/* ============================================================
   安博体育主站 · /assets/site.css
   共享壳层：reset / 设计令牌 / 中文排版 / 页眉 / 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;
  scroll-padding-top: 168px;
}

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

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

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

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

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

a { color: inherit; }

/* ---------- 2 · 设计令牌 ---------- */
:root {
  --clay: #A63A28;
  --clay-deep: #6E2418;
  --sky: #1E6FA8;
  --deep: #0E2A42;
  --jade: #17855B;
  --jade-deep: #0F6B49;
  --orange: #F26722;
  --orange-deep: #D9531A;
  --paper: #F7F3EA;
  --paper-dim: #EFE9DC;
  --ink: #12161A;
  --sand: #DDD6C7;
  --amber: #F2B233;
  --mint: #5FCB9B;
  --white: #FFFFFF;

  --font-sans: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: "Noto Serif SC", Georgia, "Songti SC", "SimSun", serif;
  --font-mono: "IBM Plex Mono", "Sarasa Mono SC", ui-monospace, SFMono-Regular,
    Menlo, Consolas, monospace;

  --wrap: 1440px;
  --gut: clamp(18px, 4vw, 40px);
  --gap: clamp(20px, 3vw, 40px);
  --header-h: 118px;
}

/* ---------- 3 · 纸面与中文排版 ---------- */
body {
  min-height: 100vh;
  padding-bottom: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.85;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    repeating-linear-gradient(0deg, rgba(14, 42, 66, 0.022) 0 1px, transparent 1px 4px),
    repeating-linear-gradient(90deg, rgba(166, 58, 40, 0.016) 0 1px, transparent 1px 5px),
    radial-gradient(circle at 14% 4%, rgba(242, 103, 34, 0.055), transparent 46%),
    radial-gradient(circle at 86% 0%, rgba(30, 111, 168, 0.06), transparent 42%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 800;
  color: var(--deep);
  line-height: 1.18;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2.4rem, 6.5vw, 5.2rem); font-weight: 900; line-height: 1.02; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.5rem, 3vw, 2.4rem); font-weight: 700; line-height: 1.2; }
h3 { font-size: clamp(1.15rem, 1.8vw, 1.5rem); font-weight: 700; }

p { max-width: 34em; }

strong { font-weight: 800; color: var(--deep); }

::selection { background: rgba(242, 103, 34, 0.28); color: var(--deep); }

:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 2px;
  border-radius: 1px;
}

/* ---------- 4 · 容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gut);
}

.prose {
  max-width: 34em;
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.9;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.prose > * + * { margin-top: 1em; }

.prose h2 { margin-top: 1.8em; }
.prose h3 { margin-top: 1.4em; }

.prose ul { list-style: disc; padding-left: 1.4em; }
.prose ol { list-style: decimal; padding-left: 1.4em; }
.prose li { margin: 0.3em 0; }

.prose a {
  color: var(--sky);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.prose a:hover { color: var(--clay); }

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clay);
}

.rule {
  height: 1px;
  border: 0;
  margin: clamp(24px, 4vw, 44px) 0;
  background: linear-gradient(90deg, var(--deep) 0 42px, var(--sand) 42px 100%);
}

/* ---------- 5 · 页眉：进度条 + 数据栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--paper);
}

.progress-track {
  position: fixed;
  inset: 0 0 auto 0;
  height: 3px;
  z-index: 120;
  background: rgba(14, 42, 66, 0.16);
  pointer-events: none;
}

.progress-track__fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--clay) 0%, var(--orange) 78%, #FFB069 100%);
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -70px;
  z-index: 200;
  padding: 11px 18px;
  background: var(--deep);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  border: 1px solid var(--sand);
  transition: top 0.18s ease;
}

.skip-link:focus { top: 12px; }

.masthead {
  background: var(--deep);
  color: var(--paper);
  border-bottom: 1px solid var(--deep);
}

.masthead__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 13px var(--gut);
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: center;
  gap: clamp(14px, 2.6vw, 36px);
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 3px;
  text-decoration: none;
  color: inherit;
}

.brand__mark {
  font-family: var(--font-sans);
  font-size: 23px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--white);
}

.brand__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.22em;
  color: #8FBBDC;
}

.roundline {
  justify-self: start;
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: none;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1;
  letter-spacing: 0.1em;
  color: #BBD3E6;
  white-space: nowrap;
}

.roundline__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--jade);
  box-shadow: 0 0 0 3px rgba(23, 133, 91, 0.28);
}

.roundline__sep { color: rgba(187, 211, 230, 0.4); }
.roundline__note { color: var(--amber); }

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

/* ---------- 6 · 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid transparent;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease,
    border-color 0.18s ease, transform 0.18s ease;
}

.btn--solid {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--white);
}
.btn--solid:hover { background: var(--orange-deep); border-color: var(--orange-deep); }
.btn--solid:active { transform: translateY(1px); }

.btn--line {
  background: transparent;
  border-color: rgba(247, 243, 234, 0.42);
  color: var(--paper);
}
.btn--line:hover { border-color: var(--orange); color: var(--orange); }

.btn--ghost {
  background: transparent;
  border-color: var(--deep);
  color: var(--deep);
}
.btn--ghost:hover { background: var(--deep); color: var(--paper); }

/* ---------- 7 · 导航开关 ---------- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  background: transparent;
  border: 1px solid rgba(247, 243, 234, 0.42);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  cursor: pointer;
  transition: border-color 0.18s ease, color 0.18s ease;
}

.nav-toggle:hover { border-color: var(--orange); color: var(--orange); }
.nav-toggle[aria-expanded="true"] {
  background: var(--clay);
  border-color: var(--clay);
  color: var(--white);
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 16px;
}

.nav-toggle__bars i {
  display: block;
  height: 2px;
  background: currentColor;
}

/* ---------- 8 · 框架式导航带 ---------- */
.frame-nav {
  background: var(--paper);
  border-bottom: 1px solid var(--deep);
}

.frame-nav__list {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gut);
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
}

.frame-nav__item { border-right: 1px solid var(--deep); }
.frame-nav__item:first-child { border-left: 1px solid var(--deep); }

.frame-nav__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 12px 20px;
  text-decoration: none;
  color: var(--deep);
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  transition: background-color 0.18s ease, color 0.18s ease;
}

.frame-nav__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--sky);
  transition: color 0.18s ease;
}

.frame-nav__link:hover { background: rgba(166, 58, 40, 0.08); color: var(--clay); }
.frame-nav__link:hover .frame-nav__num { color: var(--clay); }

.frame-nav__link[aria-current="page"] { background: var(--deep); color: var(--paper); }
.frame-nav__link[aria-current="page"] .frame-nav__num { color: var(--orange); }

/* ---------- 9 · 移动端底部数据条 ---------- */
.dock {
  display: none;
  position: fixed;
  inset: auto 0 0 0;
  z-index: 95;
  background: var(--deep);
  border-top: 3px solid var(--orange);
  padding-bottom: env(safe-area-inset-bottom, 0);
}

.dock__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.dock__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 9px 4px 8px;
  border-right: 1px solid rgba(247, 243, 234, 0.12);
  color: #BBD3E6;
  font-size: 12px;
  font-weight: 600;
  line-height: 1.2;
  text-decoration: none;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.dock__item:last-child { border-right: 0; }
.dock__item:hover { color: var(--paper); background: rgba(247, 243, 234, 0.06); }

.dock__num {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--sky);
}

.dock__item[aria-current="page"] { color: var(--orange); }
.dock__item[aria-current="page"] .dock__num { color: var(--orange); }

/* ---------- 10 · 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 96px);
  background-color: var(--clay-deep);
  color: var(--paper);
}

.footer-terrain {
  height: 16px;
  background-color: var(--clay);
  background-image:
    repeating-linear-gradient(100deg, rgba(247, 243, 234, 0.16) 0 2px, transparent 2px 11px),
    repeating-linear-gradient(80deg, rgba(242, 178, 51, 0.2) 0 2px, transparent 2px 17px),
    linear-gradient(90deg, var(--clay-deep) 0%, var(--clay) 30%, var(--orange) 62%, var(--clay) 100%);
}

.site-footer__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(34px, 5vw, 58px) var(--gut) clamp(24px, 4vw, 38px);
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.3fr;
  gap: clamp(22px, 3.4vw, 48px);
  background-image:
    repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.07) 0 1px, transparent 1px 4px),
    repeating-linear-gradient(90deg, rgba(0, 0, 0, 0.055) 0 1px, transparent 1px 5px);
}

.footer-col__title {
  margin: 0 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(247, 243, 234, 0.22);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--amber);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 5px;
  text-decoration: none;
}

.footer-brand__mark {
  font-size: 25px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--white);
}

.footer-brand__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.22em;
  color: var(--amber);
}

.footer-col__text {
  margin-top: 15px;
  max-width: 26em;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(247, 243, 234, 0.72);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer-links a {
  font-size: 15px;
  line-height: 1.5;
  color: rgba(247, 243, 234, 0.82);
  text-decoration: none;
  transition: color 0.18s ease;
}

.footer-links a:hover {
  color: var(--orange);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-links a[aria-current="page"] { color: var(--orange); }

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-contact li {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.footer-contact__key {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: rgba(242, 178, 51, 0.85);
}

.footer-contact__val {
  align-self: flex-start;
  padding: 0 0 2px;
  background: none;
  border: 0;
  border-bottom: 1px dashed rgba(247, 243, 234, 0.35);
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.5;
  letter-spacing: 0.02em;
  text-align: left;
  color: rgba(247, 243, 234, 0.92);
  cursor: pointer;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.footer-contact__val:hover { color: var(--orange); border-bottom-color: var(--orange); }
.footer-contact__val[data-copied="true"] { color: var(--mint); border-bottom-color: var(--mint); }

.footer-contact__val--static {
  cursor: default;
  border-bottom-color: transparent;
  font-family: var(--font-sans);
  font-size: 15px;
}

.footer-contact__val--static:hover {
  color: rgba(247, 243, 234, 0.92);
  border-bottom-color: transparent;
}

.footer-note {
  margin-top: 14px;
  max-width: 32em;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(247, 243, 234, 0.62);
}

.site-footer__legalbar {
  border-top: 1px solid rgba(247, 243, 234, 0.2);
}

.site-footer__legal {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 16px var(--gut) calc(22px + env(safe-area-inset-bottom, 0px));
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: rgba(247, 243, 234, 0.66);
}

.site-footer__sep {
  width: 18px;
  height: 1px;
  background: rgba(247, 243, 234, 0.35);
}

/* ---------- 11 · 编辑部骨架 ---------- */
.shell {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gut);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
  align-items: start;
}

.shell__main { min-width: 0; }

@media (min-width: 1100px) {
  .shell {
    grid-template-columns: 220px minmax(0, 1fr) 260px;
    gap: clamp(24px, 2.6vw, 44px);
  }
}

.rail {
  align-self: start;
  position: sticky;
  top: calc(var(--header-h) + 20px);
}

.rail__title {
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--sand);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clay);
}

.rail__list { display: flex; flex-direction: column; }

.rail__link {
  display: block;
  padding: 8px 0 8px 12px;
  border-left: 2px solid transparent;
  font-size: 14px;
  line-height: 1.45;
  color: var(--deep);
  text-decoration: none;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.rail__link:hover { color: var(--clay); border-left-color: var(--sand); }

.rail__link[aria-current] {
  color: var(--clay);
  font-weight: 700;
  border-left-color: var(--orange);
  background: rgba(166, 58, 40, 0.06);
}

@media (min-width: 1100px) {
  .shell__rail { position: relative; }
}

/* ---------- 12 · 章节标题组 ---------- */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--deep);
  margin-bottom: clamp(20px, 3vw, 34px);
}

.section-head__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--clay);
}

.section-head__title {
  margin: 0;
  font-size: clamp(1.4rem, 2.6vw, 2.1rem);
  font-weight: 800;
  color: var(--deep);
}

/* ---------- 13 · chips ---------- */
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 12px;
  border: 1px solid var(--deep);
  background: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--deep);
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.chip:hover { background: var(--deep); color: var(--paper); }
.chip.is-active,
.chip[aria-pressed="true"] {
  background: var(--clay);
  border-color: var(--clay);
  color: var(--white);
}

/* ---------- 14 · 数据板与数据格 ---------- */
.data-board {
  position: relative;
  overflow: hidden;
  padding: clamp(18px, 3vw, 30px);
  background: var(--deep);
  color: var(--paper);
  border: 1px solid var(--deep);
}

.data-board::after {
  content: "";
  position: absolute;
  inset: 0 0 0 auto;
  width: 44%;
  pointer-events: none;
  background: linear-gradient(135deg, transparent 42%, rgba(30, 111, 168, 0.34) 100%);
}

.data-board__label {
  position: relative;
  z-index: 1;
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--amber);
}

.data-board__value {
  position: relative;
  z-index: 1;
  display: block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(40px, 7vw, 84px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1px;
  background: var(--sand);
  border: 1px solid var(--sand);
}

.stat {
  padding: 18px 20px 20px;
  background: var(--paper);
}

.stat__value {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(34px, 5vw, 62px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--clay);
}

.stat__label {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--sky);
}

/* ---------- 15 · 面板与折叠 ---------- */
.panel {
  border: 1px solid var(--deep);
  background: #FDFBF6;
  box-shadow: 0 6px 0 -3px rgba(14, 42, 66, 0.1);
}

.panel__head {
  padding: 13px 18px;
  border-bottom: 1px solid var(--sand);
  background: var(--paper-dim);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--clay);
}

.panel__body { padding: clamp(16px, 2.4vw, 24px); }

.disclosure {
  border: 1px solid var(--deep);
  background: #FDFBF6;
}

.disclosure + .disclosure { margin-top: -1px; }

.disclosure > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 18px;
  font-size: 16px;
  font-weight: 700;
  color: var(--deep);
  cursor: pointer;
  list-style: none;
}

.disclosure > summary::-webkit-details-marker { display: none; }

.disclosure > summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--orange);
}

.disclosure[open] > summary::after { content: "\2013"; }
.disclosure[open] > summary { background: var(--paper-dim); }

.disclosure__body {
  padding: 0 18px 18px;
  max-width: 38em;
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
}

/* ---------- 16 · 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--sky);
}

.breadcrumbs a { color: var(--sky); text-decoration: none; }
.breadcrumbs a:hover { color: var(--clay); text-decoration: underline; text-underline-offset: 3px; }
.breadcrumbs__sep { color: var(--sand); }

/* ---------- 17 · 图片容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--deep);
  background-color: var(--paper-dim);
  background-image:
    radial-gradient(circle at 22% 18%, rgba(166, 58, 40, 0.16), transparent 52%),
    radial-gradient(circle at 82% 76%, rgba(30, 111, 168, 0.16), transparent 50%),
    repeating-linear-gradient(115deg, rgba(14, 42, 66, 0.05) 0 1px, transparent 1px 6px);
}

.media-frame img,
.media-frame picture img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: contrast(1.06) saturate(0.94);
}

.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--3x4 { aspect-ratio: 3 / 4; }
.media-frame--21x9 { aspect-ratio: 21 / 9; }

.media-frame__caption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 10px 14px;
  background: linear-gradient(0deg, rgba(14, 42, 66, 0.88), rgba(14, 42, 66, 0));
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--paper);
}

/* ---------- 18 · 响应式：平板 ---------- */
@media (max-width: 1099px) {
  .rail {
    position: static;
    border: 1px solid var(--sand);
    background: rgba(255, 255, 255, 0.45);
    padding: 16px 18px;
  }
}

@media (max-width: 900px) {
  html { scroll-padding-top: 120px; }

  body { padding-bottom: 66px; }

  .masthead__inner {
    grid-template-columns: minmax(0, 1fr) auto auto;
    align-items: center;
    gap: 10px 12px;
    padding: 11px var(--gut) 12px;
  }

  .brand { grid-column: 1; grid-row: 1; }
  .brand__mark { font-size: 19px; }
  .brand__tag { letter-spacing: 0.18em; }

  .masthead__actions { grid-column: 2; grid-row: 1; }
  .masthead__actions .btn--line { display: none; }
  .masthead__actions .btn--solid { padding: 9px 13px; font-size: 13px; }

  .nav-toggle { grid-column: 3; grid-row: 1; display: inline-flex; }

  .roundline {
    grid-column: 1 / -1;
    grid-row: 2;
    justify-self: start;
    font-size: 11px;
    white-space: normal;
  }

  .frame-nav {
    max-height: 0;
    overflow: hidden;
    border-bottom: 0;
    transition: max-height 0.3s ease;
  }

  .frame-nav[data-open] {
    max-height: 72vh;
    overflow-y: auto;
    border-bottom: 1px solid var(--deep);
  }

  .frame-nav__list { flex-direction: column; }

  .frame-nav__item,
  .frame-nav__item:first-child {
    border-left: 0;
    border-right: 0;
    border-bottom: 1px solid var(--sand);
  }

  .frame-nav__item:last-child { border-bottom: 0; }

  .frame-nav__link {
    padding: 15px 4px;
    font-size: 16px;
  }

  .dock { display: block; }

  .site-footer__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 28px 24px;
  }

  .footer-col--brand { grid-column: 1 / -1; }
}

/* ---------- 19 · 响应式：手机 ---------- */
@media (max-width: 560px) {
  body { font-size: 16px; }

  .site-footer__inner { grid-template-columns: minmax(0, 1fr); }

  .site-footer__legal {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .site-footer__sep { display: none; }

  .stat-grid { grid-template-columns: minmax(0, 1fr); }

  .btn { padding: 11px 15px; }
}

/* ---------- 20 · 动效与可访问性 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .progress-track__fill { transition: none; }
}