/* ==========================================================================
   365网址 · /assets/site.css
   共享外壳：设计变量、中文排版、头部、页脚、通用组件
   ========================================================================== */

:root {
  --color-surface: #fdfdfd;
  --color-surface-alt: #f4f4f4;
  --color-surface-deep: #e6e8e8;
  --color-ink: #414e4d;
  --color-ink-soft: #637473;
  --color-ink-muted: #778888;
  --color-line: #dbdedd;
  --color-primary: #1b837e;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #ddeceb;
  --color-accent: #c01be4;
  --color-accent-ink: #ffffff;
  --color-highlight: #f2d4f8;
  --color-focus: #c10ee7;
  --color-contrast-surface: #162827;
  --color-contrast-ink: #e4e7e7;
  --color-contrast-line: #435251;
  --color-contrast-accent: #d156eb;
  --overlay-scrim: linear-gradient(180deg, rgba(22, 40, 39, 0.35) 0%, rgba(22, 40, 39, 0.72) 55%, rgba(22, 40, 39, 0.92) 100%);
  --font-heading: "Source Han Sans SC", "Noto Sans SC", SimHei, "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-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(46px, 9.4vw, 120px);
  --text-figure: clamp(38px, 6.7vw, 86px);
  --weight-heading: 779;
  --weight-body: 400;
  --leading-body: 1.78;
  --leading-heading: 1.26;
  --tracking-heading: 0.006em;
  --radius-sm: 14px;
  --radius-md: 18px;
  --radius-lg: 22px;
  --radius-pill: 999px;
  --border-thin: 2px;
  --border-thick: 3px;
  --shadow-1: 0 1px 0 rgba(65, 78, 77, 0.12);
  --shadow-2: 0 2px 0 rgba(65, 78, 77, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1200px;
  --measure: 71ch;
  --gutter: 32px;
  --section-y: 66px;
  --section-y-lg: 92px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 128px;
}

body {
  margin: 0;
  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;
  text-rendering: optimizeLegibility;
}

img, svg, video { max-width: 100%; }
img { height: auto; }

a {
  color: var(--color-primary);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
a:hover { color: var(--color-accent); }

button { font: inherit; color: inherit; background: none; border: 0; }

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

::selection { background: var(--color-highlight); color: var(--color-ink); }

/* ---------- 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);
  overflow-wrap: break-word;
}
h1 { font-size: var(--text-2xl); }
h2 { font-size: var(--text-xl); }
h3 { font-size: var(--text-lg); }
h4 { font-size: var(--text-base); }

p { margin: 0 0 var(--space-3); }
p, li, dd, figcaption, td, th { line-break: strict; overflow-wrap: break-word; }

ul, ol { margin: 0 0 var(--space-3); padding-left: 1.25em; }
li { margin-bottom: var(--space-1); }

strong { font-weight: 700; }
small { font-size: var(--text-xs); }

.mono, code, kbd, samp {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.caps {
  text-transform: uppercase;
  letter-spacing: 0.14em;
}

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

.measure { max-width: var(--measure); }

.grid {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: var(--gutter);
}

.span-1 { grid-column: span 1; }
.span-2 { grid-column: span 2; }
.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }

.stack > * + * { margin-top: var(--space-3); }

.cluster {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
}

.section {
  position: relative;
  padding-block: var(--section-y);
}
.section--lg { padding-block: var(--section-y-lg); }
.section--alt { background: var(--color-surface-alt); }
.section--soft { background: var(--color-primary-soft); }
.section--highlight { background: var(--color-highlight); }
.section--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--deep h1,
.section--deep h2,
.section--deep h3,
.section--deep h4 { color: var(--color-contrast-ink); }
.section--deep p,
.section--deep li { color: var(--color-contrast-ink); }
.section--deep a { color: var(--color-contrast-accent); }
.section--deep a:hover { color: var(--color-contrast-ink); }
.section--deep .rule { border-top-color: var(--color-contrast-line); }

.rule {
  border: 0;
  border-top: 1px solid var(--color-line);
  margin: var(--space-3) 0;
}

.section-head { margin-bottom: var(--space-4); }
.section-head__title {
  margin: 0 0 var(--space-1);
  font-size: var(--text-xl);
}

.eyebrow {
  display: inline-block;
  margin: 0 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-accent);
}
.section--deep .eyebrow { color: var(--color-contrast-accent); }

.lead {
  max-width: var(--measure);
  font-size: var(--text-lg);
  line-height: 1.62;
  color: var(--color-ink-soft);
}
.section--deep .lead { color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent); }

.hero-title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 1.02;
  letter-spacing: -0.012em;
}

.stat { display: block; }
.stat__value {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--color-accent);
}
.stat__label {
  display: block;
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.section--deep .stat__value { color: var(--color-contrast-accent); }
.section--deep .stat__label { color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 12px 20px;
  background: var(--color-surface);
  color: var(--color-primary);
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-pill);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  line-height: 1.2;
  letter-spacing: 0.04em;
  text-decoration: none;
  box-shadow: var(--space-1) var(--space-1) 0 color-mix(in srgb, var(--color-primary) 26%, transparent);
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease, border-color 0.18s ease, color 0.18s ease;
}
.btn:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  transform: translate(-2px, -2px);
  box-shadow: 10px 10px 0 color-mix(in srgb, var(--color-accent) 24%, transparent);
}
.btn--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
}
.btn--primary:hover {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.btn--accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
  border-color: var(--color-accent);
  box-shadow: var(--space-1) var(--space-1) 0 color-mix(in srgb, var(--color-primary) 45%, transparent);
}
.btn--ghost {
  background: transparent;
  color: var(--color-ink-soft);
  border-color: var(--color-line);
  box-shadow: none;
}
.btn--compact {
  padding: 8px 15px;
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
}

/* ---------- 卡片 / 标签 ---------- */
.card {
  position: relative;
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  box-shadow: var(--space-1) var(--space-1) 0 color-mix(in srgb, var(--color-ink) 12%, transparent);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}
.card:hover {
  transform: translate(-4px, -4px);
  border-color: var(--color-accent);
  box-shadow: 12px 12px 0 color-mix(in srgb, var(--color-accent) 20%, transparent);
}
.card--accent { border-color: var(--color-accent); }

.float-tag {
  position: absolute;
  top: calc(var(--space-2) * -1);
  right: var(--space-3);
  z-index: 2;
  padding: 4px 10px;
  background: var(--color-accent);
  color: var(--color-accent-ink);
  border: var(--border-thin) solid var(--color-accent);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  white-space: nowrap;
}
.float-tag--primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.float-tag--dark {
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-accent);
}
.float-tag--soft {
  background: var(--color-highlight);
  border-color: var(--color-line);
  color: var(--color-ink);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background: var(--color-surface);
  color: var(--color-ink-soft);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
}
.chip--primary {
  background: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.chip--accent {
  background: var(--color-highlight);
  border-color: var(--color-accent);
  color: var(--color-accent);
}
.chip--deep {
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-accent);
}

/* ---------- 数据带 ---------- */
.data-band {
  position: relative;
  padding-block: var(--space-3);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-block: var(--border-thin) solid var(--color-contrast-line);
  overflow: hidden;
}
.data-band__inner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  align-items: stretch;
}
.data-band__item {
  flex: 1 1 180px;
  min-width: 0;
  padding-left: var(--space-2);
  border-left: 1px solid var(--color-contrast-line);
}
.data-band__num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--color-contrast-accent);
}
.data-band__label {
  display: block;
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent);
}

/* ---------- 入口面板（斜切） ---------- */
.entry-panel {
  position: relative;
  padding: var(--space-4) var(--space-3);
  background: var(--color-primary-soft);
  color: var(--color-ink);
  border-radius: var(--radius-md) var(--radius-md) 0 var(--radius-md);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
  transition: transform 0.2s ease;
}
.entry-panel--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}
.entry-panel--accent {
  background: var(--color-highlight);
  color: var(--color-ink);
}
.entry-panel--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.entry-panel:hover { transform: translateY(-4px); }
.entry-panel__title {
  margin: 0 0 var(--space-1);
  font-size: var(--text-lg);
  color: inherit;
}
.entry-panel__meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: inherit;
  opacity: 0.78;
}
.entry-panel a { color: inherit; }

/* ---------- 图片容器（页面阶段放占位/图片） ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--color-surface-deep);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
}
.media__img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}
.media__scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
}
.media__body {
  position: absolute;
  inset: auto 0 0 0;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
}
.media__body h2,
.media__body h3 { color: var(--color-contrast-ink); }
.media__caption {
  display: block;
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.media__placeholder {
  aspect-ratio: 16 / 9;
  background-image:
    linear-gradient(135deg, color-mix(in srgb, var(--color-primary) 42%, var(--color-contrast-surface)) 0%, var(--color-contrast-surface) 58%),
    linear-gradient(90deg, var(--color-contrast-line) 1px, transparent 1px),
    linear-gradient(0deg, var(--color-contrast-line) 1px, transparent 1px);
  background-size: 100% 100%, 56px 56px, 56px 56px;
}
.media--wide .media__img,
.media--wide .media__placeholder { aspect-ratio: 21 / 9; }
.media--tall .media__img,
.media--tall .media__placeholder { aspect-ratio: 4 / 5; }
.media--tilt { transform: rotate(-1.2deg); }

/* ---------- 面包屑 ---------- */
.breadcrumbs {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-line);
}
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin: 0;
  padding: var(--space-2) 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.breadcrumbs__list li { margin: 0; }
.breadcrumbs__list a {
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, currentColor 45%, transparent);
}
.breadcrumbs__list a:hover { color: var(--color-accent); }

/* ---------- 章节目录 ---------- */
.toc {
  position: sticky;
  top: 128px;
  padding: var(--space-3);
  background: var(--color-surface-deep);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
}
.toc__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.toc__list { margin: 0; padding: 0; list-style: none; }
.toc__list li { margin: 0; }
.toc__link {
  display: flex;
  gap: var(--space-1);
  padding: 7px 0;
  color: var(--color-ink-soft);
  font-size: var(--text-sm);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
.toc__link:hover { color: var(--color-ink); }
.toc__link[aria-current="true"] {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}
.toc__index {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  opacity: 0.8;
}

/* ---------- 正文与表格 ---------- */
.prose { max-width: var(--measure); }
.prose h2 { margin-top: var(--space-6); }
.prose h3 { margin-top: var(--space-4); }
.prose > *:last-child { margin-bottom: 0; }

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}
.data-table caption {
  padding-bottom: var(--space-2);
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.data-table th,
.data-table td {
  padding: var(--space-2);
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--color-line);
}
.data-table thead th {
  border-bottom: var(--border-thin) solid var(--color-ink);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
}
.data-table tbody td:first-child {
  font-family: var(--font-mono);
  color: var(--color-ink-soft);
}
.section--deep .data-table th,
.section--deep .data-table td { border-bottom-color: var(--color-contrast-line); }

/* ---------- 装饰形状 ---------- */
.deco {
  position: absolute;
  display: block;
  pointer-events: none;
  z-index: 0;
}
.deco--ring {
  top: -26px;
  right: 224px;
  width: 66px;
  height: 66px;
  border: var(--border-thick) solid var(--color-primary);
  border-radius: 50%;
  opacity: 0.45;
}
.deco--slash {
  bottom: 10px;
  right: 300px;
  width: 104px;
  height: 10px;
  background: var(--color-accent);
  border-radius: var(--radius-pill);
  transform: rotate(-24deg);
  opacity: 0.65;
}
.deco--dot {
  left: var(--space-4);
  bottom: 12px;
  width: 14px;
  height: 14px;
  background: var(--color-highlight);
  border: var(--border-thin) solid var(--color-primary);
  border-radius: 50%;
}

/* ---------- 头部 ---------- */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: var(--space-1);
  z-index: 200;
  padding: 10px 16px;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-accent);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-decoration: none;
  transform: translateY(-220%);
  transition: transform 0.18s ease;
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 70;
  background: var(--color-surface);
  border-bottom: var(--border-thick) solid var(--color-primary);
  box-shadow: var(--shadow-2);
}

.site-header__bar { position: relative; }

.site-header__deco {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.site-header__inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-2) var(--space-3);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-ink);
  text-decoration: none;
  flex: 0 0 auto;
}
.brand:hover { color: var(--color-ink); }
.brand__mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-radius: var(--radius-sm) 0 var(--radius-sm) var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.04em;
  transform: rotate(-3deg);
  box-shadow: 4px 4px 0 color-mix(in srgb, var(--color-accent) 55%, transparent);
}
.brand__text { display: block; min-width: 0; }
.brand__name {
  display: block;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.1;
  letter-spacing: 0.04em;
  white-space: nowrap;
}
.brand__tagline {
  display: block;
  max-width: 30ch;
  max-height: 1.8em;
  overflow: hidden;
  font-size: var(--text-xs);
  line-height: 1.5;
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  transition: max-height 0.24s ease, opacity 0.24s ease;
}
.site-header[data-condensed="true"] .brand__tagline {
  max-height: 0;
  opacity: 0;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  padding: 10px 14px;
  background: var(--color-surface);
  color: var(--color-ink);
  border: var(--border-thin) solid var(--color-ink);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  cursor: pointer;
}
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.site-nav {
  display: flex;
  align-items: center;
  flex: 1 1 auto;
  min-width: 0;
}
.site-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
  list-style: none;
}
.site-nav__list li { margin: 0; }
.site-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  color: var(--color-ink-soft);
  background: transparent;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  line-height: 1.2;
  letter-spacing: 0.02em;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}
.site-nav__link:hover {
  color: var(--color-ink);
  border-color: var(--color-accent);
  background: color-mix(in srgb, var(--color-highlight) 55%, transparent);
}
.site-nav__link[aria-current="page"] {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.site-nav__link[aria-current="page"]:hover {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.site-nav__index {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  opacity: 0.75;
}
.site-nav__label { white-space: nowrap; }

.site-header__side {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
  flex: 0 0 auto;
}

.nav-status {
  margin: 0;
  padding: 6px 12px;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: calc(var(--border-thick) * -1);
  height: var(--border-thick);
  background: var(--color-accent);
  transform: scaleX(var(--scroll-progress, 0));
  transform-origin: 0 50%;
  z-index: 3;
}

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  padding-block: var(--section-y);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thick) solid var(--color-primary);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -70px;
  right: -70px;
  width: 190px;
  height: 190px;
  border: var(--border-thick) solid color-mix(in srgb, var(--color-contrast-accent) 45%, transparent);
  border-radius: 50%;
}
.site-footer::after {
  content: "";
  position: absolute;
  left: -40px;
  bottom: 96px;
  width: 130px;
  height: 14px;
  background: var(--color-primary);
  border-radius: var(--radius-pill);
  transform: rotate(-28deg);
  opacity: 0.6;
}

.site-footer__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: flex-end;
  justify-content: space-between;
  padding-bottom: var(--space-4);
}
.footer-brand__name {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  letter-spacing: 0.06em;
  color: var(--color-contrast-ink);
}
.footer-brand__line {
  margin: var(--space-1) 0 0;
  max-width: 52ch;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent);
}

.footer-panels {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: var(--space-3);
  align-items: start;
}

.footer-panel {
  padding: var(--space-3);
  background: color-mix(in srgb, var(--color-contrast-ink) 5%, var(--color-contrast-surface));
  border: 1px solid var(--color-contrast-line);
  border-radius: var(--radius-md);
}
.footer-panel--intro { grid-column: span 3; }
.footer-panel--links {
  grid-column: span 2;
  margin-top: var(--space-4);
  background: var(--color-primary);
  color: var(--color-primary-ink);
}
.footer-panel--legal {
  grid-column: span 2;
  margin-top: var(--space-2);
  background: var(--color-highlight);
  color: var(--color-ink);
}
.footer-panel--contact {
  grid-column: 4 / span 4;
  background: var(--color-surface);
  color: var(--color-ink);
}

.footer-panel__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: inherit;
  opacity: 0.85;
}
.footer-panel__text {
  margin: 0;
  font-size: var(--text-sm);
  line-height: 1.7;
}

.footer-links {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--text-sm);
}
.footer-links li { margin-bottom: var(--space-1); }
.footer-links a {
  display: inline-block;
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, currentColor 38%, transparent);
  padding-bottom: 1px;
  transition: transform 0.16s ease, border-bottom-color 0.16s ease;
}
.footer-links a:hover {
  color: inherit;
  border-bottom-color: currentColor;
  transform: translateX(3px);
}

.footer-contact-list {
  margin: 0 0 var(--space-2);
  padding: 0;
  list-style: none;
  font-size: var(--text-sm);
}
.footer-contact-list li {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin: 0;
  padding: 7px 0;
  border-bottom: 1px solid var(--color-line);
}
.footer-contact-list__label {
  flex: 0 0 76px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}
.footer-contact-list__value {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink);
}
.footer-note {
  margin: 0;
  font-size: var(--text-xs);
  line-height: 1.75;
  color: var(--color-ink-soft);
}
.footer-note a {
  color: var(--color-accent);
  font-weight: 700;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  justify-content: space-between;
  margin: var(--space-4) 0 0;
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-contrast-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent);
}

/* ---------- 返回顶部 / 入场动效 ---------- */
.back-to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 80;
  padding: 10px 16px;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-accent);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  box-shadow: 6px 6px 0 color-mix(in srgb, var(--color-accent) 32%, transparent);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease, border-color 0.2s ease;
}
.back-to-top[data-shown="true"] {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.back-to-top:hover { border-color: var(--color-primary); }

[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.32s ease, transform 0.32s ease;
}
[data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1180px) {
  .nav-toggle { display: inline-flex; order: 3; }
  .nav-status { display: none; }
  .site-header__side { margin-left: 0; order: 4; }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    padding: var(--space-2) var(--space-3) var(--space-3);
    background: var(--color-surface);
    border-bottom: var(--border-thick) solid var(--color-accent);
    box-shadow: 0 10px 0 color-mix(in srgb, var(--color-primary) 18%, transparent);
  }
  .site-nav[data-open] { display: block; }
  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }
  .site-nav__link {
    justify-content: flex-start;
    padding: 12px 14px;
    font-size: var(--text-base);
    border-radius: var(--radius-sm);
  }
  .deco--ring { right: var(--space-8); }
  .deco--slash { display: none; }
}

@media (max-width: 980px) {
  .grid { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-3); }
  .span-4, .span-5, .span-6, .span-7 { grid-column: span 4; }

  .footer-panels { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-panel--intro,
  .footer-panel--links,
  .footer-panel--legal { grid-column: span 1; }
  .footer-panel--links { margin-top: var(--space-3); }
  .footer-panel--legal { margin-top: 0; }
  .footer-panel--contact { grid-column: span 2; }

  .toc { position: static; }
}

@media (max-width: 640px) {
  :root { --section-y: 48px; --section-y-lg: 64px; }

  .container { padding-inline: var(--space-2); }
  .grid { grid-template-columns: minmax(0, 1fr); }
  .span-1, .span-2, .span-3, .span-4,
  .span-5, .span-6, .span-7 { grid-column: span 1; }

  .site-header__inner { padding: var(--space-2); gap: var(--space-2); }
  .brand__tagline { display: none; }
  .brand__mark { width: 40px; height: 40px; }
  .brand__name { font-size: var(--text-base); }
  .deco--ring, .deco--dot { display: none; }

  .footer-panels { grid-template-columns: minmax(0, 1fr); }
  .footer-panel--intro,
  .footer-panel--links,
  .footer-panel--legal,
  .footer-panel--contact { grid-column: span 1; margin-top: 0; }

  .data-band__inner { gap: var(--space-3); }
  .data-band__item { flex: 1 1 100%; }
}

/* ---------- 减少动效 ---------- */
@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;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .card:hover, .btn:hover, .entry-panel:hover, .footer-links a:hover { transform: none; }
  .back-to-top { transition: none; }
}