/* 
 * 每日大赛 - 现代极简高端风格CSS
 * 设计理念：大量留白、优雅高级配色、微妙精致动画、专业科技感
 * 色彩体系：白色基调、深灰文字、蓝金渐变强调、柔和阴影
 */

/* ============ 全局重置与基础 ============ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: #2c3e50;
  background-color: #ffffff;
  overflow-x: hidden;
}

/* ============ 排版系统 ============ */
h1 {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
  color: #1a1a1a;
}

h2 {
  font-size: 2.5rem;
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin-bottom: 1.2rem;
  color: #1a1a1a;
}

h3 {
  font-size: 1.75rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 1rem;
  color: #1a1a1a;
}

h4 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.8rem;
  color: #2c3e50;
}

p {
  margin-bottom: 1rem;
  color: #555555;
  line-height: 1.8;
}

a {
  color: #0066cc;
  text-decoration: none;
  transition: color 0.3s ease;
}

a:hover {
  color: #d4a574;
}

/* ============ 容器与布局 ============ */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 2rem;
}

@media (max-width: 768px) {
  .container {
    padding: 0 1rem;
  }
}

/* ============ 导航栏 ============ */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  transition: all 0.3s ease;
}

header.scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  height: 70px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: #1a1a1a;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: transform 0.3s ease;
}

.logo:hover {
  transform: scale(1.05);
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, #0066cc, #d4a574);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 0.9rem;
}

.nav-menu {
  display: flex;
  gap: 3rem;
  list-style: none;
}

.nav-menu a {
  color: #2c3e50;
  font-weight: 500;
  font-size: 0.95rem;
  position: relative;
  transition: color 0.3s ease;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #0066cc, #d4a574);
  transition: width 0.3s ease;
}

.nav-menu a:hover::after {
  width: 100%;
}

.search-box {
  display: flex;
  align-items: center;
  background: #f5f5f5;
  border-radius: 24px;
  padding: 0.5rem 1.2rem;
  gap: 0.5rem;
  transition: all 0.3s ease;
}

.search-box:hover,
.search-box:focus-within {
  background: #efefef;
  box-shadow: 0 4px 12px rgba(0, 102, 204, 0.1);
}

.search-box input {
  border: none;
  background: transparent;
  outline: none;
  width: 150px;
  font-size: 0.9rem;
  color: #2c3e50;
}

.search-box input::placeholder {
  color: #999999;
}

.search-icon {
  width: 18px;
  height: 18px;
  color: #999999;
  cursor: pointer;
}

@media (max-width: 768px) {
  .nav-menu {
    gap: 1.5rem;
  }
  
  .search-box {
    display: none;
  }
}

/* ============ 首屏Banner ============ */
.hero {
  margin-top: 70px;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 20% 50%, rgba(0, 102, 204, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(212, 165, 116, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
  animation: fadeInUp 0.8s ease-out;
}

.hero-subtitle {
  font-size: 1rem;
  color: #0066cc;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.hero-title {
  font-size: 4rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  color: #1a1a1a;
  letter-spacing: -0.02em;
}

.hero-description {
  font-size: 1.25rem;
  color: #666666;
  margin-bottom: 2.5rem;
  line-height: 1.8;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ============ 按钮样式 ============ */
.btn {
  padding: 0.875rem 2rem;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, #0066cc, #0052a3);
  color: white;
  box-shadow: 0 4px 15px rgba(0, 102, 204, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 102, 204, 0.4);
}

.btn-secondary {
  background: white;
  color: #0066cc;
  border: 2px solid #0066cc;
}

.btn-secondary:hover {
  background: #f0f7ff;
  transform: translateY(-2px);
}

/* ============ 卡片组件 ============ */
.card {
  background: white;
  border-radius: 12px;
  padding: 2rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  transition: all 0.3s ease;
  border: 1px solid rgba(0, 0, 0, 0.04);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.card-image {
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, #f0f4ff, #fff0e6);
  border-radius: 8px;
  margin-bottom: 1.5rem;
  overflow: hidden;
  position: relative;
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.8rem;
  color: #1a1a1a;
}

.card-description {
  color: #666666;
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.card-meta {
  display: flex;
  gap: 1rem;
  font-size: 0.85rem;
  color: #999999;
}

/* ============ 视频卡片（H5 Video） ============ */
.video-card {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  background: #000;
  aspect-ratio: 16 / 9;
  cursor: pointer;
  group: 'video';
}

.video-card-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.video-card:hover .video-card-overlay {
  opacity: 1;
}

.play-button {
  width: 64px;
  height: 64px;
  background: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transform: scale(0.8);
  transition: transform 0.3s ease;
}

.video-card:hover .play-button {
  transform: scale(1);
}

.play-icon {
  width: 24px;
  height: 24px;
  fill: #0066cc;
  margin-left: 3px;
}

/* ============ 统计数据展示 ============ */
.stats-section {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  padding: 3rem 0;
}

.stat-item {
  text-align: center;
  padding: 2rem;
  background: white;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  transition: all 0.3s ease;
}

.stat-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #0066cc, #d4a574);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.stat-label {
  color: #666666;
  font-size: 0.95rem;
}

/* ============ 网格布局 ============ */
.grid {
  display: grid;
  gap: 2rem;
}

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

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* ============ 分隔符 ============ */
.section {
  padding: 5rem 0;
  position: relative;
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title h2 {
  margin-bottom: 1rem;
}

.section-description {
  color: #666666;
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

/* ============ 折叠式FAQ ============ */
.faq-item {
  border-bottom: 1px solid #efefef;
  padding: 1.5rem 0;
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  color: #1a1a1a;
  font-size: 1.05rem;
  transition: color 0.3s ease;
}

.faq-question:hover {
  color: #0066cc;
}

.faq-toggle {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #0066cc;
  font-size: 1.5rem;
  transition: transform 0.3s ease;
}

.faq-item.active .faq-toggle {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  color: #666666;
  line-height: 1.8;
  margin-top: 1rem;
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

/* ============ 用户评价 ============ */
.testimonial {
  background: white;
  border-radius: 12px;
  padding: 2rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  border-left: 4px solid #0066cc;
  transition: all 0.3s ease;
}

.testimonial:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.testimonial-content {
  color: #666666;
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: 1.5rem;
  font-style: italic;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.author-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, #0066cc, #d4a574);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 1.2rem;
}

.author-info h4 {
  margin-bottom: 0.2rem;
}

.author-role {
  color: #999999;
  font-size: 0.85rem;
}

/* ============ 页脚 ============ */
footer {
  background: #1a1a1a;
  color: #cccccc;
  padding: 3rem 0 1rem;
  margin-top: 5rem;
}

footer a {
  color: #cccccc;
}

footer a:hover {
  color: #d4a574;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h4 {
  color: white;
  margin-bottom: 1rem;
}

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

.footer-section ul li {
  margin-bottom: 0.5rem;
}

.footer-bottom {
  border-top: 1px solid #333333;
  padding-top: 2rem;
  text-align: center;
  color: #999999;
  font-size: 0.9rem;
}

.footer-bottom p {
  margin-bottom: 0.5rem;
}

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

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

@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-up {
  animation: fadeInUp 0.6s ease-out;
}

.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;
}

/* ============ 响应式设计 ============ */
@media (max-width: 768px) {
  h1 {
    font-size: 2.5rem;
  }
  
  h2 {
    font-size: 1.8rem;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-description {
    font-size: 1rem;
  }
  
  .nav-menu {
    display: none;
  }
  
  .section {
    padding: 3rem 0;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 14px;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .hero-title {
    font-size: 1.8rem;
  }
  
  .hero-buttons {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
    justify-content: center;
  }
  
  .container {
    padding: 0 1rem;
  }
}

/* ============ 实用工具类 ============ */
.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; }
.mt-5 { margin-top: 3rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }

.hidden {
  display: none;
}

.opacity-50 {
  opacity: 0.5;
}

.opacity-75 {
  opacity: 0.75;
}