:root {
  --color-surface: #fefefe;
  --color-surface-alt: #f4f4f4;
  --color-surface-deep: #e6e6e7;
  --color-ink: #37343c;
  --color-ink-soft: #65606c;
  --color-ink-muted: #7e7986;
  --color-line: #dadadb;
  --color-primary: #6f34cb;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #eae2f7;
  --color-accent: #4c800a;
  --color-accent-ink: #ffffff;
  --color-highlight: #dee7d2;
  --color-focus: #4a8203;
  --color-contrast-surface: #1c1626;
  --color-contrast-ink: #e5e4e7;
  --color-contrast-line: #484350;
  --color-contrast-accent: #8ced12;
  --overlay-scrim: linear-gradient(180deg, rgba(28, 22, 38, 0.35) 0%, rgba(28, 22, 38, 0.72) 55%, rgba(28, 22, 38, 0.92) 100%);
  --font-heading: "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --text-xs: 11.0px;
  --text-sm: 14.7px;
  --text-base: 17px;
  --text-lg: 22.7px;
  --text-xl: 30.2px;
  --text-2xl: 40.3px;
  --text-3xl: 53.7px;
  --text-4xl: 71.5px;
  --text-display: clamp(50px, 10.3vw, 132px);
  --text-figure: clamp(42px, 7.4vw, 95px);
  --weight-heading: 712;
  --weight-body: 400;
  --leading-body: 1.68;
  --leading-heading: 1.18;
  --tracking-heading: -0.01em;
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 6px;
  --radius-pill: 6px;
  --border-thin: 1px;
  --border-thick: 2px;
  --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: 1320px;
  --measure: 73ch;
  --gutter: 16px;
  --section-y: 72px;
  --section-y-lg: 101px;
}

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

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

body {
  margin: 0;
  padding-left: 18px;
  background: 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);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img, svg, video { display: block; max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; color: inherit; }
h1, h2, h3, h4, h5 {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}
p { margin: 0 0 var(--space-3); }
ul, ol { margin: 0 0 var(--space-3); padding-left: 1.15em; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: var(--border-thick) solid var(--color-focus); outline-offset: 2px; }
::selection { background: var(--color-primary-soft); color: var(--color-ink); }
[hidden] { display: none !important; }

/* ============ 布局工具 ============ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--flush { padding-top: 0; }
.section--deep { background: var(--color-surface-alt); }
.section--contrast { background: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.split { display: grid; grid-template-columns: 7fr 5fr; }
.split--even { grid-template-columns: 1fr 1fr; }
.split--5-7 { grid-template-columns: 5fr 7fr; }
.split--8-4 { grid-template-columns: 8fr 4fr; }
.split__pane { padding: var(--space-6) var(--space-4); }
.split__pane--light { background: var(--color-surface); }
.split__pane--soft { background: var(--color-surface-alt); }
.split__pane--deep { background: var(--color-surface-deep); }
.split__pane--dark { background: var(--color-contrast-surface); color: var(--color-contrast-ink); }

.grid { display: grid; gap: var(--space-3); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* ============ 排版工具 ============ */
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; letter-spacing: 0; }

.eyebrow {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.display {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 0.97;
  letter-spacing: -0.025em;
}

.figure-lg {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  line-height: 1.05;
  color: var(--color-primary);
}

.prose { max-width: var(--measure); }
.prose h2 { font-size: var(--text-2xl); margin: var(--space-6) 0 var(--space-2); }
.prose h3 { font-size: var(--text-xl); margin: var(--space-4) 0 var(--space-2); }
.prose li { margin-bottom: 6px; }

/* ============ 分隔语言 ============ */
.rule-thick {
  height: 0;
  margin: var(--space-4) 0;
  border: 0;
  border-top: var(--border-thick) solid var(--color-ink);
}
.rule-double {
  height: 8px;
  margin: var(--space-6) 0;
  border: 0;
  border-top: var(--border-thick) solid var(--color-ink);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.slash-band {
  display: block;
  height: 16px;
  background: var(--color-primary);
  clip-path: polygon(0 0, 100% 0, calc(100% - 56px) 100%, 0 100%);
}
.slash-band--rev {
  background: var(--color-contrast-accent);
  clip-path: polygon(56px 0, 100% 0, 100% 100%, 0 100%);
}

.pullquote {
  margin: var(--space-4) 0;
  padding-left: var(--space-3);
  border-left: 4px solid var(--color-primary);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: 1.45;
  color: var(--color-ink);
}
.pullquote::before {
  content: "\201C";
  margin-right: 6px;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  line-height: 0;
  vertical-align: -0.12em;
  color: var(--color-primary);
}

/* ============ 图片容器 ============ */
.figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: var(--color-surface-deep);
}
.figure img { width: 100%; height: 100%; object-fit: cover; }
.figure--16x9 { aspect-ratio: 16 / 9; }
.figure--4x3 { aspect-ratio: 4 / 3; }
.figure--1x1 { aspect-ratio: 1 / 1; }
.figure--plain { border-radius: var(--radius-sm); }
.figure--scrim::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}
.figure__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.4;
}

/* ============ 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.btn:hover { text-decoration: none; }
.btn--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
}
.btn--primary:hover { background: color-mix(in srgb, var(--color-primary) 82%, #000); border-color: color-mix(in srgb, var(--color-primary) 82%, #000); }
.btn--accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
  border-color: var(--color-accent);
}
.btn--accent:hover { background: color-mix(in srgb, var(--color-accent) 82%, #000); border-color: color-mix(in srgb, var(--color-accent) 82%, #000); }
.btn--ghost {
  background: transparent;
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}
.btn--ghost:hover { color: var(--color-contrast-accent); border-color: var(--color-contrast-accent); }
.btn--sm { padding: 6px 12px; font-size: var(--text-xs); }
.btn--link {
  padding-inline: 0;
  color: var(--color-primary);
  border-color: transparent;
  background: transparent;
}
.btn--link:hover { color: color-mix(in srgb, var(--color-primary) 78%, #000); }

/* ============ 头部 ============ */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -120px;
  z-index: 200;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-size: var(--text-sm);
  transition: top 0.15s ease;
}
.skip-link:focus { top: var(--space-2); text-decoration: none; }

.site-header { position: relative; z-index: 50; }

.frame-rail {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  z-index: 60;
  width: 18px;
  pointer-events: none;
  border-right: var(--border-thin) solid color-mix(in srgb, var(--color-line) 70%, transparent);
  background-image: repeating-linear-gradient(
    to bottom,
    color-mix(in srgb, var(--color-ink-muted) 42%, transparent) 0 1px,
    transparent 1px 16px
  );
}

.header-top {
  position: relative;
  z-index: 55;
  background: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.header-top__inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  min-height: 74px;
}

.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--color-ink); }
.brand:hover { text-decoration: none; }
.brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
}
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name { font-family: var(--font-heading); font-size: var(--text-lg); font-weight: var(--weight-heading); letter-spacing: -0.01em; }
.brand__tag { font-size: var(--text-xs); letter-spacing: 0.04em; color: var(--color-ink-muted); }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 14px;
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-sm);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  cursor: pointer;
}
.nav-toggle:hover { color: var(--color-contrast-accent); border-color: var(--color-contrast-accent); }
.nav-toggle__bars { display: inline-flex; flex-direction: column; gap: 4px; width: 16px; }
.nav-toggle__bars i { display: block; height: 2px; background: currentColor; }

.site-nav { display: block; }
.site-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin: 0;
  padding: 0;
  list-style: none;
}
.site-nav__link {
  display: inline-block;
  padding: 6px 2px;
  border-bottom: var(--border-thick) solid transparent;
  color: var(--color-ink);
  font-size: var(--text-sm);
  text-decoration: none;
}
.site-nav__link:hover {
  color: var(--color-primary);
  border-bottom-color: color-mix(in srgb, var(--color-primary) 50%, transparent);
  text-decoration: none;
}
.site-nav__link[aria-current="page"] {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.header-quick {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thick) solid var(--color-primary);
}
.header-quick__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-4);
  min-height: 58px;
  padding-block: 10px;
}
.quick-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent);
}
.quick-status__dot {
  width: 8px;
  height: 8px;
  flex: none;
  border-radius: 50%;
  background: var(--color-contrast-accent);
}
.quick-stats {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-3);
  margin: 0;
  padding: 0;
  list-style: none;
}
.quick-stat { display: inline-flex; align-items: baseline; gap: 7px; }
.quick-stat__num {
  font-size: var(--text-lg);
  font-weight: 700;
  line-height: 1.1;
  color: var(--color-contrast-accent);
}
.quick-stat__label {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}
.header-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-left: auto; }

.scroll-meter {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  z-index: 120;
  height: 3px;
  pointer-events: none;
  background: linear-gradient(90deg, var(--color-primary), var(--color-contrast-accent));
  transform: scaleX(0);
  transform-origin: 0 50%;
}

/* ============ 页脚 ============ */
.site-footer { position: relative; z-index: 10; }

.footer-index { background: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.footer-index__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.1fr;
  gap: var(--space-6);
  padding-block: var(--space-8);
}
.footer-brand__name {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: -0.01em;
}
.footer-brand__line {
  max-width: 32ch;
  margin: 0 0 var(--space-3);
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent);
}
.footer-brand__mail,
.footer-brand__tel {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-contrast-accent);
  word-break: break-all;
}
.footer-col__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
}
.footer-list { display: grid; gap: 10px; margin: 0; padding: 0; list-style: none; }
.footer-list a {
  display: inline-block;
  padding-bottom: 2px;
  border-bottom: var(--border-thin) solid transparent;
  color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent);
  font-size: var(--text-sm);
  text-decoration: none;
}
.footer-list a:hover { color: var(--color-contrast-accent); border-bottom-color: var(--color-contrast-accent); }
.footer-note {
  margin: var(--space-3) 0 0;
  font-size: var(--text-xs);
  line-height: 1.5;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, transparent);
}

.footer-mid {
  background: var(--color-surface-deep);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.footer-mid__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding-block: var(--space-3);
}
.footer-mid__statement {
  max-width: 62ch;
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.footer-ext { display: flex; flex-wrap: wrap; gap: var(--space-3); margin: 0; padding: 0; list-style: none; }
.footer-ext__link {
  display: inline-block;
  padding-bottom: 2px;
  border-bottom: var(--border-thin) solid var(--color-line);
  color: var(--color-ink);
  font-size: var(--text-sm);
  text-decoration: none;
}
.footer-ext__link:hover { color: var(--color-primary); border-bottom-color: var(--color-primary); }

.footer-legal {
  background: var(--color-surface-alt);
  border-top: var(--border-thin) solid var(--color-line);
}
.footer-legal__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding-block: var(--space-2);
}
.footer-legal__copy {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.footer-legal__links { display: flex; flex-wrap: wrap; gap: var(--space-3); margin: 0; padding: 0; list-style: none; }
.footer-legal__links a { color: var(--color-ink-muted); font-size: var(--text-xs); }
.footer-legal__links a:hover { color: var(--color-primary); }

.to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 130;
  padding: 10px 14px;
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  cursor: pointer;
}
.to-top:hover { background: color-mix(in srgb, var(--color-primary) 84%, #000); }

/* ============ 组件 ============ */
.toc { }
.toc__list { display: grid; gap: 2px; margin: 0; padding: 0; list-style: none; }
.toc__link {
  display: block;
  padding: 8px 0 8px var(--space-2);
  border-left: 3px solid var(--color-line);
  color: var(--color-ink-soft);
  font-size: var(--text-sm);
  text-decoration: none;
}
.toc__link:hover { color: var(--color-primary); border-left-color: var(--color-primary); text-decoration: none; }
.toc__link[aria-current="true"] { color: var(--color-primary); border-left-color: var(--color-primary); font-weight: 700; }

.filter-bar { display: flex; flex-wrap: wrap; gap: var(--space-1); margin-bottom: var(--space-4); }
.filter-btn {
  padding: 7px 15px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  background: var(--color-surface-deep);
  color: var(--color-ink-soft);
  font-family: inherit;
  font-size: var(--text-sm);
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.filter-btn:hover { color: var(--color-primary); border-color: var(--color-primary); }
.filter-btn[aria-pressed="true"] {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface-alt);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
}
.tag--primary { background: var(--color-primary-soft); color: var(--color-primary); border-color: var(--color-primary); }
.tag--accent { background: var(--color-highlight); color: var(--color-accent); border-color: var(--color-accent); }

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
}
.badge--live { background: var(--color-primary); color: var(--color-primary-ink); }
.badge--ok { background: var(--color-highlight); color: var(--color-accent); border: var(--border-thin) solid var(--color-accent); }

.dot {
  display: inline-block;
  flex: none;
  width: 9px;
  height: 9px;
  border: var(--border-thick) solid currentColor;
  border-radius: 50%;
}
.dot--on { background: currentColor; }

.entry {
  padding: var(--space-3) 0;
  border-bottom: var(--border-thin) solid var(--color-line);
  transition: transform 0.18s ease;
}
.entry:hover { transform: translateX(5px); }
.entry__title { margin: 0 0 var(--space-1); font-size: var(--text-lg); }
.entry__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin: 0 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.entry__body { margin: 0; color: var(--color-ink-soft); }

.card {
  padding: var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  background: var(--color-surface-alt);
}
.card__title { margin: 0 0 var(--space-1); font-size: var(--text-lg); }
.card__meta { margin: 0 0 var(--space-2); font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-ink-muted); }
.card__body { margin: 0; color: var(--color-ink-soft); font-size: var(--text-sm); }

.stat { display: block; }
.stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1.1;
  color: var(--color-primary);
}
.stat__label {
  display: block;
  margin-top: 4px;
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}
.stat--accent .stat__num { color: var(--color-accent); }
.stat--contrast .stat__num { color: var(--color-contrast-accent); }
.stat--contrast .stat__label { color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent); }

.breadcrumb { padding-block: var(--space-2); }
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.breadcrumb__item + .breadcrumb__item::before { content: "/"; margin-right: var(--space-1); color: var(--color-line); }
.breadcrumb__list a { color: var(--color-ink-soft); }
.breadcrumb__list a:hover { color: var(--color-primary); }

/* ============ 响应式 ============ */
@media (max-width: 1180px) {
  .footer-index__grid { grid-template-columns: 1.4fr 1fr 1fr; }
}

@media (max-width: 1024px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 960px) {
  body { padding-left: 0; }
  .frame-rail { display: none; }
  .split, .split--even, .split--5-7, .split--8-4 { grid-template-columns: minmax(0, 1fr); }
  .split__pane { padding: var(--space-6) var(--space-3); }
  .footer-index__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-4); }
}

@media (max-width: 860px) {
  .header-top__inner { min-height: 64px; }
  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    z-index: 70;
    max-height: 0;
    overflow: hidden;
    background: var(--color-contrast-surface);
    transition: max-height 0.28s ease;
  }
  .site-nav[data-open] {
    max-height: 70vh;
    overflow-y: auto;
    border-bottom: var(--border-thick) solid var(--color-contrast-accent);
  }
  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-1) var(--space-2) var(--space-3);
  }
  .site-nav__link {
    display: block;
    padding: 14px 0;
    font-size: var(--text-lg);
    color: var(--color-contrast-ink);
    border-bottom: var(--border-thin) solid var(--color-contrast-line);
  }
  .site-nav__link:hover { color: var(--color-contrast-accent); border-bottom-color: var(--color-contrast-line); }
  .site-nav__link[aria-current="page"] { color: var(--color-contrast-accent); border-bottom-color: var(--color-contrast-accent); }
  .header-actions { width: 100%; margin-left: 0; }
  .header-actions .btn { flex: 1 1 auto; }
  .header-quick__inner { gap: var(--space-2); }
}

@media (max-width: 720px) {
  .container { padding-inline: var(--space-2); }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .footer-index__grid { grid-template-columns: minmax(0, 1fr); }
  .figure--16x9 { aspect-ratio: 3 / 2; }
  .to-top { right: var(--space-2); bottom: var(--space-2); }
}

/* ============ 动效偏好 ============ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .entry, .btn, .filter-btn, .site-nav, .skip-link { transition: none; }
  .entry:hover { transform: none; }
}