/* ==========================================================
   OB赛场 共享样式表 /assets/site.css
   设计基调：技术蓝图式网格 · 运动档案局 · 左右分置导航
   ========================================================== */

/* ---------- 1. CSS 变量 ---------- */
:root {
  /* 色彩令牌 */
  --ob-primary: #0A1E3C;
  --ob-primary-2: #1B3A5C;
  --ob-accent: #FF6B35;
  --ob-live: #39FF14;
  --ob-sand: #D9C8A7;
  --ob-bg: #F5F6F8;
  --ob-text: #111111;
  --ob-white: #FFFFFF;

  /* 字体令牌 */
  --ob-font-heading: 'Archivo Black', 'Noto Sans SC', sans-serif;
  --ob-font-body: 'Open Sans', 'Noto Sans SC', sans-serif;
  --ob-font-data: 'JetBrains Mono', 'Noto Sans SC', monospace;
  --ob-fs-h1: 2rem;
  --ob-fs-h2: 1.5rem;
  --ob-fs-body: 1rem;
  --ob-fs-data: 0.875rem;

  /* 布局令牌 */
  --ob-container: 1200px;
  --ob-gutter: 24px;
  --ob-radius: 4px;
  --ob-shadow: 0 2px 10px rgba(10, 30, 60, 0.08);
  --ob-shadow-sm: 0 1px 4px rgba(10, 30, 60, 0.06);

  /* 动效令牌 */
  --ob-duration: 0.2s;
  --ob-easing: cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  font-family: var(--ob-font-body);
  font-size: var(--ob-fs-body);
  line-height: 1.75;
  color: var(--ob-text);
  background-color: var(--ob-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

ul,
ol {
  list-style: none;
}

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

a {
  color: inherit;
}

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

/* ---------- 3. 基础排版 ---------- */
h1,
h2,
h3,
h4 {
  font-family: var(--ob-font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--ob-primary);
}

h1 {
  font-size: var(--ob-fs-h1);
}

h2 {
  font-size: var(--ob-fs-h2);
}

h3 {
  font-size: 1.125rem;
}

code,
pre {
  font-family: var(--ob-font-data);
}

/* ---------- 4. 焦点与选区 ---------- */
:focus-visible {
  outline: 2px solid var(--ob-accent);
  outline-offset: 2px;
}

::selection {
  background: var(--ob-accent);
  color: var(--ob-white);
}

/* ---------- 5. 容器与工具类 ---------- */
.container {
  max-width: var(--ob-container);
  margin-inline: auto;
  padding-inline: var(--ob-gutter);
}

.container-narrow {
  max-width: 840px;
  margin-inline: auto;
  padding-inline: var(--ob-gutter);
}

.py-md {
  padding-block: 2rem;
}

.py-lg {
  padding-block: 4rem;
}

.mt-md {
  margin-top: 2rem;
}

.mt-lg {
  margin-top: 4rem;
}

/* ---------- 6. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--ob-primary);
  background-image:
    linear-gradient(rgba(217, 200, 167, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(217, 200, 167, 0.05) 1px, transparent 1px);
  background-size: 32px 32px;
  color: var(--ob-white);
}

/* 无障碍跳过链接 */
.skip-link {
  position: absolute;
  top: 0.25rem;
  left: 0.25rem;
  transform: translateY(-200%);
  background: var(--ob-accent);
  color: var(--ob-white);
  padding: 0.625rem 1.25rem;
  font-family: var(--ob-font-data);
  font-size: 0.875rem;
  font-weight: 700;
  text-decoration: none;
  z-index: 999;
  transition: transform var(--ob-duration) ease;
}

.skip-link:focus {
  transform: translateY(0);
}

/* 顶部传送条 */
.teleport-bar {
  background: var(--ob-primary);
  border-bottom: 1px solid rgba(217, 200, 167, 0.2);
  font-family: var(--ob-font-data);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  position: relative;
  overflow: hidden;
}

.teleport-bar::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 4px;
  background: var(--ob-accent);
  transform: skewX(-15deg);
}

.teleport-inner {
  display: flex;
  align-items: center;
}

.teleport-link {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  color: var(--ob-sand);
  text-decoration: none;
  padding: 0.375rem 0;
  width: 100%;
  transition: color var(--ob-duration) ease;
}

.teleport-link:hover {
  color: var(--ob-white);
}

.teleport-arrow {
  color: var(--ob-accent);
  font-size: 1rem;
  line-height: 1;
}

.teleport-text {
  flex: 1;
}

.teleport-code {
  color: rgba(217, 200, 167, 0.5);
  font-size: 0.625rem;
  letter-spacing: 0.25em;
  border: 1px solid rgba(217, 200, 167, 0.2);
  padding: 0.125rem 0.5rem;
}

/* 头部主区 */
.header-main {
  position: relative;
  border-bottom: 1px solid rgba(217, 200, 167, 0.15);
}

.header-main::after {
  content: '';
  position: absolute;
  bottom: -1px;
  right: 8%;
  width: 56px;
  height: 3px;
  background: var(--ob-accent);
  transform: skewX(-30deg);
  z-index: 2;
  pointer-events: none;
}

.header-main-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 68px;
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  flex-shrink: 0;
}

.brand-logo {
  position: relative;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--ob-white);
  overflow: hidden;
  flex-shrink: 0;
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 0 0 1px rgba(10, 30, 60, 0.1);
}

.brand-logo-half {
  position: absolute;
  top: 0;
  height: 100%;
  width: 50%;
}

.brand-logo-left {
  left: 0;
  background: var(--ob-primary);
}

.brand-logo-right {
  right: 0;
  background: var(--ob-accent);
}

.brand-logo-speed {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 60%;
  height: 2px;
  background: var(--ob-white);
  z-index: 2;
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.brand-name {
  font-family: var(--ob-font-heading);
  font-size: 1.5rem;
  color: var(--ob-white);
  line-height: 1.1;
  letter-spacing: 0.02em;
}

.brand-sub {
  font-family: var(--ob-font-data);
  font-size: 0.625rem;
  color: rgba(217, 200, 167, 0.6);
  letter-spacing: 0.25em;
  line-height: 1.2;
}

/* 主导航 */
.site-nav {
  display: flex;
  align-items: center;
  gap: 0.125rem;
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  color: rgba(255, 255, 255, 0.85);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.5rem 0.625rem;
  transition: color var(--ob-duration) ease;
  white-space: nowrap;
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 0.625rem;
  right: 0.625rem;
  bottom: 0;
  height: 2px;
  background: var(--ob-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--ob-duration) var(--ob-easing);
}

.nav-link:hover {
  color: var(--ob-white);
}

.nav-link:hover::after {
  transform: scaleX(1);
}

.nav-link[aria-current="page"] {
  color: var(--ob-accent);
}

.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-index {
  font-family: var(--ob-font-data);
  font-size: 0.625rem;
  color: var(--ob-accent);
  opacity: 0.7;
  letter-spacing: 0.05em;
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
}

/* 滚动进度条 */
.header-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  width: 0%;
  background: linear-gradient(90deg, var(--ob-accent) 0%, var(--ob-live) 100%);
  z-index: 5;
  pointer-events: none;
  transition: width 0.1s linear;
}

/* ---------- 7. 页脚 ---------- */
.site-footer {
  background-color: var(--ob-primary);
  background-image:
    linear-gradient(rgba(217, 200, 167, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(217, 200, 167, 0.04) 1px, transparent 1px);
  background-size: 28px 28px;
  color: rgba(255, 255, 255, 0.75);
  margin-top: 4rem;
  position: relative;
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg,
    var(--ob-accent) 0%,
    var(--ob-accent) 34%,
    var(--ob-live) 34%,
    var(--ob-live) 66%,
    var(--ob-sand) 66%,
    var(--ob-sand) 100%);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2.2fr 1fr 1fr 1.6fr;
  gap: 2.5rem;
  padding: 3rem 0 2.5rem;
}

.footer-brand-col .brand {
  margin-bottom: 1rem;
}

.brand--footer .brand-logo {
  width: 36px;
  height: 36px;
}

.brand--footer .brand-name {
  font-size: 1.25rem;
}

.footer-trust {
  font-size: 0.8125rem;
  line-height: 1.75;
  color: rgba(217, 200, 167, 0.7);
  max-width: 34ch;
}

.footer-heading {
  font-family: var(--ob-font-data);
  font-size: 0.75rem;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--ob-accent);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid rgba(217, 200, 167, 0.2);
}

.footer-link-list {
  display: grid;
  gap: 0.5rem;
}

.footer-link-item a {
  color: rgba(255, 255, 255, 0.75);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color var(--ob-duration) ease, padding-left var(--ob-duration) ease;
}

.footer-link-item a:hover {
  color: var(--ob-accent);
  padding-left: 0.25rem;
}

.footer-contact-list {
  display: grid;
  gap: 0.75rem;
}

.footer-contact-item {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
  font-size: 0.8125rem;
}

.contact-label {
  font-family: var(--ob-font-data);
  font-size: 0.625rem;
  color: var(--ob-sand);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.contact-value {
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.5;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding: 1.25rem 0;
  border-top: 1px solid rgba(217, 200, 167, 0.15);
  font-family: var(--ob-font-data);
  font-size: 0.6875rem;
  color: rgba(217, 200, 167, 0.5);
}

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

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

/* 返回顶部按钮 */
.scroll-top-btn {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  width: 44px;
  height: 44px;
  border-radius: 0;
  background: var(--ob-accent);
  color: var(--ob-white);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(255, 107, 53, 0.35);
  z-index: 90;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--ob-duration) ease, transform var(--ob-duration) ease, visibility var(--ob-duration) ease, background var(--ob-duration) ease;
}

.scroll-top-btn.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-top-btn:hover {
  background: var(--ob-primary-2);
}

.scroll-top-icon {
  font-size: 1.25rem;
  line-height: 1;
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  padding: 0.75rem 1.5rem;
  font-family: var(--ob-font-data);
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border-radius: 0;
  border: 1px solid transparent;
  background: transparent;
  color: var(--ob-primary);
  cursor: pointer;
  text-decoration: none;
  position: relative;
  overflow: hidden;
  transition: background var(--ob-duration) ease, color var(--ob-duration) ease, border-color var(--ob-duration) ease, transform 0.1s ease;
}

.btn::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  width: 100%;
  background: currentColor;
  transform: translateX(-101%);
  transition: transform var(--ob-duration) var(--ob-easing);
}

.btn:hover::after {
  transform: translateX(0);
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--ob-accent);
  color: var(--ob-white);
  border-color: var(--ob-accent);
}

.btn-primary:hover {
  background: #e85a2a;
  border-color: #e85a2a;
}

.btn-outline {
  border-color: var(--ob-primary-2);
  color: var(--ob-primary);
}

.btn-outline:hover {
  border-color: var(--ob-accent);
  color: var(--ob-accent);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.75rem;
}

/* ---------- 9. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  font-family: var(--ob-font-data);
  font-size: 0.75rem;
  line-height: 1.4;
  border: 1px solid var(--ob-primary-2);
  color: var(--ob-primary-2);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: transparent;
}

.tag-solid {
  background: var(--ob-primary-2);
  color: var(--ob-white);
  border-color: var(--ob-primary-2);
}

.tag-accent {
  background: var(--ob-accent);
  border-color: var(--ob-accent);
  color: var(--ob-white);
}

.tag-live {
  background: rgba(57, 255, 20, 0.12);
  border-color: var(--ob-live);
  color: var(--ob-primary);
}

.tag-live::before {
  content: '●';
  font-size: 0.5rem;
  margin-right: 0.375rem;
  color: var(--ob-live);
  animation: ob-pulse 2s ease-in-out infinite;
}

@keyframes ob-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

/* ---------- 10. 档案卡片 ---------- */
.card {
  position: relative;
  background: var(--ob-white);
  border: 1px solid #E2E6ED;
  border-radius: var(--ob-radius);
  box-shadow: var(--ob-shadow-sm);
  padding: 1.5rem;
  transition: border-color var(--ob-duration) ease, box-shadow var(--ob-duration) ease;
}

.card:hover {
  border-color: var(--ob-accent);
  box-shadow: var(--ob-shadow);
}

.card-index {
  position: absolute;
  top: 0.75rem;
  right: 1rem;
  font-family: var(--ob-font-data);
  font-size: 0.6875rem;
  color: var(--ob-primary-2);
  letter-spacing: 0.1em;
}

.card-title {
  font-family: var(--ob-font-heading);
  font-size: 1.125rem;
  color: var(--ob-primary);
  margin-bottom: 0.75rem;
  padding-right: 2rem;
}

.card-body {
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--ob-text);
}

/* ---------- 11. 章节标签与标题 ---------- */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--ob-font-data);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ob-accent);
}

.section-label::before {
  content: '';
  width: 24px;
  height: 1px;
  background: var(--ob-sand);
}

.section-title {
  font-family: var(--ob-font-heading);
  font-size: clamp(1.5rem, 3vw, 2rem);
  color: var(--ob-primary);
  line-height: 1.2;
  margin-top: 0.5rem;
  margin-bottom: 1.5rem;
}

/* ---------- 12. 面包屑 ---------- */
.breadcrumb {
  font-family: var(--ob-font-data);
  font-size: 0.75rem;
  color: var(--ob-primary-2);
  padding: 0.75rem 0;
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: '/';
  margin-right: 0.375rem;
  color: var(--ob-sand);
}

.breadcrumb-item a {
  color: var(--ob-primary);
  text-decoration: none;
}

.breadcrumb-item a:hover {
  color: var(--ob-accent);
}

.breadcrumb-item[aria-current="page"] {
  color: var(--ob-accent);
}

/* ---------- 13. 页面头部 ---------- */
.page-header {
  padding: 3rem 0 2rem;
  background: var(--ob-primary);
  color: var(--ob-white);
  position: relative;
  overflow: hidden;
}

.page-header::after {
  content: '';
  position: absolute;
  bottom: 0;
  right: 10%;
  width: 80px;
  height: 4px;
  background: var(--ob-accent);
  transform: skewX(-30deg);
}

.page-header-title {
  font-family: var(--ob-font-heading);
  font-size: clamp(2rem, 4vw, 3rem);
  color: var(--ob-white);
  line-height: 1.15;
}

.page-header-sub {
  margin-top: 0.5rem;
  font-family: var(--ob-font-data);
  font-size: 0.875rem;
  color: var(--ob-sand);
  letter-spacing: 0.08em;
}

/* ---------- 14. 网格系统 ---------- */
.grid-8 {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: var(--ob-gutter);
}

.col-span-2 { grid-column: span 2; }
.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-8 { grid-column: span 8; }

/* ---------- 15. 正文排版 ---------- */
.prose {
  max-width: 70ch;
  line-height: 1.8;
}

.prose h2 {
  font-size: 1.5rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

.prose h3 {
  font-size: 1.125rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.prose p {
  margin-bottom: 1.25rem;
}

.prose a {
  color: var(--ob-accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.prose a:hover {
  color: var(--ob-primary);
}

.prose ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
}

.prose ol {
  list-style: decimal;
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
}

.prose li {
  margin-bottom: 0.375rem;
}

.prose blockquote {
  border-left: 3px solid var(--ob-sand);
  padding-left: 1rem;
  margin: 1.5rem 0;
  color: var(--ob-primary-2);
  font-style: italic;
}

/* ---------- 16. 图片框架 ---------- */
.image-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background-color: var(--ob-primary-2);
  background-image:
    linear-gradient(rgba(217, 200, 167, 0.12) 1px, transparent 1px),
    linear-gradient(90deg, rgba(217, 200, 167, 0.12) 1px, transparent 1px);
  background-size: 20px 20px;
  border: 1px solid rgba(217, 200, 167, 0.25);
  line-height: 0;
}

.image-frame::before {
  content: 'IMG';
  position: absolute;
  top: 0.5rem;
  right: 0.75rem;
  font-family: var(--ob-font-data);
  font-size: 0.625rem;
  color: rgba(255, 255, 255, 0.6);
  background: rgba(10, 30, 60, 0.75);
  padding: 0.125rem 0.375rem;
  letter-spacing: 0.1em;
  z-index: 2;
  line-height: 1.4;
}

.image-frame::after {
  content: '';
  position: absolute;
  inset: 0;
  border: 1px solid rgba(255, 255, 255, 0.08);
  pointer-events: none;
  z-index: 1;
}

.image-frame img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

.image-frame-16x9 { aspect-ratio: 16 / 9; }
.image-frame-4x3 { aspect-ratio: 4 / 3; }
.image-frame-3x2 { aspect-ratio: 3 / 2; }
.image-frame-1x1 { aspect-ratio: 1 / 1; }

/* ---------- 17. 数据值展示 ---------- */
.data-values {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
}

.data-value {
  font-family: var(--ob-font-data);
  font-size: 1.75rem;
  color: var(--ob-primary);
  line-height: 1.2;
}

.data-value-label {
  display: block;
  font-size: 0.6875rem;
  color: var(--ob-primary-2);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-top: 0.25rem;
}

/* ---------- 18. 响应式 ---------- */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }

  .grid-8 {
    grid-template-columns: repeat(4, 1fr);
  }

  .col-span-2,
  .col-span-3,
  .col-span-5,
  .col-span-6 {
    grid-column: span 4;
  }

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

@media (max-width: 960px) {
  /* 移动导航 */
  .nav-toggle {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.25rem;
    background: transparent;
    border: 1px solid rgba(217, 200, 167, 0.4);
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    color: var(--ob-white);
    line-height: 1;
    transition: border-color var(--ob-duration) ease;
  }

  .nav-toggle:hover {
    border-color: var(--ob-accent);
  }

  .nav-toggle-bars {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 20px;
  }

  .nav-toggle-bar {
    display: block;
    height: 2px;
    background: var(--ob-white);
    width: 100%;
    transition: transform 0.3s var(--ob-easing), opacity 0.3s var(--ob-easing);
  }

  .nav-toggle.is-active .nav-toggle-bar:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }

  .nav-toggle.is-active .nav-toggle-bar:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.is-active .nav-toggle-bar:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }

  .nav-toggle-label {
    font-family: var(--ob-font-data);
    font-size: 0.625rem;
    color: var(--ob-sand);
    letter-spacing: 0.08em;
  }

  /* 导航折叠面板 */
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    background: var(--ob-primary);
    margin: 0;
    padding: 0;
    border-top: 1px solid rgba(217, 200, 167, 0.15);
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    opacity: 0;
    transition: max-height 0.35s var(--ob-easing), opacity 0.25s ease, visibility 0.25s ease;
  }

  .site-nav[data-open="true"] {
    max-height: 480px;
    overflow-y: auto;
    visibility: visible;
    opacity: 1;
    border-bottom: 1px solid rgba(217, 200, 167, 0.15);
  }

  .nav-link {
    display: flex;
    gap: 0.75rem;
    padding: 0.875rem var(--ob-gutter);
    border-top: 1px solid rgba(217, 200, 167, 0.08);
    font-size: 0.9375rem;
    white-space: normal;
  }

  .nav-link::after {
    display: none;
  }

  .nav-link[aria-current="page"] {
    background: rgba(255, 107, 53, 0.08);
    border-left: 3px solid var(--ob-accent);
    padding-left: calc(var(--ob-gutter) - 3px);
  }

  .header-main::after {
    right: 6%;
    width: 40px;
  }
}

@media (max-width: 600px) {
  :root {
    --ob-gutter: 16px;
  }

  .teleport-code {
    display: none;
  }

  .brand-name {
    font-size: 1.25rem;
  }

  .brand-sub {
    letter-spacing: 0.18em;
  }

  .brand-logo {
    width: 34px;
    height: 34px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding-top: 2.5rem;
  }

  .footer-trust {
    max-width: none;
  }

  .grid-8 {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .col-span-2,
  .col-span-3,
  .col-span-4,
  .col-span-5,
  .col-span-6,
  .col-span-8 {
    grid-column: span 2;
  }

  .scroll-top-btn {
    right: 1rem;
    bottom: 1rem;
    width: 40px;
    height: 40px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* ---------- 19. 降级动效 ---------- */
@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;
  }

  .header-progress {
    transition: none;
  }

  .tag-live::before {
    animation: none;
  }
}