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

/* The vertical line */
.timeline::before {
  content: '';
  position: absolute;
  width: 4px;
  background-color: rgba(0, 0, 0, 0.2);  /* 更柔和的线条颜色 */
  top: 0;
  bottom: 0;
  left: 50%;
  margin-left: -2px;
}

/* 暗色模式下的垂直线 */
html.dark .timeline::before {
  background-color: rgba(255, 255, 255, 0.15);
}

/* Container for content */
.timeline-container {
  position: relative;
  margin: 4rem 0;
}

/* Left containers */
.timeline-container.left {
  padding-right: calc(50% + 30px);
}

/* Right containers */
.timeline-container.right {
  padding-left: calc(50% + 30px);
}

/* Arrow indicators instead of dots */
.timeline-container.left::after,
.timeline-container.right::after {
  content: '';
  position: absolute;
  top: 1.5rem;
  width: 0;
  height: 0;
  border-style: solid;
  z-index: 1;
}

/* Left arrow pointing LEFT (fixed direction) */
.timeline-container.left::after {
  right: calc(50% - 25px);
  border-width: 10px 15px 10px 0;
  border-color: transparent #0069d9 transparent transparent;  /* 更深的蓝色 */
}

/* Right arrow pointing RIGHT (fixed direction) */
.timeline-container.right::after {
  left: calc(50% - 25px);
  border-width: 10px 0 10px 15px;
  border-color: transparent transparent transparent #0069d9;  /* 更深的蓝色 */
}

/* Date marker on the center line */
.timeline-container::before {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  background-color: #0069d9;  /* 更深的蓝色 */
  top: 1.5rem;
  border-radius: 50%;
  box-shadow: 0 0 10px rgba(0, 105, 217, 0.5);  /* 匹配的阴影 */
  z-index: 2;
}

.timeline-container.left::before {
  right: 50%;
  margin-right: -10px;
}

.timeline-container.right::before {
  left: 50%;
  margin-left: -10px;
}

/* The actual content */
.timeline-content {
  padding: 1.5rem;
  background-color: rgba(245, 245, 250, 0.8);  /* 更舒适的淡蓝灰色背景 */
  border-radius: 12px;
  border-left: 4px solid #0069d9;  /* 更深的蓝色 */
  position: relative;
  transition: all 0.3s ease;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.08);  /* 更柔和的阴影 */
}

/* 暗色模式下的内容背景 */
html.dark .timeline-content {
  background-color: rgba(60, 60, 60, 0.3);
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
}

.timeline-content:hover {
  background-color: rgba(230, 240, 255, 0.9);  /* 悬停时的柔和蓝色背景 */
  transform: translateY(-5px);
}

/* 暗色模式下的悬停效果 */
html.dark .timeline-content:hover {
  background-color: rgba(0, 123, 255, 0.1);
}

/* Date styling */
.timeline-date {
  display: inline-block;
  color: #fff;
  font-weight: 600;
  margin-bottom: 0.75rem;
  background-color: #0069d9;  /* 更深的蓝色 */
  padding: 4px 12px;
  border-radius: 16px;
  font-size: 0.95rem;
}

/* Heading styling */
.timeline-content h3 {
  margin: 0.5rem 0 1rem 0;
  color: #2c3e50;  /* 更柔和的深色，提高可读性 */
}

/* 暗色模式下的标题颜色 */
html.dark .timeline-content h3 {
  color: #fff;
}

/* Content styling */
.timeline-content p {
  margin: 0;
  line-height: 1.6;
  color: #3a4a5a;  /* 浅色模式下更舒适的文字颜色 */
}

/* 暗色模式下的段落文字颜色 */
html.dark .timeline-content p {
  color: rgba(255, 255, 255, 0.9);
}

/* Timeline details list styling */
.timeline-details ul {
  margin-left: 1.25rem;
}

.timeline-details li {
  margin: 0.5rem 0;
  position: relative;
  color: #3a4a5a;  /* 浅色模式下更舒适的文字颜色 */
}

/* 暗色模式下的列表文字颜色 */
html.dark .timeline-details li {
  color: rgba(255, 255, 255, 0.9);
}

.timeline-details li::before {
  content: '';
  position: absolute;
  left: -1.25rem;
  top: 0.5rem;
  width: 6px;
  height: 6px;
  background-color: #0069d9;  /* 更深的蓝色 */
  border-radius: 50%;
}

/* Responsive design */
@media screen and (max-width: 768px) {
  .timeline::before {
    left: 30px;
    margin-left: 0;
  }
  
  .timeline-container.left,
  .timeline-container.right {
    padding-left: 70px;
    padding-right: 0;
  }
  
  .timeline-container.left::before,
  .timeline-container.right::before {
    left: 30px;
    margin-left: -10px;
    margin-right: 0;
  }
  
  /* In mobile view, all arrows point right */
  .timeline-container.left::after,
  .timeline-container.right::after {
    left: 52px;
    border-width: 10px 0 10px 15px;
    border-color: transparent transparent transparent #0069d9;  /* 更深的蓝色 */
  }
  
  .timeline-content {
    width: 100%;
  }
}

/* Animation classes */
.timeline-container {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.5s ease;
}

.timeline-container.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 社交链接样式 */
.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  margin-top: 20px;
}

.social-links a {
  display: inline-flex;
  align-items: center;
  padding: 10px 18px;
  background-color: rgba(245, 245, 250, 0.8);  /* 匹配时间线内容背景 */
  border-radius: 24px;
  text-decoration: none;
  transition: all 0.3s ease;
  border: 1px solid rgba(0, 0, 0, 0.1);  /* 浅色模式下的边框 */
  color: #3a4a5a;  /* 浅色模式下更舒适的文字颜色 */
}

/* 暗色模式下的社交链接样式 */
html.dark .social-links a {
  background-color: rgba(80, 80, 80, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.9);
}

.social-links a:hover {
  background-color: rgba(230, 240, 255, 0.9);  /* 悬停时的柔和蓝色背景 */
  transform: translateY(-2px);
  border-color: rgba(0, 105, 217, 0.3);  /* 匹配主题蓝色 */
}

/* 暗色模式下的社交链接悬停样式 */
html.dark .social-links a:hover {
  background-color: rgba(0, 123, 255, 0.2);
  border-color: rgba(0, 123, 255, 0.3);
}