:root {
  --color-surface: #ecebeb;
  --color-surface-alt: #e4e2e2;
  --color-surface-deep: #d8d6d6;
  --color-ink: #493e3c;
  --color-ink-soft: #72635f;
  --color-ink-muted: #8a7975;
  --color-line: #cfcccc;
  --color-primary: #d2411e;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e8d3ce;
  --color-accent: #d63a14;
  --color-accent-ink: #ffffff;
  --color-highlight: #e8cbc4;
  --color-focus: #c52d07;
  --color-contrast-surface: #301c18;
  --color-contrast-ink: #e7e5e4;
  --color-contrast-line: #584845;
  --color-contrast-accent: #ec5632;
  --overlay-scrim: linear-gradient(180deg, rgba(48, 28, 24, 0.35) 0%, rgba(48, 28, 24, 0.72) 55%, rgba(48, 28, 24, 0.92) 100%);
  --font-heading: "Kaiti SC", STKaiti, KaiTi, "Songti SC", serif;
  --font-body: "Songti SC", "PingFang SC", "Microsoft YaHei", serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 11.7px;
  --text-sm: 15.6px;
  --text-base: 18px;
  --text-lg: 24.0px;
  --text-xl: 32.0px;
  --text-2xl: 42.6px;
  --text-3xl: 56.8px;
  --text-4xl: 75.8px;
  --text-display: clamp(36px, 7.5vw, 96px);
  --text-figure: clamp(30px, 5.4vw, 69px);
  --weight-heading: 564;
  --weight-body: 400;
  --leading-body: 1.89;
  --leading-heading: 1.21;
  --tracking-heading: 0.014em;
  --radius-sm: 1px;
  --radius-md: 1px;
  --radius-lg: 1px;
  --radius-pill: 1px;
  --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: 1020px;
  --measure: 65ch;
  --gutter: 32px;
  --section-y: 133px;
  --section-y-lg: 186px;
}

/* ---------- 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);
  background-image:
    radial-gradient(120% 55% at 6% 0%, color-mix(in srgb, var(--color-surface-deep) 38%, transparent) 0%, transparent 58%),
    radial-gradient(85% 45% at 98% 74%, color-mix(in srgb, var(--color-surface-alt) 58%, transparent) 0%, transparent 62%);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
}
img, svg, video { display: block; max-width: 100%; height: auto; }
ul, ol { margin: 0; padding: 0; list-style: none; }
button { font: inherit; color: inherit; }
a {
  color: var(--color-ink);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--color-primary) 40%, transparent);
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}
a:hover { color: var(--color-accent); text-decoration-color: var(--color-accent); }
:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 3px; border-radius: var(--radius-sm); }

/* ---------- 中文排版 ---------- */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
h1 { font-size: var(--text-2xl); }
h2 { font-size: var(--text-xl); }
h3 { font-size: var(--text-lg); }
h4, h5, h6 { font-size: var(--text-base); }
p { margin: 0 0 var(--space-3); }
.display {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 1.05;
  letter-spacing: var(--tracking-heading);
}
.figure-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}
.lead {
  max-width: var(--measure);
  margin: 0 0 var(--space-4);
  font-size: var(--text-lg);
  line-height: 1.7;
  color: var(--color-ink-soft);
}
.meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  font-variant-numeric: tabular-nums;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.22em;
  color: var(--color-ink-muted);
}
.eyebrow::before {
  content: "";
  width: 18px;
  height: var(--border-thin);
  background-color: var(--color-primary);
}
.prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}
.prose h2 { margin: var(--space-6) 0 var(--space-2); }
.prose h3 { margin: var(--space-4) 0 var(--space-2); }
.prose ul, .prose ol { margin: 0 0 var(--space-3); padding-left: var(--space-3); list-style: disc; }
.prose li { margin-bottom: var(--space-1); }
.prose blockquote {
  margin: var(--space-4) 0;
  padding-left: var(--space-3);
  border-left: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 45%, transparent);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  color: var(--color-ink-soft);
}
.prose > :last-child { margin-bottom: 0; }

/* ---------- 布局 ---------- */
.wrap {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--deep { background-color: var(--color-surface-alt); }
.section--deeper { background-color: var(--color-surface-deep); }
.section--flush { padding-block: var(--space-8); }
.section-head { max-width: var(--measure); margin-bottom: var(--space-6); }
.grid {
  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-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }
.offset-1 { grid-column-start: 2; }
.offset-2 { grid-column-start: 3; }

/* ---------- 头部：杂志报头 ---------- */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -120px;
  z-index: 100;
  padding: var(--space-2) var(--space-4);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.12em;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: top 0.2s ease;
}
.skip-link:focus { top: var(--space-2); color: var(--color-contrast-ink); }

.site-header {
  position: relative;
  background-color: var(--color-surface);
  background-image: linear-gradient(180deg, color-mix(in srgb, var(--color-surface-alt) 65%, transparent), transparent);
}
.site-header::after {
  content: "";
  display: block;
  height: var(--border-thin);
  background: linear-gradient(90deg, transparent 0%, color-mix(in srgb, var(--color-line) 90%, transparent) 18%, color-mix(in srgb, var(--color-line) 90%, transparent) 82%, transparent 100%);
}
.header-inner {
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-4) var(--space-4) 0;
}
.masthead-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}
.masthead-utility {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}
.masthead-action { flex: 0 0 auto; }
.brand {
  display: block;
  padding: var(--space-4) 0 var(--space-1);
  text-align: center;
  text-decoration: none;
  color: var(--color-ink);
}
.brand-name {
  display: block;
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  font-weight: var(--weight-heading);
  line-height: 1.06;
  letter-spacing: 0.08em;
}
.brand-line {
  display: block;
  margin-top: var(--space-1);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  letter-spacing: 0.34em;
  color: var(--color-ink-soft);
}
.brand:hover .brand-name { color: var(--color-primary); }
.masthead-tagline {
  margin: var(--space-2) 0 0;
  text-align: center;
  font-size: var(--text-sm);
  letter-spacing: 0.2em;
  color: var(--color-ink-muted);
}
.nav-bar { position: relative; margin-top: var(--space-4); }
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-2);
  background-color: transparent;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-ink) 20%, transparent);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  letter-spacing: 0.16em;
  color: var(--color-ink);
  cursor: pointer;
}
.nav-toggle-text { letter-spacing: 0.16em; }
.nav-toggle-mark { position: relative; display: inline-block; width: 18px; height: 8px; }
.nav-toggle-mark::before,
.nav-toggle-mark::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: var(--border-thin);
  background-color: currentColor;
}
.nav-toggle-mark::before { top: 0; }
.nav-toggle-mark::after { bottom: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-mark { opacity: 0.45; }
.site-nav {
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-line) 55%, transparent);
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-line) 55%, transparent);
}
.nav-list {
  display: flex;
  justify-content: center;
  gap: var(--space-1);
  padding: var(--space-2) 0;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.nav-list::-webkit-scrollbar { display: none; }
.nav-link {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-sm);
  letter-spacing: 0.12em;
  color: var(--color-ink-soft);
  text-decoration: none;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  transition: color 0.3s ease, background-color 0.3s ease;
}
.nav-link:hover { background-color: var(--color-primary-soft); color: var(--color-ink); }
.nav-link[aria-current="page"] { color: var(--color-primary); }
.nav-link[aria-current="page"]::before {
  content: "";
  display: inline-block;
  width: 5px;
  height: 5px;
  margin-right: var(--space-1);
  vertical-align: middle;
  background-color: var(--color-primary);
  border-radius: var(--radius-sm);
}

/* 阅读进度：朱红细线 */
.progress-rail {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 80;
  pointer-events: none;
  background-color: transparent;
}
.progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background-color: var(--color-primary);
  opacity: 0;
  transition: opacity 0.3s ease;
}
.progress-rail.is-active .progress-bar { opacity: 1; }

/* ---------- 页脚：同色延续 ---------- */
.site-footer {
  margin-top: var(--section-y);
  background-color: var(--color-surface);
  background-image: linear-gradient(180deg, transparent, color-mix(in srgb, var(--color-surface-deep) 45%, transparent));
  padding-block: var(--space-8) var(--space-6);
}
.footer-inner {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
.footer-inner::before {
  content: "";
  display: block;
  height: var(--border-thin);
  margin-bottom: var(--space-8);
  background: linear-gradient(90deg, color-mix(in srgb, var(--color-line) 88%, transparent) 0%, color-mix(in srgb, var(--color-line) 25%, transparent) 100%);
}
.footer-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
  gap: var(--space-6);
  align-items: start;
}
.footer-brand-name {
  display: block;
  margin-bottom: var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.08em;
  color: var(--color-ink);
  text-decoration: none;
}
.footer-brand-name:hover { color: var(--color-primary); }
.footer-brand-line {
  margin: 0;
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}
.footer-help {
  margin: 0;
  max-width: 44ch;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.footer-columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-8);
}
.footer-col-title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.24em;
  color: var(--color-ink-muted);
}
.footer-links { display: grid; gap: var(--space-1); }
.footer-links a {
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-ink-soft);
  text-decoration: none;
}
.footer-links a:hover { color: var(--color-primary); }
.footer-contact { margin-top: var(--space-6); }
.footer-contact-line {
  margin: 0 0 var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-8);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-line) 60%, transparent);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.footer-legal-icp, .footer-legal-year { margin: 0; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  background-color: transparent;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.3;
  letter-spacing: 0.12em;
  color: var(--color-ink);
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}
.btn-ghost { border-color: color-mix(in srgb, var(--color-ink) 24%, transparent); }
.btn-ghost:hover {
  background-color: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 55%, transparent);
  color: var(--color-ink);
}
.btn-primary { background-color: var(--color-primary); color: var(--color-primary-ink); }
.btn-primary:hover { background-color: var(--color-accent); color: var(--color-accent-ink); }
.btn-contrast { background-color: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.btn-contrast:hover { color: var(--color-contrast-accent); }
.btn-sm { padding: var(--space-1) var(--space-3); font-size: var(--text-xs); letter-spacing: 0.16em; }

/* ---------- 徽章与编号 ---------- */
.badge {
  display: inline-block;
  padding: 2px var(--space-2);
  background-color: var(--color-surface-deep);
  color: var(--color-ink-soft);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  font-variant-numeric: tabular-nums;
}
.badge-primary { background-color: var(--color-primary); color: var(--color-primary-ink); }
.badge-contrast { background-color: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.badge-soft { background-color: var(--color-primary-soft); color: var(--color-ink); }
.num-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 32px;
  padding: 2px 6px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
}
.num-badge--quiet {
  background-color: transparent;
  color: var(--color-primary);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 45%, transparent);
}

/* ---------- 编号条目流 ---------- */
.index-list { margin: 0; }
.index-item {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr) auto;
  align-items: baseline;
  gap: var(--space-2) var(--space-3);
  padding: var(--space-3) var(--space-2);
  margin-inline: calc(var(--space-2) * -1);
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-line) 42%, transparent);
  transition: background-color 0.3s ease;
}
.index-item:hover { background-color: color-mix(in srgb, var(--color-primary-soft) 60%, transparent); }
.index-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
}
.index-body { min-width: 0; }
.index-title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}
.index-desc {
  margin: var(--space-1) 0 0;
  max-width: var(--measure);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.index-meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

/* ---------- 矩阵（功能特性等） ---------- */
.matrix {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-4) var(--space-6);
}
.matrix-cell {
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-line) 60%, transparent);
}
.matrix-cell h3 { margin-bottom: var(--space-1); font-size: var(--text-lg); }
.matrix-cell p { margin: 0; font-size: var(--text-sm); color: var(--color-ink-soft); }

/* ---------- 焦墨反色块 ---------- */
.contrast-block {
  padding: var(--space-6);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-radius: var(--radius-sm);
}
.contrast-block a { color: var(--color-contrast-accent); text-decoration: none; }
.contrast-block a:hover { color: var(--color-contrast-ink); text-decoration: underline; }
.contrast-label {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent);
}
.contrast-figure {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-contrast-accent);
  font-variant-numeric: tabular-nums;
}
.contrast-note {
  margin: var(--space-2) 0 0;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, transparent);
}
.contrast-rule {
  height: var(--border-thin);
  margin-block: var(--space-3);
  background-color: var(--color-contrast-line);
}

/* ---------- 图像：贴在纸面上 ---------- */
.figure {
  margin: 0;
  padding: var(--space-2);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-line) 85%, transparent);
  border-radius: var(--radius-sm);
}
.figure-media {
  position: relative;
  overflow: hidden;
  background-color: var(--color-surface-deep);
  border-radius: var(--radius-sm);
  aspect-ratio: 4 / 3;
}
.figure--wide .figure-media { aspect-ratio: 16 / 9; }
.figure--tall .figure-media { aspect-ratio: 3 / 4; }
.figure-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure-scrim {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: flex-end;
  padding: var(--space-3);
  background: var(--overlay-scrim);
}
.figure-overlay-text {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  color: var(--color-contrast-ink);
}
.figure-caption {
  margin-top: var(--space-2);
  padding-inline: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

/* ---------- 筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  margin-block: var(--space-4) var(--space-6);
}
.filter-btn {
  padding: var(--space-1) var(--space-3);
  background-color: transparent;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-ink) 20%, transparent);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-ink-soft);
  cursor: pointer;
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}
.filter-btn:hover { background-color: var(--color-primary-soft); color: var(--color-ink); }
.filter-btn[aria-pressed="true"] {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.filter-status {
  margin: 0 0 0 auto;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  font-variant-numeric: tabular-nums;
}
[data-filter-item][hidden] { display: none !important; }

/* ---------- 面包屑 ---------- */
.breadcrumb { margin-bottom: var(--space-4); }
.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.breadcrumb-list li { display: inline-flex; align-items: center; }
.breadcrumb-list li + li::before {
  content: "/";
  margin-right: var(--space-2);
  color: color-mix(in srgb, var(--color-ink-muted) 60%, transparent);
}
.breadcrumb-list a { color: var(--color-ink-muted); text-decoration: none; }
.breadcrumb-list a:hover { color: var(--color-primary); }
.breadcrumb-list [aria-current="page"] { color: var(--color-ink-soft); }

/* ---------- 显现 ---------- */
[data-reveal] { transition: opacity 0.8s ease, transform 0.8s ease; }
.js-ready [data-reveal] { opacity: 0; transform: translateY(12px); }
.js-ready [data-reveal].is-visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  :root { --gutter: 24px; }
  .grid { gap: var(--space-3) var(--space-4); }
  .col-3, .col-4, .col-5 { grid-column: span 6; }
  .col-6, .col-7, .col-8 { grid-column: span 12; }
  .offset-1, .offset-2 { grid-column-start: auto; }
  .section { padding-block: var(--space-8); }
  .section--lg { padding-block: var(--section-y); }
  .footer-head { grid-template-columns: minmax(0, 1fr); gap: var(--space-4); }
  .footer-columns { gap: var(--space-4); }
}

@media (max-width: 767px) {
  .header-inner { padding: var(--space-3) var(--space-3) 0; }
  .nav-toggle { display: inline-flex; }
  .site-nav { border-top: 0; border-bottom: 0; display: none; }
  .site-nav[data-open] {
    display: block;
    margin-top: var(--space-2);
    border-top: var(--border-thin) solid color-mix(in srgb, var(--color-line) 55%, transparent);
    border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-line) 55%, transparent);
  }
  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-1) 0;
    overflow-x: visible;
  }
  .nav-link {
    display: block;
    padding: var(--space-2) var(--space-3);
    border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-line) 35%, transparent);
  }
  .nav-list li:last-child .nav-link { border-bottom: 0; }
  .nav-link[aria-current="page"] { background-color: var(--color-primary-soft); }
  .index-item { grid-template-columns: 48px minmax(0, 1fr); }
  .index-meta { grid-column: 2; }
  .filter-status { margin-left: 0; }
}

@media (max-width: 620px) {
  .masthead-top {
    flex-direction: column;
    align-items: center;
    gap: var(--space-2);
    text-align: center;
  }
  .brand-name { font-size: var(--text-2xl); letter-spacing: 0.06em; }
  .brand-line { letter-spacing: 0.22em; }
  .masthead-tagline { letter-spacing: 0.12em; }
  .grid { grid-template-columns: repeat(12, minmax(0, 1fr)); }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8 { grid-column: span 12; }
  .footer-columns { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .contrast-block { padding: var(--space-4); }
  .footer-legal { flex-direction: column; align-items: flex-start; }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .js-ready [data-reveal] { opacity: 1; transform: none; }
}