  justify-self: end;
  gap: var(--space-4);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.nav-list a {
  position: relative;
  display: inline-block;
  padding-block: 4px;
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  transition: color 180ms ease-out;
}
.nav-list a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 1px;
  background-color: var(--color-primary);
  transition: width 200ms ease-out;
}
.nav-list a:hover { color: var(--color-ink); }
.nav-list a:hover::after { width: 100%; }
.nav-list a[aria-current="page"] { color: var(--color-primary); }
.nav-list a[aria-current="page"]::after { width: 14px; }

.nav-list--aux {
  margin-left: var(--space-3);
  padding-left: var(--space-3);
  border-left: var(--border-thin) solid var(--color-line);
  gap: var(--space-3);
}
.nav-list--aux a {
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.1em;
}

.status-line {
  grid-area: status;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}
.status-dot {
  width: 4px;
  height: 4px;
  background-color: var(--color-accent);
  border-radius: var(--radius-sm);
}
.status-sep { color: var(--color-line); }
.status-batch { color: var(--color-accent); }

.read-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 160ms linear;
}

/* ---------- 页脚 ---------- */
.site-footer {
  margin-top: var(--section-y);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.footer-shell {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2) var(--space-6);
  padding-block: var(--space-6);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
}

.footer-brand {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  letter-spacing: 0.14em;
  color: var(--color-contrast-ink);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}
.footer-links a {
  position: relative;
  color: var(--color-contrast-ink);
  transition: color 180ms ease-out;
}
.footer-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 1px;
  background-color: var(--color-contrast-accent);
  transition: width 200ms ease-out;
}
.footer-links a:hover { color: var(--color-contrast-accent); }
.footer-links a:hover::after { width: 100%; }

.footer-meta {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px;
  font-family: var(--font-mono);
  color: color-mix(in srgb, var(--color-contrast-ink) 66%, var(--color-contrast-surface));
}
.footer-icp { color: var(--color-contrast-ink); }
.footer-sep { color: var(--color-contrast-line); }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .section { padding-block: var(--space-8); }
  .section--lg { padding-block: var(--space-8); }
  .site-footer { margin-top: var(--space-8); }

  .header-shell {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand toggle"
      "nav nav"
      "status status";
    gap: 0;
    padding-block: 10px var(--space-2);
  }

  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    flex-direction: column;
    align-items: flex-start;
    justify-self: stretch;
    gap: 0;
    margin-top: var(--space-2);
  }
  .site-header[data-open="true"] .site-nav { display: flex; }

  .nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    width: 100%;
  }
  .nav-list a {
    display: block;
    width: 100%;
    padding-block: var(--space-2);
    font-size: var(--text-base);
  }
  .nav-list a::after { bottom: 8px; }

  .nav-list--aux {
    margin-left: 0;
    padding-left: 0;
    padding-top: var(--space-2);
    border-left: 0;
    border-top: var(--border-thin) solid var(--color-line);
    width: 100%;
  }
  .nav-list--aux a {
    font-size: var(--text-sm);
    padding-block: var(--space-1);
  }

  .status-line {
    padding-top: var(--space-2);
    white-space: normal;
  }

  .footer-shell {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }

  .col-3, .col-4, .col-6, .col-8, .col-9 { grid-column: span 12; }

  .entry {
    grid-template-columns: minmax(52px, auto) minmax(0, 1fr);
  }
  .entry-meta {
    grid-column: 2;
    white-space: normal;
  }
}

@media (max-width: 560px) {
  .brand-line { display: none; }
  .filter-count { margin-left: 0; width: 100%; }
  .lede { font-size: var(--text-base); }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .read-progress { transition: none; }
}