/* =========================================================
   宇博官方网 · 共享样式表 /assets/site.css
   目录型内容地图 · 刊头导航 · 玻璃层与实色层并置
   ========================================================= */

/* ---------- 1. 基础重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd {
  margin: 0;
}

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

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

[hidden] { display: none !important; }

/* ---------- 2. 设计变量 ---------- */
:root {
  /* 色彩 */
  --yb-blue:        #1B4B8F;
  --yb-deep:        #0F2F5C;
  --yb-bright:      #3C7BE0;
  --yb-ice:         #EAF2FD;
  --yb-teal:        #0E9E8F;
  --yb-teal-soft:   #E2F6F2;
  --yb-orange:      #EF8722;
  --yb-orange-soft: #FFF1E1;
  --yb-violet:      #6C4CF1;
  --yb-ink:         #101828;
  --yb-muted:       #5B6675;
  --yb-surface:     #F6F8FB;
  --yb-white:       #FFFFFF;
  --yb-line:        #DCE4EF;
  --yb-line-soft:   rgba(27, 75, 143, 0.12);

  /* 间距（24 / 32 / 48 / 72 四档） */
  --yb-gap-1: 24px;
  --yb-gap-2: 32px;
  --yb-gap-3: 48px;
  --yb-gap-4: 72px;

  /* 圆角 */
  --yb-r-sm: 14px;
  --yb-r-lg: 20px;
  --yb-r-pill: 999px;

  /* 结构 */
  --yb-shell: 1220px;
  --yb-shadow-soft: 0 18px 46px rgba(15, 47, 92, 0.10);
  --yb-shadow-line: 0 2px 10px rgba(27, 75, 143, 0.12);

  /* 字体 */
  --yb-font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
             "Source Han Sans SC", "Noto Sans CJK SC", system-ui,
             -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* ---------- 3. 中文排版 ---------- */
body {
  font-family: var(--yb-font);
  font-size: 16.5px;
  line-height: 1.75;
  color: var(--yb-ink);
  background-color: var(--yb-surface);
  background-image:
    radial-gradient(900px 420px at 12% -6%, rgba(14, 158, 143, 0.06), transparent 62%),
    radial-gradient(760px 380px at 92% 4%, rgba(108, 76, 241, 0.055), transparent 60%);
  background-repeat: no-repeat;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.24;
  letter-spacing: -0.012em;
  color: var(--yb-deep);
}

h1 { font-size: clamp(32px, 4.4vw, 58px); letter-spacing: -0.02em; }
h2 { font-size: clamp(24px, 2.6vw, 36px); }
h3 { font-size: clamp(18px, 1.5vw, 22px); font-weight: 700; color: var(--yb-ink); line-height: 1.4; }

p { line-height: 1.75; }

a { color: var(--yb-bright); text-decoration-color: rgba(60, 123, 224, 0.4); }
a:hover { text-decoration-color: currentColor; }

strong { font-weight: 700; color: var(--yb-deep); }

.yb-num {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: 0.01em;
}

.yb-copy p + p { margin-top: 14px; }
.yb-copy p { max-width: 42em; }

.yb-lead {
  font-size: 18px;
  line-height: 1.8;
  color: var(--yb-muted);
  max-width: 44ch;
}

.yb-eyebrow {
  display: inline-block;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--yb-teal);
  margin-bottom: 12px;
}

/* ---------- 4. 布局容器 ---------- */
.yb-shell {
  width: min(100% - 40px, var(--yb-shell));
  margin-inline: auto;
}

.yb-section { padding: 56px 0; }
.yb-section--tight { padding: 32px 0; }
.yb-section--roomy { padding: 72px 0; }

.yb-section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px 32px;
  margin-bottom: 32px;
}

.yb-rule {
  height: 1px;
  border: 0;
  background: var(--yb-line);
  margin: 0;
}

.yb-grid { display: grid; gap: var(--yb-gap-1); }
.yb-grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.yb-grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.yb-grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 4fr); }
.yb-grid--wide { grid-template-columns: minmax(0, 8fr) minmax(0, 4fr); }

/* ---------- 5. 卡片 / 面板 / 标签 ---------- */
.yb-card {
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-radius: var(--yb-r-sm);
  padding: var(--yb-gap-1);
}

.yb-card--lg {
  border-radius: var(--yb-r-lg);
  padding: var(--yb-gap-2);
}

.yb-panel {
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: var(--yb-r-lg);
  box-shadow: var(--yb-shadow-soft);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  backdrop-filter: blur(14px) saturate(150%);
  padding: var(--yb-gap-2);
}

.yb-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--yb-r-pill);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: var(--yb-ice);
  color: var(--yb-blue);
}

.yb-tag--teal   { background: var(--yb-teal-soft);   color: #0A7C70; }
.yb-tag--warm   { background: var(--yb-orange-soft); color: #B85F0B; }
.yb-tag--violet { background: #EFEBFE;               color: #5238C6; }
.yb-tag--muted  { background: #EDF1F7;               color: var(--yb-muted); }

/* ---------- 6. 按钮 ---------- */
.yb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: var(--yb-r-pill);
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.3;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease,
              border-color 0.18s ease, box-shadow 0.18s ease;
}

.yb-btn--primary {
  background: var(--yb-blue);
  color: var(--yb-white);
  box-shadow: 0 8px 20px rgba(27, 75, 143, 0.24);
}
.yb-btn--primary:hover { background: var(--yb-deep); color: var(--yb-white); }

.yb-btn--ghost {
  background: var(--yb-white);
  color: var(--yb-blue);
  border-color: rgba(27, 75, 143, 0.24);
}
.yb-btn--ghost:hover {
  border-color: var(--yb-blue);
  background: var(--yb-ice);
  color: var(--yb-deep);
}

.yb-btn--teal { background: var(--yb-teal); color: var(--yb-white); }
.yb-btn--teal:hover { background: #0A7C70; color: var(--yb-white); }

.yb-btn--warm { background: var(--yb-orange); color: var(--yb-white); }
.yb-btn--warm:hover { background: #D6741A; color: var(--yb-white); }

.yb-btn--sm { padding: 8px 16px; font-size: 13.5px; }

/* ---------- 7. 提示块 / 步骤符号 ---------- */
.yb-callout {
  border-radius: var(--yb-r-sm);
  border-left: 4px solid var(--yb-teal);
  background: var(--yb-teal-soft);
  color: #0B5C54;
  padding: 20px 22px;
  font-size: 15px;
}
.yb-callout--warm { background: var(--yb-orange-soft); border-left-color: var(--yb-orange); color: #8A4A08; }
.yb-callout--blue { background: var(--yb-ice);         border-left-color: var(--yb-blue);   color: var(--yb-deep); }

.yb-step-num {
  display: block;
  font-size: clamp(72px, 9vw, 140px);
  font-weight: 800;
  line-height: 0.82;
  letter-spacing: -0.04em;
  color: var(--yb-blue);
  font-variant-numeric: tabular-nums;
}
.yb-step-num--warm { color: var(--yb-orange); }
.yb-step-num--teal { color: var(--yb-teal); }

.yb-rail { position: relative; padding-left: 24px; }
.yb-rail::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--yb-teal), var(--yb-bright) 55%, var(--yb-orange));
}

/* ---------- 8. 主题筛选 ---------- */
.yb-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.yb-filter__btn {
  padding: 8px 16px;
  border: 1px solid rgba(27, 75, 143, 0.2);
  border-radius: var(--yb-r-pill);
  background: rgba(255, 255, 255, 0.72);
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  color: var(--yb-blue);
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease,
              border-color 0.18s ease, box-shadow 0.18s ease;
}
.yb-filter__btn:hover { border-color: var(--yb-blue); background: var(--yb-white); }
.yb-filter__btn[aria-pressed="true"] {
  background: var(--yb-blue);
  border-color: var(--yb-blue);
  color: var(--yb-white);
  box-shadow: 0 6px 16px rgba(27, 75, 143, 0.26);
}

/* ---------- 9. 面包屑 ---------- */
.yb-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 8px;
  font-size: 13px;
  color: var(--yb-muted);
  margin-bottom: 20px;
}
.yb-breadcrumb li { display: flex; align-items: center; }
.yb-breadcrumb li + li::before {
  content: "›";
  margin-right: 8px;
  color: rgba(91, 102, 117, 0.45);
}
.yb-breadcrumb a { color: var(--yb-muted); text-decoration: none; }
.yb-breadcrumb a:hover { color: var(--yb-blue); }
.yb-breadcrumb [aria-current="page"] { color: var(--yb-deep); font-weight: 600; }

/* ---------- 10. 图片容器基础规则 ---------- */
.yb-media {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--yb-r-lg);
  border: 1px solid var(--yb-line-soft);
  background: linear-gradient(135deg, #EAF2FD 0%, #E2F6F2 54%, #FFF1E1 100%);
}
.yb-media > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.yb-media--16x9   { aspect-ratio: 16 / 9; }
.yb-media--4x3    { aspect-ratio: 4 / 3; }
.yb-media--square { aspect-ratio: 1 / 1; }
.yb-media--device {
  aspect-ratio: 21 / 9;
  background: linear-gradient(120deg, #0F2F5C 0%, #1B4B8F 44%, #0E9E8F 100%);
}

.yb-media__grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.5;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.16) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.16) 1px, transparent 1px);
  background-size: 44px 44px;
}

.yb-media__caption {
  margin-top: 12px;
  font-size: 13px;
  color: var(--yb-muted);
}

/* ---------- 11. 入视口渐显 ---------- */
[data-reveal].is-armed {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.32s ease, transform 0.32s ease;
}
[data-reveal].is-armed.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 12. 跳转链接与焦点 ---------- */
.yb-skip {
  position: absolute;
  left: 16px;
  top: -72px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: 0 0 12px 12px;
  background: var(--yb-deep);
  color: var(--yb-white);
  font-size: 14px;
  text-decoration: none;
  transition: top 0.18s ease;
}
.yb-skip:focus { top: 0; color: var(--yb-white); }

:focus-visible {
  outline: 3px solid var(--yb-violet);
  outline-offset: 2px;
  border-radius: 6px;
}
.yb-skip:focus-visible { outline-offset: -3px; }

/* ---------- 13. 刊头 ---------- */
.yb-masthead {
  position: sticky;
  top: 0;
  z-index: 80;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(246, 248, 251, 0.88));
  border-bottom: 1px solid var(--yb-line-soft);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  backdrop-filter: blur(16px) saturate(160%);
  box-shadow: 0 10px 30px rgba(15, 47, 92, 0.06);
}

.yb-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 3px;
  background: rgba(27, 75, 143, 0.10);
}
.yb-progress__bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--yb-teal), var(--yb-bright) 52%, var(--yb-orange));
  transition: width 0.12s linear;
}

.yb-masthead__top {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
  padding: 15px 0 13px;
}

.yb-mini { min-width: 0; }
.yb-mini__list {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  font-size: 13px;
}
.yb-mini__list a {
  color: var(--yb-muted);
  text-decoration: none;
  letter-spacing: 0.02em;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}
.yb-mini__list a:hover { color: var(--yb-blue); border-bottom-color: rgba(27, 75, 143, 0.4); }
.yb-mini__list a[aria-current="page"] { color: var(--yb-blue); font-weight: 700; }

.yb-brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  text-decoration: none;
  padding: 0 8px;
}
.yb-brand__mark {
  position: relative;
  font-size: 23px;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: var(--yb-deep);
  line-height: 1.2;
}
.yb-brand__mark::after {
  content: "";
  position: absolute;
  right: -14px;
  top: 50%;
  width: 6px;
  height: 6px;
  margin-top: -3px;
  border-radius: 2px;
  background: var(--yb-teal);
}
.yb-brand__sub {
  font-size: 10.5px;
  letter-spacing: 0.3em;
  color: var(--yb-muted);
  font-variant-numeric: tabular-nums;
}

.yb-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 16px;
  min-width: 0;
}

.yb-quick {
  font-size: 13.5px;
  color: var(--yb-teal);
  text-decoration: none;
  border-bottom: 1px dashed rgba(14, 158, 143, 0.5);
  padding-bottom: 2px;
  white-space: nowrap;
  transition: color 0.18s ease, border-color 0.18s ease;
}
.yb-quick:hover { color: var(--yb-deep); border-bottom-color: var(--yb-deep); }

.yb-nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 15px;
  border: 1px solid rgba(27, 75, 143, 0.22);
  border-radius: var(--yb-r-pill);
  background: var(--yb-white);
  font-family: inherit;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--yb-blue);
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}
.yb-nav-toggle__bars {
  display: block;
  width: 16px;
  height: 2px;
  background: currentColor;
  box-shadow: 0 -5px 0 currentColor, 0 5px 0 currentColor;
}
.yb-masthead[data-open] .yb-nav-toggle {
  background: var(--yb-orange);
  border-color: var(--yb-orange);
  color: var(--yb-white);
}

.yb-nav {
  position: relative;
  display: block;
  border-top: 1px solid var(--yb-line-soft);
  background: rgba(234, 242, 253, 0.62);
}

.yb-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px;
  padding: 7px 0;
}

.yb-nav__link {
  display: block;
  padding: 9px 18px;
  border-radius: var(--yb-r-pill);
  font-size: 15px;
  font-weight: 500;
  color: var(--yb-deep);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}
.yb-nav__link:hover {
  background: var(--yb-white);
  color: var(--yb-blue);
  box-shadow: var(--yb-shadow-line);
}
.yb-nav__link[aria-current="page"] {
  background: var(--yb-blue);
  color: var(--yb-white);
  font-weight: 600;
  box-shadow: 0 6px 18px rgba(27, 75, 143, 0.3);
}
.yb-nav__link[aria-current="page"]:hover {
  background: var(--yb-deep);
  color: var(--yb-white);
}

/* ---------- 14. 页脚 ---------- */
.yb-footer {
  margin-top: var(--yb-gap-4);
  background: var(--yb-deep);
  color: rgba(255, 255, 255, 0.76);
}
.yb-footer::before {
  content: "";
  display: block;
  height: 4px;
  background: linear-gradient(90deg, var(--yb-teal), var(--yb-bright) 48%, var(--yb-violet) 74%, var(--yb-orange));
}

.yb-footer__grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr 1.5fr;
  gap: 40px;
  padding: 56px 0 44px;
}

.yb-footer__mark {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--yb-white);
  line-height: 1.3;
}

.yb-footer__tag {
  max-width: 30ch;
  margin-top: 12px;
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.62);
}

.yb-footer__brand .yb-btn { margin-top: 20px; }
.yb-footer .yb-btn--ghost {
  background: rgba(255, 255, 255, 0.06);
  color: var(--yb-white);
  border-color: rgba(255, 255, 255, 0.34);
}
.yb-footer .yb-btn--ghost:hover {
  background: rgba(255, 255, 255, 0.16);
  border-color: rgba(255, 255, 255, 0.6);
  color: var(--yb-white);
}

.yb-footer__title {
  margin-bottom: 16px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: rgba(255, 255, 255, 0.5);
}

.yb-footer__list li { margin-bottom: 10px; }
.yb-footer__list a {
  font-size: 14.5px;
  color: rgba(255, 255, 255, 0.82);
  text-decoration: none;
  transition: color 0.18s ease;
}
.yb-footer__list a:hover {
  color: var(--yb-white);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.yb-footer__meta .yb-footer__list li {
  display: flex;
  gap: 12px;
  align-items: baseline;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.84);
}
.yb-footer__label {
  flex: 0 0 64px;
  font-size: 12.5px;
  color: rgba(255, 255, 255, 0.45);
}

.yb-footer__address {
  margin-top: 16px;
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.6);
}

.yb-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 28px;
  padding: 22px 0 36px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.56);
}

.yb-footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}
.yb-footer__legal a {
  color: rgba(255, 255, 255, 0.72);
  text-decoration: none;
}
.yb-footer__legal a:hover { color: var(--yb-white); }

.yb-footer__note {
  flex-basis: 100%;
  font-size: 12.5px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.45);
}

/* ---------- 15. 返回顶部 ---------- */
.yb-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 70;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border: 1px solid rgba(27, 75, 143, 0.2);
  border-radius: var(--yb-r-sm);
  background: rgba(255, 255, 255, 0.86);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow: 0 12px 26px rgba(15, 47, 92, 0.16);
  color: var(--yb-blue);
  font-family: inherit;
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  transition: opacity 0.2s ease, transform 0.2s ease, background-color 0.18s ease;
}
.yb-top:hover { background: var(--yb-white); }
.yb-top.is-hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
}

/* ---------- 16. 响应式：平板 ---------- */
@media (max-width: 1080px) {
  .yb-grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .yb-grid--split,
  .yb-grid--wide { grid-template-columns: 1fr; }
  .yb-footer__grid { grid-template-columns: 1fr 1fr; gap: 36px; }
  .yb-footer__brand { grid-column: 1 / -1; }
}

/* ---------- 17. 响应式：移动刊头与抽屉导航 ---------- */
@media (max-width: 920px) {
  .yb-shell { width: min(100% - 32px, var(--yb-shell)); }

  .yb-masthead__top {
    grid-template-columns: 1fr auto;
    gap: 12px;
    padding: 12px 0;
  }

  .yb-mini,
  .yb-actions { display: none; }

  .yb-brand {
    grid-column: 1;
    grid-row: 1;
    align-items: flex-start;
    padding: 0;
  }
  .yb-brand__mark { font-size: 20px; }
  .yb-brand__sub { letter-spacing: 0.2em; }

  .yb-nav-toggle {
    display: inline-flex;
    grid-column: 2;
    grid-row: 1;
    justify-self: end;
  }

  .yb-nav {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    border-top: 1px solid var(--yb-line);
    background: var(--yb-white);
    box-shadow: 0 24px 48px rgba(15, 47, 92, 0.18);
    max-height: calc(100vh - 96px);
    overflow-y: auto;
  }

  .yb-masthead[data-open] .yb-nav { display: block; }

  .yb-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 12px 0 20px;
  }

  .yb-nav__link {
    padding: 14px 16px;
    border-radius: 12px;
    font-size: 16px;
  }
  .yb-nav__link:hover { box-shadow: none; background: var(--yb-ice); }
}

/* ---------- 18. 响应式：手机 ---------- */
@media (max-width: 680px) {
  body { font-size: 16px; }

  .yb-section { padding: 40px 0; }
  .yb-section--roomy { padding: 48px 0; }

  .yb-grid--2,
  .yb-grid--3 { grid-template-columns: 1fr; }

  .yb-card--lg,
  .yb-panel { padding: var(--yb-gap-1); }

  .yb-footer__grid {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 40px 0 32px;
  }

  .yb-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .yb-lead { font-size: 16.5px; max-width: none; }

  .yb-top { right: 16px; bottom: 16px; }
}

/* ---------- 19. 降低动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  [data-reveal].is-armed {
    opacity: 0;
    transform: none;
    transition: opacity 0.2s linear;
  }
  [data-reveal].is-armed.is-in { opacity: 1; }

  .yb-progress__bar { transition: none; }
  .yb-nav__link,
  .yb-btn,
  .yb-filter__btn,
  .yb-nav-toggle,
  .yb-quick,
  .yb-top,
  .yb-skip { transition: none; }
}