/* ============================================================
   YOBO赛场 · /assets/site.css
   共享外壳：重置 / 令牌 / 中文排版 / 头部 / 页脚 / 通用组件
   ============================================================ */

/* ---------- 1. 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, fieldset {
  margin: 0;
}

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

a { color: inherit; text-decoration: none; }

table { border-collapse: collapse; width: 100%; }

/* ---------- 2. Tokens ---------- */
:root {
  --ink: #0B1B2B;
  --ink-soft: #12293D;
  --ink-line: #1B3850;
  --ice: #F4F7F8;
  --cream: #EFE9DF;
  --frost: #DCE8EE;
  --slate: #8A9497;
  --slate-deep: #5E6A6E;
  --moss: #6F7F63;
  --clay: #B46A4F;
  --cyan: #18D6C4;
  --cyan-deep: #0FA396;
  --amber: #F28C28;

  --glass: rgba(244, 247, 248, 0.58);
  --glass-dark: rgba(11, 27, 43, 0.72);
  --line-ink: rgba(11, 27, 43, 0.14);
  --line-ink-strong: rgba(11, 27, 43, 0.28);
  --line-ice: rgba(244, 247, 248, 0.16);

  --font-display: "Barlow Condensed", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, "Noto Sans SC", monospace;

  --step-display: clamp(2rem, 5vw, 4.6rem);
  --step-h2: clamp(1.5rem, 3vw, 2.4rem);
  --step-h3: clamp(1.125rem, 1.6vw, 1.375rem);
  --step-body: clamp(1rem, calc(0.95rem + 0.25vw), 1.125rem);
  --step-caption: 0.8125rem;

  --gutter: clamp(1rem, 4vw, 2.5rem);
  --shell: 1280px;
  --radius: 3px;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
  --shadow-lift: 0 14px 32px rgba(11, 27, 43, 0.14);
}

/* ---------- 3. 基础与中文排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: var(--step-body);
  line-height: 1.75;
  font-weight: 400;
  color: var(--ink);
  background-color: var(--ice);
  background-image: linear-gradient(180deg, rgba(220, 232, 238, 0.55) 0%, rgba(244, 247, 248, 0) 42%);
  background-repeat: no-repeat;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.02;
  letter-spacing: 0.01em;
  text-wrap: balance;
}

h1 { font-size: var(--step-display); line-height: 0.95; }
h2 { font-size: var(--step-h2); }
h3 { font-size: var(--step-h3); line-height: 1.25; font-weight: 500; }

p { text-wrap: pretty; }

strong { font-weight: 700; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

#main-content {
  display: block;
  scroll-margin-top: 1rem;
}
#main-content:focus { outline: none; }

/* ---------- 4. 工具类 ---------- */
.mono,
.index-num {
  font-family: var(--font-mono);
  font-feature-settings: "tnum" 1;
  letter-spacing: 0.06em;
}

.index-num {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--slate-deep);
}

.eyebrow,
.section-head__eyebrow {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--slate-deep);
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: 0;
  z-index: 120;
  transform: translate(-50%, -130%);
  padding: 0.7rem 1.15rem;
  background: var(--cyan);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  border-radius: 0 0 var(--radius) var(--radius);
  transition: transform 0.18s var(--ease);
}
.skip-link:focus { transform: translate(-50%, 0); }

/* ---------- 6. 头部：刻度带 ---------- */
.site-header {
  position: relative;
  z-index: 50;
  background: var(--ink);
  color: var(--ice);
  border-bottom: 1px solid var(--line-ice);
}

.header-rail {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(0.75rem, 2vw, 1.5rem);
  padding: 0.5rem var(--gutter);
  border-bottom: 1px solid var(--line-ice);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(244, 247, 248, 0.62);
}

.header-rail__label { white-space: nowrap; }

.header-rail__label--muted { color: rgba(244, 247, 248, 0.4); }

.header-rail__ticks {
  flex: 1 1 auto;
  min-width: 48px;
  max-width: 320px;
  height: 8px;
  background-image: repeating-linear-gradient(
    to right,
    rgba(24, 214, 196, 0.72) 0 2px,
    transparent 2px 14px
  );
  opacity: 0.9;
}

.header-rail__progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--amber));
  transform: scaleX(0);
  transform-origin: 0 50%;
  will-change: transform;
}

/* ---------- 7. 头部：居中刊头 ---------- */
.masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: clamp(0.75rem, 2vw, 1.5rem);
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(1.1rem, 2.6vw, 2rem) var(--gutter) clamp(0.9rem, 2vw, 1.4rem);
  text-align: center;
}

.masthead__meta {
  justify-self: start;
  padding-left: 0.9rem;
  border-left: 2px solid var(--amber);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  line-height: 1.5;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(244, 247, 248, 0.45);
}

.masthead__center {
  display: grid;
  gap: 0.35rem;
  justify-items: center;
}

.masthead__brand {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.9rem, 5vw, 3.25rem);
  line-height: 0.95;
  letter-spacing: 0.03em;
  color: var(--ice);
  transition: color 0.18s var(--ease);
}
.masthead__brand:hover,
.masthead__brand:focus-visible { color: var(--cyan); }

.masthead__descriptor {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: rgba(244, 247, 248, 0.6);
}

.masthead__side {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: clamp(0.5rem, 1.2vw, 1rem);
}

.header-utility {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.header-utility__link {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  padding: 0.35rem 0;
  color: rgba(244, 247, 248, 0.7);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.header-utility__link:hover,
.header-utility__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: rgba(24, 214, 196, 0.55);
}

/* ---------- 8. 头部：移动导航按钮 ---------- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.7rem;
  border: 1px solid rgba(244, 247, 248, 0.28);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ice);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.nav-toggle:hover,
.nav-toggle:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
  background: rgba(24, 214, 196, 0.08);
}

.nav-toggle__bars {
  display: grid;
  gap: 3px;
  width: 16px;
}
.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

.site-header[data-open] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

.nav-toggle__text {
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
}

/* ---------- 9. 头部：栏目 ---------- */
.site-nav {
  border-top: 1px solid var(--line-ice);
  background: rgba(11, 27, 43, 0.94);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(0.25rem, 1.4vw, 1.75rem);
  max-width: var(--shell);
  margin-inline: auto;
  padding: 0.8rem var(--gutter);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
}

.site-nav__item { position: relative; }

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 0.45rem 0.15rem;
  color: rgba(244, 247, 248, 0.76);
  transition: color 0.18s var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.05rem;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.18s var(--ease);
}

.site-nav__link:hover,
.site-nav__link:focus-visible { color: var(--ice); }
.site-nav__link:hover::after,
.site-nav__link:focus-visible::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] {
  color: var(--cyan);
  font-weight: 500;
}
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: 50%;
  top: -0.35rem;
  width: 4px;
  height: 4px;
  margin-left: -2px;
  background: var(--amber);
  border-radius: 50%;
}

/* ---------- 10. 容器与章节 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(2rem, 5vw, 3.75rem); }

.section-head {
  display: grid;
  gap: 0.4rem;
  margin-bottom: clamp(1rem, 2.4vw, 1.75rem);
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--line-ink);
}

.section-head__index {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--cyan-deep);
}

.section-head__title { font-size: var(--step-h2); }

.section-head__note {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--slate-deep);
  max-width: 62ch;
}

/* ---------- 11. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.72rem 1.2rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease),
              border-color 0.18s var(--ease), transform 0.18s var(--ease);
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--primary {
  background: var(--cyan);
  color: var(--ink);
}
.btn--primary:hover,
.btn--primary:focus-visible { background: #3BE7D8; }

.btn--ghost {
  background: transparent;
  border-color: rgba(244, 247, 248, 0.38);
  color: var(--ice);
}
.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
}

.btn--outline {
  background: transparent;
  border-color: var(--ink);
  color: var(--ink);
}
.btn--outline:hover,
.btn--outline:focus-visible {
  background: var(--ink);
  color: var(--ice);
}

.btn--amber {
  background: var(--amber);
  color: var(--ink);
}
.btn--amber:hover,
.btn--amber:focus-visible { background: #FF9F45; }

/* ---------- 12. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.18rem 0.55rem;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: var(--frost);
  color: var(--ink);
}

.tag--mint { background: var(--moss); color: #FFFFFF; }
.tag--clay { background: var(--clay); color: #FFFFFF; }
.tag--cyan { background: var(--cyan); color: var(--ink); }
.tag--amber { background: var(--amber); color: var(--ink); }

/* ---------- 13. 面包屑 ---------- */
.breadcrumbs {
  border-bottom: 1px solid var(--line-ink);
  background: rgba(220, 232, 238, 0.45);
}

.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 0.65rem var(--gutter);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--slate-deep);
}

.breadcrumbs__item { display: inline-flex; align-items: center; gap: 0.4rem; }

.breadcrumbs__link {
  color: var(--ink-soft);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.breadcrumbs__link:hover,
.breadcrumbs__link:focus-visible {
  color: var(--cyan-deep);
  border-bottom-color: rgba(15, 163, 150, 0.6);
}

.breadcrumbs__sep { color: var(--slate); }

/* ---------- 14. Bento 模块板 ---------- */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(12px, 1.6vw, 20px);
}

.bento {
  position: relative;
  grid-column: span 12;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  min-width: 0;
  padding: clamp(1rem, 2.2vw, 1.75rem);
  background: var(--cream);
  border: 1px solid var(--line-ink);
  border-radius: var(--radius);
}

.bento--span3 { grid-column: span 3; }
.bento--span4 { grid-column: span 4; }
.bento--span5 { grid-column: span 5; }
.bento--span6 { grid-column: span 6; }
.bento--span7 { grid-column: span 7; }
.bento--span8 { grid-column: span 8; }

.bento--frost { background: var(--frost); }

.bento--ink {
  background: var(--ink);
  color: var(--ice);
  border-color: rgba(244, 247, 248, 0.14);
}

.bento--glass {
  background: var(--glass);
  border-color: rgba(244, 247, 248, 0.45);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.bento--line {
  background: transparent;
  border: 1px dashed var(--line-ink-strong);
}

/* ---------- 15. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  isolation: isolate;
  aspect-ratio: 16 / 10;
  border-radius: var(--radius);
  background-image: linear-gradient(160deg, #DCE8EE 0%, #8A9497 56%, #0B1B2B 100%);
}

.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image: repeating-linear-gradient(
    115deg,
    rgba(244, 247, 248, 0.22) 0 1px,
    transparent 1px 34px
  );
  opacity: 0.65;
  pointer-events: none;
}

.media-frame__img,
.media-frame img,
.media-frame video {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.media-frame__tag {
  position: absolute;
  left: 0.75rem;
  bottom: 0.75rem;
  z-index: 2;
  padding: 0.2rem 0.55rem;
  background: rgba(11, 27, 43, 0.84);
  color: var(--ice);
  border-left: 2px solid var(--cyan);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
}

/* ---------- 16. 滚动显现 ---------- */
[data-reveal] { opacity: 1; transform: none; }

html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.4s var(--ease), transform 0.42s var(--ease);
}

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

/* ---------- 17. 页脚 ---------- */
.site-footer {
  margin-top: clamp(3rem, 6vw, 5rem);
  background: var(--ink);
  color: var(--ice);
  border-top: 1px solid var(--line-ice);
}

.footer-inner {
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(2rem, 4vw, 3.5rem) var(--gutter) clamp(1.25rem, 2vw, 1.75rem);
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1.6fr);
  gap: clamp(1.5rem, 3vw, 3rem);
  padding-bottom: clamp(1.5rem, 3vw, 2.25rem);
  border-bottom: 1px solid var(--line-ice);
}

.footer-brand {
  display: grid;
  gap: 0.5rem;
  align-content: start;
}

.footer-brand__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  line-height: 1.05;
  letter-spacing: 0.04em;
}

.footer-brand__line {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.footer-brand__note {
  max-width: 36ch;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: rgba(244, 247, 248, 0.72);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(1rem, 2vw, 1.75rem);
}

.footer-col { display: grid; align-content: start; gap: 0.75rem; }

.footer-col__title {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(244, 247, 248, 0.48);
}

.footer-col__list { display: grid; gap: 0.4rem; }

.footer-link {
  display: inline-block;
  padding: 0.15rem 0;
  font-size: 0.9375rem;
  color: rgba(244, 247, 248, 0.82);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.footer-link:hover,
.footer-link:focus-visible {
  color: var(--cyan);
  border-bottom-color: rgba(24, 214, 196, 0.6);
}

.footer-contact {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(1rem, 2vw, 1.75rem);
  padding-block: clamp(1.25rem, 2.5vw, 1.75rem);
  border-bottom: 1px solid var(--line-ice);
}

.footer-contact__item { display: grid; gap: 0.35rem; align-content: start; }

.footer-contact__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(244, 247, 248, 0.45);
}

.footer-contact__value {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--ice);
  overflow-wrap: anywhere;
}

.footer-hours {
  grid-column: 1 / -1;
  max-width: 72ch;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: rgba(244, 247, 248, 0.62);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  padding-top: clamp(1rem, 2vw, 1.5rem);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: rgba(244, 247, 248, 0.55);
}

.footer-legal__text { line-height: 1.6; }

.footer-legal__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.25rem;
}

.footer-legal__link {
  color: rgba(244, 247, 248, 0.62);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.footer-legal__link:hover,
.footer-legal__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: rgba(24, 214, 196, 0.55);
}

/* ---------- 18. 平板 ---------- */
@media (max-width: 1080px) {
  .bento-grid { grid-template-columns: repeat(8, minmax(0, 1fr)); }
  .bento--span3,
  .bento--span4,
  .bento--span5 { grid-column: span 4; }
  .bento--span6,
  .bento--span7,
  .bento--span8 { grid-column: span 8; }
  .footer-contact { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- 19. 移动 ---------- */
@media (max-width: 900px) {
  .header-rail { font-size: 0.625rem; letter-spacing: 0.12em; }
  .header-rail__label--muted { display: none; }
  .header-rail__ticks { display: none; }

  .masthead {
    grid-template-columns: minmax(0, 1fr);
    justify-items: center;
    gap: 0.5rem;
    position: relative;
  }
  .masthead__meta { display: none; }
  .masthead__side {
    position: absolute;
    right: var(--gutter);
    top: 50%;
    transform: translateY(-50%);
  }
  .header-utility { display: none; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    position: fixed;
    inset: auto 0 0 0;
    z-index: 80;
    max-height: 72vh;
    overflow-y: auto;
    border-top: 2px solid var(--cyan);
    box-shadow: 0 -24px 48px rgba(11, 27, 43, 0.5);
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }
  .site-header[data-open] .site-nav { display: block; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.35rem var(--gutter) 1rem;
  }
  .site-nav__item + .site-nav__item { border-top: 1px solid var(--line-ice); }
  .site-nav__link { display: block; padding: 0.95rem 0.25rem; font-size: 0.9375rem; }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] { background: rgba(24, 214, 196, 0.12); }
  .site-nav__link[aria-current="page"]::before {
    left: 0;
    top: 50%;
    margin-top: -2px;
  }

  body.is-nav-open { overflow: hidden; }

  .footer-top { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.25rem; }
  .footer-legal { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 720px) {
  .bento-grid { grid-template-columns: minmax(0, 1fr); }
  .bento { grid-column: 1 / -1; }
}

@media (max-width: 560px) {
  .masthead__brand { font-size: clamp(1.7rem, 8vw, 2.3rem); }
  .masthead__descriptor { font-size: 0.6875rem; letter-spacing: 0.1em; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-contact { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 20. 降低动效 ---------- */
@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;
  }

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

  .btn:hover { transform: none; }
  .header-rail__progress { transition: none; }
}