:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --gray: #666666;
  --border: rgba(0, 0, 0, 0.03);
}

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

html {
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 0 2rem;
}

header {
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  color: var(--gray);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color 0.2s;
}

.back-btn:hover {
  color: var(--text);
}

main {
  flex: 1;
  padding: 3rem 0;
}

article {
  text-align: center;
}

h1 {
  font-size: 1.8rem;
  font-weight: 400;
  margin-bottom: 0.3rem;
  letter-spacing: 0.02em;
}

.subtitle {
  color: var(--gray);
  font-size: 0.9rem;
  margin-bottom: 2rem;
}

.timeline {
  text-align: left;
}

.empty-text {
  color: var(--gray);
  font-size: 0.95rem;
  text-align: center;
  padding: 3rem 0;
}

.update-item {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--border);
}

.update-item:last-child {
  border-bottom: none;
}

.update-date {
  font-size: 0.8rem;
  color: var(--gray);
  margin-bottom: 0.35rem;
}

.update-title {
  font-size: 1.05rem;
  font-weight: 500;
  margin-bottom: 0.4rem;
}

.update-content {
  font-size: 0.9rem;
  color: var(--gray);
  line-height: 1.7;
}

.update-content ul {
  margin-left: 1.1rem;
  margin-top: 0.4rem;
}

.update-content li {
  margin-bottom: 0.2rem;
}

footer {
  padding: 1.5rem 0;
  text-align: center;
  border-top: 1px solid var(--border);
  margin-top: auto;
}

footer p {
  color: var(--gray);
  font-size: 0.8rem;
}

@media (max-width: 480px) {
  .container {
    padding: 0 1.25rem;
  }

  h1 {
    font-size: 1.5rem;
  }

  .subtitle {
    font-size: 0.85rem;
  }

  main {
    padding: 2rem 0;
  }

  .empty-text {
    padding: 2rem 0;
  }
}