/* ==========================================================================
   MELBET 中文专区 · 共享样式 /assets/site.css
   骨架：框架式导轨导航 + 珠宝色分区 + 展览画册式留白节奏
   ========================================================================== */

/* ---------- 1. 变量 ---------- */
:root {
  /* 深色骨架 */
  --ink: #060A16;
  --ink-2: #0D1530;

  /* 珠宝色分区 */
  --indigo: #1A2050;
  --teal: #07332F;
  --wine: #4A1526;

  /* 交互色 */
  --blue: #2F6BFF;
  --blue-soft: #8FB4FF;
  --cyan: #29F2DC;
  --orange: #FF8B3D;
  --orange-soft: #FFC79B;

  /* 文字与线条 */
  --text: #E9EEFB;
  --muted: #98A6C9;
  --rail-line: #2B3A6B;
  --rail-line-2: #3E5390;

  /* 尺寸 */
  --top-h: 60px;
  --rail-w: 240px;
  --rail-r: 52px;
  --frame-max: 1320px;

  /* 动效 */
  --ease: cubic-bezier(.2, .8, .2, 1);
  --t-fast: 120ms;
  --t-mid: 180ms;
  --t-slow: 240ms;

  /* 字体 */
  --sans: "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --narrow: "Oswald", "Archivo Narrow", "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC", Arial, sans-serif;
  --mono: ui-monospace, "JetBrains Mono", "IBM Plex Mono", SFMono-Regular, Menlo, Consolas, "Courier New", monospace;
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  min-height: 100vh;
  padding-top: var(--top-h);
  font-family: var(--sans);
  font-size: 16px;
  font-weight: 500;
  line-height: 1.9;
  color: var(--text);
  background-color: var(--ink);
  background-image:
    radial-gradient(1100px 620px at 6% -10%, rgba(26, 32, 80, .92), transparent 62%),
    radial-gradient(880px 520px at 96% 2%, rgba(7, 51, 47, .62), transparent 60%),
    radial-gradient(720px 480px at 38% 108%, rgba(74, 21, 38, .45), transparent 66%),
    linear-gradient(180deg, #060A16 0%, #0A1024 46%, #060A16 100%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(43, 58, 107, .55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(43, 58, 107, .55) 1px, transparent 1px);
  background-size: 72px 72px;
  opacity: .18;
}

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

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -.02em;
  color: var(--text);
}

p { margin: 0; }

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

a {
  color: var(--blue-soft);
  text-decoration: none;
  transition: color var(--t-fast) var(--ease);
}

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

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

button { -webkit-appearance: none; appearance: none; }

hr {
  border: 0;
  border-top: 2px solid var(--rail-line);
  margin: 0;
}

::selection {
  background: var(--cyan);
  color: #04121A;
}

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

main {
  display: block;
  position: relative;
  z-index: 1;
}

/* ---------- 3. 通用排版与容器 ---------- */
.container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--frame-max);
  margin: 0 auto;
  padding: 0 20px;
}

@media (min-width: 768px) {
  .container { padding: 0 28px; }
}

@media (min-width: 1100px) {
  .container { padding: 0 40px; }
}

.section {
  position: relative;
  z-index: 1;
  padding: 56px 0;
}

.section--tight { padding: 36px 0; }
.section--wide { padding: 68px 0; }

@media (min-width: 900px) {
  .section { padding: 80px 0; }
  .section--tight { padding: 48px 0; }
  .section--wide { padding: 104px 0; }
}

.rule {
  height: 2px;
  width: 100%;
  background: var(--rail-line);
  border: 0;
}

.rule--accent {
  background: linear-gradient(90deg, var(--blue), var(--cyan) 45%, transparent);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: currentColor;
}

.lead {
  font-size: 17px;
  line-height: 1.85;
  font-weight: 500;
  color: var(--blue-soft);
}

@media (min-width: 900px) {
  .lead { font-size: 19px; }
}

.prose {
  max-width: 68ch;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--text);
}

.prose p { margin: 0 0 1.35em; }
.prose p:last-child { margin-bottom: 0; }

.prose h2 {
  margin: 1.8em 0 .7em;
  font-size: 26px;
}

.prose h3 {
  margin: 1.6em 0 .6em;
  font-size: 20px;
}

.prose ul, .prose ol {
  margin: 0 0 1.35em;
  padding-left: 0;
}

.prose ul li, .prose ol li {
  position: relative;
  padding-left: 26px;
  margin-bottom: .55em;
}

.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 12px;
  height: 2px;
  background: var(--cyan);
}

.prose ol { counter-reset: proseList; }

.prose ol li::before {
  counter-increment: proseList;
  content: counter(proseList, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--cyan);
  letter-spacing: .08em;
}

.note {
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.8;
  letter-spacing: .06em;
  color: var(--muted);
}

.mono {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .08em;
}

.vert-label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .3em;
  color: var(--muted);
  writing-mode: vertical-rl;
  text-orientation: mixed;
}

/* ---------- 4. 栅格 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 24px;
}

.grid--gap-sm { gap: 14px; }
.grid--gap-lg { gap: 32px; }

@media (min-width: 900px) {
  .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; }
  .span-8 { grid-column: span 8; }
  .span-12 { grid-column: span 12; }
}

.stack > * + * { margin-top: 18px; }
.stack--lg > * + * { margin-top: 32px; }

/* ---------- 5. 珠宝色分区与卡片 ---------- */
.zone-indigo,
.zone-teal,
.zone-wine,
.zone-blue {
  position: relative;
  z-index: 1;
  border: 2px solid var(--rail-line);
  border-radius: 2px;
  box-shadow: 10px 10px 0 rgba(6, 10, 22, .85);
  padding: 28px 22px;
}

.zone-indigo { background: linear-gradient(158deg, rgba(26, 32, 80, .92), rgba(13, 21, 48, .94)); }
.zone-teal { background: linear-gradient(158deg, rgba(7, 51, 47, .92), rgba(6, 12, 24, .94)); }
.zone-wine { background: linear-gradient(158deg, rgba(74, 21, 38, .9), rgba(6, 10, 22, .95)); }
.zone-blue { background: linear-gradient(158deg, rgba(47, 107, 255, .22), rgba(13, 21, 48, .95)); }

@media (min-width: 768px) {
  .zone-indigo, .zone-teal, .zone-wine, .zone-blue { padding: 36px 32px; }
}

.card {
  position: relative;
  display: block;
  padding: 22px;
  border: 2px solid var(--rail-line);
  border-radius: 2px;
  background: linear-gradient(160deg, rgba(26, 32, 80, .58), rgba(13, 21, 48, .88));
  box-shadow: 8px 8px 0 rgba(6, 10, 22, .85);
  color: var(--text);
  transition:
    transform var(--t-mid) var(--ease),
    border-color var(--t-mid) var(--ease),
    box-shadow var(--t-mid) var(--ease);
}

.card:hover,
.card:focus-visible {
  transform: translate(-2px, -2px);
  border-color: var(--cyan);
  box-shadow: 12px 12px 0 rgba(6, 10, 22, .9);
  color: var(--text);
}

.card--flat {
  background: rgba(13, 21, 48, .7);
  box-shadow: none;
}

.card--flat:hover { transform: none; box-shadow: none; }

.card--frame {
  background: transparent;
  box-shadow: none;
  border-color: var(--rail-line-2);
}

@media (min-width: 768px) {
  .card { padding: 26px; }
}

/* ---------- 6. 标签与数据 ---------- */
.tag {
  display: inline-block;
  padding: 4px 9px;
  border: 2px solid var(--rail-line);
  border-radius: 2px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--muted);
  white-space: nowrap;
}

.tag--cyan { border-color: var(--cyan); color: var(--cyan); }
.tag--orange { border-color: var(--orange); color: var(--orange-soft); }
.tag--blue { border-color: var(--blue); color: var(--blue-soft); }

.stat { display: block; }

.stat__num {
  display: block;
  font-family: var(--mono);
  font-size: 28px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -.01em;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}

.stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 7. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 2px solid var(--rail-line);
  border-radius: 2px;
  background-color: rgba(13, 21, 48, .9);
  background-image:
    linear-gradient(135deg, rgba(26, 32, 80, .85), rgba(7, 51, 47, .45)),
    repeating-linear-gradient(90deg, rgba(43, 58, 107, .5) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(0deg, rgba(43, 58, 107, .5) 0 1px, transparent 1px 34px);
  box-shadow: 8px 8px 0 rgba(6, 10, 22, .85);
  transition: border-color var(--t-mid) var(--ease), transform var(--t-mid) var(--ease);
}

.media-frame:hover { border-color: var(--cyan); }

.media-frame > img,
.media-frame > svg,
.media-frame > picture > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--strip { aspect-ratio: 21 / 9; }

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 10px 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--text);
  background: linear-gradient(180deg, rgba(6, 10, 22, 0), rgba(6, 10, 22, .92));
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 40px;
  padding: 0 16px;
  border: 2px solid transparent;
  border-radius: 2px;
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  white-space: nowrap;
  cursor: pointer;
  transition:
    background-color var(--t-fast) var(--ease),
    border-color var(--t-fast) var(--ease),
    color var(--t-fast) var(--ease),
    transform var(--t-fast) var(--ease),
    box-shadow var(--t-fast) var(--ease);
}

.btn--primary {
  background-color: var(--blue);
  border-color: var(--blue);
  color: #FFFFFF;
  box-shadow: 4px 4px 0 rgba(41, 242, 220, .28);
}

.btn--primary:hover {
  background-color: #4A80FF;
  border-color: #4A80FF;
  color: #FFFFFF;
  transform: translate(-1px, -1px);
  box-shadow: 6px 6px 0 rgba(41, 242, 220, .42);
}

.btn--ghost {
  background-color: transparent;
  border-color: var(--rail-line-2);
  color: var(--text);
}

.btn--ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.btn--collect {
  background-color: transparent;
  border-color: var(--orange);
  color: var(--orange-soft);
}

.btn--collect:hover {
  background-color: rgba(255, 139, 61, .12);
  color: #FFFFFF;
}

.btn--collect[aria-pressed="true"] {
  background-color: var(--orange);
  border-color: var(--orange);
  color: #1A0D04;
}

.btn__dot {
  width: 8px;
  height: 8px;
  flex: 0 0 auto;
  border-radius: 50%;
  background-color: currentColor;
}

@keyframes collectPulse {
  0% { box-shadow: 0 0 0 0 rgba(255, 139, 61, .55); }
  100% { box-shadow: 0 0 0 16px rgba(255, 139, 61, 0); }
}

.btn--collect.is-pulse {
  animation: collectPulse .55s var(--ease) 1;
}

/* ---------- 9. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 400;
  padding: 10px 16px;
  border: 2px solid #04121A;
  border-radius: 2px;
  background-color: var(--cyan);
  color: #04121A;
  font-size: 14px;
  font-weight: 700;
  transform: translateY(-200%);
  transition: transform var(--t-fast) var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
  color: #04121A;
}

/* ---------- 10. 顶部横梁与品牌 ---------- */
.site-header {
  position: relative;
  z-index: 60;
}

.frame-top {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 80;
  height: var(--top-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 16px;
  background: linear-gradient(180deg, #0B1226 0%, #070C1B 100%);
  border-bottom: 2px solid var(--rail-line);
}

@media (min-width: 768px) {
  .frame-top { padding: 0 22px; }
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  color: var(--text);
}

.brand:hover { color: #FFFFFF; }

.brand__mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 2px solid var(--blue);
  border-radius: 2px;
  background: linear-gradient(140deg, rgba(47, 107, 255, .38), rgba(41, 242, 220, .16));
  box-shadow: 3px 3px 0 rgba(6, 10, 22, .9);
  font-family: var(--mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0;
  color: var(--cyan);
}

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

.brand__name {
  font-family: var(--narrow);
  font-size: 16px;
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: .06em;
  color: var(--text);
}

.brand__line {
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.5;
  letter-spacing: .1em;
  color: var(--muted);
  white-space: nowrap;
}

.brand--footer { margin-bottom: 16px; }

@media (max-width: 640px) {
  .brand__line { display: none; }
}

.frame-top__actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

@media (max-width: 860px) {
  .frame-top__actions .btn--primary { display: none; }
}

/* ---------- 11. 框架式导轨导航 ---------- */
.frame-nav {
  position: fixed;
  top: var(--top-h);
  left: 0;
  bottom: 0;
  z-index: 70;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 14px 20px;
  overflow-y: auto;
  overscroll-behavior: contain;
  background: linear-gradient(180deg, #0A1024 0%, #0D1530 55%, #101A3C 100%);
  border-right: 2px solid var(--rail-line);
}

.frame-nav__caption {
  padding: 0 12px 12px;
  border-bottom: 2px solid var(--rail-line);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .28em;
  text-transform: uppercase;
  color: var(--muted);
}

.frame-nav__list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 4px;
}

.frame-nav__link {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  align-items: center;
  gap: 10px;
  padding: 12px;
  border: 2px solid transparent;
  border-radius: 2px;
  color: var(--text);
  font-size: 15px;
  font-weight: 600;
  transition:
    background-color var(--t-fast) var(--ease),
    border-color var(--t-fast) var(--ease),
    color var(--t-fast) var(--ease);
}

.frame-nav__link:hover {
  background-color: rgba(47, 107, 255, .12);
  border-color: var(--rail-line);
  color: #FFFFFF;
}

.frame-nav__num {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .08em;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
  transition: color var(--t-fast) var(--ease);
}

.frame-nav__link:hover .frame-nav__num { color: var(--cyan); }

.frame-nav__link[aria-current="page"] {
  background: linear-gradient(90deg, rgba(47, 107, 255, .32), rgba(47, 107, 255, .06));
  border-color: var(--blue);
  box-shadow: inset 3px 0 0 var(--cyan);
  color: #FFFFFF;
}

.frame-nav__link[aria-current="page"] .frame-nav__num { color: var(--cyan); }

.frame-nav__label {
  min-width: 0;
  overflow-wrap: anywhere;
}

.frame-nav__foot {
  margin-top: auto;
  padding: 14px 12px 0;
  border-top: 2px solid var(--rail-line);
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.8;
  letter-spacing: .05em;
  color: var(--muted);
}

/* ---------- 12. 右侧装饰导轨 ---------- */
.frame-rail {
  position: fixed;
  top: var(--top-h);
  right: 0;
  bottom: 0;
  z-index: 50;
  width: var(--rail-r);
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 22px;
  background: linear-gradient(180deg, #080D1E 0%, #0B1226 100%);
  border-left: 2px solid var(--rail-line);
}

.frame-rail__mark {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .24em;
  color: var(--rail-line-2);
}

.frame-rail__line {
  width: 2px;
  height: 110px;
  background: linear-gradient(180deg, var(--blue), var(--cyan));
}

.frame-rail__tag {
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .3em;
  color: var(--muted);
}

/* ---------- 13. 移动导航按钮 ---------- */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 40px;
  padding: 0 12px;
  border: 2px solid var(--rail-line);
  border-radius: 2px;
  background-color: transparent;
  color: var(--text);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .06em;
  cursor: pointer;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}

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

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

.nav-toggle__bars {
  display: grid;
  gap: 4px;
}

.nav-toggle__bar {
  display: block;
  width: 16px;
  height: 2px;
  background-color: currentColor;
}

.nav-toggle__text { white-space: nowrap; }

@media (max-width: 420px) {
  .nav-toggle__text { display: none; }
}

/* ---------- 14. 滚动进度 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 200;
  height: 3px;
  pointer-events: none;
  background-color: transparent;
}

.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--blue), var(--cyan));
  transition: width .08s linear;
}

/* ---------- 15. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 14px;
  border: 2px solid var(--rail-line);
  border-radius: 2px;
  background-color: rgba(13, 21, 48, .94);
  color: var(--text);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition:
    opacity var(--t-mid) var(--ease),
    transform var(--t-mid) var(--ease),
    visibility var(--t-mid),
    border-color var(--t-fast) var(--ease),
    color var(--t-fast) var(--ease);
}

.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.to-top:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.to-top__arrow {
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1;
}

@media (max-width: 560px) {
  .to-top__text { display: none; }
}

/* ---------- 16. 页脚 ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: 40px;
  padding: 56px 20px 22px;
  border-top: 2px solid var(--rail-line);
  background: linear-gradient(180deg, #0A1024 0%, #060A16 72%);
}

@media (min-width: 768px) {
  .site-footer { padding: 60px 28px 24px; }
}

@media (min-width: 1100px) {
  .site-footer { padding: 72px 40px 26px; }
}

.site-footer__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px 28px;
  max-width: var(--frame-max);
  margin: 0 auto;
}

@media (min-width: 640px) {
  .site-footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 1100px) {
  .site-footer__grid { grid-template-columns: 1.5fr 1fr 1fr 1.35fr; }
}

.site-footer__brand { min-width: 0; }

.site-footer__note {
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

.site-footer__col { min-width: 0; }

.site-footer__title {
  position: relative;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--rail-line);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .16em;
  color: var(--text);
}

.site-footer__title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 38px;
  height: 2px;
  background-color: var(--cyan);
}

.site-footer__list li { margin: 0; }

.site-footer__list a {
  display: inline-block;
  padding: 5px 0;
  font-size: 14px;
  color: var(--muted);
  transition: color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}

.site-footer__list a:hover {
  color: var(--cyan);
  transform: translateX(3px);
}

.site-footer__contact li {
  padding: 6px 0;
}

.site-footer__label {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--rail-line-2);
}

.site-footer__value {
  display: block;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text);
  overflow-wrap: anywhere;
}

.site-footer__legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  max-width: var(--frame-max);
  margin: 40px auto 0;
  padding-top: 18px;
  border-top: 2px solid var(--rail-line);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--muted);
}

/* ---------- 17. 显现动效 ---------- */
html.is-js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity .5s var(--ease),
    transform .5s var(--ease);
}

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

/* ---------- 18. 桌面端框架偏移 ---------- */
@media (min-width: 1100px) {
  :root {
    --top-h: 68px;
    --rail-w: 236px;
  }

  body {
    padding-left: var(--rail-w);
    padding-right: var(--rail-r);
  }

  .frame-nav {
    padding: 28px 16px 22px;
  }

  .frame-rail {
    display: flex;
  }

  .nav-toggle {
    display: none;
  }

  .to-top {
    right: calc(var(--rail-r) + 20px);
  }
}

@media (min-width: 1400px) {
  :root { --rail-w: 264px; }
}

/* ---------- 19. 平板与移动端导航折叠 ---------- */
@media (max-width: 1099px) {
  .frame-nav {
    top: var(--top-h);
    left: 0;
    right: 0;
    bottom: auto;
    width: auto;
    max-height: calc(100vh - var(--top-h));
    padding: 14px 16px 20px;
    border-right: 0;
    border-bottom: 2px solid var(--rail-line);
    box-shadow: 0 24px 48px rgba(0, 0, 0, .55);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition:
      opacity var(--t-mid) var(--ease),
      transform var(--t-mid) var(--ease),
      visibility var(--t-mid);
  }

  .frame-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .frame-nav__caption { padding-bottom: 10px; }

  .frame-nav__link { padding: 11px 12px; }

  .frame-nav__foot {
    margin-top: 12px;
    padding-top: 12px;
  }
}

/* ---------- 20. 无障碍与降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

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

  .to-top {
    transform: none;
  }
}