/* ============================================
   体看台 · 全站共享样式 /assets/site.css
   ============================================ */

/* ---------- 1. CSS Variables ---------- */
:root {
  /* 色彩体系 */
  --color-primary: #0A1F44;
  --color-primary-light: #16325B;
  --color-primary-lighter: #2C4E7A;
  --color-primary-tint: #D9E2EC;
  --color-accent-yellow: #FFD100;
  --color-accent-orange: #FF6B00;
  --color-base-white: #FFFFFF;
  --color-text-muted: #4A5B73;
  --color-border: #2C4E7A;
  --color-overlay: rgba(10, 31, 68, 0.8);
  --color-glass: rgba(10, 31, 68, 0.72);

  /* 渐变与纹理 */
  --gradient-yellow-orange: linear-gradient(90deg, #FFD100 0%, #FF6B00 100%);
  --gradient-header-fade: linear-gradient(to bottom, rgba(10, 31, 68, 0.88) 0%, rgba(10, 31, 68, 0.45) 60%, transparent 100%);
  --gradient-caption: linear-gradient(to top, rgba(10, 31, 68, 0.85) 0%, transparent 100%);

  /* 字体 */
  --font-display: 'Oswald', Impact, 'Arial Black', sans-serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'Roboto Mono', 'Consolas', monospace;

  /* 字号 */
  --font-hero: clamp(2.5rem, 6vw, 4.5rem);
  --font-section-title: clamp(1.8rem, 3vw, 2.5rem);
  --font-card-title: 1.25rem;
  --font-body-size: 1rem;
  --font-caption: 0.875rem;

  /* 布局 */
  --container-width: 1200px;
  --header-height: 72px;

  /* 间距 */
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;
  --space-7: 96px;
  --space-8: 128px;

  /* 缓动 */
  --ease-fast: 0.15s ease;
  --ease-standard: 0.25s ease;
  --ease-slow: 0.35s ease;
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  font-size: var(--font-body-size);
  line-height: 1.65;
  color: var(--color-primary);
  background-color: var(--color-base-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

ul,
ol {
  list-style: none;
}

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

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

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.5px;
}

h1 {
  font-size: var(--font-hero);
}

h2 {
  font-size: var(--font-section-title);
}

h3 {
  font-size: var(--font-card-title);
}

h4 {
  font-size: 1.125rem;
}

h5 {
  font-size: 1rem;
}

h6 {
  font-size: var(--font-caption);
}

p {
  margin-bottom: 1em;
}

p:last-child {
  margin-bottom: 0;
}

/* ---------- 3. 焦点可见性 ---------- */
:focus-visible {
  outline: 2px solid var(--color-accent-yellow);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: -200px;
  left: var(--space-2);
  z-index: 3000;
  background: var(--color-accent-yellow);
  color: var(--color-primary);
  font-weight: 600;
  font-size: 14px;
  padding: var(--space-2) var(--space-3);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 0 100%);
  transition: top var(--ease-standard);
}

.skip-link:focus {
  top: var(--space-2);
}

#main-content {
  display: block;
  outline: none;
  min-height: 60vh;
}

/* ---------- 5. 容器与区块 ---------- */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-3);
}

.container--narrow {
  max-width: 860px;
}

.container--wide {
  max-width: 1400px;
}

.section {
  padding: var(--space-7) 0;
}

.section--tight {
  padding: var(--space-5) 0;
}

.section--alt {
  background: var(--color-primary-tint);
}

.section--dark {
  background: var(--color-primary);
  color: var(--color-base-white);
}

/* ---------- 6. 栅格 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-4);
}

.grid--gap-sm {
  gap: var(--space-2);
}

.grid--gap-lg {
  gap: var(--space-5);
}

.col-span-3 {
  grid-column: span 3;
}

.col-span-4 {
  grid-column: span 4;
}

.col-span-5 {
  grid-column: span 5;
}

.col-span-6 {
  grid-column: span 6;
}

.col-span-7 {
  grid-column: span 7;
}

.col-span-8 {
  grid-column: span 8;
}

.col-span-9 {
  grid-column: span 9;
}

.col-span-12 {
  grid-column: span 12;
}

/* ---------- 7. 头部 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: var(--gradient-header-fade);
  transition: background-color var(--ease-standard), box-shadow var(--ease-standard), backdrop-filter var(--ease-standard);
}

.site-header[data-scrolled] {
  background: var(--color-overlay);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: 0 4px 24px rgba(10, 31, 68, 0.42);
  border-bottom: 1px solid rgba(217, 226, 236, 0.08);
}

.site-header__inner {
  max-width: var(--container-width);
  margin: 0 auto;
  height: 100%;
  padding: 0 var(--space-3);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.site-header__brand {
  flex-shrink: 0;
}

/* ---------- 8. 滚动进度条 ---------- */
.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: var(--gradient-yellow-orange);
  z-index: 10;
  transition: width 0.08s ease-out;
  pointer-events: none;
}

/* ---------- 9. 品牌标识 ---------- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}

.brand__mark {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--color-primary);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  overflow: hidden;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
  flex-shrink: 0;
}

.brand__char {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 24px;
  line-height: 1;
  color: var(--color-accent-yellow);
  transform: translateY(-1px);
  z-index: 1;
}

.brand__slash {
  position: absolute;
  top: 50%;
  left: -18%;
  width: 136%;
  height: 3px;
  background: var(--color-accent-orange);
  transform: rotate(-42deg);
  transform-origin: center;
  opacity: 0.92;
  z-index: 2;
}

.brand__text {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 22px;
  letter-spacing: 3px;
  color: var(--color-base-white);
  line-height: 1;
  white-space: nowrap;
}

.site-footer__brand {
  max-width: 360px;
}

.site-footer__brand .brand__text {
  color: var(--color-base-white);
}

/* ---------- 10. 导航 ---------- */
.site-nav {
  margin-left: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.site-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 10px 14px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.3px;
  color: var(--color-base-white);
  white-space: nowrap;
  position: relative;
  text-shadow: 0 1px 4px rgba(10, 31, 68, 0.65);
  transition: color var(--ease-fast), background-color var(--ease-fast);
}

.site-nav__link::after {
  content: '';
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 5px;
  height: 2px;
  background: var(--gradient-yellow-orange);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--ease-standard);
}

.site-nav__link:hover {
  color: var(--color-accent-yellow);
}

.site-nav__link:hover::after,
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-accent-yellow);
}

.site-nav__index {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 400;
  color: var(--color-accent-orange);
  letter-spacing: 0;
  line-height: 1;
  width: 20px;
  text-align: right;
  text-shadow: none;
}

.site-nav__item {
  position: relative;
}

/* ---------- 11. 汉堡按钮 ---------- */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 12px 10px;
  background: var(--color-primary);
  clip-path: polygon(0 0, calc(100% - 6px) 0, 100% 6px, 100% 100%, 0 100%);
  position: relative;
  z-index: 1002;
}

.nav-toggle__bar {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-base-white);
  transition: transform var(--ease-standard), opacity var(--ease-fast);
}

/* ---------- 12. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  border: none;
  cursor: pointer;
  background: transparent;
  color: var(--color-primary);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: transform var(--ease-standard), box-shadow var(--ease-standard), background-color var(--ease-standard), color var(--ease-standard);
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn--accent {
  background: var(--color-accent-yellow);
  color: var(--color-primary);
}

.btn--accent:hover {
  background: #FFD900;
  box-shadow: 0 6px 20px rgba(255, 209, 0, 0.35);
}

.btn--orange {
  background: var(--color-accent-orange);
  color: var(--color-base-white);
}

.btn--orange:hover {
  background: #FF7A1A;
  box-shadow: 0 6px 20px rgba(255, 107, 0, 0.3);
}

.btn--ghost {
  background: rgba(255, 255, 255, 0.12);
  color: var(--color-base-white);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.22);
  box-shadow: none;
}

.btn--ghost-dark {
  background: rgba(10, 31, 68, 0.08);
  color: var(--color-primary);
}

.btn--ghost-dark:hover {
  background: rgba(10, 31, 68, 0.15);
  box-shadow: none;
}

.header-cta {
  flex-shrink: 0;
}

/* ---------- 13. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: var(--space-4);
  font-size: 14px;
  color: var(--color-text-muted);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb__link {
  color: var(--color-text-muted);
  transition: color var(--ease-fast);
}

.breadcrumb__link:hover {
  color: var(--color-accent-orange);
}

.breadcrumb__current {
  color: var(--color-primary);
  font-weight: 600;
}

.breadcrumb__sep {
  color: var(--color-border);
  font-family: var(--font-mono);
  font-size: 11px;
}

/* ---------- 14. 章节标题组 ---------- */
.section-head {
  margin-bottom: var(--space-5);
}

.section-head__index {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--color-accent-orange);
}

.section-head__index::before {
  content: '';
  display: inline-block;
  width: 32px;
  height: 3px;
  background: var(--gradient-yellow-orange);
  transform: skewX(-45deg);
}

.section-head__title {
  margin-top: var(--space-2);
  color: var(--color-primary);
  letter-spacing: 1px;
  line-height: 1.15;
}

.section-head__desc {
  margin-top: var(--space-2);
  color: var(--color-text-muted);
  max-width: 680px;
}

.section--dark .section-head__title {
  color: var(--color-base-white);
}

.section--dark .section-head__desc {
  color: rgba(255, 255, 255, 0.65);
}

.section--dark .section-head__index {
  color: var(--color-accent-yellow);
}

/* ---------- 15. 卡片 ---------- */
.card {
  background: var(--color-base-white);
  border: 1px solid var(--color-border);
  padding: var(--space-4);
  position: relative;
  transition: transform var(--ease-standard), box-shadow var(--ease-standard), border-color var(--ease-standard);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(10, 31, 68, 0.12);
  border-color: var(--color-primary-lighter);
}

.card--dark {
  background: var(--color-primary);
  border-color: transparent;
  color: var(--color-base-white);
}

.card--dark:hover {
  box-shadow: 0 12px 28px rgba(10, 31, 68, 0.38);
  border-color: transparent;
}

.card--yellow {
  background: var(--color-accent-yellow);
  border-color: transparent;
  color: var(--color-primary);
}

.card--yellow:hover {
  box-shadow: 0 10px 24px rgba(255, 209, 0, 0.3);
  border-color: transparent;
}

.card--clip {
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 18px 100%, 0 calc(100% - 18px));
}

.card__title {
  font-size: var(--font-card-title);
  font-weight: 700;
  margin-bottom: var(--space-2);
  letter-spacing: 0.5px;
}

.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
  letter-spacing: 0.5px;
}

.card__body {
  font-size: 15px;
  line-height: 1.6;
  color: var(--color-text-muted);
}

.card--dark .card__body {
  color: rgba(255, 255, 255, 0.65);
}

.card--yellow .card__body {
  color: rgba(10, 31, 68, 0.75);
}

.card--dark .card__meta {
  color: rgba(255, 255, 255, 0.4);
}

.card--yellow .card__meta {
  color: rgba(10, 31, 68, 0.6);
}

/* ---------- 16. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.5px;
  background: var(--color-primary-tint);
  color: var(--color-primary);
}

.tag--yellow {
  background: var(--color-accent-yellow);
  color: var(--color-primary);
}

.tag--orange {
  background: var(--color-accent-orange);
  color: var(--color-base-white);
}

.tag--outline {
  background: transparent;
  border: 1px solid var(--color-border);
}

/* ---------- 17. 控制台面板 ---------- */
.panel {
  background: rgba(10, 31, 68, 0.04);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent-orange);
  padding: var(--space-3) var(--space-4);
  margin-bottom: var(--space-3);
}

.panel--status {
  border-left-color: var(--color-accent-yellow);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.3px;
  background: rgba(10, 31, 68, 0.06);
}

.panel--dark {
  background: var(--color-primary);
  border-color: var(--color-primary);
  border-left-color: var(--color-accent-yellow);
  color: var(--color-base-white);
}

/* ---------- 18. 数据统计 ---------- */
.stat {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 600;
  color: var(--color-primary);
  line-height: 1;
  letter-spacing: -1px;
}

.stat--yellow {
  color: var(--color-accent-yellow);
}

.stat--orange {
  color: var(--color-accent-orange);
}

.stat__label {
  display: block;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 400;
  color: var(--color-text-muted);
  margin-top: var(--space-1);
  letter-spacing: 0.5px;
}

/* ---------- 19. 图片容器 ---------- */
.figure {
  position: relative;
  overflow: hidden;
  background: var(--color-primary);
}

.figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.45s ease;
}

.figure:hover img {
  transform: scale(1.03);
}

.figure--16-9 {
  aspect-ratio: 16 / 9;
}

.figure--4-3 {
  aspect-ratio: 4 / 3;
}

.figure--1-1 {
  aspect-ratio: 1 / 1;
}

.figure--3-2 {
  aspect-ratio: 3 / 2;
}

.figure--21-9 {
  aspect-ratio: 21 / 9;
}

.figure--clip {
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 24px 100%, 0 calc(100% - 24px));
}

.figure--clipped {
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 24px 100%, 0 calc(100% - 24px));
}

.figure__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  right: 0;
  padding: var(--space-3);
  background: var(--gradient-caption);
  color: var(--color-base-white);
  font-size: 13px;
  font-weight: 500;
  line-height: 1.5;
}

/* ---------- 20. 正文排版 ---------- */
.prose {
  max-width: 720px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--color-text-muted);
}

.prose h2 {
  margin-top: var(--space-5);
  margin-bottom: var(--space-2);
  color: var(--color-primary);
}

.prose h3 {
  margin-top: var(--space-4);
  margin-bottom: var(--space-2);
  color: var(--color-primary);
}

.prose p {
  margin-bottom: var(--space-3);
}

.prose ul,
.prose ol {
  padding-left: 1.5em;
  margin-bottom: var(--space-3);
}

.prose ul {
  list-style: disc;
}

.prose ol {
  list-style: decimal;
}

.prose li {
  margin-bottom: 0.5em;
}

.prose a {
  color: var(--color-primary);
  font-weight: 500;
  border-bottom: 2px solid var(--color-accent-yellow);
  transition: border-color var(--ease-fast), color var(--ease-fast);
}

.prose a:hover {
  border-bottom-color: var(--color-accent-orange);
  color: var(--color-accent-orange);
}

/* ---------- 21. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--color-primary);
  color: rgba(255, 255, 255, 0.85);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-yellow-orange);
  z-index: 2;
}

.site-footer::after {
  content: '';
  position: absolute;
  right: -80px;
  bottom: -80px;
  width: 240px;
  height: 240px;
  background: rgba(255, 107, 0, 0.1);
  transform: rotate(45deg);
  pointer-events: none;
}

.site-footer__top {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: var(--space-7) var(--space-3) var(--space-5);
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.6fr;
  gap: var(--space-5);
  position: relative;
  z-index: 1;
}

.site-footer__trust {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.55);
  margin-top: var(--space-3);
  max-width: 320px;
  border-left: 3px solid var(--color-accent-yellow);
  padding-left: var(--space-2);
}

.site-footer__heading {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--color-accent-yellow);
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  position: relative;
}

.site-footer__heading::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 36px;
  height: 2px;
  background: var(--gradient-yellow-orange);
  transform: skewX(-45deg);
}

.site-footer__nav ul,
.site-footer__legal ul,
.site-footer__contact ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.site-footer__nav a,
.site-footer__legal a {
  color: rgba(255, 255, 255, 0.72);
  font-size: 14px;
  transition: color var(--ease-fast), padding-left var(--ease-fast);
}

.site-footer__nav a:hover,
.site-footer__legal a:hover {
  color: var(--color-accent-yellow);
  padding-left: 4px;
}

.site-footer__contact li {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.52);
  line-height: 1.65;
  word-break: break-all;
}

.site-footer__bottom {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: var(--space-3) var(--space-3);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: var(--space-2) var(--space-5);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.42);
  position: relative;
  z-index: 1;
}

.site-footer__bottom p {
  margin: 0;
}

/* ---------- 22. 平板响应 ---------- */
@media (max-width: 991px) {
  .nav-toggle {
    display: inline-flex;
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
    opacity: 0;
    transform: scaleX(0.5);
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }

  .site-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    z-index: 1001;
    max-height: calc(100vh - var(--header-height));
    overflow-y: auto;
    background: var(--color-primary);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    padding: var(--space-2) 0 var(--space-3);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-12px);
    transition: transform var(--ease-standard), opacity var(--ease-standard), visibility 0s var(--ease-standard);
  }

  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    transition: transform var(--ease-standard), opacity var(--ease-standard);
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__item {
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .site-nav__item:last-child {
    border-bottom: none;
  }

  .site-nav__link {
    display: flex;
    align-items: center;
    padding: 14px var(--space-3);
    font-size: 16px;
    text-shadow: none;
  }

  .site-nav__link::after {
    display: none;
  }

  .site-nav__link[aria-current="page"] {
    background: rgba(255, 209, 0, 0.1);
    border-left: 3px solid var(--color-accent-yellow);
    color: var(--color-accent-yellow);
  }

  .site-nav__index {
    font-size: 12px;
    width: 32px;
    text-align: left;
    color: var(--color-accent-orange);
  }

  .header-cta {
    margin-left: auto;
    padding: 10px 18px;
    font-size: 13px;
  }

  .col-span-3,
  .col-span-4,
  .col-span-5 {
    grid-column: span 6;
  }

  .col-span-6,
  .col-span-7,
  .col-span-8,
  .col-span-9 {
    grid-column: span 12;
  }

  .site-footer__top {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4) var(--space-5);
  }

  .site-footer__brand {
    grid-column: span 2;
  }
}

/* ---------- 23. 手机响应 ---------- */
@media (max-width: 599px) {
  :root {
    --header-height: 64px;
  }

  .site-header__inner {
    padding: 0 var(--space-2);
    gap: var(--space-1);
  }

  .brand__mark {
    width: 38px;
    height: 38px;
  }

  .brand__char {
    font-size: 21px;
  }

  .brand__text {
    font-size: 20px;
    letter-spacing: 2px;
  }

  .header-cta {
    padding: 9px 14px;
    font-size: 12px;
  }

  .section {
    padding: var(--space-6) 0;
  }

  .section--tight {
    padding: var(--space-4) 0;
  }

  .grid {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .col-span-3,
  .col-span-4,
  .col-span-5,
  .col-span-6,
  .col-span-7,
  .col-span-8,
  .col-span-9,
  .col-span-12 {
    grid-column: span 1;
  }

  .site-footer__top {
    grid-template-columns: 1fr;
    padding: var(--space-6) var(--space-3) var(--space-4);
  }

  .site-footer__brand {
    grid-column: span 1;
  }

  .site-footer__bottom {
    flex-direction: column;
    text-align: center;
    gap: var(--space-1);
  }

  .figure__caption {
    padding: var(--space-2);
    font-size: 12px;
  }

  .card {
    padding: var(--space-3);
  }
}

/* ---------- 24. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

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

  .scroll-progress {
    transition: none;
  }

  .brand__slash {
    transition: none;
  }
}