/* ============================================================
   云开赛场 V4 · 共享样式 /assets/site.css
   母题：数据作战室 × 看台灯光
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root {
  --void-900: #04070F;
  --void-800: #071026;
  --void-700: #0B1730;
  --glass: #12203C;
  --cyan: #35F0D8;
  --cyan-deep: #12A79B;
  --orange: #FF7C2E;
  --violet: #7B6BFF;
  --warm: #F6F2E9;
  --mist: #9DB0C8;
  --grid: #1E3355;
  --green: #3EE08A;

  --glass-55: rgba(18, 32, 60, 0.55);
  --glass-72: rgba(18, 32, 60, 0.72);
  --line-soft: rgba(30, 51, 85, 0.72);
  --line-hard: rgba(30, 51, 85, 1);

  --font-display: "Source Han Sans SC", "Noto Sans SC", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular,
    Menlo, Consolas, monospace;

  --shell: 1240px;
  --gutter: clamp(18px, 4.2vw, 56px);
  --r-sm: 2px;
  --r-md: 4px;
  --ease: cubic-bezier(0.22, 0.68, 0.32, 1);
  --bar-h: 64px;
  --nav-h: 56px;
}

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

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

body, h1, h2, h3, h4, h5, h6, p, figure, blockquote, ul, ol, dl, dd { margin: 0; }
ul, ol { list-style: none; padding: 0; }
img, svg, video, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}
table { border-collapse: collapse; width: 100%; }
input, select, textarea { font: inherit; }

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  background:
    radial-gradient(1100px 560px at 82% -8%, rgba(53, 240, 216, 0.075), transparent 62%),
    radial-gradient(900px 520px at 3% 18%, rgba(123, 107, 255, 0.075), transparent 65%),
    var(--void-900);
  color: var(--warm);
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--warm);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

h1 { font-size: clamp(36px, 5.4vw, 76px); }
h2 { font-size: clamp(28px, 3.6vw, 48px); }
h3 { font-size: clamp(22px, 2.4vw, 32px); }
h4 { font-size: clamp(18px, 1.8vw, 22px); letter-spacing: -0.01em; }

p { color: var(--mist); }
strong, b { color: var(--warm); font-weight: 700; }

::selection { background: var(--cyan); color: #03130F; }

/* 焦点统一为 2px 电子青描边 */
:where(a, button, [tabindex], input, select, textarea):focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: var(--r-sm);
}

/* ---------- 4. 布局工具 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.main-content { display: block; scroll-margin-top: 130px; }

.section { padding-block: clamp(56px, 8vw, 120px); }
.section-head { margin-bottom: clamp(24px, 3.4vw, 44px); }
.section-title { color: var(--warm); }
.section-kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}
.section-kicker::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--cyan);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.2vw, 32px);
}
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }
.offset-up-1 { transform: translateY(-40px); }
.offset-up-2 { transform: translateY(-80px); }

@media (max-width: 900px) {
  .col-4, .col-5, .col-7, .col-8 { grid-column: span 12; }
  .offset-up-1, .offset-up-2 { transform: none; }
}

@media (max-width: 900px) {
  .grid-12 { gap: 20px; }
}

/* ---------- 5. 通用组件 ---------- */
.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.index-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.rule-tick {
  height: 8px;
  width: 100%;
  background-image: repeating-linear-gradient(
    90deg,
    var(--grid) 0,
    var(--grid) 1px,
    transparent 1px,
    transparent 28px
  );
  opacity: 0.9;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border: 1px solid var(--grid);
  border-radius: var(--r-sm);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
  line-height: 1.6;
  white-space: nowrap;
}
.tag-cyan { color: var(--cyan); border-color: rgba(53, 240, 216, 0.42); }
.tag-orange { color: var(--orange); border-color: rgba(255, 124, 46, 0.42); }
.tag-green { color: var(--green); border-color: rgba(62, 224, 138, 0.42); }
.tag-violet { color: var(--violet); border-color: rgba(123, 107, 255, 0.42); }

.panel {
  background: var(--void-700);
  border: 1px solid var(--grid);
  border-radius: var(--r-md);
  padding: clamp(18px, 2.2vw, 30px);
}

.panel-glass {
  background: var(--glass-55);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  padding: clamp(14px, 1.8vw, 22px);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.4;
  white-space: nowrap;
  transition: background-color 0.18s var(--ease), border-color 0.18s var(--ease),
    color 0.18s var(--ease), transform 0.18s var(--ease);
}
.btn-primary { background: var(--cyan); color: #03130F; }
.btn-primary:hover { background: #5FF5E2; }
.btn-primary:active { background: var(--cyan-deep); }
.btn-ghost {
  border-color: var(--grid);
  color: var(--warm);
  background: var(--glass-55);
}
.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan); }
.btn-sm { padding: 8px 15px; font-size: 13px; }
.btn-block { width: 100%; }

/* 面包屑 */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--mist);
  padding-block: 18px 0;
}
.breadcrumbs a { color: var(--mist); transition: color 0.18s var(--ease); }
.breadcrumbs a:hover { color: var(--cyan); }
.breadcrumbs .sep { color: var(--grid); font-family: var(--font-mono); }
.breadcrumbs [aria-current="page"] { color: var(--warm); }

/* 图片容器（页面阶段放 <img> 占位） */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--void-700);
  border: 1px solid var(--grid);
  border-radius: var(--r-md);
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.04);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(4, 7, 15, 0) 45%, rgba(4, 7, 15, 0.62));
}
.media-caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* 章节渐显 */
.reveal { opacity: 0; transform: translateY(12px); }
.reveal.is-visible {
  opacity: 1;
  transform: none;
  transition: opacity 0.32s var(--ease), transform 0.32s var(--ease);
}

/* ---------- 6. Skip link ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--cyan);
  color: #03130F;
  font-size: 14px;
  font-weight: 700;
  border-radius: var(--r-sm);
  transform: translateY(-180%);
  transition: transform 0.22s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible { transform: translateY(0); }

/* ---------- 7. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: rgba(4, 7, 15, 0.86);
  border-bottom: 1px solid var(--line-hard);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  backdrop-filter: blur(16px) saturate(140%);
}

/* 7.1 上层品牌说明条 */
.header-brandbar {
  height: var(--bar-h);
  display: flex;
  align-items: center;
  overflow: hidden;
  background: linear-gradient(180deg, rgba(18, 32, 60, 0.72), rgba(11, 23, 48, 0.56));
  border-bottom: 1px solid var(--line-soft);
  transition: height 0.28s var(--ease), border-color 0.28s var(--ease);
}

.site-header.is-condensed .header-brandbar {
  height: 40px;
  border-bottom-color: transparent;
}

.brandbar-inner {
  display: flex;
  align-items: center;
  gap: 18px;
  width: 100%;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

.brand-mark {
  position: relative;
  display: block;
  width: 22px;
  height: 22px;
  flex: none;
  border: 1px solid var(--cyan);
  border-radius: 1px;
  background: rgba(53, 240, 216, 0.08);
}
.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  background: var(--cyan);
}
.brand-mark::before {
  left: 4px;
  right: 4px;
  top: 50%;
  height: 1px;
  transform: translateY(-50%);
}
.brand-mark::after {
  top: 4px;
  bottom: 4px;
  left: 50%;
  width: 1px;
  transform: translateX(-50%);
}

.brand-name {
  font-size: clamp(17px, 1.6vw, 20px);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--warm);
  white-space: nowrap;
}

.brand-tagline {
  font-size: 13px;
  line-height: 1.5;
  color: var(--mist);
  padding-left: 18px;
  border-left: 1px solid var(--line-hard);
  white-space: nowrap;
  overflow: hidden;
  transition: opacity 0.24s var(--ease), padding 0.24s var(--ease);
}

.site-header.is-condensed .brand-tagline {
  opacity: 0;
  padding-left: 0;
  border-left-color: transparent;
}

.brandbar-meta {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 12px;
  flex: none;
}

.refresh-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 11px;
  border: 1px solid var(--line-hard);
  border-radius: var(--r-sm);
  background: rgba(7, 16, 38, 0.5);
  font-size: 12px;
  line-height: 1.5;
  color: var(--mist);
  font-family: var(--font-mono);
  white-space: nowrap;
  transition: border-color 0.28s var(--ease), box-shadow 0.28s var(--ease);
}

.refresh-dot {
  width: 7px;
  height: 7px;
  flex: none;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 0 rgba(62, 224, 138, 0.55);
  animation: rc-breathe 3.2s ease-in-out infinite;
}

.refresh-label { letter-spacing: 0.02em; }
.refresh-sep { color: var(--grid); }
.refresh-time { color: var(--orange); font-weight: 600; }

/* 刷新脉冲环 */
.refresh-chip.is-tick {
  border-color: rgba(255, 124, 46, 0.7);
  box-shadow: 0 0 0 1px rgba(255, 124, 46, 0.35), 0 0 18px rgba(255, 124, 46, 0.28);
}
.refresh-chip.is-tick .refresh-dot {
  background: var(--orange);
  animation: rc-pulse 0.9s ease-out;
}

@keyframes rc-breathe {
  0%, 100% { box-shadow: 0 0 0 0 rgba(62, 224, 138, 0.5); }
  50% { box-shadow: 0 0 0 4px rgba(62, 224, 138, 0); }
}
@keyframes rc-pulse {
  0% { box-shadow: 0 0 0 0 rgba(255, 124, 46, 0.7); }
  100% { box-shadow: 0 0 0 12px rgba(255, 124, 46, 0); }
}

.site-header.is-condensed .btn-sm {
  padding: 5px 12px;
  font-size: 12px;
}

/* 7.2 下层栏目导航 */
.header-navbar {
  position: relative;
  background: rgba(7, 16, 38, 0.55);
}

.navbar-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(14px, 3vw, 32px);
  min-height: var(--nav-h);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 2px;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--warm);
}
.nav-toggle-mark {
  display: inline-flex;
  flex-direction: column;
  justify-content: space-between;
  width: 18px;
  height: 12px;
  flex: none;
}
.nav-toggle-mark i {
  display: block;
  height: 1.5px;
  width: 100%;
  background: var(--warm);
  border-radius: 1px;
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}
.site-header.nav-open .nav-toggle-mark i:nth-child(1) {
  transform: translateY(5.25px) rotate(45deg);
}
.site-header.nav-open .nav-toggle-mark i:nth-child(2) { opacity: 0; }
.site-header.nav-open .nav-toggle-mark i:nth-child(3) {
  transform: translateY(-5.25px) rotate(-45deg);
}
.nav-toggle[aria-expanded="true"] { color: var(--cyan); }

.primary-nav { min-width: 0; }

.nav-list {
  display: flex;
  align-items: stretch;
  gap: clamp(12px, 2.4vw, 30px);
}

.nav-item { display: flex; }

.nav-list a {
  position: relative;
  display: inline-flex;
  align-items: center;
  height: var(--nav-h);
  font-size: 15px;
  font-weight: 500;
  color: var(--mist);
  transition: color 0.2s var(--ease);
}
.nav-list a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.24s var(--ease);
}
.nav-list a:hover { color: var(--warm); }
.nav-list a:hover::after { transform: scaleX(1); }
.nav-list a[aria-current="page"] {
  color: var(--warm);
  font-weight: 700;
}
.nav-list a[aria-current="page"]::after { transform: scaleX(1); }

.nav-version {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--cyan-deep);
  border: 1px solid var(--line-hard);
  border-radius: var(--r-sm);
  padding: 3px 8px;
  line-height: 1.6;
  flex: none;
}

.nav-drawer-status { display: none; }

.nav-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: rgba(30, 51, 85, 0.75);
  overflow: hidden;
}
.nav-progress-fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan-deep), var(--cyan));
  transition: width 0.12s linear;
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 120px);
  background: linear-gradient(180deg, var(--void-900) 0%, var(--void-800) 38%, #050B18 100%);
  border-top: 1px solid var(--line-hard);
  color: var(--mist);
  font-size: 14px;
}
.site-footer .rule-tick { opacity: 0.7; }

.footer-strip {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) minmax(0, 1.9fr);
  gap: clamp(28px, 5vw, 72px);
  padding-block: clamp(38px, 5vw, 64px) clamp(26px, 3.2vw, 40px);
}

.footer-mark {
  display: inline-block;
  font-size: clamp(24px, 2.6vw, 32px);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--warm);
  line-height: 1.2;
  transition: color 0.2s var(--ease);
}
.footer-mark:hover { color: var(--cyan); }

.footer-intro {
  margin-top: 14px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

.footer-version {
  margin-top: 16px;
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan-deep);
}

.footer-groups {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 40px);
}

.footer-group-title {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 14px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}
.footer-group-title::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--cyan);
  flex: none;
}

.footer-group ul {
  display: grid;
  gap: 9px;
}
.footer-group a {
  position: relative;
  display: inline-block;
  padding-bottom: 2px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
  transition: color 0.2s var(--ease);
}
.footer-group a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s var(--ease);
}
.footer-group a:hover { color: var(--warm); }
.footer-group a:hover::after { transform: scaleX(1); }

.footer-contact-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 34px;
  padding-block: 20px;
  border-top: 1px solid var(--line-soft);
  font-size: 13px;
}

.footer-contact-item {
  display: inline-flex;
  align-items: baseline;
  gap: 9px;
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}
.footer-contact-key {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan-deep);
  flex: none;
}
.footer-contact-value {
  color: var(--warm);
  word-break: break-all;
}
.footer-contact-item--wide { flex-basis: 100%; }

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border: 1px solid var(--line-hard);
  border-radius: var(--r-sm);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
  background: rgba(53, 240, 216, 0.06);
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease),
    background-color 0.2s var(--ease);
}
.copy-btn:hover {
  border-color: var(--cyan);
  background: rgba(53, 240, 216, 0.14);
}
.copy-btn:active { color: var(--warm); }

.footer-legal-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  padding-block: 18px 30px;
  border-top: 1px solid var(--line-soft);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}
.footer-legal { margin: 0; color: var(--warm); font-size: 12.5px; }
.footer-refresh-note { margin: 0; color: var(--mist); font-size: 12.5px; }
.footer-legal-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-left: auto;
}
.footer-legal-nav a {
  font-size: 12.5px;
  color: var(--mist);
  transition: color 0.2s var(--ease);
}
.footer-legal-nav a:hover { color: var(--cyan); }

/* ---------- 9. 响应式 ---------- */
@media (max-width: 1024px) {
  .brand-tagline { display: none; }
}

@media (max-width: 900px) {
  :root { --nav-h: 52px; }

  .nav-toggle { display: inline-flex; }
  .nav-version { display: none; }

  .primary-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 95;
    max-height: min(70vh, 460px);
    overflow-y: auto;
    padding: 10px 18px 18px;
    background: linear-gradient(180deg, rgba(7, 16, 38, 0.99), rgba(4, 7, 15, 0.99));
    border: 1px solid var(--line-hard);
    border-top: 0;
    border-radius: 0 0 var(--r-md) var(--r-md);
    box-shadow: 0 22px 48px rgba(0, 0, 0, 0.55);
  }
  .primary-nav[data-open] { display: block; }

  .nav-list {
    flex-direction: column;
    gap: 0;
  }
  .nav-item + .nav-item { border-top: 1px solid var(--line-soft); }
  .nav-list a {
    width: 100%;
    height: auto;
    padding: 14px 2px;
    font-size: 16px;
  }
  .nav-list a::after { display: none; }
  .nav-list a[aria-current="page"] {
    color: var(--cyan);
    padding-left: 16px;
  }
  .nav-list a[aria-current="page"]::before {
    content: "";
    position: absolute;
    left: 2px;
    top: 50%;
    width: 6px;
    height: 6px;
    margin-top: -3px;
    background: var(--cyan);
  }

  .nav-drawer-status {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 14px;
    padding-top: 14px;
    border-top: 1px solid var(--line-soft);
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--mist);
  }

  .refresh-label, .refresh-sep { display: none; }

  .footer-strip { grid-template-columns: 1fr; gap: 32px; }
  .footer-groups { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-legal-nav { margin-left: 0; }
}

@media (max-width: 640px) {
  :root { --bar-h: 58px; }

  .brandbar-meta { gap: 8px; }
  .refresh-chip { padding: 4px 8px; font-size: 11px; }
  .brand-name { font-size: 16px; }
  .brand-mark { width: 18px; height: 18px; }
  .brandbar-meta .btn-sm { padding: 5px 10px; font-size: 12px; }

  .footer-groups { grid-template-columns: 1fr; gap: 24px; }
  .footer-contact-bar { flex-direction: column; align-items: flex-start; gap: 12px; }
  .footer-legal-bar { flex-direction: column; align-items: flex-start; gap: 10px; }
}

@media (max-width: 400px) {
  .brandbar-meta .btn-sm { display: none; }
}

/* ---------- 10. 降级动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
  .nav-progress-fill { transition: none; }
}