/* ========== 全局基础 ========== */
:root {
  --brand-50: #f0f7ff;
  --brand-500: #3b82f6;
  --brand-600: #2563eb;
  --brand-700: #1d4ed8;
  --brand-900: #0a2540;
  --accent-500: #ff6b35;
  --accent-600: #ea580c;
  --ok-500: #10b981;
  --max-content-width: 72rem;
}

html { scroll-behavior: smooth; }

body {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 暗色滚动条 */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 5px; }
.dark ::-webkit-scrollbar-thumb { background: #475569; }

/* ========== 文章卡片 ========== */
.article-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 1rem;
  transition: all 0.2s ease;
  text-decoration: none;
  color: inherit;
}
.dark .article-card { background: #0f172a; border-color: #1e293b; }

.article-card:hover {
  border-color: var(--brand-500);
  transform: translateY(-2px);
  box-shadow: 0 10px 30px -10px rgba(37, 99, 235, 0.3);
}

.article-card .accent-bar {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--brand-500), var(--accent-500));
  border-radius: 1rem 1rem 0 0;
  opacity: 0;
  transition: opacity 0.2s ease;
}
.article-card:hover .accent-bar { opacity: 1; }

.article-card .title { font-weight: 700; font-size: 1.125rem; line-height: 1.4; margin-bottom: 0.5rem; }
.article-card .summary { color: #64748b; font-size: 0.875rem; line-height: 1.6; margin-bottom: 1rem; flex: 1; }
.dark .article-card .summary { color: #94a3b8; }

.article-card .meta { display: flex; align-items: center; gap: 0.75rem; font-size: 0.75rem; color: #64748b; }
.dark .article-card .meta { color: #94a3b8; }

.tag {
  display: inline-block;
  padding: 0.125rem 0.625rem;
  font-size: 0.7rem;
  font-weight: 600;
  border-radius: 9999px;
  background: var(--brand-50);
  color: var(--brand-700);
}
.dark .tag { background: rgba(59, 130, 246, 0.15); color: #93c5fd; }

.cat-tag {
  display: inline-block;
  padding: 0.125rem 0.5rem;
  font-size: 0.7rem;
  font-weight: 600;
  border-radius: 4px;
  background: #f1f5f9;
  color: #475569;
}
.dark .cat-tag { background: #1e293b; color: #cbd5e1; }

/* ========== 文章详情 Markdown 渲染 ========== */
.markdown {
  font-size: 1.0625rem;
  line-height: 1.85;
  color: #334155;
}
.dark .markdown { color: #cbd5e1; }

.markdown h1 { font-size: 2.25rem; font-weight: 800; margin: 2.5rem 0 1rem; line-height: 1.25; color: #0f172a; }
.dark .markdown h1 { color: #f1f5f9; }

.markdown h2 {
  font-size: 1.75rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
  padding-top: 1rem;
  border-top: 1px solid #e2e8f0;
  color: #0f172a;
}
.dark .markdown h2 { color: #f1f5f9; border-color: #1e293b; }

.markdown h3 {
  font-size: 1.375rem;
  font-weight: 700;
  margin: 1.75rem 0 0.75rem;
  color: #0f172a;
}
.dark .markdown h3 { color: #f1f5f9; }

.markdown h4 { font-size: 1.125rem; font-weight: 600; margin: 1.25rem 0 0.5rem; }

.markdown p { margin: 1rem 0; }
.markdown strong { font-weight: 700; color: #0f172a; }
.dark .markdown strong { color: #f1f5f9; }

.markdown ul, .markdown ol { margin: 1rem 0; padding-left: 1.5rem; }
.markdown li { margin: 0.5rem 0; }
.markdown ul li { list-style-type: disc; }
.markdown ol li { list-style-type: decimal; }

.markdown blockquote {
  margin: 1.5rem 0;
  padding: 1rem 1.5rem;
  border-left: 4px solid var(--accent-500);
  background: rgba(255, 107, 53, 0.05);
  border-radius: 0 0.5rem 0.5rem 0;
  font-style: italic;
  color: #475569;
}
.dark .markdown blockquote { background: rgba(255, 107, 53, 0.1); color: #cbd5e1; }

.markdown code {
  background: #f1f5f9;
  padding: 0.125rem 0.375rem;
  border-radius: 0.25rem;
  font-family: 'Menlo', 'Monaco', monospace;
  font-size: 0.9em;
  color: #be185d;
}
.dark .markdown code { background: #1e293b; color: #f0abfc; }

.markdown pre {
  background: #0f172a;
  color: #e2e8f0;
  padding: 1rem;
  border-radius: 0.5rem;
  overflow-x: auto;
  margin: 1rem 0;
  font-size: 0.875rem;
}
.markdown pre code { background: transparent; color: inherit; padding: 0; }

.markdown table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 0.5rem;
  overflow: hidden;
}
.dark .markdown table { background: #0f172a; border-color: #1e293b; }

.markdown table th,
.markdown table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid #e2e8f0;
  text-align: left;
}
.dark .markdown table th,
.dark .markdown table td { border-color: #1e293b; }

.markdown table th {
  background: #f8fafc;
  font-weight: 700;
  color: #0f172a;
}
.dark .markdown table th { background: #1e293b; color: #f1f5f9; }

.markdown table tr:last-child td { border-bottom: 0; }

.markdown hr {
  border: 0;
  border-top: 1px solid #e2e8f0;
  margin: 2rem 0;
}
.dark .markdown hr { border-color: #1e293b; }

.markdown a { color: var(--brand-600); text-decoration: underline; text-underline-offset: 2px; }
.markdown a:hover { color: var(--brand-700); }

/* ========== 工具卡片 ========== */
.tool-card {
  padding: 1.5rem;
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 1rem;
  transition: all 0.2s ease;
}
.dark .tool-card { background: #0f172a; border-color: #1e293b; }
.tool-card:hover { border-color: var(--brand-500); }

.tool-input {
  width: 100%;
  padding: 0.625rem 0.875rem;
  border: 1px solid #cbd5e1;
  border-radius: 0.5rem;
  background: white;
  font-size: 0.95rem;
  transition: border-color 0.15s;
}
.dark .tool-input { background: #1e293b; border-color: #475569; color: #f1f5f9; }
.tool-input:focus { outline: none; border-color: var(--brand-500); box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15); }

.tool-result {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--brand-50);
  border-radius: 0.5rem;
  font-size: 0.95rem;
  line-height: 1.6;
  color: #1e293b;
  display: none;
}
.dark .tool-result { background: rgba(59, 130, 246, 0.1); color: #e2e8f0; }
.tool-result.show { display: block; }

.tool-result .big-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--brand-600);
}
.dark .tool-result .big-number { color: #60a5fa; }

/* ========== 阅读进度条 ========== */
.reading-progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--brand-500), var(--accent-500));
  width: 0%;
  z-index: 100;
  transition: width 0.1s linear;
}

/* ========== 过滤器按钮 ========== */
.filter-btn {
  padding: 0.375rem 0.875rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 9999px;
  border: 1px solid #e2e8f0;
  background: white;
  color: #475569;
  cursor: pointer;
  transition: all 0.15s;
}
.dark .filter-btn { background: #0f172a; border-color: #1e293b; color: #cbd5e1; }
.filter-btn:hover { border-color: var(--brand-500); color: var(--brand-600); }
.filter-btn.active {
  background: var(--brand-600);
  color: white;
  border-color: var(--brand-600);
}

/* ========== 文章目录 ========== */
.toc {
  position: sticky;
  top: 5rem;
  padding: 1rem 1.25rem;
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  border: 1px solid #e2e8f0;
  border-radius: 0.75rem;
  font-size: 0.875rem;
  max-height: calc(100vh - 7rem);
  overflow-y: auto;
}
.dark .toc { background: rgba(15, 23, 42, 0.7); border-color: #1e293b; }

.toc h4 { font-weight: 700; margin-bottom: 0.5rem; color: #0f172a; }
.dark .toc h4 { color: #f1f5f9; }

.toc ul { list-style: none; padding: 0; margin: 0; }
.toc li { margin: 0.25rem 0; }
.toc a { color: #64748b; text-decoration: none; transition: color 0.15s; line-height: 1.5; display: block; }
.dark .toc a { color: #94a3b8; }
.toc a:hover { color: var(--brand-600); }
.toc a.active { color: var(--brand-600); font-weight: 600; }
.toc .h3 { padding-left: 1rem; font-size: 0.8rem; }

/* ========== 响应式 ========== */
@media (max-width: 768px) {
  .toc { display: none; }
  .markdown { font-size: 1rem; }
  .markdown h1 { font-size: 1.875rem; }
  .markdown h2 { font-size: 1.5rem; }
  .markdown h3 { font-size: 1.25rem; }
  .markdown table { font-size: 0.85rem; }
  .markdown table th,
  .markdown table td { padding: 0.5rem; }
}

/* ========== 动画 ========== */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fadeUp 0.5s ease forwards; }

/* ========== 工具提示 ========== */
[data-tooltip] {
  position: relative;
  cursor: help;
  border-bottom: 1px dotted var(--brand-500);
}
[data-tooltip]:after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  padding: 0.5rem 0.75rem;
  background: #0f172a;
  color: white;
  font-size: 0.8rem;
  border-radius: 0.375rem;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  z-index: 50;
}
[data-tooltip]:hover:after { opacity: 1; }

/* ========== 打印 ========== */
@media print {
  header, footer, .toc, .reading-progress, .no-print { display: none !important; }
  body { background: white; color: black; }
  .markdown h2 { page-break-before: always; }
}