/* ===== 3377体育 官方网站 - 完整样式表 ===== */
/* 设计风格：现代运动风 + 毛玻璃 + 渐变 + 圆角 + 暗色模式 + 响应式 + 动画 */

/* ===== CSS 变量（主题色） ===== */
:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --primary-light: #4a9eff;
  --secondary: #ff6f00;
  --accent: #00c853;
  --bg-light: #f5f8fe;
  --bg-dark: #0d1117;
  --text-light: #1a1a2e;
  --text-dark: #e6edf3;
  --card-light: #ffffff;
  --card-dark: #161b22;
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
  --radius: 16px;
  --radius-sm: 8px;
  --radius-lg: 24px;
  --transition: 0.3s ease;
  --transition-slow: 0.5s ease;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --max-width: 1200px;
  --header-height: 64px;
}

/* ===== 重置 & 基础 ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font);
  background: var(--bg-light);
  color: var(--text-light);
  line-height: 1.6;
  transition: background var(--transition), color var(--transition);
  min-height: 100vh;
  overflow-x: hidden;
}

/* 暗色模式 */
body.dark-mode {
  background: var(--bg-dark);
  color: var(--text-dark);
}

/* 链接 */
a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}
body.dark-mode a {
  color: var(--primary-light);
}
body.dark-mode a:hover {
  color: #6ab0ff;
}

/* 容器 */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* 图片 */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ===== 排版 ===== */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.5em;
}

p {
  margin-bottom: 1em;
}

/* ===== 按钮通用 ===== */
.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: 40px;
  font-weight: 700;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  text-align: center;
  text-decoration: none;
}
.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: 12px 0;
  font-size: 0.9rem;
  color: #666;
  background: transparent;
}
body.dark-mode .breadcrumb {
  color: #aaa;
}
.breadcrumb a {
  color: var(--primary);
}
.breadcrumb span {
  font-weight: 500;
}

/* ===== 头部 ===== */
header {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  padding: 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(26,115,232,0.92);
  box-shadow: 0 2px 20px rgba(0,0,0,0.1);
  height: var(--header-height);
  display: flex;
  align-items: center;
}
header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  gap: 12px;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: 1px;
  white-space: nowrap;
}
.logo span {
  color: var(--secondary);
}

/* 导航 */
nav {
  display: flex;
  align-items: center;
  gap: 4px;
}
nav a {
  color: white;
  margin: 0 8px;
  font-weight: 500;
  position: relative;
  padding: 6px 0;
  font-size: 0.95rem;
  white-space: nowrap;
  text-decoration: none;
}
nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: white;
  transition: width var(--transition);
}
nav a:hover::after {
  width: 100%;
}
nav a:hover {
  color: white;
  text-decoration: none;
}

/* 菜单切换按钮（移动端） */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 1.8rem;
  cursor: pointer;
  padding: 4px 8px;
  line-height: 1;
}

/* 搜索框 */
.search-box {
  display: flex;
  align-items: center;
}
.search-box input {
  padding: 8px 14px;
  border: none;
  border-radius: 20px;
  outline: none;
  font-size: 0.85rem;
  width: 130px;
  transition: width var(--transition), box-shadow var(--transition);
  background: rgba(255,255,255,0.2);
  color: white;
}
.search-box input::placeholder {
  color: rgba(255,255,255,0.7);
}
.search-box input:focus {
  width: 180px;
  background: rgba(255,255,255,0.3);
  box-shadow: 0 0 0 2px rgba(255,255,255,0.3);
}
.search-box button {
  background: var(--secondary);
  border: none;
  color: white;
  padding: 8px 16px;
  border-radius: 20px;
  margin-left: 6px;
  cursor: pointer;
  font-size: 0.85rem;
  transition: background var(--transition);
}
.search-box button:hover {
  background: #e65c00;
}

/* 暗色切换按钮 */
.dark-toggle {
  background: none;
  border: 2px solid rgba(255,255,255,0.6);
  color: white;
  border-radius: 50%;
  width: 38px;
  height: 38px;
  cursor: pointer;
  font-size: 1.1rem;
  transition: background var(--transition), border-color var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.dark-toggle:hover {
  background: rgba(255,255,255,0.2);
  border-color: white;
}

/* ===== 英雄区 ===== */
.hero {
  background: linear-gradient(135deg, #1a73e8 0%, #4a9eff 50%, #00c853 100%);
  color: white;
  padding: 60px 0 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
  min-height: 500px;
  display: flex;
  align-items: center;
}
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 10%, transparent 10%);
  background-size: 60px 60px;
  animation: moveBg 25s linear infinite;
  pointer-events: none;
}
@keyframes moveBg {
  0% { transform: translate(0,0); }
  100% { transform: translate(60px,60px); }
}
.hero-content {
  position: relative;
  z-index: 1;
  width: 100%;
}
.hero h1 {
  font-size: 3rem;
  margin-bottom: 16px;
  text-shadow: 0 2px 15px rgba(0,0,0,0.15);
  animation: fadeInUp 0.8s ease;
}
.hero p {
  font-size: 1.2rem;
  max-width: 700px;
  margin: 0 auto 30px;
  opacity: 0.9;
  animation: fadeInUp 1s ease;
}
.hero .btn {
  background: white;
  color: var(--primary);
  box-shadow: 0 4px 20px rgba(0,0,0,0.15);
  animation: fadeInUp 1.2s ease;
}
.hero .btn:hover {
  background: #f0f4ff;
  color: var(--primary-dark);
}

/* 英雄区滑动卡片 */
.hero-banner {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-top: 40px;
  flex-wrap: wrap;
}
.hero-banner .slide {
  background: rgba(255,255,255,0.12);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius);
  padding: 24px 20px;
  min-width: 180px;
  flex: 1;
  max-width: 300px;
  transition: transform var(--transition), background var(--transition);
  border: 1px solid rgba(255,255,255,0.1);
}
.hero-banner .slide:hover {
  transform: translateY(-8px) scale(1.02);
  background: rgba(255,255,255,0.2);
}
.hero-banner .slide svg {
  width: 56px;
  height: 56px;
  fill: white;
  margin-bottom: 12px;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.1));
}
.hero-banner .slide h3 {
  font-size: 1.2rem;
  margin-bottom: 6px;
}
.hero-banner .slide p {
  font-size: 0.85rem;
  opacity: 0.8;
  margin: 0;
}

/* ===== 通用区块 ===== */
.section {
  padding: 70px 0;
}
.section-title {
  text-align: center;
  margin-bottom: 48px;
}
.section-title h2 {
  font-size: 2.2rem;
  position: relative;
  display: inline-block;
  margin-bottom: 0;
}
.section-title h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--primary);
  margin: 12px auto 0;
  border-radius: 2px;
  transition: width var(--transition);
}
.section-title h2:hover::after {
  width: 80px;
}

/* 网格布局 */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

/* ===== 卡片 ===== */
.card {
  background: var(--card-light);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  background: rgba(255,255,255,0.85);
  border: 1px solid rgba(255,255,255,0.3);
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  opacity: 0;
  transition: opacity var(--transition);
}
.card:hover::before {
  opacity: 1;
}
body.dark-mode .card {
  background: var(--card-dark);
  box-shadow: 0 4px 20px rgba(0,0,0,0.4);
  border-color: rgba(255,255,255,0.05);
}
.card:hover {
  transform: translateY(-8px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.12);
}
body.dark-mode .card:hover {
  box-shadow: 0 16px 40px rgba(0,0,0,0.5);
}
.card svg {
  width: 48px;
  height: 48px;
  fill: var(--primary);
  margin-bottom: 16px;
  transition: transform var(--transition);
}
.card:hover svg {
  transform: scale(1.1);
}
.card h3 {
  font-size: 1.3rem;
  margin-bottom: 10px;
}
.card p {
  font-size: 0.95rem;
  opacity: 0.85;
  margin-bottom: 0;
}
.card time {
  display: block;
  margin-top: 12px;
  font-size: 0.85rem;
  color: #888;
}

/* ===== 统计区 ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 24px;
  text-align: center;
}
.stat-item {
  padding: 28px 16px;
  background: linear-gradient(135deg, var(--primary-light), var(--primary));
  border-radius: var(--radius);
  color: white;
  transition: transform var(--transition), box-shadow var(--transition);
}
.stat-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(26,115,232,0.3);
}
.stat-item .number {
  font-size: 2.8rem;
  font-weight: 800;
  line-height: 1.2;
}
.stat-item .label {
  font-size: 1rem;
  opacity: 0.9;
  margin-top: 4px;
}

/* ===== 时间线 ===== */
.timeline {
  position: relative;
  padding-left: 30px;
  margin: 20px 0;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 10px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--primary);
  border-radius: 1px;
}
.timeline-item {
  margin-bottom: 24px;
  position: relative;
  padding-left: 10px;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: -24px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--primary);
  border-radius: 50%;
  border: 2px solid white;
  box-shadow: 0 0 0 2px var(--primary);
}
body.dark-mode .timeline-item::before {
  border-color: var(--bg-dark);
}

/* ===== FAQ ===== */
.faq-item {
  border-bottom: 1px solid #ddd;
  padding: 18px 0;
  cursor: pointer;
  transition: background var(--transition);
}
body.dark-mode .faq-item {
  border-color: #333;
}
.faq-item:hover {
  background: rgba(26,115,232,0.03);
}
body.dark-mode .faq-item:hover {
  background: rgba(255,255,255,0.03);
}
.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  font-size: 1.05rem;
}
.faq-question span {
  font-size: 1.4rem;
  transition: transform var(--transition);
  color: var(--primary);
}
.faq-item.active .faq-question span {
  transform: rotate(45deg);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
  padding-top: 0;
  color: #555;
}
body.dark-mode .faq-answer {
  color: #bbb;
}
.faq-item.active .faq-answer {
  max-height: 300px;
  padding-top: 12px;
}

/* ===== 页脚 ===== */
.footer {
  background: linear-gradient(135deg, #0d1117, #161b22);
  color: #ccc;
  padding: 50px 0 30px;
}
.footer .container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 36px;
}
.footer h4 {
  color: white;
  margin-bottom: 14px;
  font-size: 1.1rem;
}
.footer a {
  color: #aaa;
  text-decoration: none;
  display: inline-block;
  margin-bottom: 6px;
  transition: color var(--transition);
}
.footer a:hover {
  color: white;
  text-decoration: underline;
}
.footer p {
  margin-bottom: 6px;
  font-size: 0.9rem;
}
.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid #333;
  margin-top: 30px;
  font-size: 0.85rem;
  color: #888;
}
.footer-bottom p {
  margin-bottom: 4px;
}

/* ===== 回到顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 50%;
  width: 52px;
  height: 52px;
  font-size: 1.5rem;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
  transition: transform var(--transition), background var(--transition), opacity var(--transition);
  display: none;
  z-index: 999;
  align-items: center;
  justify-content: center;
}
.back-to-top:hover {
  transform: scale(1.1);
  background: var(--primary-dark);
}

/* ===== 动画关键帧 ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ===== 滚动动画（IntersectionObserver配合类） ===== */
.fade-in {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 响应式设计 ===== */

/* 平板 */
@media (max-width: 992px) {
  .hero h1 {
    font-size: 2.4rem;
  }
  .hero p {
    font-size: 1.05rem;
  }
  .section-title h2 {
    font-size: 1.8rem;
  }
  .grid {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
  }
  .hero-banner .slide {
    min-width: 150px;
  }
}

/* 手机 */
@media (max-width: 768px) {
  :root {
    --header-height: 56px;
  }

  header .container {
    flex-wrap: wrap;
    gap: 6px;
  }

  .logo {
    font-size: 1.3rem;
  }

  nav {
    display: none;
    width: 100%;
    text-align: center;
    margin-top: 8px;
    background: rgba(26,115,232,0.98);
    border-radius: var(--radius-sm);
    padding: 12px 0;
    flex-direction: column;
    gap: 0;
  }
  nav.active {
    display: flex;
  }
  nav a {
    display: block;
    margin: 6px 0;
    padding: 8px 16px;
    font-size: 1rem;
  }
  nav a::after {
    display: none;
  }

  .menu-toggle {
    display: block;
  }

  .search-box input {
    width: 90px;
    font-size: 0.8rem;
    padding: 6px 10px;
  }
  .search-box input:focus {
    width: 120px;
  }
  .search-box button {
    padding: 6px 12px;
    font-size: 0.8rem;
  }

  .dark-toggle {
    width: 34px;
    height: 34px;
    font-size: 1rem;
  }

  .hero {
    padding: 40px 0 60px;
    min-height: auto;
  }
  .hero h1 {
    font-size: 1.8rem;
  }
  .hero p {
    font-size: 0.95rem;
    margin-bottom: 20px;
  }
  .hero .btn {
    padding: 10px 28px;
    font-size: 0.95rem;
  }
  .hero-banner {
    gap: 16px;
    margin-top: 24px;
  }
  .hero-banner .slide {
    min-width: 130px;
    padding: 16px 14px;
  }
  .hero-banner .slide svg {
    width: 40px;
    height: 40px;
  }

  .section {
    padding: 50px 0;
  }
  .section-title {
    margin-bottom: 32px;
  }
  .section-title h2 {
    font-size: 1.5rem;
  }

  .grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .card {
    padding: 20px 18px;
  }
  .card svg {
    width: 40px;
    height: 40px;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .stat-item {
    padding: 20px 12px;
  }
  .stat-item .number {
    font-size: 2rem;
  }

  .footer .container {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .back-to-top {
    width: 44px;
    height: 44px;
    font-size: 1.2rem;
    bottom: 20px;
    right: 20px;
  }

  .breadcrumb {
    font-size: 0.8rem;
    padding: 8px 0;
  }
}

/* 小手机 */
@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.5rem;
  }
  .hero p {
    font-size: 0.85rem;
  }
  .hero-banner .slide {
    min-width: 100%;
    max-width: 100%;
  }
  .grid {
    gap: 12px;
  }
  .card {
    padding: 16px 14px;
  }
  .section-title h2 {
    font-size: 1.3rem;
  }
  .footer .container {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
}

/* ===== 暗色模式偏好（系统级） ===== */
@media (prefers-color-scheme: dark) {
  body:not(.light-mode) {
    background: var(--bg-dark);
    color: var(--text-dark);
  }
  body:not(.light-mode) .card {
    background: var(--card-dark);
    border-color: rgba(255,255,255,0.05);
  }
  body:not(.light-mode) .faq-item {
    border-color: #333;
  }
  body:not(.light-mode) .breadcrumb {
    color: #aaa;
  }
}

/* ===== 打印样式 ===== */
@media print {
  header, .back-to-top, .menu-toggle, .dark-toggle, .search-box {
    display: none !important;
  }
  .hero {
    background: white !important;
    color: black !important;
    padding: 20px 0;
  }
  .card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ddd;
  }
  .section {
    padding: 20px 0;
  }
}

/* ===== 辅助功能 ===== */
.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;
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--primary-light);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--primary);
}

/* ===== 选中文本颜色 ===== */
::selection {
  background: var(--primary);
  color: white;
}
body.dark-mode ::selection {
  background: var(--primary-light);
  color: #000;
}