:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --bg: #ffffff;
  --bg-secondary: #f9fafb;
  --text: #1f2937;
  --text-secondary: #6b7280;
  --border: #e5e7eb;
  --success: #10b981;
  --danger: #ef4444;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
  --radius: 12px;
  --max-width: 800px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111827;
    --bg-secondary: #1f2937;
    --text: #f3f4f6;
    --text-secondary: #9ca3af;
    --border: #374151;
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.5);
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  min-height: 100vh;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* 导航 */
.navbar {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}
.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}
.navbar .logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
}
.navbar .nav-links a {
  margin-left: 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.navbar .nav-links a:hover { color: var(--primary); }

/* Hero 区域 */
.hero {
  text-align: center;
  padding: 80px 20px 60px;
  background: linear-gradient(135deg, var(--primary) 0%, #8b5cf6 100%);
  color: white;
}
.hero .avatar {
  width: 96px; height: 96px;
  border-radius: 50%;
  border: 4px solid rgba(255,255,255,0.3);
  margin-bottom: 20px;
  background: rgba(255,255,255,0.2);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
}
.hero h1 { font-size: 2rem; margin-bottom: 12px; }
.hero p { font-size: 1.05rem; opacity: 0.9; max-width: 500px; margin: 0 auto; }

/* 文章列表 */
.posts-section { padding: 48px 0; }
.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--primary);
  display: inline-block;
}
.post-list { display: flex; flex-direction: column; gap: 16px; }
.post-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all 0.2s;
  cursor: pointer;
}
.post-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
  border-color: var(--primary);
}
.post-card h3 {
  font-size: 1.2rem;
  margin-bottom: 8px;
  color: var(--text);
}
.post-card .meta {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}
.post-card .summary {
  color: var(--text-secondary);
  font-size: 0.95rem;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}
.post-card .tags { margin-top: 12px; }
.tag {
  display: inline-block;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.8rem;
  margin-right: 6px;
}

/* 文章详情 */
.post-detail { padding: 48px 0; }
.post-detail h1 {
  font-size: 2rem;
  margin-bottom: 16px;
  line-height: 1.3;
}
.post-detail .meta {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}
.post-content {
  font-size: 1.05rem;
  line-height: 1.8;
}
.post-content h1, .post-content h2, .post-content h3 {
  margin: 24px 0 12px;
}
.post-content p { margin-bottom: 16px; }
.post-content code {
  background: var(--bg-secondary);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}
.post-content pre {
  background: var(--bg-secondary);
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 16px;
}
.post-content pre code { background: none; padding: 0; }
.post-content blockquote {
  border-left: 4px solid var(--primary);
  padding-left: 16px;
  margin: 16px 0;
  color: var(--text-secondary);
}
.post-content img { max-width: 100%; border-radius: 8px; }
.post-content ul, .post-content ol { padding-left: 24px; margin-bottom: 16px; }

.back-btn {
  display: inline-block;
  margin-bottom: 24px;
  color: var(--text-secondary);
  font-size: 0.9rem;
}
.back-btn:hover { color: var(--primary); }

/* 管理后台 */
.admin-layout { display: flex; min-height: 100vh; }
.admin-sidebar {
  width: 220px;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  padding: 24px 0;
}
.admin-sidebar .logo {
  padding: 0 24px 24px;
  font-size: 1.1rem;
  font-weight: 700;
  border-bottom: 1px solid var(--border);
  margin-bottom: 16px;
}
.admin-sidebar a {
  display: block;
  padding: 12px 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.admin-sidebar a:hover, .admin-sidebar a.active {
  background: var(--bg);
  color: var(--primary);
}
.admin-main { flex: 1; padding: 32px; overflow-y: auto; }
.admin-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 32px;
}
.admin-header h1 { font-size: 1.5rem; }

/* 表单 */
.form-group { margin-bottom: 20px; }
.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  font-size: 0.9rem;
}
.form-group input, .form-group textarea, .form-group select {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.1);
}
.form-group textarea { resize: vertical; min-height: 200px; }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: var(--bg-secondary); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { background: var(--border); }
.btn-danger { background: var(--danger); color: white; }
.btn-danger:hover { opacity: 0.9; }
.btn-sm { padding: 6px 12px; font-size: 0.85rem; }

/* 表格 */
.table { width: 100%; border-collapse: collapse; }
.table th, .table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
}
.table th { background: var(--bg-secondary); font-weight: 600; }
.table tr:hover { background: var(--bg-secondary); }

/* 登录页 */
.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary) 0%, #8b5cf6 100%);
}
.login-card {
  background: var(--bg);
  padding: 40px;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 380px;
}
.login-card h1 { text-align: center; margin-bottom: 8px; }
.login-card .subtitle { text-align: center; color: var(--text-secondary); margin-bottom: 32px; font-size: 0.9rem; }

/* Toast 提示 */
.toast {
  position: fixed;
  top: 24px;
  right: 24px;
  padding: 12px 20px;
  border-radius: 8px;
  color: white;
  font-size: 0.9rem;
  z-index: 1000;
  animation: slideIn 0.3s;
}
.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }
@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* 分页 */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 32px;
}
.pagination button {
  padding: 8px 14px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  border-radius: 8px;
  cursor: pointer;
}
.pagination button.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}
.pagination button:disabled { opacity: 0.5; cursor: not-allowed; }

/* 空状态 */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-secondary);
}
.empty-state .icon { font-size: 3rem; margin-bottom: 16px; }

/* 页脚 */
.footer {
  text-align: center;
  padding: 32px 20px;
  color: var(--text-secondary);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
  margin-top: 48px;
}

/* Markdown 编辑器预览分割 */
.editor-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.preview-box {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  min-height: 400px;
  overflow-y: auto;
  background: var(--bg-secondary);
}

@media (max-width: 768px) {
  .editor-row { grid-template-columns: 1fr; }
  .admin-layout { flex-direction: column; }
  .admin-sidebar { width: 100%; padding: 16px 0; }
  .admin-sidebar a { display: inline-block; }
  .hero h1 { font-size: 1.5rem; }
}