/* ============================================================
   老版本棋牌 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 头部 / 页脚 / 通用组件
   ============================================================ */

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

:root {
  --ink: #0B1410;
  --deep: #12241C;
  --panel: #1C3A2C;
  --panel-up: #21473400;
  --pine: #2C5A42;
  --gilt: #C8A24A;
  --gilt-lift: #E4C878;
  --cinnabar: #B23A2E;
  --cinnabar-lift: #D9604E;
  --amber: #E8A657;
  --paper: #EFE6D4;
  --paper-dim: #D8CBB2;
  --inktype: #101A14;
  --sage: #8FA396;

  --rail-w: 184px;
  --gap: 24px;
  --pad: clamp(20px, 4vw, 56px);
  --band: 8px;

  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --t-fast: 120ms ease;
  --t-mid: 200ms ease;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 72px;
}

body {
  margin: 0;
  padding-top: var(--band);
  min-height: 100vh;
  display: grid;
  grid-template-columns: var(--rail-w) minmax(0, 1fr);
  grid-template-areas:
    "rail canvas"
    "foot foot";
  grid-template-rows: minmax(0, 1fr) auto;
  background-color: var(--deep);
  background-image:
    linear-gradient(to right, rgba(44, 90, 66, 0.20) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(44, 90, 66, 0.20) 1px, transparent 1px);
  background-size: 48px 48px;
  color: var(--paper);
  font-family: var(--sans);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::before {
  content: "";
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--band);
  z-index: 120;
  background-color: var(--gilt);
  background-image: repeating-linear-gradient(90deg, rgba(11, 20, 16, 0.45) 0 1px, transparent 1px 16px);
  border-bottom: 1px solid rgba(11, 20, 16, 0.6);
}

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

h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.18;
  margin: 0 0 0.5em;
  color: var(--paper);
}
h1 { font-size: clamp(40px, 7vw, 88px); }
h2 { font-size: clamp(28px, 4vw, 46px); }
h3 { font-size: clamp(21px, 2.6vw, 29px); }
h4 { font-size: 20px; }

p { margin: 0 0 1.2em; }
ul, ol { margin: 0 0 1.2em; padding-left: 1.2em; }
li { margin-bottom: 0.4em; }
a { color: inherit; }
hr { border: 0; }

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

:focus-visible {
  outline: 2px solid var(--gilt-lift);
  outline-offset: 2px;
  box-shadow: 0 0 0 3px rgba(11, 20, 16, 0.9);
}

/* ---------- skip link ---------- */
.skip-to-main {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  transform: translateY(-180%);
  padding: 12px 18px;
  background: var(--gilt);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  text-decoration: none;
  border: 2px solid var(--ink);
  transition: transform var(--t-mid);
}
.skip-to-main:focus { transform: translateY(0); }

/* ---------- 主体画布 ---------- */
#main-content {
  grid-area: canvas;
  min-width: 0;
  padding: 0 var(--pad);
}

/* ---------- 左侧时间轴头部 ---------- */
.site-header {
  grid-area: rail;
  position: sticky;
  top: var(--band);
  align-self: start;
  z-index: 40;
  height: calc(100vh - var(--band));
  height: calc(100dvh - var(--band));
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--ink);
  border-right: 2px solid var(--pine);
}

.brand-block {
  display: block;
  padding: 20px 16px 18px;
  border-bottom: 2px solid var(--pine);
  text-decoration: none;
  transition: background-color var(--t-fast), border-color var(--t-fast);
}
.brand-block:hover { background: var(--deep); border-bottom-color: var(--gilt); }

.brand-mark {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--gilt);
  margin-bottom: 8px;
}
.brand-name {
  display: block;
  font-family: var(--serif);
  font-weight: 900;
  font-size: 23px;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--paper);
}
.brand-sub {
  display: block;
  margin-top: 7px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  line-height: 1.5;
  color: var(--sage);
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 12px;
  background: var(--deep);
  color: var(--gilt);
  border: 2px solid var(--pine);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  cursor: pointer;
  transition: background-color var(--t-fast), border-color var(--t-fast), color var(--t-fast);
}
.nav-toggle:hover { background: var(--panel); border-color: var(--gilt); color: var(--gilt-lift); }

.nav-toggle-bars { display: block; width: 16px; }
.nav-toggle-bars i {
  display: block;
  height: 2px;
  margin: 3px 0;
  background: currentColor;
  transition: transform var(--t-fast), opacity var(--t-fast);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars i:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars i:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars i:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

.rail-pin {
  display: block;
  padding: 14px 16px;
  text-decoration: none;
  background: var(--deep);
  border-bottom: 2px solid var(--pine);
  transition: background-color var(--t-fast), border-color var(--t-fast);
}
.rail-pin-label {
  display: block;
  font-family: var(--serif);
  font-weight: 900;
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--gilt);
  transition: color var(--t-fast);
}
.rail-pin-note {
  display: block;
  margin-top: 3px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--sage);
}
.rail-pin:hover { background: var(--panel); border-bottom-color: var(--gilt); }
.rail-pin:hover .rail-pin-label { color: var(--gilt-lift); }

.rail-nav {
  position: relative;
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  padding: 16px 0 18px;
}

.rail-list { list-style: none; margin: 0; padding: 0; }
.rail-list > li { margin: 0; }

.rail-link {
  display: grid;
  grid-template-columns: 20px 26px minmax(0, 1fr);
  align-items: center;
  gap: 8px;
  padding: 11px 16px 11px 16px;
  border-left: 3px solid transparent;
  color: var(--sage);
  font-size: 15px;
  text-decoration: none;
  transition: background-color var(--t-fast), color var(--t-fast), border-color var(--t-fast);
}
.rail-tick {
  width: 14px;
  height: 2px;
  background: var(--pine);
  transition: width var(--t-fast), background-color var(--t-fast);
}
.rail-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--pine);
  transition: color var(--t-fast);
}
.rail-text { letter-spacing: 0.02em; }

.rail-link:hover {
  background: var(--panel);
  color: var(--paper);
  border-left-color: var(--gilt);
}
.rail-link:hover .rail-tick { width: 20px; background: var(--gilt-lift); }
.rail-link:hover .rail-num { color: var(--gilt); }

.rail-link[aria-current="page"] {
  background: var(--panel);
  color: var(--paper);
  border-left-color: var(--gilt);
}
.rail-link[aria-current="page"] .rail-tick { width: 20px; background: var(--gilt-lift); }
.rail-link[aria-current="page"] .rail-num { color: var(--gilt-lift); }

.rail-foot {
  border-top: 2px solid var(--pine);
}
.rail-foot .rail-pin { border-bottom: 0; }

/* ---------- 页脚 ---------- */
.site-footer {
  grid-area: foot;
  background: var(--ink);
  border-top: 2px solid var(--pine);
  color: var(--paper);
}

.foot-top {
  display: grid;
  grid-template-columns: minmax(0, 300px) minmax(0, 1fr);
  gap: 40px;
  padding: 44px var(--pad) 34px;
  border-bottom: 1px solid var(--pine);
}

.foot-brand-name {
  font-family: var(--serif);
  font-weight: 900;
  font-size: 30px;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--paper);
}
.foot-brand-sub {
  margin: 10px 0 0;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--sage);
}

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

.foot-col-title {
  font-family: var(--serif);
  font-weight: 900;
  font-size: 15px;
  letter-spacing: 0.02em;
  margin: 0 0 14px;
  color: var(--gilt);
}

.foot-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.foot-links > li { margin: 0; }
.foot-links a {
  font-size: 15px;
  color: var(--sage);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast), border-color var(--t-fast);
}
.foot-links a:hover { color: var(--gilt-lift); border-bottom-color: var(--gilt); }

.foot-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 36px;
  padding: 20px var(--pad);
  border-bottom: 1px solid var(--pine);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--sage);
}
.foot-contact-item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0;
}
.foot-k { color: var(--gilt); }

.foot-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px;
  padding: 18px var(--pad);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--sage);
}
.foot-compliance, .foot-year { margin: 0; }
.foot-year { color: var(--gilt); }

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 22px;
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-decoration: none;
  border: 2px solid var(--gilt);
  background: transparent;
  color: var(--gilt);
  box-shadow: 5px 5px 0 var(--ink);
  cursor: pointer;
  transition: background-color var(--t-fast), color var(--t-fast), border-color var(--t-fast),
              transform var(--t-fast), box-shadow var(--t-fast);
}
.btn:hover {
  background: var(--gilt);
  color: var(--ink);
  border-color: var(--gilt-lift);
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--ink);
}
.btn--solid { background: var(--gilt); color: var(--ink); }
.btn--solid:hover { background: var(--gilt-lift); border-color: var(--gilt-lift); }
.btn--ghost { border-color: var(--pine); color: var(--paper); }
.btn--ghost:hover { background: var(--panel); border-color: var(--gilt); color: var(--gilt-lift); }

/* ---------- 面包屑 ---------- */
.crumb { padding: 22px 0 0; }
.crumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--sage);
}
.crumb-list > li { margin: 0; }
.crumb-list > li + li::before { content: "/"; margin-right: 8px; color: var(--pine); }
.crumb-list a {
  color: var(--sage);
  text-decoration: none;
  border-bottom: 1px solid var(--pine);
  transition: color var(--t-fast), border-color var(--t-fast);
}
.crumb-list a:hover { color: var(--gilt-lift); border-bottom-color: var(--gilt); }
.crumb-list [aria-current="page"] { color: var(--gilt); }

/* ---------- 文本容器 ---------- */
.prose {
  max-width: 72ch;
  font-size: 17px;
  line-height: 1.75;
  color: var(--paper);
}
.prose > p + p { margin-top: 1.2em; }
.prose a { color: var(--gilt-lift); }

.measure { max-width: 72ch; }

.lede {
  max-width: 60ch;
  font-size: clamp(18px, 2.2vw, 22px);
  line-height: 1.65;
  color: var(--paper);
}

/* ---------- 暖纸色阅读面 ---------- */
.paper {
  background: var(--paper);
  color: var(--inktype);
  border: 2px solid var(--ink);
  box-shadow: 8px 8px 0 rgba(11, 20, 16, 0.85);
  padding: 32px clamp(20px, 4vw, 48px);
}
.paper h1, .paper h2, .paper h3, .paper h4 { color: var(--inktype); }
.paper .prose, .paper .lede { color: var(--inktype); }
.paper a { color: var(--cinnabar); }
.paper a:hover { color: var(--inktype); }
.paper hr, .paper .rule { background: var(--paper-dim); }

/* ---------- 蓝图网格 ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gap);
}
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }

/* ---------- 章节 ---------- */
.section { padding: 56px 0; }
.section--tight { padding: 32px 0; }
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 16px;
  padding-bottom: 12px;
  margin-bottom: 26px;
  border-bottom: 2px solid var(--pine);
}
.section-head h2 { margin: 0; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--gilt);
}
.eyebrow::before { content: ""; width: 26px; height: 2px; background: var(--cinnabar); }

.annot-v {
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--sage);
}

.num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.05em;
}

.rule { height: 2px; background: var(--pine); margin: 0; }

/* ---------- 面板 ---------- */
.panel {
  background: var(--panel);
  border: 2px solid var(--pine);
  padding: 24px;
  transition: background-color var(--t-fast), border-color var(--t-fast);
}
.panel:hover { background: #214533; border-color: var(--gilt); }
.panel-title {
  font-family: var(--serif);
  font-weight: 900;
  font-size: 24px;
  letter-spacing: -0.02em;
  margin: 0 0 10px;
  color: var(--paper);
}

/* ---------- 折叠卡片 ---------- */
.fold {
  border: 2px solid var(--pine);
  background: var(--deep);
  transition: border-color var(--t-fast);
}
.fold + .fold { margin-top: -2px; }
.fold:hover { border-color: var(--gilt); }
.fold > summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  cursor: pointer;
  list-style: none;
  font-family: var(--serif);
  font-weight: 900;
  font-size: 20px;
  letter-spacing: -0.01em;
  color: var(--paper);
  transition: background-color var(--t-fast), color var(--t-fast);
}
.fold > summary::-webkit-details-marker { display: none; }
.fold > summary::before {
  content: "";
  width: 12px;
  height: 2px;
  background: var(--gilt);
  flex: 0 0 auto;
  transition: background-color var(--t-fast);
}
.fold > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--mono);
  font-size: 18px;
  color: var(--gilt);
}
.fold[open] > summary { background: var(--panel); color: var(--gilt-lift); }
.fold[open] > summary::before { background: var(--cinnabar); }
.fold[open] > summary::after { content: "-"; color: var(--cinnabar-lift); }
.fold > summary:hover { background: var(--panel); color: var(--gilt-lift); }
.fold-body {
  padding: 18px 20px 22px;
  border-top: 2px solid var(--pine);
}

/* ---------- 标签 ---------- */
.tag {
  display: inline-block;
  padding: 3px 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  border: 1px solid var(--gilt);
  color: var(--gilt);
}
.tag--red { border-color: var(--cinnabar); color: var(--cinnabar-lift); }

/* ---------- 图片容器 ---------- */
.figure {
  position: relative;
  display: block;
  margin: 0;
  border: 2px solid var(--pine);
  background: var(--panel);
  overflow: hidden;
  transition: border-color var(--t-fast);
}
.figure:hover { border-color: var(--gilt); }
.figure img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}
.figure--tall img { aspect-ratio: 4 / 5; }
.figure--wide img { aspect-ratio: 21 / 9; }

.figure-media {
  width: 100%;
  aspect-ratio: 16 / 10;
  background-color: var(--panel);
  background-image: repeating-linear-gradient(45deg, rgba(44, 90, 66, 0.55) 0 1px, transparent 1px 12px);
}
.figure--tall .figure-media { aspect-ratio: 4 / 5; }
.figure--wide .figure-media { aspect-ratio: 21 / 9; }

.figure figcaption {
  padding: 10px 14px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--sage);
  border-top: 1px solid var(--pine);
}

.figure-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

/* ---------- 时间轴 ---------- */
.timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 30px;
  border-left: 2px solid var(--pine);
}
.timeline > li {
  position: relative;
  padding: 0 0 24px;
  margin: 0;
}
.timeline > li::before {
  content: "";
  position: absolute;
  left: -37px;
  top: 12px;
  width: 14px;
  height: 2px;
  background: var(--gilt);
}
.timeline > li:last-child { padding-bottom: 0; }

/* ---------- 数据读出 ---------- */
.metric {
  display: block;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.05;
  letter-spacing: 0.02em;
  color: var(--amber);
}
.metric-label {
  display: block;
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--sage);
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 130;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 16px;
  background: var(--ink);
  color: var(--gilt);
  border: 2px solid var(--gilt);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--t-mid), transform var(--t-mid), visibility 0s linear 200ms,
              background-color var(--t-fast), color var(--t-fast);
}
.back-to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition: opacity var(--t-mid), transform var(--t-mid), visibility 0s linear 0s,
              background-color var(--t-fast), color var(--t-fast);
}
.back-to-top:hover { background: var(--gilt); color: var(--ink); }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1180px) {
  :root { --rail-w: 164px; }
  .rail-link { font-size: 14px; padding: 10px 12px; }
  .brand-name { font-size: 21px; }
}

@media (max-width: 960px) {
  body {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas:
      "rail"
      "canvas"
      "foot";
    grid-template-rows: auto minmax(0, 1fr) auto;
  }

  .site-header {
    position: sticky;
    top: var(--band);
    height: auto;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand toggle"
      "pin pin"
      "foot foot";
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    border-right: 0;
    border-bottom: 2px solid var(--pine);
    overflow: visible;
  }

  .brand-block {
    grid-area: brand;
    padding: 4px 8px 4px 0;
    border-bottom: 0;
    min-width: 0;
  }
  .brand-block:hover { background: transparent; border-bottom-color: transparent; }
  .brand-mark { font-size: 10px; letter-spacing: 0.24em; margin-bottom: 3px; }
  .brand-name { font-size: 19px; }
  .brand-sub { display: none; }

  .nav-toggle { grid-area: toggle; display: inline-flex; }

  .rail-pin {
    padding: 9px 12px;
    border: 2px solid var(--gilt);
    background: transparent;
    text-align: center;
  }
  .rail-pin-note { display: none; }
  .rail-pin-label { font-size: 14px; }
  .rail-pin:hover { background: var(--panel); border-color: var(--gilt-lift); }

  .site-header > .rail-pin { grid-area: pin; }
  .rail-foot { grid-area: foot; border-top: 4px solid var(--deep); }
  .rail-foot .rail-pin { border: 2px solid var(--gilt); }

  .rail-nav {
    position: fixed;
    left: 0; right: 0; bottom: 0;
    top: auto;
    z-index: 150;
    max-height: 78vh;
    overflow-y: auto;
    padding: 16px 0 22px;
    background: var(--ink);
    border-top: 2px solid var(--gilt);
    visibility: hidden;
    transform: translateY(101%);
    transition: transform 220ms ease, visibility 0s linear 220ms;
  }
  .rail-nav[data-open] {
    visibility: visible;
    transform: translateY(0);
    transition: transform 220ms ease, visibility 0s linear 0s;
  }
  .rail-link { padding: 14px 20px; font-size: 16px; }

  #main-content { padding: 0 20px; }

  .foot-top {
    grid-template-columns: minmax(0, 1fr);
    gap: 30px;
    padding: 34px 20px 28px;
  }
  .foot-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .foot-contact { flex-direction: column; gap: 8px; padding: 18px 20px; }
  .foot-base { padding: 16px 20px; }

  .section { padding: 40px 0; }
}

@media (max-width: 640px) {
  .grid-12 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9 { grid-column: span 4; }
  .col-12 { grid-column: span 4; }

  .foot-grid { grid-template-columns: minmax(0, 1fr); }

  .back-to-top { right: 12px; bottom: 12px; padding: 10px 12px; }
  .back-to-top span { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}