/* ==========================================================================
   博万主站 · 共享样式 /assets/site.css
   档案室 × 野外考察笔记：砂白阅读基底、红土与松绿纵向分区、矿物蓝只做状态
   ========================================================================== */

/* 1. Reset ---------------------------------------------------------------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 110px;
}

body,
figure,
blockquote,
dl,
dd,
p,
h1,
h2,
h3,
h4,
ul,
ol {
  margin: 0;
}

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

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

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

a { color: inherit; }

main { display: block; }

/* 2. 变量 ---------------------------------------------------------------- */
:root {
  --sand-050: #F6EFE4;
  --sand-100: #EDE2D2;
  --laterite-700: #6E2E1C;
  --laterite-900: #3A1B12;
  --laterite-500: #A0472B;
  --laterite-200: #E4C7B6;
  --pine-900: #14301F;
  --pine-700: #1F4A31;
  --pine-300: #7FA98C;
  --mineral-600: #1F5D7A;
  --ink-900: #1A1714;
  --ink-500: #5C534B;

  --font-display: "HarmonyOS Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Source Han Serif SC", "Noto Serif SC", "Songti SC", Georgia, serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", "Roboto Mono", Consolas, monospace;

  --rail-w: 64px;
  --header-h: 76px;
  --header-h-compact: 48px;
  --gutter: clamp(16px, 4vw, 48px);
  --section-pad: clamp(52px, 7vw, 116px);
  --maxw: 1280px;
  --radius: 2px;
  --shadow-hard: 6px 6px 0 rgba(58, 27, 18, 0.18);
  --shadow-card: 4px 4px 0 var(--laterite-900);
  --line-strong: 2px solid var(--laterite-900);
  --line-soft: 1px solid var(--laterite-200);
}

/* 3. 基础排版 ------------------------------------------------------------ */
body {
  background: var(--sand-050);
  color: var(--ink-900);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: 0.01em;
}

h1 { font-size: clamp(30px, 4.6vw, 54px); }
h2 { font-size: clamp(24px, 3vw, 36px); }
h3 { font-size: clamp(19px, 2vw, 24px); }
h4 { font-size: 17px; }

p { text-wrap: pretty; }

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

:focus-visible {
  outline: 3px solid var(--mineral-600);
  outline-offset: 2px;
}

.site-footer :focus-visible { outline-color: var(--sand-050); }

::selection {
  background: var(--laterite-700);
  color: var(--sand-050);
}

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

/* 4. 布局与容器 ---------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: var(--section-pad);
}

.section--paper { background: var(--sand-050); }
.section--sand100 { background: var(--sand-100); }

.section--laterite {
  background: var(--laterite-700);
  color: var(--sand-050);
}

.section--pine {
  background: var(--pine-900);
  color: var(--sand-050);
}

.section--laterite h1,
.section--laterite h2,
.section--laterite h3,
.section--pine h1,
.section--pine h2,
.section--pine h3 { color: var(--sand-050); }

.band { height: 10px; background: var(--laterite-700); }
.band--pine { background: var(--pine-700); }
.band--sand { background: var(--sand-100); }
.band--thin { height: 6px; }
.band--thick { height: 14px; }

.grid12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}

.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-12 { grid-column: span 12; }

.aside-note {
  grid-column: span 3;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-500);
  border-top: 2px solid var(--laterite-200);
  padding-top: 12px;
}

.prose {
  max-width: 68ch;
  line-height: 1.85;
}

.prose p + p { margin-top: 1.1em; }
.prose ul,
.prose ol { padding-left: 1.2em; list-style: disc; }
.prose li + li { margin-top: 0.4em; }

.lede {
  font-family: var(--font-serif);
  font-size: clamp(17px, 1.6vw, 21px);
  line-height: 1.7;
  color: var(--ink-500);
  max-width: 62ch;
}

.section--laterite .lede,
.section--pine .lede { color: rgba(246, 239, 228, 0.82); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--laterite-500);
}

.section--laterite .eyebrow,
.section--pine .eyebrow { color: var(--laterite-200); }

.rule {
  border: 0;
  border-top: var(--line-soft);
  margin: 0;
}

/* 5. 章节头 -------------------------------------------------------------- */
.section-head {
  display: grid;
  gap: 16px;
  max-width: 78ch;
  margin-bottom: clamp(28px, 4vw, 56px);
}

.section-head__num {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(48px, 9vw, 120px);
  line-height: 0.86;
  letter-spacing: -0.04em;
  color: var(--laterite-700);
}

.section--laterite .section-head__num,
.section--pine .section-head__num { color: var(--laterite-200); }

.section-head__title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(24px, 3.2vw, 40px);
  line-height: 1.2;
}

.section-head__lead { max-width: 62ch; color: var(--ink-500); }
.section--laterite .section-head__lead,
.section--pine .section-head__lead { color: rgba(246, 239, 228, 0.82); }

.section-head__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-500);
}

/* 6. 按钮 ---------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 22px;
  border: var(--line-strong);
  border-radius: var(--radius);
  background: var(--sand-100);
  color: var(--laterite-900);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  box-shadow: var(--shadow-card);
  cursor: pointer;
  transition: background 0.18s ease, color 0.18s ease, transform 0.12s ease, box-shadow 0.12s ease;
}

.btn:hover { background: var(--laterite-700); color: var(--sand-050); }

.btn:active {
  transform: translate(3px, 3px);
  box-shadow: 1px 1px 0 var(--laterite-900);
}

.btn--primary { background: var(--laterite-700); color: var(--sand-050); }
.btn--primary:hover { background: var(--laterite-900); }

.btn--ghost {
  background: transparent;
  border-color: var(--laterite-700);
  color: var(--laterite-700);
  box-shadow: none;
}

.btn--ghost:hover { background: var(--laterite-700); color: var(--sand-050); }

.btn--sm { padding: 9px 14px; font-size: 13px; }

/* 7. 面包屑 -------------------------------------------------------------- */
.breadcrumb {
  background: var(--sand-100);
  border-bottom: var(--line-soft);
  padding-block: 16px;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-500);
}

.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: 10px;
}

.breadcrumb__sep { color: var(--laterite-200); }

.breadcrumb__link {
  color: var(--laterite-500);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.breadcrumb__link:hover { border-bottom-color: var(--laterite-500); }

.breadcrumb [aria-current="page"] { color: var(--ink-900); }

/* 8. 索引卡 -------------------------------------------------------------- */
.card {
  background: var(--sand-050);
  border: var(--line-strong);
  border-radius: var(--radius);
  box-shadow: var(--shadow-hard);
  padding: clamp(18px, 2.2vw, 28px);
}

.card--index { background: var(--sand-100); }

.card--pine {
  background: var(--pine-900);
  color: var(--sand-050);
}

.card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 26px;
  letter-spacing: 0.02em;
  color: var(--laterite-500);
  margin-bottom: 8px;
}

.card__title {
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 8px;
}

.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-500);
}

.card__body { font-size: 15px; color: var(--ink-500); }

.card--pine .card__meta,
.card--pine .card__body { color: rgba(246, 239, 228, 0.75); }

/* 9. 数据表 -------------------------------------------------------------- */
.table-wrap {
  overflow-x: auto;
  background: var(--sand-050);
  border: var(--line-strong);
  box-shadow: var(--shadow-hard);
}

.data-table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  font-size: 14px;
}

.data-table caption {
  text-align: left;
  padding: 14px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-500);
  border-bottom: var(--line-soft);
}

.data-table th {
  background: var(--pine-700);
  color: var(--sand-050);
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 12px;
  letter-spacing: 0.1em;
  text-align: left;
  padding: 12px 16px;
}

.data-table td {
  padding: 12px 16px;
  border-bottom: var(--line-soft);
  vertical-align: top;
}

.data-table tbody tr:nth-child(even) { background: var(--sand-100); }
.data-table tbody tr:hover { background: var(--laterite-200); }

/* 10. 标签与数字锚点 ------------------------------------------------------ */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid var(--laterite-500);
  border-radius: var(--radius);
  background: var(--sand-050);
  color: var(--laterite-500);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
}

.tag--pine { border-color: var(--pine-700); color: var(--pine-700); }

.tag--active {
  background: var(--mineral-600);
  border-color: var(--mineral-600);
  color: var(--sand-050);
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  background: var(--laterite-200);
  border: var(--line-strong);
}

.stat {
  background: var(--sand-050);
  padding: 22px;
}

.stat__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(30px, 4vw, 52px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--laterite-700);
}

.stat__label {
  margin-top: 10px;
  font-size: 13px;
  color: var(--ink-500);
}

/* 11. 图片容器基础规则（页面阶段放图） ------------------------------------ */
.figure { margin: 0; }

.media-frame {
  position: relative;
  overflow: hidden;
  border: var(--line-strong);
  border-radius: var(--radius);
  background: var(--sand-100);
  box-shadow: var(--shadow-hard);
}

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

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

.media-frame__tag {
  position: absolute;
  left: 0;
  top: 0;
  z-index: 1;
  padding: 5px 10px;
  background: var(--laterite-900);
  color: var(--sand-050);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
}

.media-frame__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 10px 12px;
  background: rgba(26, 23, 20, 0.82);
  color: var(--sand-050);
  font-size: 12px;
  line-height: 1.6;
}

.figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-500);
}

/* 12. 滚动显现（JS 协议） ------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s cubic-bezier(0.2, 0.7, 0.3, 1),
              transform 0.55s cubic-bezier(0.2, 0.7, 0.3, 1);
}

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

/* 13. Skip link ---------------------------------------------------------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 200;
  padding: 10px 16px;
  background: var(--laterite-900);
  color: var(--sand-050);
  border: 2px solid var(--sand-050);
  font-family: var(--font-mono);
  font-size: 13px;
  text-decoration: none;
}

.skip-link:focus {
  left: 8px;
  top: 8px;
}

/* 14. 左侧档案脊线 -------------------------------------------------------- */
.site-rail {
  display: none;
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  z-index: 70;
  width: var(--rail-w);
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  background: var(--sand-100);
  border-right: 3px solid var(--laterite-700);
}

.site-rail__brand {
  writing-mode: vertical-rl;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--laterite-900);
}

.site-rail__meta {
  writing-mode: vertical-rl;
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--ink-500);
}

/* 15. 页头 --------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--sand-050);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 32px);
  min-height: var(--header-h);
  transition: min-height 0.25s ease;
}

.brand {
  flex: 0 0 auto;
  display: block;
  text-decoration: none;
  line-height: 1.15;
}

.brand__mark {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -0.01em;
  color: var(--laterite-900);
}

.brand__meta {
  display: block;
  margin-top: 3px;
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-500);
}

.primary-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
}

.primary-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(2px, 0.6vw, 12px);
}

.primary-nav__link {
  display: inline-block;
  padding: 8px 10px;
  border-bottom: 2px solid transparent;
  color: var(--ink-900);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  white-space: nowrap;
  text-decoration: none;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.primary-nav__link:hover {
  color: var(--laterite-700);
  border-bottom-color: var(--laterite-500);
}

.primary-nav__link[aria-current="page"] {
  color: var(--mineral-600);
  border-bottom-color: var(--mineral-600);
}

.nav-tools {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 14px;
  margin-left: auto;
}

.tool-note {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--ink-500);
}

.tool-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 11px;
  border: var(--line-strong);
  border-radius: var(--radius);
  background: var(--sand-100);
  color: var(--laterite-900);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  box-shadow: 3px 3px 0 var(--laterite-900);
  transition: background 0.18s ease, color 0.18s ease;
}

.tool-link:hover { background: var(--laterite-700); color: var(--sand-050); }
.tool-link__key { font-size: 13px; color: var(--mineral-600); }
.tool-link:hover .tool-link__key { color: var(--sand-050); }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  border: var(--line-strong);
  border-radius: var(--radius);
  background: var(--sand-100);
  color: var(--laterite-900);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  box-shadow: 3px 3px 0 var(--laterite-900);
  cursor: pointer;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  background: currentColor;
  transition: background 0.18s ease;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s ease;
}

.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-5px) rotate(-45deg); }

.scroll-progress {
  position: relative;
  height: 3px;
  background: var(--laterite-700);
  overflow: hidden;
}

.scroll-progress__fill {
  display: block;
  width: 0;
  height: 100%;
  background: var(--mineral-600);
  transition: width 0.12s linear;
}

.site-header[data-compact] .site-header__inner { min-height: var(--header-h-compact); }
.site-header[data-compact] .brand__meta { display: none; }
.site-header[data-compact] .tool-note { display: none; }
.site-header[data-compact] .tool-link__label { display: none; }

/* 16. 页脚 --------------------------------------------------------------- */
.site-footer {
  background: var(--laterite-900);
  color: var(--sand-050);
  border-top: 6px solid var(--laterite-700);
}

.site-footer__inner { padding-block: clamp(36px, 5vw, 64px) 0; }

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1.3fr 0.9fr;
  border-top: 1px solid rgba(246, 239, 228, 0.18);
}

.footer-col {
  padding: 30px 26px 36px;
  border-left: 1px solid rgba(246, 239, 228, 0.18);
}

.footer-col:first-child { border-left: 0; padding-left: 0; }

.footer-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: -0.01em;
  color: var(--sand-050);
}

.footer-brand__sub {
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(246, 239, 228, 0.7);
}

.footer-legal-id {
  display: inline-block;
  margin-top: 14px;
  padding: 4px 9px;
  border: 1px solid rgba(246, 239, 228, 0.35);
  border-radius: var(--radius);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: rgba(246, 239, 228, 0.85);
}

.footer-col__title {
  margin-bottom: 14px;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--laterite-200);
}

.footer-list li {
  font-size: 14px;
  line-height: 1.6;
  padding-block: 5px;
  color: rgba(246, 239, 228, 0.85);
}

.footer-list a {
  text-decoration: none;
  border-bottom: 1px solid rgba(246, 239, 228, 0.3);
  transition: border-color 0.18s ease, color 0.18s ease;
}

.footer-list a:hover {
  color: var(--sand-100);
  border-bottom-color: var(--sand-050);
}

.footer-ledger {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin-top: clamp(28px, 4vw, 44px);
  padding-block: 14px;
  border-top: 1px solid rgba(246, 239, 228, 0.18);
  border-bottom: 1px solid rgba(246, 239, 228, 0.18);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: rgba(246, 239, 228, 0.45);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 24px;
  padding-block: 18px 22px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(246, 239, 228, 0.7);
}

/* 17. 响应式 ------------------------------------------------------------- */
@media (max-width: 1180px) {
  .tool-note { display: none; }
}

@media (max-width: 1024px) {
  .col-3 { grid-column: span 6; }
  .col-6 { grid-column: span 12; }
  .col-7,
  .col-8 { grid-column: span 12; }
  .aside-note { grid-column: span 12; }
}

@media (max-width: 959px) {
  .nav-toggle { display: inline-flex; }

  .primary-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: block;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
    padding: 8px 0 16px;
    background: var(--sand-100);
    border-top: 3px solid var(--laterite-700);
    border-bottom: 3px solid var(--laterite-700);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s ease;
  }

  .primary-nav[data-open] {
    visibility: visible;
    opacity: 1;
    transform: none;
  }

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

  .primary-nav__link {
    display: block;
    padding: 14px var(--gutter);
    border-bottom: 1px solid var(--laterite-200);
    border-left: 0;
    font-size: 16px;
  }

  .primary-nav__link[aria-current="page"] {
    border-bottom-color: var(--laterite-200);
    border-left: 4px solid var(--mineral-600);
    color: var(--mineral-600);
  }

  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-col { border-left: 1px solid rgba(246, 239, 228, 0.18); }
  .footer-col:nth-child(odd) { border-left: 0; padding-left: 0; }
}

@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }
  .site-rail { display: flex; }
}

@media (max-width: 640px) {
  :root { --header-h: 64px; }

  .col-3,
  .col-4,
  .col-5 { grid-column: span 12; }

  .brand__mark { font-size: 17px; }
  .brand__meta { display: none; }

  .footer-grid { grid-template-columns: 1fr; }
  .footer-col,
  .footer-col:nth-child(odd) {
    border-left: 0;
    padding-inline: 0;
  }

  .btn { width: 100%; justify-content: center; }
}

/* 18. 动效降级 ----------------------------------------------------------- */
@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;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .scroll-progress__fill { transition: none; }
}