/* 全局样式 */
:root {
  --primary-color: #4f46e5;
  --primary-hover: #4338ca;
  --text-color: #1f2937;
  --text-secondary: #6b7280;
  --bg-color: #f9fafb;
  --card-bg: #ffffff;
  --border-color: #e5e7eb;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
    sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--bg-color);
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

/* 标题样式 */
h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-color);
  margin-bottom: 0.5rem;
  line-height: 1.2;
}

/* 日期样式 */
body > p:first-of-type {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 2rem;
  font-style: italic;
}

/* 文章段落样式 */
body > p:not(:first-of-type) {
  color: var(--text-color);
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 1.25rem;
  text-align: justify;
  animation: fadeIn 0.3s ease forwards;
}

/* 列表样式 */
ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

li {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

li:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

/* 链接样式 */
a {
  display: block;
  color: var(--primary-color);
  text-decoration: none;
  font-size: 1.1rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
}

/* 响应式设计 */
@media (max-width: 640px) {
  body {
    padding: 1.5rem 0.75rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  li {
    padding: 0.875rem 1rem;
  }
  
  a {
    font-size: 1rem;
  }
}

/* 动画效果 */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

li {
  animation: fadeIn 0.3s ease forwards;
}

li:nth-child(1) { animation-delay: 0.05s; }
li:nth-child(2) { animation-delay: 0.1s; }
li:nth-child(3) { animation-delay: 0.15s; }
li:nth-child(4) { animation-delay: 0.2s; }
li:nth-child(5) { animation-delay: 0.25s; }
li:nth-child(6) { animation-delay: 0.3s; }
li:nth-child(7) { animation-delay: 0.35s; }
li:nth-child(8) { animation-delay: 0.4s; }
li:nth-child(9) { animation-delay: 0.45s; }
li:nth-child(10) { animation-delay: 0.5s; }
li:nth-child(11) { animation-delay: 0.55s; }
li:nth-child(12) { animation-delay: 0.6s; }
li:nth-child(13) { animation-delay: 0.65s; }
li:nth-child(14) { animation-delay: 0.7s; }
li:nth-child(15) { animation-delay: 0.75s; }
li:nth-child(16) { animation-delay: 0.8s; }
li:nth-child(17) { animation-delay: 0.85s; }
li:nth-child(18) { animation-delay: 0.9s; }
li:nth-child(19) { animation-delay: 0.95s; }
li:nth-child(20) { animation-delay: 1s; }
li:nth-child(21) { animation-delay: 1.05s; }
li:nth-child(22) { animation-delay: 1.1s; }