/* 全局样式 */
:root {
  --primary-color: #2c7fb8;
  --secondary-color: #7fcdbb;
  --accent-color: #41b6c4;
  --dark-color: #253494;
  --light-color: #f5f5f5;
  --text-color: #333;
  --light-text-color: #fff;
  --border-radius: 8px;
  --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

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

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

h1, h2, h3, h4, h5, h6 {
  font-family: 'Noto Serif SC', serif;
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 1rem;
  color: var(--dark-color);
}

p {
  margin-bottom: 1rem;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--dark-color);
}

img {
  max-width: 100%;
  height: auto;
  border-radius: var(--border-radius);
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header & Hero Section */
.hero {
  position: relative;
  height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: white;
  background-color: var(--dark-color);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.6;
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.hero-title {
  font-size: 3.5rem;
  margin-bottom: 1rem;
  color: white;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

.hero-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  color: white;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}

/* Sections */
.section {
  padding: 5rem 0;
}

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

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 100px;
  height: 4px;
  background-color: var(--accent-color);
  border-radius: 2px;
}

/* Cards */
.card {
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  padding: 2rem;
  margin-bottom: 2rem;
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.card-title {
  color: var(--primary-color);
  margin-bottom: 1rem;
  font-size: 1.5rem;
}

.card-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  margin-bottom: 1.5rem;
}

/* Features */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
}

.feature {
  text-align: center;
  padding: 2rem;
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}

.feature:hover {
  transform: translateY(-5px);
}

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

/* Tables */
.table-container {
  overflow-x: auto;
  margin-bottom: 2rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  background-color: white;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--box-shadow);
}

th, td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

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

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

tr:hover {
  background-color: #f1f1f1;
}

/* References */
.references {
  background-color: #f9f9f9;
  padding: 2rem;
  border-radius: var(--border-radius);
}

.reference-item {
  margin-bottom: 0.75rem;
  padding-left: 1.5rem;
  position: relative;
}

.reference-item::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--primary-color);
}

/* Footer */
.footer {
  background-color: var(--dark-color);
  color: white;
  padding: 3rem 0;
  text-align: center;
}

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

/* Responsive */
@media (max-width: 768px) {
  .hero {
    height: 450px;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-subtitle {
    font-size: 1.2rem;
  }
  
  .section {
    padding: 3rem 0;
  }
}

/* Chart container */
.chart-container {
  background-color: white;
  padding: 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  margin-bottom: 2rem;
}

/* Compare table styling */
.compare-table th {
  background-color: var(--primary-color);
}

.compare-table .highlight {
  background-color: rgba(127, 205, 187, 0.2);
}

/* Timeline */
.timeline {
  position: relative;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 0;
}

.timeline::after {
  content: '';
  position: absolute;
  width: 6px;
  background-color: var(--primary-color);
  top: 0;
  bottom: 0;
  left: 50%;
  margin-left: -3px;
}

.timeline-item {
  padding: 10px 40px;
  position: relative;
  width: 50%;
}

.timeline-item::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  right: -10px;
  background-color: white;
  border: 4px solid var(--accent-color);
  top: 15px;
  border-radius: 50%;
  z-index: 1;
}

.left {
  left: 0;
}

.right {
  left: 50%;
}

.left::after {
  right: -10px;
}

.right::after {
  left: -10px;
}

.timeline-content {
  padding: 20px 30px;
  background-color: white;
  position: relative;
  border-radius: 6px;
  box-shadow: var(--box-shadow);
}

@media screen and (max-width: 768px) {
  .timeline::after {
    left: 31px;
  }
  
  .timeline-item {
    width: 100%;
    padding-left: 70px;
    padding-right: 25px;
  }
  
  .timeline-item::after {
    left: 21px;
  }
  
  .left::after, .right::after {
    left: 21px;
  }
  
  .right {
    left: 0;
  }
}

/* Mermaid diagram container */
.mermaid-container {
  background-color: white;
  padding: 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  margin: 2rem 0;
  text-align: center;
}

/* Citation style */
.citation {
  color: var(--primary-color);
  font-size: 0.85em;
  vertical-align: super;
  text-decoration: none;
}

/* Animation for cards */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 1s ease forwards;
}

/* Report time */
.report-time {
  text-align: right;
  font-style: italic;
  color: #666;
  margin-top: 2rem;
}