:root {
  --color-surface: #f0efef;
  --color-surface-alt: #e8e6e6;
  --color-surface-deep: #dcdada;
  --color-ink: #49433c;
  --color-ink-soft: #6c655b;
  --color-ink-muted: #898176;
  --color-line: #d2d0cf;
  --color-primary: #8e7248;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e2ded8;
  --color-accent: #cf441b;
  --color-accent-ink: #ffffff;
  --color-highlight: #ead0c9;
  --color-focus: #c3370e;
  --color-contrast-surface: #1d1a15;
  --color-contrast-ink: #e7e6e4;
  --color-contrast-line: #494743;
  --color-contrast-accent: #e25227;
  --overlay-scrim: linear-gradient(180deg, rgba(29, 26, 21, 0.35) 0%, rgba(29, 26, 21, 0.72) 55%, rgba(29, 26, 21, 0.92) 100%);
  --font-heading: "Songti SC", "Source Han Serif SC", "Noto Serif SC", SimSun, serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-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, 103px);
  --text-figure: clamp(33px, 5.8vw, 74px);
  --weight-heading: 695;
  --weight-body: 400;
  --leading-body: 1.82;
  --leading-heading: 1.19;
  --tracking-heading: -0.003em;
  --radius-sm: 4px;
  --radius-md: 5px;
  --radius-lg: 6px;
  --radius-pill: 6px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: 0 1px 0 rgba(73, 67, 60, 0.12);
  --shadow-2: 0 2px 0 rgba(73, 67, 60, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1240px;
  --measure: 69ch;
  --gutter: 24px;
  --section-y: 79px;
  --section-y-lg: 111px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 104px;
}

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);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

body.is-nav-locked { overflow: hidden; }

img,
picture,
svg,
video { max-width: 100%; display: block; }

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

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

a:hover { color: var(--color-focus); }

ul, ol { margin: 0; padding: 0; list-style: none; }

hr { border: 0; margin: 0; }

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

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ============================================================
   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);
  text-wrap: balance;
}

h1 { font-size: clamp(var(--text-2xl), 5vw, var(--text-4xl)); }
h2 { font-size: clamp(var(--text-xl), 3.4vw, var(--text-3xl)); }
h3 { font-size: var(--text-lg); }
h4 { font-size: var(--text-base); }
h5, h6 { font-size: var(--text-sm); }

p { margin: 0 0 var(--space-2); }

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.lead {
  font-size: var(--text-lg);
  color: var(--color-ink-soft);
  line-height: 1.6;
}

.fig-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

/* ============================================================
   容器与栅格
   ============================================================ */
.container {
  width: min(calc(100% - var(--space-6)), var(--container));
  margin-inline: auto;
}

.container--tight { width: min(calc(100% - var(--space-6)), 900px); margin-inline: auto; }

.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-surface-deep); }

.prose { max-width: var(--measure); }
.prose > * + * { margin-top: var(--space-2); }
.prose p { margin: 0; }
.prose ul,
.prose ol { padding-left: var(--space-3); margin: var(--space-2) 0; }
.prose li { list-style: disc; margin-bottom: 6px; padding-left: 2px; }
.prose ol li { list-style: decimal; }
.prose strong { font-weight: 600; color: var(--color-ink); }

.grid { display: grid; gap: var(--gutter); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.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)); }

@media (max-width: 1000px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 680px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }
}

/* ============================================================
   纸片面板 / 深色数据屏
   ============================================================ */
.paper {
  position: relative;
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-1);
  padding: var(--space-4);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.paper:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}

.paper--flat:hover { transform: none; box-shadow: var(--shadow-1); }

.paper--alt { background-color: var(--color-surface-alt); }
.paper--deep { background-color: var(--color-surface-deep); }

.panel--contrast {
  position: relative;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-md);
  padding: var(--space-4);
}

.panel--contrast h1,
.panel--contrast h2,
.panel--contrast h3,
.panel--contrast h4 { color: var(--color-contrast-ink); }

.panel--contrast .fig-label,
.panel--contrast .index-num { color: var(--color-contrast-accent); }

.screen {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.screen h1,
.screen h2,
.screen h3,
.screen h4 { color: var(--color-contrast-ink); }

.screen a { color: var(--color-contrast-ink); }

.screen .lead { color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent); }

.panel-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.panel-head > h2,
.panel-head > h3 { margin: 0; }

/* ============================================================
   编号 / 刻度 / 贴纸 / 强调
   ============================================================ */
.index-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-primary);
  display: inline-block;
}

.divider-index {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin: var(--space-3) 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

.divider-index::after {
  content: "";
  flex: 1 1 auto;
  height: 6px;
  background-image: repeating-linear-gradient(
    90deg,
    var(--color-line) 0 1px,
    transparent 1px 9px
  );
  background-size: 9px 6px;
  background-repeat: repeat-x;
  background-position: left bottom;
}

.panel--contrast .divider-index,
.screen .divider-index { color: var(--color-contrast-line); }

.panel--contrast .divider-index::after,
.screen .divider-index::after {
  background-image: repeating-linear-gradient(
    90deg,
    var(--color-contrast-line) 0 1px,
    transparent 1px 9px
  );
}

.ticks {
  display: inline-block;
  width: 72px;
  height: 7px;
  background-image: repeating-linear-gradient(
    90deg,
    var(--color-line) 0 1px,
    transparent 1px 8px
  );
  vertical-align: middle;
}

.panel--contrast .ticks,
.screen .ticks {
  background-image: repeating-linear-gradient(
    90deg,
    var(--color-contrast-line) 0 1px,
    transparent 1px 8px
  );
}

.sticker {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  line-height: 1.5;
  color: var(--color-ink-soft);
  background-color: var(--color-primary-soft);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  transform: rotate(-1.5deg);
  white-space: nowrap;
}

.sticker--primary {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.sticker--accent {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.sticker--steel {
  background-color: var(--color-surface-deep);
  border-color: var(--color-line);
  color: var(--color-ink-soft);
}

.sticker--corner {
  position: absolute;
  top: -11px;
  left: var(--space-3);
  z-index: 3;
}

button.sticker,
a.sticker { cursor: pointer; }

button.sticker[aria-pressed="true"],
a.sticker[aria-current="true"] {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
  transform: rotate(0deg);
}

.callout {
  position: relative;
  margin: var(--space-3) 0 var(--space-3) var(--space-4);
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-highlight);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-ink);
}

.callout::before {
  content: "\201C";
  position: absolute;
  left: calc(-1 * var(--space-4));
  top: -10px;
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  line-height: 1;
  color: var(--color-primary);
}

.callout > :last-child { margin-bottom: 0; }

/* ============================================================
   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);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1.4;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.16s ease, box-shadow 0.16s ease,
              background-color 0.16s ease, color 0.16s ease,
              border-color 0.16s ease;
}

.btn:hover { transform: translateY(-1px); text-decoration: none; }

.btn--primary {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: var(--shadow-1);
}

.btn--primary:hover { background-color: color-mix(in srgb, var(--color-primary) 86%, #000); color: var(--color-primary-ink); box-shadow: var(--shadow-2); }

.btn--accent {
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  box-shadow: var(--shadow-1);
}

.btn--accent:hover { background-color: color-mix(in srgb, var(--color-accent) 86%, #000); color: var(--color-accent-ink); box-shadow: var(--shadow-2); }

.btn--ghost {
  background-color: transparent;
  border-color: var(--color-line);
  color: var(--color-ink);
}

.btn--ghost:hover { background-color: var(--color-primary-soft); color: var(--color-ink); }

.panel--contrast .btn--ghost,
.screen .btn--ghost {
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}

.panel--contrast .btn--ghost:hover,
.screen .btn--ghost:hover {
  background-color: color-mix(in srgb, var(--color-contrast-ink) 12%, transparent);
  color: var(--color-contrast-ink);
}

.btn--sm { padding: 7px 12px; font-size: var(--text-xs); }
.btn--block { width: 100%; }

/* ============================================================
   图片容器（页面阶段放置图片占位）
   ============================================================ */
.media {
  position: relative;
  overflow: hidden;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  background-color: var(--color-surface-deep);
  box-shadow: var(--shadow-1);
}

.media img {
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  display: block;
}

.media--wide img { aspect-ratio: 16 / 9; }
.media--tall img { aspect-ratio: 3 / 4; }
.media--square img { aspect-ratio: 1 / 1; }

.media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  opacity: 0;
  transition: opacity 0.2s ease;
  pointer-events: none;
  z-index: 1;
}

.media--has-caption::after { opacity: 1; }

.media__caption {
  position: absolute;
  left: var(--space-2);
  bottom: var(--space-2);
  z-index: 2;
  max-width: calc(100% - var(--space-4));
  padding: 5px 10px;
  background-color: var(--color-surface);
  color: var(--color-ink-soft);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  line-height: 1.5;
  transform: rotate(-1deg);
}

/* ============================================================
   面包屑
   ============================================================ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
  margin-bottom: var(--space-3);
}

.breadcrumb a { color: var(--color-ink-soft); text-decoration: none; }
.breadcrumb a:hover { color: var(--color-primary); text-decoration: underline; }
.breadcrumb__sep { color: var(--color-line); }

.panel--contrast .breadcrumb,
.screen .breadcrumb { color: var(--color-contrast-line); }

.panel--contrast .breadcrumb a,
.screen .breadcrumb a { color: var(--color-contrast-ink); }

/* ============================================================
   标签页 / 横向滚动带 / 显现
   ============================================================ */
.tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: var(--space-3);
}

.tabs__tab {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 14px;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, transform 0.18s ease;
}

.tabs__tab:hover { background-color: var(--color-primary-soft); color: var(--color-ink); }

.tabs__tab[aria-selected="true"] {
  background-color: var(--color-surface);
  color: var(--color-ink);
  transform: translateY(-2px);
  box-shadow: var(--shadow-1);
}

.tabs__tab[aria-selected="true"]::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 3px;
  height: 2px;
  border-radius: 1px;
  background-color: var(--color-focus);
}

.tabs__panel { animation: tab-in 0.18s ease both; }
.tabs__panel[hidden] { display: none; }

.panel--contrast .tabs__tab,
.screen .tabs__tab {
  background-color: transparent;
  border-color: var(--color-contrast-line);
  color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent);
}

.panel--contrast .tabs__tab[aria-selected="true"],
.screen .tabs__tab[aria-selected="true"] {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

@keyframes tab-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

.rail {
  display: flex;
  gap: var(--space-3);
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  padding: var(--space-2) var(--space-1) var(--space-3);
  margin-inline: calc(-1 * var(--space-1));
  scrollbar-width: thin;
  scrollbar-color: var(--color-line) transparent;
}

.rail > * {
  flex: 0 0 auto;
  scroll-snap-align: start;
}

.rail::-webkit-scrollbar { height: 8px; }
.rail::-webkit-scrollbar-track { background: transparent; }
.rail::-webkit-scrollbar-thumb { background: var(--color-line); border-radius: var(--radius-sm); }

html.js-ready [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.4s ease, transform 0.4s ease;
}

html.js-ready [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ============================================================
   跳过链接
   ============================================================ */
.skip-link {
  position: fixed;
  top: var(--space-1);
  left: var(--space-1);
  z-index: 200;
  padding: 10px 16px;
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow-2);
  transform: translateY(-200%);
  transition: transform 0.18s ease;
}

.skip-link:focus {
  transform: translateY(0);
  color: var(--color-accent-ink);
}

/* ============================================================
   头部
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 60;
  --hdr-fg: var(--color-contrast-ink);
  --hdr-fg-soft: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent);
  --hdr-line: var(--color-contrast-line);
  background-color: transparent;
  color: var(--hdr-fg);
  transition: background-color 0.2s ease, box-shadow 0.2s ease;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(29, 26, 21, 0.72) 0%, rgba(29, 26, 21, 0) 100%);
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.site-header.is-scrolled {
  --hdr-fg: var(--color-ink);
  --hdr-fg-soft: var(--color-ink-soft);
  --hdr-line: var(--color-line);
  background-color: var(--color-surface);
  box-shadow: var(--shadow-2);
}

.site-header.is-scrolled::before { opacity: 0; }

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 2px;
  width: 100%;
  background-color: var(--color-primary);
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
  will-change: transform;
}

.site-header__inner {
  position: relative;
  width: min(calc(100% - var(--space-6)), var(--container));
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: 88px;
  transition: min-height 0.2s ease;
}

.site-header.is-scrolled .site-header__inner { min-height: 64px; }

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-width: 0;
}

.brand__link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-width: 0;
  text-decoration: none;
  color: inherit;
}

.brand__link:hover { color: inherit; }

.brand__mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1;
  transform: rotate(-2deg);
}

.brand__text { display: flex; flex-direction: column; min-width: 0; }

.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  line-height: 1.3;
  color: var(--hdr-fg);
  white-space: nowrap;
}

.brand__tagline {
  font-size: var(--text-xs);
  line-height: 1.4;
  color: var(--hdr-fg-soft);
  white-space: nowrap;
}

.brand__version {
  flex: none;
  padding: 2px 8px;
  font-size: var(--text-xs);
  line-height: 1.6;
  color: var(--hdr-fg-soft);
  border: var(--border-thin) solid var(--hdr-line);
  border-radius: var(--radius-sm);
  transform: rotate(1.5deg);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  font-size: var(--text-sm);
  color: var(--hdr-fg);
  border: var(--border-thin) solid var(--hdr-line);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: border-color 0.18s ease, background-color 0.18s ease;
}

.nav-toggle:hover { border-color: var(--color-primary); }

.nav-toggle[aria-expanded="true"] { border-color: var(--color-primary); }

.nav-toggle__icon {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 16px;
  height: 10px;
}

.nav-toggle__icon span {
  display: block;
  width: 16px;
  height: 2px;
  border-radius: 1px;
  background-color: currentColor;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-width: 0;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.site-nav__item { position: relative; }

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 10px;
  font-size: var(--text-sm);
  line-height: 1.4;
  color: var(--hdr-fg-soft);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color 0.18s ease, background-color 0.18s ease;
}

.site-nav__link:hover {
  color: var(--hdr-fg);
  background-color: color-mix(in srgb, var(--color-primary) 16%, transparent);
}

.site-nav__link[aria-current="page"] { color: var(--hdr-fg); }

.site-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 1px;
  height: 2px;
  border-radius: 1px;
  background-color: var(--color-focus);
}

.site-nav__num {
  font-size: var(--text-xs);
  color: var(--color-primary);
}

.site-header.is-scrolled .site-nav__num { color: var(--color-primary); }

.site-nav__cta { flex: none; }

@media (max-width: 1180px) {
  .site-nav__link { font-size: var(--text-xs); padding: 8px 7px; }
  .site-header__inner { gap: var(--space-2); }
}

@media (max-width: 1000px) {
  .brand__tagline { display: none; }
}

@media (max-width: 960px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 75;
    width: min(340px, 88vw);
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: var(--space-3);
    padding: calc(var(--space-8) + var(--space-2)) var(--space-3) var(--space-4);
    overflow-y: auto;
    background-color: var(--color-surface);
    color: var(--color-ink);
    --hdr-fg: var(--color-ink);
    --hdr-fg-soft: var(--color-ink-soft);
    --hdr-line: var(--color-line);
    box-shadow: var(--shadow-2);
    transform: translateX(104%);
    transition: transform 0.22s ease;
  }

  .site-nav[data-open] { transform: translateX(0); }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__link {
    justify-content: flex-start;
    padding: 13px 8px;
    font-size: var(--text-base);
    color: var(--color-ink);
    border-radius: 0;
  }

  .site-nav__link[aria-current="page"] { color: var(--color-ink); }

  .site-nav__link[aria-current="page"]::after {
    left: 0;
    right: auto;
    bottom: 6px;
    width: 22px;
    height: 2px;
  }

  .site-nav__num { color: var(--color-primary); }

  .site-nav__cta {
    margin-top: var(--space-2);
    justify-content: center;
  }
}

@media (max-width: 560px) {
  .brand__mark { width: 32px; height: 32px; font-size: var(--text-base); }
  .brand__name { font-size: var(--text-xs); }
  .brand__version { display: none; }
  .site-header__inner { min-height: 68px; }
  .site-header.is-scrolled .site-header__inner { min-height: 58px; }
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  position: relative;
  background-color: var(--color-surface-alt);
  color: var(--color-ink);
  padding-top: var(--section-y);
  padding-bottom: calc(var(--space-8) + var(--space-4));
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background-image: repeating-linear-gradient(
    90deg,
    var(--color-line) 0 1px,
    transparent 1px 10px
  );
  opacity: 0.9;
}

.site-footer__inner {
  width: min(calc(100% - var(--space-6)), var(--container));
  margin-inline: auto;
}

.site-footer__top {
  display: grid;
  grid-template-columns: 1.1fr 1.7fr 1.2fr;
  gap: var(--space-6);
  align-items: start;
}

.site-footer__brand-name {
  margin: 0 0 var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.site-footer__brand-line {
  margin: 0 0 var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.site-footer__meta {
  margin: 0 0 4px;
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

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

.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: var(--tracking-heading);
  color: var(--color-ink);
}

.footer-col__list { display: flex; flex-direction: column; gap: 2px; }

.footer-col__link {
  display: inline-block;
  padding: 5px 0;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: color 0.16s ease, transform 0.16s ease;
}

.footer-col__link:hover {
  color: var(--color-primary);
  transform: translateX(2px);
}

.contact-list { display: flex; flex-direction: column; gap: var(--space-2); }

.contact-list__item { display: flex; flex-direction: column; gap: 2px; }

.contact-list__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.contact-list__value {
  font-size: var(--text-sm);
  color: var(--color-ink);
  word-break: break-word;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-8);
}

.site-footer__legal,
.site-footer__icp {
  margin: 0;
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

.site-footer__icp { letter-spacing: 0.06em; }

.feedback-anchor {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 55;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 16px;
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-2);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1.3;
  text-decoration: none;
  transform: rotate(-1.2deg);
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

.feedback-anchor:hover {
  color: var(--color-accent-ink);
  background-color: color-mix(in srgb, var(--color-accent) 88%, #000);
  transform: rotate(-1.2deg) translateY(-2px);
  box-shadow: 0 3px 0 rgba(73, 67, 60, 0.22);
}

.feedback-anchor__dot {
  width: 7px;
  height: 7px;
  flex: none;
  border-radius: 50%;
  background-color: var(--color-accent-ink);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-accent-ink) 28%, transparent);
}

@media (max-width: 1040px) {
  .site-footer__top { grid-template-columns: 1fr 1fr; }
  .site-footer__contact { grid-column: 1 / -1; }
  .contact-list { flex-direction: row; flex-wrap: wrap; gap: var(--space-3); }
  .contact-list__item { min-width: 200px; }
}

@media (max-width: 680px) {
  .site-footer__top { grid-template-columns: minmax(0, 1fr); gap: var(--space-4); }
  .site-footer__cols { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-3); }
  .contact-list { flex-direction: column; gap: var(--space-2); }
  .site-footer__contact { grid-column: auto; }
  .site-footer__bottom { margin-top: var(--space-6); }
  .feedback-anchor {
    right: var(--space-2);
    bottom: var(--space-2);
    padding: 9px 12px;
    font-size: var(--text-xs);
  }
}

/* ============================================================
   动效偏好
   ============================================================ */
@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;
    scroll-behavior: auto !important;
  }

  html.js-ready [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .paper:hover,
  .btn:hover,
  .feedback-anchor:hover { transform: none; }
}