:root {
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --accent-color: #e74c3c;
  --text-color: #333;
  --light-gray: #f5f6fa;
  --white: #ffffff;
}

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

body {
  font-family: 'Source Sans 3', sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--light-gray);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

.section {
  padding: 4rem 0;
}

.title-row {
  text-align: center;
  margin-bottom: 2rem;
}

.title {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.author-col {
  text-align: center;
  margin-bottom: 2rem;
}

.author-text {
  color: var(--secondary-color);
  text-decoration: none;
  font-size: 1.2rem;
}

.button-row {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin: 2rem 0;
}

.link-button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255, 255, 255, 0.1);
  color: white;
  padding: 0.8rem 1.5rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.3s ease;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.link-button:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.link-button::before {
  font-family: "Font Awesome 5 Free";
  font-weight: 900;
}

.link-button[href*="paper"]::before {
  content: "\f02d"; /* Book icon */
}

.link-button[href*="github.com"]::before {
  content: "\f09b"; /* GitHub icon */
}

.link-button[href*="dataset"]::before {
  content: "\f1c0"; /* Database icon */
}

.tldr {
  background-color: var(--white);
  padding: 1.5rem;
  border-radius: 8px;
  margin: 2rem 0;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.section-header {
  color: var(--primary-color);
  margin: 2rem 0 1rem;
  font-size: 1.8rem;
}

.paragraph {
  margin-bottom: 2rem;
  line-height: 1.8;
}

.leaderboard-container {
  background-color: var(--white);
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  overflow-x: auto;
}

.leaderboard-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
}

.leaderboard-table th,
.leaderboard-table td {
  padding: 0.8rem;
  text-align: center;
  border: 1px solid #ddd;
}

.leaderboard-table th {
  background-color: var(--primary-color);
  color: var(--white);
}

.leaderboard-table tr:nth-child(even) {
  background-color: #f9f9f9;
}

.leaderboard-table tr:hover {
  background-color: #f5f5f5;
}

.highlight {
  color: var(--accent-color);
  font-weight: bold;
}

.category-specs {
  margin-top: 2rem;
}

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

.category-item {
  background-color: var(--light-gray);
  padding: 1rem;
  border-radius: 5px;
}

.category-item h4 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.category-item ul {
  list-style-type: none;
}

.category-item li {
  margin: 0.5rem 0;
}

.leaderboard-note {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: #666;
}

@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }
  
  .title {
    font-size: 2rem;
  }
  
  .button-row {
    flex-direction: column;
    align-items: center;
  }
  
  .link-button {
    width: 100%;
    text-align: center;
  }
}

/* 导航栏样式 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: var(--white);
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  z-index: 1000;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  color: var(--primary-color);
  text-decoration: none;
  font-size: 1.5rem;
  font-weight: bold;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: var(--text-color);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

.nav-links a:hover {
  color: var(--secondary-color);
}

/* 返回顶部按钮样式 */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 40px;
  height: 40px;
  background-color: var(--secondary-color);
  color: var(--white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
  transition: background-color 0.3s ease;
  z-index: 999;
}

.back-to-top:hover {
  background-color: #2980b9;
}

/* 响应式导航栏 */
@media (max-width: 768px) {
  .nav-container {
    flex-direction: column;
    gap: 1rem;
  }

  .nav-links {
    flex-direction: column;
    align-items: center;
    gap: 1rem;
  }
}

/* 调整主内容区域的上边距，为固定导航栏留出空间 */
.section {
  padding-top: 6rem;
}

/* Hero Section */
.hero-section {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  padding: 4rem 0;
  margin-bottom: 2rem;
}

.hero-section .title {
  color: white;
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero-section .author-text {
  color: rgba(255, 255, 255, 0.9);
  font-size: 1.2rem;
  text-decoration: none;
}

.hero-section .author-text:hover {
  color: white;
}