/* Reset and Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  color: #2c3e50;
  line-height: 1.8;
  min-height: 100vh;
}

.ui-style-5 {
  --primary-color: #3498db;
  --secondary-color: #2ecc71;
  --accent-color: #e74c3c;
  --text-color: #2c3e50;
  --bg-color: #ffffff;
  --border-color: #ddd;
}

/* Header */
header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  font-size: 28px;
  font-weight: bold;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  transition: transform 0.3s;
}

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

nav ul {
  list-style: none;
  display: flex;
  flex-wrap: nowrap;
  gap: 35px;
  align-items: center;
}

nav a {
  color: #555;
  text-decoration: none;
  font-size: 16px;
  font-weight: 500;
  transition: all 0.3s;
  position: relative;
  white-space: nowrap;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #667eea, #764ba2);
  transition: width 0.3s;
}

nav a:hover {
  color: #667eea;
}

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

/* Main Container */
main {
  min-height: calc(100vh - 200px);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 60px 20px;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
  border-radius: 20px;
  margin-bottom: 60px;
}

.hero h1 {
  font-size: 42px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Site Intro */
.site-intro {
  background: white;
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
  margin-bottom: 50px;
}

.site-intro h2 {
  font-size: 28px;
  margin-bottom: 25px;
  color: #2c3e50;
}

.site-intro p {
  font-size: 16px;
  line-height: 2;
  margin-bottom: 20px;
  color: #555;
}

.site-intro a {
  color: #667eea;
  text-decoration: none;
  border-bottom: 1px solid #667eea;
  transition: all 0.3s;
}

.site-intro a:hover {
  color: #764ba2;
  border-bottom-color: #764ba2;
}

/* Sections */
section {
  margin-bottom: 60px;
}

section h2 {
  font-size: 32px;
  margin-bottom: 30px;
  color: #2c3e50;
  position: relative;
  padding-bottom: 15px;
}

section h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 80px;
  height: 4px;
  background: linear-gradient(90deg, #667eea, #764ba2);
  border-radius: 2px;
}

/* Video Grid */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 30px;
}

.video-card {
  background: white;
  border-radius: 15px;
  padding: 25px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
  transition: all 0.3s;
  border: 2px solid transparent;
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
  border-color: #667eea;
}

.video-card h3 {
  font-size: 20px;
  margin-bottom: 15px;
}

.video-card h3 a {
  color: #2c3e50;
  text-decoration: none;
  transition: color 0.3s;
}

.video-card h3 a:hover {
  color: #667eea;
}

.meta {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 15px;
}

.meta span {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 4px 12px;
  border-radius: 15px;
  font-size: 13px;
}

.one-line {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 15px;
}

.btn {
  display: inline-block;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 10px 25px;
  border-radius: 25px;
  text-decoration: none;
  transition: all 0.3s;
  font-weight: 500;
}

.btn:hover {
  transform: scale(1.05);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

/* Entry Grid */
.entry-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.entry-card {
  background: white;
  padding: 35px;
  border-radius: 15px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
  transition: all 0.3s;
}

.entry-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.entry-card h3 {
  font-size: 24px;
  margin-bottom: 15px;
}

.entry-card h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.entry-card h3 a:hover {
  color: #667eea;
}

.entry-card p {
  color: #666;
  line-height: 1.8;
}

/* Video List */
.video-list {
  background: white;
  border-radius: 15px;
  padding: 30px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.video-item {
  padding: 20px 0;
  border-bottom: 1px solid #eee;
}

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

.video-item h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.video-item h3 a {
  color: #2c3e50;
  text-decoration: none;
  transition: color 0.3s;
}

.video-item h3 a:hover {
  color: #667eea;
}

.video-item .meta {
  margin-bottom: 10px;
}

.video-item .meta span {
  background: #f0f0f0;
  color: #666;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 12px;
}

.video-item p {
  color: #666;
  font-size: 14px;
}

/* Page Header */
.page-header {
  text-align: center;
  margin-bottom: 50px;
  padding: 40px 20px;
  background: white;
  border-radius: 15px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.page-header h1 {
  font-size: 36px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-header .intro {
  color: #666;
  font-size: 16px;
  line-height: 2;
  max-width: 900px;
  margin: 0 auto;
}

/* Year Group */
.year-group {
  margin-bottom: 50px;
}

.year-title {
  font-size: 28px;
  margin-bottom: 25px;
  color: #667eea;
}

.video-grid-compact {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
}

.video-card-compact {
  background: white;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 3px 15px rgba(0, 0, 0, 0.08);
  transition: all 0.3s;
}

.video-card-compact:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
}

.video-card-compact h3 {
  font-size: 16px;
  margin-bottom: 10px;
}

.video-card-compact h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.video-card-compact h3 a:hover {
  color: #667eea;
}

.video-card-compact .summary {
  color: #666;
  font-size: 13px;
  line-height: 1.6;
}

/* Top List */
.top-list {
  background: white;
  border-radius: 15px;
  padding: 30px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.top-item {
  display: flex;
  gap: 25px;
  padding: 25px 0;
  border-bottom: 2px solid #f0f0f0;
  transition: all 0.3s;
}

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

.top-item:hover {
  background: #f9f9f9;
  margin: 0 -20px;
  padding: 25px 20px;
  border-radius: 10px;
}

.rank-number {
  flex-shrink: 0;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: bold;
  border-radius: 10px;
}

.top-content {
  flex: 1;
}

.top-content h3 {
  font-size: 22px;
  margin-bottom: 10px;
}

.top-content h3 a {
  color: #2c3e50;
  text-decoration: none;
  transition: color 0.3s;
}

.top-content h3 a:hover {
  color: #667eea;
}

.tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin: 12px 0;
}

.tag {
  background: #f0f0f0;
  color: #666;
  padding: 4px 12px;
  border-radius: 12px;
  font-size: 12px;
}

.tag.highlight {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.recommendation {
  color: #555;
  line-height: 1.8;
  font-size: 15px;
}

/* Topic Page */
.topic-header {
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
}

.topic-intro {
  margin-top: 20px;
}

.topic-intro p {
  margin-bottom: 15px;
  text-align: left;
}

.topic-list {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.topic-item {
  background: white;
  border-radius: 15px;
  padding: 30px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
  transition: all 0.3s;
}

.topic-item:hover {
  box-shadow: 0 10px 35px rgba(0, 0, 0, 0.12);
  transform: translateY(-2px);
}

.topic-item-header h3 {
  font-size: 24px;
  margin-bottom: 12px;
}

.topic-item-header h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.topic-item-header h3 a:hover {
  color: #667eea;
}

.topic-analysis {
  color: #555;
  line-height: 2;
  font-size: 15px;
  margin-top: 15px;
}

/* Latest List */
.latest-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.latest-item {
  background: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 3px 15px rgba(0, 0, 0, 0.08);
  display: flex;
  gap: 20px;
  transition: all 0.3s;
}

.latest-item:hover {
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
  transform: translateX(5px);
}

.latest-date {
  flex-shrink: 0;
  width: 120px;
  padding: 10px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border-radius: 8px;
  text-align: center;
  font-weight: bold;
}

.latest-content {
  flex: 1;
}

.latest-content h3 {
  font-size: 20px;
  margin-bottom: 10px;
}

.latest-content h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.latest-content h3 a:hover {
  color: #667eea;
}

.brief {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

/* Detail Page */
.detail-page {
  max-width: 900px;
}

.video-detail {
  background: white;
  border-radius: 15px;
  padding: 50px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.detail-header h1 {
  font-size: 32px;
  margin-bottom: 30px;
  color: #2c3e50;
}

.basic-info,
.one-line,
.summary,
.review,
.related {
  margin-bottom: 40px;
  padding-bottom: 30px;
  border-bottom: 2px solid #f0f0f0;
}

.basic-info:last-child,
.review:last-child,
.related:last-child {
  border-bottom: none;
}

.basic-info h2,
.one-line h2,
.summary h2,
.review h2,
.related h2 {
  font-size: 24px;
  margin-bottom: 20px;
  color: #667eea;
}

.info-list {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 15px;
  line-height: 1.8;
}

.info-list dt {
  font-weight: bold;
  color: #555;
}

.info-list dd {
  color: #333;
}

.highlight-text {
  font-size: 18px;
  color: #667eea;
  font-weight: 500;
  line-height: 1.8;
  padding: 20px;
  background: rgba(102, 126, 234, 0.05);
  border-left: 4px solid #667eea;
  border-radius: 5px;
}

.summary p,
.review-text {
  font-size: 16px;
  line-height: 2;
  color: #555;
}

.review-text {
  padding: 20px;
  background: #f9f9f9;
  border-radius: 10px;
  font-style: italic;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
}

.related-card {
  background: #f9f9f9;
  padding: 20px;
  border-radius: 12px;
  transition: all 0.3s;
}

.related-card:hover {
  background: #f0f0f0;
  transform: translateY(-2px);
}

.related-card h3 {
  font-size: 16px;
  margin-bottom: 10px;
}

.related-card h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.related-card h3 a:hover {
  color: #667eea;
}

.related-card p {
  color: #666;
  font-size: 13px;
  line-height: 1.6;
}

/* More Link */
.more-link {
  text-align: center;
  margin-top: 30px;
}

.more-link a {
  display: inline-block;
  color: #667eea;
  text-decoration: none;
  font-size: 16px;
  font-weight: 500;
  padding: 12px 30px;
  border: 2px solid #667eea;
  border-radius: 25px;
  transition: all 0.3s;
}

.more-link a:hover {
  background: #667eea;
  color: white;
  transform: scale(1.05);
}

/* Footer */
footer {
  background: rgba(44, 62, 80, 0.95);
  color: white;
  padding: 40px 20px;
  margin-top: 80px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
}

.footer-container p {
  margin-bottom: 20px;
  font-size: 14px;
}

.footer-container nav {
  display: flex;
  justify-content: center;
  gap: 25px;
  flex-wrap: wrap;
}

.footer-container nav a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s;
}

.footer-container nav a:hover {
  color: white;
}

/* Responsive */
@media (max-width: 768px) {
  .header-container {
    padding: 0 15px;
    height: 55px;
  }

  .logo {
    font-size: 20px;
    flex-shrink: 0;
  }

  nav ul {
    gap: 8px;
    flex: 1;
    justify-content: flex-end;
  }

  nav li {
    flex: 1 1 0;
    min-width: 0;
    text-align: center;
  }

  nav a {
    font-size: 11px;
    padding: 4px 2px;
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  nav a::after {
    display: none;
  }

  .hero h1 {
    font-size: 28px;
  }

  .page-header h1 {
    font-size: 26px;
  }

  section h2 {
    font-size: 24px;
  }

  .video-grid,
  .video-grid-compact {
    grid-template-columns: 1fr;
  }

  .top-item {
    flex-direction: column;
    gap: 15px;
  }

  .latest-item {
    flex-direction: column;
  }

  .latest-date {
    width: 100%;
  }

  .video-detail {
    padding: 25px;
  }

  .info-list {
    grid-template-columns: 80px 1fr;
  }

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

@media (max-width: 480px) {
  .container {
    padding: 20px 15px;
  }

  .site-intro {
    padding: 25px;
  }

  .hero {
    padding: 40px 15px;
  }
}