/* =========================================================
   MANBETX赛场 · /assets/site.css
   共享外壳 + 基础组件（reset / 变量 / 中文排版 / 刊头 / 页脚 / 通用件）
   ========================================================= */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 8.5rem;
}

body { margin: 0; }

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
summary { cursor: pointer; }
summary::-webkit-details-marker { display: none; }
[hidden] { display: none !important; }
main { display: block; }

/* ---------- 2. 设计变量 ---------- */
:root {
  --ink-900: #05070D;
  --ink-800: #0B1220;
  --ink-600: #16233A;
  --line: #24344F;
  --pulse: #38F5A5;
  --pulse-dim: #1E8F63;
  --volt: #FF7A2F;
  --paper: #F2F6FB;
  --fog: #9DB0C8;
  --mist: #D7E2F0;

  --font-display: "Manrope", "HarmonyOS Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", "Cascadia Mono", "Consolas", "Liberation Mono", monospace;

  --radius: 2px;
  --shell: min(1240px, 100% - 2.5rem);
  --gutter: clamp(1.25rem, 3vw, 2rem);
  --section: clamp(3.25rem, 8vw, 7rem);
  --gap: clamp(1rem, 2vw, 1.75rem);
  --ease: cubic-bezier(.22, .68, .32, 1);
  --masthead-h: 8.5rem;
}

/* ---------- 3. 页面基底与中文排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: clamp(1rem, .55vw + .88rem, 1.125rem);
  line-height: 1.7;
  font-weight: 400;
  letter-spacing: .01em;
  color: var(--mist);
  background-color: var(--ink-900);
  background-image:
    linear-gradient(90deg, rgba(36, 52, 79, .42) 1px, transparent 1px),
    linear-gradient(180deg, rgba(36, 52, 79, .32) 1px, transparent 1px);
  background-size: 88px 88px;
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.1;
  color: var(--paper);
}

h1 { font-size: clamp(2.6rem, 7.5vw, 6.4rem); font-weight: 900; line-height: .98; }
h2 { font-size: clamp(1.6rem, 3vw, 2.6rem); }
h3 { font-size: clamp(1.15rem, 1.6vw, 1.5rem); }

strong, b { font-weight: 700; color: var(--paper); }
time, code, kbd, samp { font-family: var(--font-mono); letter-spacing: .04em; }

::selection { background: var(--pulse); color: var(--ink-900); }

:focus-visible {
  outline: 2px solid var(--pulse);
  outline-offset: 2px;
}

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

.grid {
  display: grid;
  gap: var(--gap);
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.stack > * + * { margin-top: 1rem; }
.stack-lg > * + * { margin-top: clamp(1.75rem, 4vw, 3rem); }

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

/* ---------- 5. 文本层级件 ---------- */
.eyebrow {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .28em;
  text-transform: uppercase;
  color: var(--pulse);
}

.lede {
  font-size: clamp(1.05rem, 1.3vw, 1.28rem);
  line-height: 1.68;
  color: var(--mist);
  max-width: 52ch;
}

.prose {
  max-width: 68ch;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--mist);
}
.prose p + p { margin-top: 1.1em; }
.prose h2 { margin-top: 2.2em; margin-bottom: .7em; }
.prose h3 { margin-top: 1.8em; margin-bottom: .6em; }
.prose ul, .prose ol { margin: 1.1em 0; padding-left: 1.4em; list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: .5em; }
.prose a { color: var(--pulse); border-bottom: 1px solid var(--pulse-dim); }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .78rem 1.35rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: transparent;
  font-family: var(--font-body);
  font-size: .86rem;
  font-weight: 600;
  letter-spacing: .03em;
  color: var(--mist);
  transition: color .18s ease, border-color .18s ease, background-color .18s ease, transform .18s ease;
}
.btn:hover { border-color: var(--pulse); color: var(--paper); }
.btn:active { transform: translateY(1px); }

.btn--pulse {
  background: var(--pulse);
  border-color: var(--pulse);
  color: var(--ink-900);
  font-weight: 800;
}
.btn--pulse:hover { background: var(--pulse-dim); border-color: var(--pulse-dim); color: var(--paper); }

.btn--volt {
  background: var(--volt);
  border-color: var(--volt);
  color: var(--ink-900);
  font-weight: 800;
}
.btn--volt:hover { background: #e8651d; border-color: #e8651d; color: var(--ink-900); }

.btn--ghost { border-color: var(--line); color: var(--fog); }
.btn--ghost:hover { border-color: var(--pulse); color: var(--pulse); background: rgba(56, 245, 165, .06); }

/* ---------- 7. 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .45rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .14em;
  color: var(--fog);
}
.crumbs li { display: flex; align-items: center; gap: .45rem; }
.crumbs li::after { content: "/"; color: var(--line); }
.crumbs li:last-child::after { content: ""; }
.crumbs a { color: var(--fog); transition: color .16s ease; }
.crumbs a:hover { color: var(--pulse); }
.crumbs [aria-current="page"] { color: var(--paper); }

/* ---------- 8. 图片容器（供页面阶段放置图片） ---------- */
.figure {
  position: relative;
  overflow: hidden;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-600);
}
.figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .6s var(--ease);
}
.figure:hover img { transform: scale(1.03); }
.figure--wide { aspect-ratio: 21 / 9; }
.figure--tall { aspect-ratio: 4 / 5; }
.figure--square { aspect-ratio: 1 / 1; }

.figure--placeholder::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(135deg, rgba(56, 245, 165, .07) 0 2px, transparent 2px 10px);
}
.figure--placeholder::after {
  content: "赛场影像 / 数据光带";
  position: absolute;
  left: 1rem;
  bottom: .9rem;
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .22em;
  color: var(--fog);
}

.figure__caption {
  margin-top: .6rem;
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .12em;
  color: var(--fog);
}

/* ---------- 9. 章节体系 ---------- */
.chapter {
  position: relative;
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  column-gap: clamp(1rem, 2vw, 1.75rem);
  row-gap: 1.25rem;
  padding-block: var(--section);
  border-top: 1px solid var(--line);
}
.chapter__head { grid-column: 1 / -1; display: grid; gap: .7rem; }
.chapter__body { grid-column: 1 / -1; }
.chapter__label {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .28em;
  text-transform: uppercase;
  color: var(--pulse);
}
.chapter__title { font-size: clamp(1.6rem, 3vw, 2.6rem); }
.chapter__lead { color: var(--fog); max-width: 56ch; }
.chapter__num {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: clamp(3.5rem, 11vw, 8.75rem);
  line-height: .8;
  letter-spacing: .02em;
  color: rgba(242, 246, 251, .12);
  pointer-events: none;
  user-select: none;
}

/* ---------- 10. 数据条 ---------- */
.strip {
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.strip__cell {
  flex: 1 1 160px;
  display: grid;
  gap: .3rem;
  padding: .95rem 1.1rem;
  background: var(--ink-800);
}
.strip__key {
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--fog);
}
.strip__val {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  letter-spacing: .04em;
  color: var(--paper);
}
.strip__val--pulse { color: var(--pulse); }
.strip__val--volt { color: var(--volt); }

/* ---------- 11. 卡片 ---------- */
.card {
  display: block;
  padding: clamp(1rem, 2vw, 1.5rem);
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color .2s ease, background-color .2s ease;
}
.card:hover { border-color: var(--pulse-dim); }
.card--spot { border-left: 3px solid var(--pulse); }

/* ---------- 12. 分段切换 ---------- */
.segmented {
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.segmented__tab {
  flex: 1 1 auto;
  padding: .7rem 1.1rem;
  background: var(--ink-800);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .16em;
  text-align: center;
  color: var(--fog);
  transition: background-color .18s ease, color .18s ease;
}
.segmented__tab:hover { color: var(--paper); }
.segmented__tab[aria-selected="true"] {
  background: var(--pulse);
  color: var(--ink-900);
  font-weight: 700;
}
.segmented__panel { padding-top: 1.5rem; }

/* ---------- 13. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  left: 1rem;
  top: -5rem;
  z-index: 400;
  padding: .75rem 1.15rem;
  background: var(--pulse);
  color: var(--ink-900);
  font-weight: 800;
  font-size: .86rem;
  border-radius: var(--radius);
  transition: top .2s var(--ease);
}
.skip-link:focus { top: .9rem; }

/* ---------- 14. 滚动进度 ---------- */
.scroll-pulse {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 320;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--pulse) 0%, var(--pulse) 55%, var(--volt) 100%);
  pointer-events: none;
}

/* ---------- 15. 刊头 ---------- */
.masthead {
  position: sticky;
  top: 0;
  z-index: 300;
  background: rgba(5, 7, 13, .95);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.masthead__live {
  display: flex;
  align-items: center;
  gap: .55rem;
  max-height: 2.6rem;
  padding: .42rem var(--gutter);
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: .64rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--fog);
  transition: max-height .3s var(--ease), padding .3s var(--ease), opacity .2s ease, border-color .3s ease;
}
.masthead__live-dot {
  flex: none;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--pulse);
  animation: pulseRing 2.4s ease-out infinite;
}
.masthead.is-condensed .masthead__live {
  max-height: 0;
  padding-block: 0;
  opacity: 0;
  border-color: transparent;
}

@keyframes pulseRing {
  0%   { box-shadow: 0 0 0 0 rgba(56, 245, 165, .55); }
  70%  { box-shadow: 0 0 0 9px rgba(56, 245, 165, 0); }
  100% { box-shadow: 0 0 0 0 rgba(56, 245, 165, 0); }
}

.masthead__inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1rem;
  width: var(--shell);
  margin-inline: auto;
  padding-block: 1.15rem .9rem;
  transition: padding .3s var(--ease);
}
.masthead.is-condensed .masthead__inner { padding-block: .7rem; }

.masthead__nav--lead { justify-self: start; }
.masthead__nav--trail { justify-self: end; }
.masthead__list { display: flex; align-items: center; gap: clamp(.85rem, 2vw, 1.7rem); }
.masthead__item { display: flex; align-items: center; }

.masthead__link {
  position: relative;
  display: inline-block;
  padding-block: .35rem;
  font-size: .875rem;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--mist);
  transition: color .18s ease;
}
.masthead__link::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 1px;
  background: var(--pulse);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .22s var(--ease);
}
.masthead__link:hover { color: var(--paper); }
.masthead__link:hover::after { transform: scaleX(1); }
.masthead__link[aria-current="page"] { color: var(--pulse); }
.masthead__link[aria-current="page"]::after { transform: scaleX(1); }

.masthead__brand {
  display: grid;
  justify-items: center;
  gap: .2rem;
  text-align: center;
}
.masthead__wordmark {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.15rem, 2.1vw, 1.5rem);
  letter-spacing: -.02em;
  line-height: 1;
  color: var(--paper);
}
.masthead__wordmark-cn { margin-left: .14em; color: var(--pulse); }
.masthead__tagline {
  font-family: var(--font-mono);
  font-size: .58rem;
  line-height: 1;
  letter-spacing: .3em;
  color: var(--fog);
}

.masthead__toggle {
  display: none;
  align-items: center;
  gap: .55rem;
  padding: .55rem .8rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .2em;
  color: var(--mist);
  transition: border-color .18s ease, color .18s ease;
}
.masthead__toggle:hover { border-color: var(--pulse); color: var(--pulse); }
.masthead__bars { display: grid; gap: 3px; width: 14px; }
.masthead__bars i {
  display: block;
  height: 1.5px;
  background: currentColor;
  transition: transform .2s var(--ease), opacity .2s ease;
}
.masthead[data-open="true"] .masthead__bars i:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.masthead[data-open="true"] .masthead__bars i:nth-child(2) { opacity: 0; }
.masthead[data-open="true"] .masthead__bars i:nth-child(3) { transform: translateY(-4.5px) rotate(-45deg); }

.masthead__ticker {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .6rem 1.2rem;
  width: var(--shell);
  margin-inline: auto;
  padding-block: .55rem .7rem;
  border-top: 1px solid var(--line);
}
.masthead__brief {
  display: flex;
  align-items: baseline;
  gap: .55rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .06em;
  color: var(--fog);
}
.masthead__brief-key { letter-spacing: .2em; color: var(--volt); }
.masthead__brief-val { color: var(--mist); }

.masthead__tools { display: flex; flex-wrap: wrap; align-items: center; gap: .45rem; }
.masthead__tool {
  display: inline-block;
  padding: .4rem .78rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .06em;
  white-space: nowrap;
  color: var(--fog);
  transition: color .18s ease, border-color .18s ease, background-color .18s ease;
}
.masthead__tool:hover { color: var(--pulse); border-color: var(--pulse); }
.masthead__tool--pulse {
  background: var(--pulse);
  border-color: var(--pulse);
  color: var(--ink-900);
  font-weight: 700;
}
.masthead__tool--pulse:hover {
  background: var(--pulse-dim);
  border-color: var(--pulse-dim);
  color: var(--paper);
}

/* ---------- 16. 页脚 ---------- */
.sitefoot {
  position: relative;
  margin-top: clamp(4rem, 10vw, 8rem);
  background: var(--ink-800);
  border-top: 1px solid var(--line);
  color: var(--fog);
}
.sitefoot__band {
  height: 3px;
  background: linear-gradient(90deg, var(--pulse) 0 34%, var(--volt) 34% 42%, var(--line) 42% 100%);
}

.sitefoot__inner {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
  width: var(--shell);
  margin-inline: auto;
  padding-block: clamp(2.5rem, 6vw, 4.5rem);
}

.sitefoot__brand {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.35rem;
  letter-spacing: -.02em;
  color: var(--paper);
}
.sitefoot__brand span { margin-left: .16em; color: var(--pulse); }
.sitefoot__tagline {
  margin-top: .45rem;
  font-family: var(--font-mono);
  font-size: .64rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--fog);
}
.sitefoot__claim {
  margin-top: 1.1rem;
  max-width: 34ch;
  font-size: .9rem;
  line-height: 1.7;
  color: var(--fog);
}

.sitefoot__cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1.75rem 2rem;
}
.sitefoot__col-title {
  margin-bottom: .9rem;
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--pulse);
}
.sitefoot__col-list { display: grid; gap: .55rem; font-size: .9rem; }
.sitefoot__col-list a {
  display: inline-block;
  color: var(--mist);
  border-bottom: 1px solid transparent;
  transition: color .16s ease, border-color .16s ease;
}
.sitefoot__col-list a:hover { color: var(--pulse); border-color: var(--pulse); }

.sitefoot__updates {
  width: var(--shell);
  margin-inline: auto;
  padding-block: 1.1rem;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.timeline__summary {
  display: flex;
  align-items: baseline;
  gap: .9rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--fog);
}
.timeline__label { color: var(--paper); }
.timeline__hint { color: var(--fog); }
.timeline__summary::after {
  content: "+";
  margin-left: auto;
  color: var(--pulse);
  font-size: .95rem;
  line-height: 1;
}
.timeline[open] .timeline__summary::after { content: "−"; }

.timeline__list { margin-top: 1.1rem; border-top: 1px solid var(--line); }
.timeline__item {
  display: grid;
  grid-template-columns: 5.5rem minmax(0, 1fr);
  gap: 1rem;
  align-items: baseline;
  padding-block: .68rem;
  border-bottom: 1px solid var(--line);
  font-size: .9rem;
}
.timeline__item:last-child { border-bottom: 0; }
.timeline__time {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .12em;
  color: var(--pulse);
}
.timeline__text { color: var(--mist); }

.sitefoot__contact {
  display: grid;
  gap: 1rem;
  width: var(--shell);
  margin-inline: auto;
  padding-block: 1.7rem;
}
.sitefoot__contact-label {
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--volt);
}
.sitefoot__contact-body { display: grid; gap: 1rem; }
.sitefoot__contact-list { display: grid; gap: .8rem 1.5rem; }
.sitefoot__contact-item { display: grid; gap: .25rem; }
.sitefoot__contact-key {
  font-family: var(--font-mono);
  font-size: .6rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--fog);
}
.sitefoot__contact-val { font-size: .9rem; color: var(--paper); }
.sitefoot__contact-val--mono { font-family: var(--font-mono); letter-spacing: .04em; word-break: break-all; }
.sitefoot__contact-note { font-size: .8rem; line-height: 1.65; color: var(--fog); }

.sitefoot__legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .7rem 1.6rem;
  width: var(--shell);
  margin-inline: auto;
  padding-block: 1.2rem 2.2rem;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .12em;
  color: var(--fog);
}
.sitefoot__legal-links { display: flex; flex-wrap: wrap; gap: 1.2rem; }
.sitefoot__legal-links a { color: var(--fog); transition: color .16s ease; }
.sitefoot__legal-links a:hover { color: var(--pulse); }

/* ---------- 17. 入场显现 ---------- */
.reveal-in { animation: riseIn .52s var(--ease) both; animation-delay: var(--reveal-delay, 0ms); }
@keyframes riseIn {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: none; }
}

@keyframes fadeStep {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: none; }
}
@media (prefers-reduced-motion: no-preference) {
  .segmented__panel:not([hidden]) { animation: fadeStep .2s ease both; }
}

/* ---------- 18. 平板 ---------- */
@media (max-width: 960px) {
  .masthead__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: .65rem;
    padding-block: .85rem .7rem;
  }
  .masthead__brand {
    grid-column: 1;
    grid-row: 1;
    justify-self: start;
    justify-items: start;
    text-align: left;
  }
  .masthead__tagline { display: none; }
  .masthead__toggle { grid-column: 2; grid-row: 1; display: inline-flex; }

  .masthead__nav {
    grid-column: 1 / -1;
    display: none;
    width: 100%;
    justify-self: stretch;
    padding-top: .85rem;
    border-top: 1px solid var(--line);
  }
  .masthead__nav--lead { grid-row: 2; }
  .masthead__nav--trail { grid-row: 3; }
  .masthead[data-open="true"] .masthead__nav { display: block; }

  .masthead__list { flex-direction: column; align-items: stretch; gap: 0; }
  .masthead__item { border-bottom: 1px solid var(--line); }
  .masthead__item:last-child { border-bottom: 0; }
  .masthead__link { display: block; padding: .85rem .2rem; font-size: 1rem; }
  .masthead__link::after { display: none; }

  .masthead__ticker { padding-block: .5rem .65rem; }
  .masthead__brief { display: none; }
  .masthead__tools { width: 100%; justify-content: space-between; }

  .chapter__head,
  .chapter__body { grid-column: 1 / -1; }

  .sitefoot__contact-note { max-width: 60ch; }
}

/* ---------- 19. 桌面端 ---------- */
@media (min-width: 961px) {
  .chapter__head { grid-column: 1 / 9; }
  .chapter__body { grid-column: 1 / 9; }
  .chapter__num {
    grid-column: 9 / -1;
    justify-self: end;
    align-self: start;
    margin-top: -.15em;
    order: 2;
  }
  .sitefoot__inner { grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); }
  .sitefoot__contact { grid-template-columns: minmax(0, 3fr) minmax(0, 9fr); }
  .sitefoot__contact-list { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 961px) and (max-width: 1180px) {
  .chapter__head,
  .chapter__body { grid-column: 1 / -1; }
  .chapter__num { grid-column: 1 / -1; order: 0; }
}

/* ---------- 20. 手机 ---------- */
@media (max-width: 640px) {
  :root { --shell: min(1240px, 100% - 1.75rem); }

  h1 { font-size: clamp(2.3rem, 11vw, 3.2rem); }

  .masthead__tool { padding: .38rem .6rem; font-size: .66rem; }
  .masthead__toggle-text { display: none; }

  .timeline__item { grid-template-columns: 1fr; gap: .2rem; }
  .sitefoot__legal { flex-direction: column; align-items: flex-start; gap: .6rem; }
  .strip__cell { flex: 1 1 100%; }
}

/* ---------- 21. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .scroll-pulse { display: none; }
  .masthead__live-dot { animation: none; }
}