/* ==========================================================================
   球速赛场 — /assets/site.css
   共享层：reset / 设计变量 / 中文排版 / 刊头 / 栏目 / 页脚 /
   通用按钮 / 面包屑 / 容器网格 / 基础数据组件 / 图片容器
   ========================================================================== */

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

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

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--c-deep);
  color: var(--c-paper);
  font-family: var(--f-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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, picture { display: block; max-width: 100%; }
a { color: var(--c-cyan); text-decoration-thickness: 1px; text-underline-offset: 3px; }
button { font: inherit; color: inherit; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; height: 1px; background: var(--c-line); }

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

.u-visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ---------- 2. 设计变量 ---------- */
:root {
  /* 色彩 */
  --c-deep:   #071A2F;
  --c-navy:   #0D2742;
  --c-cyan:   #26E0FF;
  --c-lime:   #B6FF3B;
  --c-alert:  #FF5A36;
  --c-paper:  #F4F8FB;
  --c-mist:   #9BB0C3;
  --c-ink:    #02070D;
  --c-line:   #1E4766;
  --focus:    #B6FF3B;

  /* 字体 */
  --f-display: 'Barlow Condensed', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --f-body:    'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --f-mono:    'JetBrains Mono', 'Roboto Mono', 'SFMono-Regular', Consolas, monospace;

  /* 字号 */
  --fs-hero:    clamp(2.6rem, 7vw, 5.5rem);
  --fs-section: clamp(1.7rem, 3.6vw, 2.75rem);
  --fs-data:    clamp(2.2rem, 5vw, 4.5rem);
  --fs-body:    clamp(1rem, 0.35vw + 0.92rem, 1.125rem);
  --fs-small:   clamp(0.72rem, 0.18vw + 0.68rem, 0.8125rem);

  /* 间距 */
  --sp-1: 4px;  --sp-2: 8px;  --sp-3: 12px;
  --sp-4: 16px; --sp-5: 24px; --sp-6: 32px;
  --sp-7: 48px; --sp-8: 64px; --sp-9: 96px;

  /* 结构 */
  --shell-max: 1200px;
  --gutter: clamp(16px, 4vw, 40px);
  --radius-soft: 14px;

  /* 动效 */
  --speed: 200ms;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 中文排版基线 ---------- */
p, li, dd, dt { word-break: break-word; }
h1, h2, h3, h4 { text-wrap: balance; }
p { text-wrap: pretty; }

/* ---------- 4. 跳过导航 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--c-lime);
  color: var(--c-ink);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  border: 2px solid var(--c-ink);
  transform: translateY(-180%);
  transition: transform 0.18s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline: 3px solid var(--c-cyan);
  outline-offset: 2px;
}

/* ---------- 5. 容器与网格 ---------- */
.container {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

@media (max-width: 1000px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 820px) {
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 600px) {
  .grid--4 { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 6. 区块 ---------- */
.section {
  position: relative;
  padding-block: clamp(40px, 6vw, 80px);
}
.section--paper {
  background: var(--c-paper);
  color: var(--c-ink);
}
.section--navy {
  background: var(--c-navy);
}

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px 32px;
  margin-bottom: clamp(20px, 3vw, 34px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--c-cyan);
}
.eyebrow::before {
  content: "";
  width: 18px;
  height: 2px;
  background: currentColor;
}

.section-title {
  margin-top: 8px;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: var(--fs-section);
  line-height: 1.15;
  letter-spacing: -0.01em;
}

.lede {
  max-width: 62ch;
  font-size: var(--fs-body);
  color: var(--c-mist);
}
.section--paper .lede { color: #3D5468; }

/* ---------- 7. 刊头 ---------- */
.site-header {
  position: relative;
  z-index: 60;
  background: var(--c-deep);
  border-bottom: 1px solid var(--c-line);
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(30, 71, 102, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 71, 102, 0.32) 1px, transparent 1px);
  background-size: 64px 64px, 64px 64px;
  opacity: 0.55;
  -webkit-mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.9), transparent 94%);
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.9), transparent 94%);
}

/* 顶部滚动进度条 */
.scroll-meter {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 200;
  pointer-events: none;
}
.scroll-meter__fill {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-lime));
}

.masthead {
  position: relative;
  z-index: 1;
}
.masthead__tick {
  display: block;
  height: 6px;
  background: repeating-linear-gradient(90deg, var(--c-cyan) 0 2px, transparent 2px 16px);
  opacity: 0.32;
}

.masthead__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  grid-template-areas: "tagline brand entry";
  align-items: center;
  gap: clamp(12px, 2.5vw, 36px);
  padding-block: clamp(14px, 2.2vw, 22px) clamp(12px, 2vw, 18px);
}

.masthead__tagline {
  grid-area: tagline;
  justify-self: start;
  max-width: 24ch;
  font-size: var(--fs-small);
  line-height: 1.65;
  letter-spacing: 0.06em;
  color: var(--c-mist);
}

.masthead__brand {
  grid-area: brand;
  justify-self: center;
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: var(--c-paper);
  text-decoration: none;
  transition: transform var(--speed) var(--ease);
}
.masthead__brand:hover { transform: translateY(-2px); }
.masthead__brand:focus-visible { outline: 2px solid var(--c-lime); outline-offset: 4px; }

.masthead__mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  font-family: var(--f-mono);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--c-deep);
  background: linear-gradient(135deg, var(--c-cyan), var(--c-lime));
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
}

.masthead__nameline {
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.masthead__title {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(1.35rem, 2.6vw, 2rem);
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--c-paper);
}
.masthead__sub {
  font-family: var(--f-mono);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.3em;
  color: var(--c-cyan);
}

/* 短路径浮层 */
.quick-entry {
  grid-area: entry;
  justify-self: end;
  display: inline-flex;
  flex-direction: column;
  gap: 2px;
  padding: 8px 22px 9px 18px;
  text-decoration: none;
  background: rgba(38, 224, 255, 0.12);
  box-shadow: inset 0 0 0 1px rgba(38, 224, 255, 0.5);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  transition: background var(--speed) var(--ease), transform var(--speed) var(--ease);
}
.quick-entry__label {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--c-paper);
}
.quick-entry__route {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-lime);
}
.quick-entry:hover {
  background: rgba(38, 224, 255, 0.24);
  transform: translateY(-2px);
}
.quick-entry:focus-visible {
  outline: 2px solid var(--c-lime);
  outline-offset: 3px;
}

/* ---------- 8. 栏目条 ---------- */
.nav-shell {
  position: relative;
  z-index: 1;
  background: var(--c-navy);
  border-top: 1px solid rgba(30, 71, 102, 0.9);
  border-bottom: 1px solid rgba(30, 71, 102, 0.9);
}
.nav-shell__inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  position: relative;
}

.site-nav { width: 100%; }
.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: clamp(2px, 1.2vw, 22px);
}
.site-nav__item { position: relative; }

.site-nav__link {
  position: relative;
  display: block;
  padding: 14px 8px 15px;
  color: var(--c-mist);
  font-size: 14.5px;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-decoration: none;
  transition: color var(--speed) var(--ease);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 8px;
  right: 8px;
  bottom: 7px;
  height: 2px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--speed) var(--ease), background var(--speed) var(--ease);
}
.site-nav__link:hover { color: var(--c-paper); }
.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] { color: var(--c-cyan); }
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--c-lime);
}

.site-nav__link:focus-visible {
  outline: 2px solid var(--c-lime);
  outline-offset: 2px;
  color: var(--c-paper);
}

/* 移动栏目按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 20px;
  background: rgba(38, 224, 255, 0.08);
  border: 0;
  box-shadow: inset 0 0 0 1px var(--c-line);
  color: var(--c-paper);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.16em;
  cursor: pointer;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
  transition: background var(--speed) var(--ease), color var(--speed) var(--ease);
}
.nav-toggle:hover { background: rgba(38, 224, 255, 0.18); color: var(--c-cyan); }
.nav-toggle:focus-visible { outline: 2px solid var(--c-lime); outline-offset: 3px; }

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 16px;
}
.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: var(--c-cyan);
  transition: transform var(--speed) var(--ease), opacity var(--speed) var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

/* 移动端栏目状态 */
@media (max-width: 860px) {
  .masthead__inner {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas: "brand" "tagline" "entry";
    justify-items: center;
    text-align: center;
    gap: 12px;
    padding-block: 16px 14px;
  }
  .masthead__tagline { max-width: 30ch; }
  .quick-entry { padding: 7px 18px 8px 16px; }

  .nav-shell__inner {
    flex-direction: column;
    align-items: stretch;
    padding-block: 8px;
  }
  .nav-toggle {
    display: inline-flex;
    align-self: center;
  }
  .site-nav {
    display: none;
    margin-top: 10px;
  }
  .site-nav[data-open] { display: block; }
  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .site-nav__item { border-top: 1px solid rgba(30, 71, 102, 0.7); }
  .site-nav__item:first-child { border-top: 0; }
  .site-nav__link {
    padding: 14px 6px;
    text-align: center;
    font-size: 15px;
  }
  .site-nav__link::after { left: 35%; right: 35%; bottom: 8px; }
}

/* ---------- 9. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--c-ink);
  color: var(--c-paper);
  border-top: 1px solid var(--c-line);
}

.footer__ticks {
  display: block;
  height: 8px;
  background: repeating-linear-gradient(90deg, rgba(38, 224, 255, 0.55) 0 2px, transparent 2px 18px);
  opacity: 0.5;
}

.footer__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr) minmax(0, 1.25fr);
  gap: clamp(24px, 4vw, 56px);
  padding-block: clamp(34px, 5vw, 58px);
  border-bottom: 1px solid rgba(30, 71, 102, 0.7);
}

.footer__brand {
  display: inline-block;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(1.45rem, 2.6vw, 2rem);
  line-height: 1.1;
  letter-spacing: 0.04em;
  color: var(--c-paper);
  text-decoration: none;
  transition: color var(--speed) var(--ease);
}
.footer__brand:hover { color: var(--c-cyan); }
.footer__brand:focus-visible { outline: 2px solid var(--c-lime); outline-offset: 3px; }

.footer__summary {
  margin-top: 12px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-mist);
}

.footer__nav-title,
.footer__contact-title {
  margin-bottom: 14px;
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.26em;
  color: var(--c-cyan);
}

.footer__nav-list { display: grid; gap: 9px; }

.footer__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--c-paper);
  font-size: 14px;
  text-decoration: none;
  transition: color var(--speed) var(--ease), transform var(--speed) var(--ease);
}
.footer__link::before {
  content: "";
  width: 10px;
  height: 2px;
  background: var(--c-line);
  transition: background var(--speed) var(--ease), width var(--speed) var(--ease);
}
.footer__link:hover { color: var(--c-lime); transform: translateX(3px); }
.footer__link:hover::before { background: var(--c-lime); width: 16px; }
.footer__link:focus-visible {
  outline: 2px solid var(--c-lime);
  outline-offset: 3px;
  color: var(--c-lime);
}

.footer__contact-list { display: grid; gap: 10px; }

.footer__contact-row {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 10px;
  font-size: 13.5px;
  line-height: 1.65;
}
.footer__contact-row dt {
  padding-top: 2px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--c-mist);
}
.footer__contact-row dd {
  margin: 0;
  color: var(--c-paper);
  word-break: break-word;
}

.footer__note {
  margin-top: 14px;
  padding-left: 10px;
  border-left: 2px solid var(--c-alert);
  font-size: 12px;
  line-height: 1.7;
  color: var(--c-mist);
}

.footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-block: 18px 22px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--c-mist);
}
.footer__copyright { margin: 0; }
.footer__icp {
  margin: 0;
  font-family: var(--f-mono);
  letter-spacing: 0.06em;
}

@media (max-width: 1000px) {
  .footer__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }
  .footer__brand-block { grid-column: 1 / -1; }
}
@media (max-width: 640px) {
  .footer__grid { grid-template-columns: minmax(0, 1fr); }
  .footer__base {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

/* ---------- 10. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 26px;
  font-family: var(--f-body);
  font-size: 14.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-decoration: none;
  border: 0;
  cursor: pointer;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  transition: transform var(--speed) var(--ease), background var(--speed) var(--ease),
              color var(--speed) var(--ease), box-shadow var(--speed) var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn:focus-visible { outline: 2px solid var(--c-lime); outline-offset: 3px; }

.btn--primary {
  background: var(--c-cyan);
  color: var(--c-ink);
}
.btn--primary:hover { background: #5CEBFF; }

.btn--lime {
  background: var(--c-lime);
  color: var(--c-ink);
}
.btn--lime:hover { background: #C9FF6B; }

.btn--ghost {
  background: transparent;
  color: var(--c-paper);
  box-shadow: inset 0 0 0 1px var(--c-line);
}
.btn--ghost:hover {
  color: var(--c-cyan);
  box-shadow: inset 0 0 0 1px var(--c-cyan);
}

.btn--alert {
  background: var(--c-alert);
  color: var(--c-ink);
}
.btn--alert:hover { background: #FF7455; }

/* ---------- 11. 面包屑 ---------- */
.breadcrumbs { padding-block: 16px 0; }

.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--c-mist);
}
.breadcrumbs__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  color: var(--c-line);
}
.breadcrumbs__link {
  color: var(--c-mist);
  text-decoration: none;
  transition: color var(--speed) var(--ease);
}
.breadcrumbs__link:hover { color: var(--c-cyan); }
.breadcrumbs__link:focus-visible { outline: 2px solid var(--c-lime); outline-offset: 2px; }
.breadcrumbs__current { color: var(--c-paper); }

/* ---------- 12. 数据组件 ---------- */
.metric {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.metric__value {
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: var(--fs-data);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-paper);
}
.metric__label {
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--c-mist);
}
.metric--lime .metric__value { color: var(--c-lime); }
.metric--cyan .metric__value { color: var(--c-cyan); }
.metric--alert .metric__value { color: var(--c-alert); }

.data-figure {
  display: inline-flex;
  align-items: baseline;
  gap: 4px;
  font-family: var(--f-mono);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.01em;
}
.data-figure__value {
  font-size: var(--fs-data);
  color: var(--c-paper);
}
.data-figure__unit {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--c-mist);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 600;
  line-height: 1.7;
  letter-spacing: 0.1em;
  box-shadow: inset 0 0 0 1px currentColor;
}
.tag--cyan { color: var(--c-cyan); }
.tag--lime { color: var(--c-lime); }
.tag--alert { color: var(--c-alert); }
.tag--solid {
  background: var(--c-lime);
  color: var(--c-ink);
  box-shadow: none;
}

.rule-ticks {
  height: 10px;
  background: repeating-linear-gradient(90deg, var(--c-line) 0 1px, transparent 1px 12px);
  opacity: 0.9;
}

/* ---------- 13. 斜切卡片 ---------- */
.slant-card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  background: var(--c-navy);
  color: var(--c-paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
  transition: transform var(--speed) var(--ease), background var(--speed) var(--ease);
}
.slant-card:hover {
  transform: translateY(-3px);
  background: #12314F;
}
.slant-card:focus-within {
  outline: 2px solid var(--c-lime);
  outline-offset: 3px;
}
.section--paper .slant-card {
  background: #FFFFFF;
  color: var(--c-ink);
}
.section--paper .slant-card:hover { background: #EDF4FA; }

/* ---------- 14. 正文长文 ---------- */
.prose {
  max-width: 70ch;
  font-size: var(--fs-body);
  line-height: 1.72;
  color: var(--c-paper);
}
.prose > * + * { margin-top: 1.1em; }
.prose h2,
.prose h3 {
  font-family: var(--f-display);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin-top: 1.8em;
}
.prose h2 { font-size: clamp(1.5rem, 2.6vw, 2rem); }
.prose h3 { font-size: clamp(1.15rem, 1.8vw, 1.35rem); }
.prose ul,
.prose ol {
  padding-left: 1.25em;
  list-style: disc;
}
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 0.4em; }
.prose a { color: var(--c-cyan); }
.prose strong { font-weight: 700; color: var(--c-paper); }

.prose--paper { color: #17293B; }
.prose--paper strong { color: var(--c-ink); }
.prose--paper a { color: #0A6E8A; }

/* ---------- 15. 图片容器（为页面阶段预留） ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(140deg, var(--c-navy), var(--c-deep));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}
.media-frame__inner {
  position: relative;
  aspect-ratio: 16 / 9;
  background-image:
    repeating-linear-gradient(90deg, rgba(38, 224, 255, 0.16) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(0deg, rgba(38, 224, 255, 0.1) 0 1px, transparent 1px 34px);
}
.media-frame__inner > img,
.media-frame__inner > svg,
.media-frame__inner > picture {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide .media-frame__inner { aspect-ratio: 21 / 9; }
.media-frame--square .media-frame__inner { aspect-ratio: 1 / 1; }
.media-frame--portrait .media-frame__inner { aspect-ratio: 4 / 5; }

.media-frame__caption {
  display: block;
  padding: 10px 14px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-mist);
  box-shadow: inset 0 1px 0 rgba(30, 71, 102, 0.85);
}

/* ---------- 16. 滚动显现 ---------- */
html.has-reveal .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
html.has-reveal .reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 17. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(12px, 3vw, 28px);
  bottom: clamp(12px, 3vw, 28px);
  z-index: 120;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  padding: 0;
  background: var(--c-navy);
  border: 0;
  box-shadow: inset 0 0 0 1px var(--c-line);
  color: var(--c-cyan);
  font-family: var(--f-mono);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--speed) var(--ease), transform var(--speed) var(--ease),
              visibility var(--speed), background var(--speed) var(--ease), color var(--speed) var(--ease);
}
.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.to-top:hover {
  background: rgba(38, 224, 255, 0.16);
  color: var(--c-lime);
}
.to-top:focus-visible { outline: 2px solid var(--c-lime); outline-offset: 3px; }

/* ---------- 18. 降低动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  html { scroll-behavior: auto; }
  html.has-reveal .reveal {
    opacity: 1;
    transform: none;
  }
  .btn:hover,
  .slant-card:hover,
  .quick-entry:hover,
  .masthead__brand:hover,
  .site-nav__link:hover::after { transform: none; }
}