/* ============================================================
   乐竞主场 · Site CSS / assets/site.css
   共享样式：变量 / 基础 / 页头 / 页脚 / 通用组件
   ============================================================ */

/* ---------- 1. 设计变量 ---------- */
:root {
  --color-primary: #0A1F44;
  --color-accent: #FF6B35;
  --color-accent-dark: #E55A20;
  --color-cyan: #00C2D1;
  --color-bg: #F8F1E4;
  --color-text: #2C2C2C;
  --color-card: #E3E8F0;
  --color-glass: rgba(255,255,255,0.7);
  --color-data-blue: #1A3A6B;
  --color-data-orange: #FF9F68;
  --color-heading: #0A1F44;

  --font-heading: "Noto Sans SC", "Roboto Condensed", sans-serif;
  --font-body: "Noto Sans SC", "Helvetica Neue", sans-serif;
  --font-data: "Roboto Mono", "JetBrains Mono", monospace;

  --fs-1: 12px;
  --fs-2: 14px;
  --fs-3: 16px;
  --fs-4: 19px;
  --fs-5: 23px;
  --fs-6: 28px;
  --fs-7: 34px;
  --fs-8: 41px;

  --container: 1200px;
  --header-top: 14px;
  --header-h: 64px;
  --header-total: calc(var(--header-top) + var(--header-h));

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;

  --shadow-sm: 0 2px 10px rgba(10,31,68,0.08);
  --shadow-md: 0 8px 32px rgba(10,31,68,0.12);
  --shadow-lg: 0 16px 48px rgba(10,31,68,0.18);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-total) + 16px);
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-3);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image: radial-gradient(rgba(10,31,68,0.04) 1px, transparent 1px);
  background-size: 28px 28px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- 3. 排版 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.15;
  color: var(--color-heading);
  letter-spacing: -0.02em;
  margin: 0;
}

h1 {
  font-size: clamp(32px, 5vw, var(--fs-8));
}

h2 {
  font-size: clamp(26px, 4vw, var(--fs-7));
}

h3 {
  font-size: clamp(22px, 3vw, var(--fs-6));
}

h4 {
  font-size: var(--fs-5);
}

h5 {
  font-size: var(--fs-4);
}

h6 {
  font-size: var(--fs-3);
}

p {
  margin: 0 0 1em;
}

a {
  color: var(--color-cyan);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-accent);
}

ul, ol {
  padding-left: 1.5em;
}

::selection {
  background: rgba(255,107,53,0.25);
}

/* ---------- 4. 布局工具 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 24px);
}

.section {
  padding: 72px 0;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 40px;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-data);
  font-size: var(--fs-1);
  font-weight: 600;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin: 0 0 10px;
}

.section-kicker::before {
  content: "";
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: var(--color-accent);
}

.section-title {
  font-size: clamp(26px, 4vw, var(--fs-7));
  margin: 0 0 8px;
}

.section-desc {
  max-width: 540px;
  font-size: var(--fs-2);
  color: rgba(44,44,44,0.72);
  margin: 0;
}

.grid-6 {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 24px;
}

.divider {
  border: none;
  height: 1px;
  background: rgba(10,31,68,0.1);
  margin: 48px 0;
}

/* ---------- 5. 头部 ---------- */
.skip-link {
  position: fixed;
  top: -80px;
  left: 24px;
  z-index: 210;
  padding: 12px 22px;
  background: var(--color-primary);
  color: #fff;
  font-size: var(--fs-2);
  font-weight: 600;
  text-decoration: none;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  transition: top 0.3s ease;
}

.skip-link:hover {
  color: #fff;
}

.skip-link:focus {
  top: 0;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 120;
  padding: var(--header-top) 20px 0;
  pointer-events: none;
  transition: padding 0.3s ease;
}

.scroll-progress-wrap {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 210;
  pointer-events: none;
  background: transparent;
}

.scroll-progress-bar {
  display: block;
  height: 100%;
  width: 0;
  border-radius: 0 2px 2px 0;
  background: linear-gradient(90deg, var(--color-cyan) 0%, var(--color-accent) 100%);
}

.header-shell {
  max-width: calc(var(--container) + 24px);
  margin: 0 auto;
  background: rgba(255,255,255,0.72);
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  border: 1px solid rgba(10,31,68,0.06);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-md);
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
  pointer-events: auto;
}

.site-header.scrolled .header-shell {
  background: rgba(255,255,255,0.86);
  box-shadow: var(--shadow-lg);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: var(--header-h);
  padding: 0 18px 0 22px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
  text-decoration: none;
}

.brand-mark {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: var(--color-primary);
  color: var(--color-bg);
  font-family: var(--font-data);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.06em;
  box-shadow: 0 4px 14px rgba(10,31,68,0.25);
}

.brand-mark::after {
  content: "";
  position: absolute;
  top: -2px;
  right: -2px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid #fff;
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  line-height: 1.1;
}

.brand-cn {
  font-family: var(--font-heading);
  font-size: 21px;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.05em;
  line-height: 1.2;
}

.brand-en {
  font-family: var(--font-data);
  font-size: 9px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: rgba(10,31,68,0.5);
  line-height: 1;
}

.brand:hover {
  opacity: 0.85;
}

/* --- 主导航 --- */
.site-nav {
  height: 100%;
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item {
  list-style: none;
  margin: 0;
}

.nav-link {
  display: block;
  padding: 9px 14px;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: var(--fs-2);
  font-weight: 600;
  color: rgba(10,31,68,0.7);
  text-decoration: none;
  letter-spacing: 0.02em;
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-link:hover {
  color: var(--color-primary);
  background: rgba(10,31,68,0.06);
}

.nav-link[aria-current="page"] {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 14px rgba(10,31,68,0.25);
}

.nav-link[aria-current="page"]::after {
  content: "";
  display: inline-block;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-accent);
  margin-left: 6px;
  vertical-align: 2px;
}

.nav-link[aria-current="page"]:hover {
  color: #fff;
  background: var(--color-primary);
}

/* --- 移动菜单按钮 --- */
.nav-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  border: none;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  transition: background-color 0.25s ease;
}

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

.nav-toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--color-bg);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- 返回顶部 --- */
.to-top {
  position: fixed;
  right: 28px;
  bottom: 32px;
  z-index: 110;
  width: 48px;
  height: 48px;
  border: none;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-bg);
  box-shadow: var(--shadow-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s, background-color 0.25s ease;
}

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

.to-top:hover {
  background: var(--color-accent);
}

.to-top-icon {
  font-family: var(--font-body);
  font-size: 22px;
  font-weight: 700;
  line-height: 1;
}

/* --- 屏幕阅读器 --- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 88px;
  background: var(--color-primary);
  color: rgba(248,241,228,0.75);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-accent) 70%);
  z-index: 1;
}

.site-footer::after {
  content: "LJ";
  position: absolute;
  right: -30px;
  bottom: -70px;
  font-family: var(--font-data);
  font-size: 260px;
  font-weight: 700;
  line-height: 1;
  color: rgba(255,255,255,0.025);
  pointer-events: none;
}

.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 64px clamp(16px, 4vw, 24px) 0;
  position: relative;
  z-index: 1;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2.2fr 1fr 1fr 1.7fr;
  gap: 48px;
  padding-bottom: 48px;
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 26px;
  font-weight: 700;
  color: var(--color-bg);
  text-decoration: none;
  letter-spacing: 0.04em;
}

.footer-logo:hover {
  color: var(--color-bg);
  opacity: 0.9;
}

.footer-logo-accent {
  color: var(--color-accent);
}

.footer-trust {
  margin: 16px 0 0;
  max-width: 340px;
  font-size: var(--fs-2);
  line-height: 1.8;
  color: rgba(248,241,228,0.6);
}

.footer-title {
  margin: 0 0 18px;
  padding-bottom: 10px;
  position: relative;
  font-family: var(--font-heading);
  font-size: var(--fs-4);
  font-weight: 700;
  color: var(--color-bg);
  letter-spacing: 0.02em;
}

.footer-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 24px;
  height: 3px;
  border-radius: 2px;
  background: var(--color-accent);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  color: rgba(248,241,228,0.7);
  font-size: var(--fs-2);
  text-decoration: none;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-links a:hover {
  color: var(--color-cyan);
  padding-left: 4px;
}

.footer-contact {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-contact-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: var(--fs-2);
  color: rgba(248,241,228,0.7);
  line-height: 1.6;
}

.footer-contact-item::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  margin-top: 9px;
  flex-shrink: 0;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 22px 0;
  border-top: 1px solid rgba(248,241,228,0.12);
  font-size: var(--fs-1);
  color: rgba(248,241,228,0.45);
}

.footer-copy {
  margin: 0;
}

.footer-icp {
  margin: 0;
}

/* ---------- 7. 通用组件 ---------- */
/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 26px;
  border-radius: var(--radius-pill);
  border: 2px solid transparent;
  font-family: var(--font-body);
  font-size: var(--fs-2);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color 0.25s ease, color 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  color: #fff;
  box-shadow: 0 6px 20px rgba(229,90,32,0.3);
}

.btn-outline {
  background: transparent;
  border-color: rgba(10,31,68,0.28);
  color: var(--color-primary);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  background: rgba(10,31,68,0.04);
  color: var(--color-primary);
}

.btn-ghost {
  background: rgba(10,31,68,0.06);
  color: var(--color-primary);
}

.btn-ghost:hover {
  background: rgba(10,31,68,0.12);
  color: var(--color-primary);
}

/* 卡片 */
.card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 30px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.card-glass {
  background: var(--color-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,0.5);
  border-radius: var(--radius-md);
  padding: 30px;
  box-shadow: var(--shadow-sm);
}

/* 标签 */
.tag {
  display: inline-block;
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  background: rgba(0,194,209,0.1);
  color: #008b96;
  font-size: var(--fs-1);
  font-weight: 700;
  letter-spacing: 0.06em;
}

/* 数据数字 */
.data-number {
  font-family: var(--font-data);
  font-size: var(--fs-8);
  font-weight: 700;
  line-height: 1;
  color: var(--color-primary);
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}

/* 数据统计网格 */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.stat-item {
  background: var(--color-card);
  border-radius: var(--radius-md);
  padding: 24px;
  position: relative;
  overflow: hidden;
}

.stat-item::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 3px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.stat-item:hover::after {
  transform: scaleX(1);
}

/* 展览卡 */
.exhibit-card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 26px;
  box-shadow: var(--shadow-sm);
  position: relative;
}

.exhibit-number {
  display: block;
  font-family: var(--font-data);
  font-size: var(--fs-1);
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.12em;
  margin-bottom: 10px;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  font-size: var(--fs-2);
  color: rgba(44,44,44,0.5);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb li + li::before {
  content: "/";
  color: rgba(10,31,68,0.3);
  font-family: var(--font-data);
}

.breadcrumb-link {
  color: rgba(10,31,68,0.55);
  text-decoration: none;
}

.breadcrumb-link:hover {
  color: var(--color-primary);
}

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

/* 内页页首 */
.page-hero {
  position: relative;
  padding: calc(var(--header-total) + 48px) 0 40px;
}

.page-title {
  font-size: clamp(32px, 5vw, var(--fs-8));
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-primary);
  line-height: 1.08;
  margin: 6px 0 12px;
}

.lead {
  font-size: var(--fs-4);
  line-height: 1.6;
  color: rgba(44,44,44,0.7);
  max-width: 660px;
  margin: 0;
}

/* ---------- 8. 图片占位容器 ---------- */
.img-16x9,
.img-4x3,
.img-square {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-card), #dfe6f0);
}

.img-16x9 {
  aspect-ratio: 16 / 9;
}

.img-4x3 {
  aspect-ratio: 4 / 3;
}

.img-square {
  aspect-ratio: 1;
}

.img-16x9::before,
.img-4x3::before,
.img-square::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(rgba(26,58,107,0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(26,58,107,0.06) 1px, transparent 1px);
  background-size: 24px 24px;
}

.img-16x9::after,
.img-4x3::after,
.img-square::after {
  content: "";
  position: absolute;
  inset: 12px;
  border: 1.5px dashed rgba(26,58,107,0.18);
  border-radius: calc(var(--radius-md) - 6px);
}

/* ---------- 9. 响应式 ---------- */
@media (max-width: 960px) {
  :root {
    --header-top: 10px;
    --header-h: 56px;
  }

  .grid-6 {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    top: calc(var(--header-total) + 12px);
    left: 20px;
    right: 20px;
    height: auto;
    max-height: calc(100vh - var(--header-total) - 24px);
    overflow-y: auto;
    background: rgba(255,255,255,0.96);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid rgba(10,31,68,0.08);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 12px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-12px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
  }

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

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .nav-link {
    display: block;
    width: 100%;
    padding: 13px 16px;
    border-radius: 12px;
    font-size: 15px;
    white-space: normal;
  }

  .nav-link[aria-current="page"] {
    background: rgba(10,31,68,0.82);
  }
}

@media (max-width: 768px) {
  .section {
    padding: 48px 0;
  }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .to-top {
    right: 20px;
    bottom: 20px;
  }
}

@media (max-width: 600px) {
  .grid-6 {
    grid-template-columns: 1fr;
  }

  .stat-grid {
    grid-template-columns: 1fr;
  }

  .brand-en {
    display: none;
  }
}

/* ---------- 10. 可达性与动效 ---------- */
:focus-visible {
  outline: 3px solid var(--color-cyan);
  outline-offset: 2px;
  border-radius: 4px;
}

#main-content {
  scroll-margin-top: calc(var(--header-total) + 24px);
  min-height: 60vh;
}

@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;
  }
}