:root {
  --bg-color: #ffffff;
  --text-color: #333333;
  --link-color: #007bff;
  --header-bg: #f8f9fa;
  --footer-bg: #f8f9fa;
  --border-color: #e9ecef;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --link-color: #66b2ff;
    --header-bg: #2d2d2d;
    --footer-bg: #2d2d2d;
    --border-color: #404040;
  }
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-sans);
  margin: 0;
  padding: 0;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
}

header {
  background-color: var(--header-bg);
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header h1 {
  margin: 0;
  font-size: 1.5rem;
}

nav a {
  margin-left: 1.5rem;
  text-decoration: none;
  color: var(--text-color);
  font-weight: 500;
}

nav a:hover {
  color: var(--link-color);
}

main {
  max-width: 800px;
  margin: 2rem auto;
  padding: 0 1.5rem;
  min-height: 70vh;
}

.intro {
  margin-bottom: 3rem;
}

.intro h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.posts-list {
  list-style: none;
  padding: 0;
}

.post-item {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.post-item h3 {
  margin: 0 0 0.5rem 0;
}

.post-item h3 a {
  text-decoration: none;
  color: var(--text-color);
}

.post-item h3 a:hover {
  color: var(--link-color);
}

.post-meta {
  font-size: 0.9rem;
  color: #888;
}

footer {
  background-color: var(--footer-bg);
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.9rem;
}

.filing-info {
  margin-top: 1rem;
  color: #666;
}

.filing-info a {
  color: inherit;
  text-decoration: none;
}

.filing-info a:hover {
  text-decoration: underline;
}

.error-page {
  text-align: center;
  padding: 5rem 1rem;
}

.error-page h2 {
  font-size: 4rem;
  margin-bottom: 1rem;
}