/* === 基础重置 === */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 18px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #333;
  background: #fafaf8;
  line-height: 1.8;
}

/* === 容器 === */
.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
}

/* === 头部 === */
header {
  text-align: center;
  padding: 60px 0 40px;
}

header h1 {
  font-size: 2rem;
  font-weight: 400;
  letter-spacing: 0.05em;
  color: #1a1a1a;
}

.subtitle {
  color: #999;
  font-size: 0.95rem;
  margin-top: 6px;
}

/* === 导航 === */
nav {
  border-top: 1px solid #e8e8e4;
  border-bottom: 1px solid #e8e8e4;
  padding: 14px 0;
  margin-bottom: 50px;
}

nav .container {
  display: flex;
  justify-content: center;
  gap: 36px;
}

nav a {
  text-decoration: none;
  color: #888;
  font-size: 0.95rem;
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

nav a:hover,
nav a.active {
  color: #333;
  border-color: #333;
}

/* === 内容区 === */
main {
  min-height: 50vh;
}

/* === 头像区 === */
.hero {
  text-align: center;
  padding: 20px 0 50px;
}

.avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  object-fit: cover;
  display: inline-block;
  margin-bottom: 20px;
}

.hero h2 {
  font-weight: 400;
  font-size: 1.3rem;
  margin-bottom: 8px;
}

.hero p {
  color: #888;
  font-size: 0.95rem;
}

/* === 预览卡片 === */
.preview h3 {
  font-weight: 400;
  font-size: 1rem;
  color: #999;
  margin-bottom: 16px;
}

.card-list {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.card {
  flex: 1 1 200px;
  display: block;
  padding: 28px 24px;
  text-decoration: none;
  background: #fff;
  border: 1px solid #e8e8e4;
  border-radius: 6px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.card:hover {
  border-color: #ccc;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}

.card h4 {
  color: #333;
  font-weight: 500;
  font-size: 1rem;
  margin-bottom: 6px;
}

.card p {
  color: #999;
  font-size: 0.85rem;
}

/* === 文章列表 === */
.page-title {
  font-weight: 400;
  font-size: 1.3rem;
  margin-bottom: 28px;
  color: #1a1a1a;
}

.article-list {
  list-style: none;
}

.article-list li {
  padding: 20px 0;
  border-bottom: 1px solid #eee;
}

.article-list li:last-child {
  border-bottom: none;
}

.article-list a {
  text-decoration: none;
  color: #1a1a1a;
  font-size: 1.05rem;
}

.article-list a:hover {
  text-decoration: underline;
}

.article-date {
  color: #aaa;
  font-size: 0.8rem;
  margin-top: 4px;
}

.article-excerpt {
  color: #888;
  font-size: 0.9rem;
  margin-top: 6px;
}

/* === PDF 列表 === */
.pdf-list {
  list-style: none;
}

.pdf-list li {
  padding: 20px 0;
  border-bottom: 1px solid #eee;
  display: flex;
  align-items: center;
  gap: 14px;
}

.pdf-list li:last-child {
  border-bottom: none;
}

.pdf-icon {
  font-size: 1.6rem;
  flex-shrink: 0;
}

.pdf-list a {
  text-decoration: none;
  color: #1a1a1a;
  font-size: 1.05rem;
}

.pdf-list a:hover {
  text-decoration: underline;
}

.pdf-info {
  color: #aaa;
  font-size: 0.8rem;
  margin-top: 2px;
}

/* === 页脚 === */
footer {
  text-align: center;
  padding: 50px 0 40px;
  color: #ccc;
  font-size: 0.8rem;
}

/* === 响应式 === */
@media (max-width: 500px) {
  .card-list {
    flex-direction: column;
  }

  header {
    padding: 40px 0 30px;
  }

  nav .container {
    gap: 24px;
  }
}