/* ==========================================
   专注挑战 - 全局样式表
   品牌色：深紫色(#1a0033) + 金色(#FFB84D) + 粉红(#FF6B9D)
   ========================================== */

:root {
  --primary-dark: #1a0033;
  --primary-light: #2d0052;
  --accent-gold: #FFB84D;
  --accent-pink: #FF6B9D;
  --accent-purple: #9D4EDD;
  --text-light: #FFFFFF;
  --text-dark: #1a0033;
  --bg-light: #F8F5FF;
  --border-color: #E8E0FF;
  --shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.15);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg-light);
  color: var(--text-dark);
  line-height: 1.6;
  overflow-x: hidden;
}

/* ==================== 排版系统 ==================== */

h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 1rem;
  letter-spacing: -0.5px;
}

h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 0.8rem;
}

h3 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 0.6rem;
}

h4 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--primary-dark);
}

p {
  font-size: 1rem;
  color: #555;
  margin-bottom: 1rem;
}

a {
  color: var(--accent-gold);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

/* ==================== 容器与布局 ==================== */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 60px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
  padding-bottom: 1rem;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-gold), var(--accent-pink));
  border-radius: 2px;
}

/* ==================== 按钮样式 ==================== */

.btn {
  display: inline-block;
  padding: 12px 30px;
  border-radius: 25px;
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  font-size: 1rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-gold), var(--accent-pink));
  color: white;
  box-shadow: var(--shadow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: transparent;
  color: var(--accent-gold);
  border: 2px solid var(--accent-gold);
}

.btn-secondary:hover {
  background: var(--accent-gold);
  color: white;
}

.btn-small {
  padding: 8px 20px;
  font-size: 0.9rem;
}

/* ==================== 卡片组件 ==================== */

.card {
  background: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
  border: 1px solid var(--border-color);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.card-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 8px;
  margin-bottom: 15px;
}

.card-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 0.5rem;
}

.card-text {
  font-size: 0.95rem;
  color: #666;
  margin-bottom: 1rem;
}

/* ==================== 视频卡片 ==================== */

.video-card {
  position: relative;
  overflow: hidden;
  border-radius: 12px;
  aspect-ratio: 16 / 9;
  background: #000;
}

.video-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.video-card:hover img {
  transform: scale(1.05);
}

.video-play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 60px;
  height: 60px;
  background: rgba(255, 107, 157, 0.9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 10;
}

.video-card:hover .video-play-btn {
  opacity: 1;
}

.video-play-btn::after {
  content: '▶';
  color: white;
  font-size: 24px;
  margin-left: 3px;
}

.video-info {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.8));
  padding: 20px;
  color: white;
}

.video-title {
  font-weight: 600;
  margin-bottom: 5px;
}

.video-stats {
  font-size: 0.85rem;
  opacity: 0.9;
}

/* ==================== 网格布局 ==================== */

.grid {
  display: grid;
  gap: 30px;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* ==================== 头部导航 ==================== */

header {
  background: white;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary-dark);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--accent-gold), var(--accent-pink));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 30px;
  align-items: center;
}

nav a {
  color: var(--text-dark);
  font-weight: 500;
  position: relative;
  transition: color 0.3s ease;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-gold);
  transition: width 0.3s ease;
}

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

nav a:hover::after {
  width: 100%;
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-light);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 8px 15px;
  gap: 8px;
}

.search-box input {
  border: none;
  background: transparent;
  outline: none;
  width: 150px;
  font-size: 0.95rem;
}

.search-box input::placeholder {
  color: #999;
}

.search-icon {
  cursor: pointer;
  color: var(--accent-gold);
}

/* ==================== 移动菜单 ==================== */

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--primary-dark);
}

/* ==================== 页脚 ==================== */

footer {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
  color: white;
  padding: 40px 0 20px;
  margin-top: 60px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 30px;
}

.footer-section h4 {
  color: var(--accent-gold);
  margin-bottom: 15px;
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: 8px;
}

.footer-section a {
  color: rgba(255, 255, 255, 0.8);
  transition: color 0.3s ease;
}

.footer-section a:hover {
  color: var(--accent-gold);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  padding-top: 20px;
  text-align: center;
  font-size: 0.9rem;
  opacity: 0.9;
}

.qr-code-section {
  display: flex;
  gap: 30px;
  justify-content: center;
  margin: 20px 0;
  flex-wrap: wrap;
}

.qr-item {
  text-align: center;
}

.qr-item img {
  width: 100px;
  height: 100px;
  margin-bottom: 10px;
}

/* ==================== 响应式设计 ==================== */

@media (max-width: 768px) {
  h1 {
    font-size: 1.8rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  h3 {
    font-size: 1.2rem;
  }

  .section {
    padding: 40px 0;
  }

  nav ul {
    gap: 15px;
  }

  .search-box input {
    width: 100px;
  }

  .mobile-menu-toggle {
    display: block;
  }

  nav ul {
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    gap: 0;
    display: none;
    padding: 20px;
    box-shadow: var(--shadow);
  }

  nav ul.active {
    display: flex;
  }

  nav a {
    display: block;
    padding: 10px 0;
    border-bottom: 1px solid var(--border-color);
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }

  h1 {
    font-size: 1.5rem;
  }

  h2 {
    font-size: 1.2rem;
  }

  .btn {
    padding: 10px 20px;
    font-size: 0.9rem;
  }

  .section-title {
    margin-bottom: 2rem;
  }
}

/* ==================== 动画效果 ==================== */

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

.slide-in-left {
  animation: slideInLeft 0.6s ease-out;
}

.slide-in-right {
  animation: slideInRight 0.6s ease-out;
}

/* ==================== 工具类 ==================== */

.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.hidden {
  display: none;
}

.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }

.opacity-75 {
  opacity: 0.75;
}

.opacity-50 {
  opacity: 0.5;
}

.logo-icon img {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: 50%;
  object-fit: cover;
}