/* 
 * 微波技术在高分子材料与聚合物合成领域的研究 (2020-2025)
 * 主样式表
 */

/* 基础样式 */
:root {
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --accent-color: #e74c3c;
  --light-color: #ecf0f1;
  --dark-color: #2c3e50;
  --text-color: #333333;
  --background-color: #ffffff;
  --section-bg-light: #f9f9f9;
  --section-bg-dark: #eef2f5;
  --border-radius: 8px;
  --box-shadow: 0 4px 6px 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', 'Noto Serif SC', Tahoma, Arial, Roboto, "Droid Sans", "Helvetica Neue", "Droid Sans Fallback", "Heiti SC", "Hiragino Sans GB", Simsun, sans-self;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--background-color);
  overflow-x: hidden;
}

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

p {
  margin-bottom: 1.5rem;
}

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

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 导航栏 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: rgba(255, 255, 255, 0.95);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  transition: var(--transition);
  backdrop-filter: blur(10px);
}

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

.navbar-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
}

.navbar-logo span {
  color: var(--secondary-color);
}

.navbar-menu {
  display: flex;
  list-style: none;
}

.navbar-item {
  margin-left: 1.5rem;
}

.navbar-link {
  color: var(--primary-color);
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
}

.navbar-link:after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: 0;
  left: 0;
  background-color: var(--secondary-color);
  transition: var(--transition);
}

.navbar-link:hover:after,
.navbar-link.active:after {
  width: 100%;
}

.navbar-link.active {
  color: var(--secondary-color);
}

/* Hero 区域 */
.hero {
  position: relative;
  height: 80vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: var(--dark-color);
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.7;
}

.hero-content {
  position: relative;
  z-index: 1;
  color: white;
  text-align: left;
  max-width: 800px;
  padding: 2rem;
}

.hero-subtitle {
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  color: var(--light-color);
  font-weight: 300;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  line-height: 1.2;
  color: white;
}

.hero-description {
  font-size: 1.25rem;
  margin-bottom: 2rem;
  max-width: 600px;
}

/* 内容部分 */
.section {
  padding: 5rem 0;
}

.section:nth-child(even) {
  background-color: var(--section-bg-light);
}

.section:nth-child(odd) {
  background-color: var(--section-bg-dark);
}

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

.section-title {
  font-size: 2.5rem;
  color: var(--primary-color);
  position: relative;
  display: inline-block;
  padding-bottom: 0.5rem;
}

.section-title:after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: 80px;
  height: 3px;
  background-color: var(--secondary-color);
}

.section-subtitle {
  font-size: 1.2rem;
  color: #666;
  margin-top: 1rem;
}

/* 卡片样式 */
.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 10px 20px rgba(0, 0, 0, 0.1);
}

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

/* 表格样式 */
.table-container {
  overflow-x: auto;
  margin: 2rem 0;
}

table {
  width: 100%;
  border-collapse: collapse;
}

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

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

table tr:nth-child(even) {
  background-color: var(--section-bg-light);
}

/* 图表容器 */
.chart-container {
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  padding: 2rem;
  margin: 2rem 0;
}

.chart-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  text-align: center;
}

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

.footer-content {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}

.footer-column {
  flex: 1;
  min-width: 250px;
  margin-bottom: 2rem;
}

.footer-title {
  font-size: 1.2rem;
  margin-bottom: 1.5rem;
  color: white;
}

.footer-bottom {
  text-align: center;
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* 响应式设计 */
@media (max-width: 992px) {
  .hero-title {
    font-size: 2.5rem;
  }
  
  .section-title {
    font-size: 2rem;
  }
}

@media (max-width: 768px) {
  .navbar-menu {
    position: fixed;
    top: 60px;
    left: 0;
    width: 100%;
    background-color: white;
    flex-direction: column;
    align-items: center;
    padding: 1rem 0;
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
    transition: 0.3s ease;
  }
  
  .navbar-menu.active {
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
  }
  
  .navbar-item {
    margin: 0.5rem 0;
  }
  
  .hero-title {
    font-size: 2rem;
  }
  
  .section-title {
    font-size: 1.8rem;
  }
}

/* 动画效果 */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 数据可视化样式 */
.mermaid {
  margin: 2rem 0;
  text-align: center;
}

/* 报告时间样式 */
.report-time {
  text-align: right;
  font-style: italic;
  color: #666;
  margin-top: 2rem;
  font-size: 0.9rem;
}