/* ═══════════════════════════════════════════════
   Design System — 丞相大人博客
   CSS Variables | Card Layout | Sidebar | Responsive
   ═══════════════════════════════════════════════ */

:root {
  /* Colors */
  --color-bg: #f8f9fa;
  --color-surface: #ffffff;
  --color-text: #2d3436;
  --color-text-secondary: #636e72;
  --color-text-muted: #b2bec3;
  --color-primary: #e53e3e;
  --color-primary-hover: #c53030;
  --color-primary-light: #fff5f5;
  --color-accent: #3182ce;
  --color-accent-light: #ebf8ff;
  --color-border: #e2e8f0;
  --color-border-light: #edf2f7;
  --color-code-bg: #f7fafc;
  --color-pre-bg: #1a202c;
  --color-pre-text: #e2e8f0;
  --color-shadow: rgba(0,0,0,0.06);
  --color-shadow-hover: rgba(0,0,0,0.12);

  /* Category badge colors */
  --cat-技术: #3182ce;
  --cat-AI工具: #38a169;
  --cat-一人公司: #dd6b20;
  --cat-心屿: #805ad5;
  --cat-技术-bg: #ebf8ff;
  --cat-AI工具-bg: #f0fff4;
  --cat-一人公司-bg: #fffaf0;
  --cat-心屿-bg: #faf5ff;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", Menlo, Courier, monospace;
  --font-size-base: 16px;
  --line-height-base: 1.8;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Layout */
  --sidebar-width: 260px;
  --content-max-width: 780px;
  --radius: 8px;
  --radius-sm: 4px;
  --radius-lg: 12px;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; }
body {
  margin: 0; padding: 0;
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--color-text);
  background: var(--color-bg);
}

/* Links */
a { color: var(--color-primary); text-decoration: none; transition: color 0.15s; }
a:hover { color: var(--color-primary-hover); text-decoration: underline; }

/* ═══ Layout ═══ */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  max-width: 1100px;
  margin: 0 auto;
  min-height: 100vh;
}

.main-content {
  padding: var(--space-xl) var(--space-2xl);
  max-width: var(--content-max-width);
}

/* ═══ Sidebar ═══ */
.sidebar {
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  padding: var(--space-xl) var(--space-md);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.sidebar-inner h3 { font-size: 1rem; margin: 0 0 var(--space-lg); }
.sidebar-inner h3 a { color: var(--color-text); }
.sidebar-inner h3 a:hover { color: var(--color-primary); text-decoration: none; }

.sidebar-section { margin-bottom: var(--space-xl); }
.sidebar-section h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-sm);
}

.sidebar-list {
  list-style: none; padding: 0; margin: 0;
}
.sidebar-list li {
  padding: 3px 0;
  font-size: 0.88rem;
}
.sidebar-list li a { color: var(--color-text-secondary); }
.sidebar-list li a:hover { color: var(--color-primary); }

.count {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  background: var(--color-border-light);
  padding: 1px 6px;
  border-radius: 10px;
  margin-left: 4px;
}

/* Search box */
.search-box { margin-bottom: var(--space-md); }
.search-box input {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.88rem;
  font-family: var(--font-sans);
  outline: none;
  transition: border-color 0.15s;
}
.search-box input:focus { border-color: var(--color-primary); }

/* Sidebar tags */
.sidebar-tags { display: flex; flex-wrap: wrap; gap: 4px; }
.tag-cloud-item {
  display: inline-block;
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: 2px 0;
  transition: color 0.15s;
  line-height: 1.5;
}
.tag-cloud-item:hover { color: var(--color-primary); text-decoration: none; }
.tag-count { font-size: 0.65rem; color: var(--color-text-muted); margin-left: 1px; }

/* Archive year list */
.archive-year {
  font-weight: 600;
  font-size: 0.9rem;
  margin-top: var(--space-sm);
}
.archive-year ul { list-style: none; padding-left: var(--space-md); }

/* ═══ Page Header ═══ */
.page-header {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-lg);
  border-bottom: 2px solid var(--color-primary);
}
.page-header h1 { font-size: 1.8rem; margin: 0 0 var(--space-xs); }
.page-header p { color: var(--color-text-secondary); margin: 0; }

/* ═══ Card ═══ */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg) var(--space-xl);
  margin-bottom: var(--space-lg);
  box-shadow: 0 1px 3px var(--color-shadow);
  transition: box-shadow 0.2s, transform 0.2s;
}
.card:hover {
  box-shadow: 0 4px 12px var(--color-shadow-hover);
  transform: translateY(-1px);
}
.card-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
  flex-wrap: wrap;
}
.card-date, .card-rt {
  font-size: 0.82rem;
  color: var(--color-text-muted);
}
.card-title {
  font-size: 1.25rem;
  margin: 0 0 var(--space-sm);
  line-height: 1.4;
}
.card-title a { color: var(--color-text); }
.card-title a:hover { color: var(--color-primary); text-decoration: none; }
.card-desc {
  color: var(--color-text-secondary);
  font-size: 0.92rem;
  margin: 0 0 var(--space-sm);
  line-height: 1.6;
}
.card-tags { display: flex; gap: 4px; flex-wrap: wrap; margin-top: var(--space-sm); }

/* Category badge */
.cat-badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.78rem;
  font-weight: 600;
  color: #fff;
  text-decoration: none;
  white-space: nowrap;
}
.cat-badge:hover { opacity: 0.85; text-decoration: none; color: #fff; }

/* Category badge colors (use style attribute fallback, but CSS classes for known cats) */
.cat-badge[href*="技术"]:not([href*="技术实践"]) { background: var(--cat-技术); }
.cat-badge[href*="AI工具"] { background: var(--cat-AI工具); }
.cat-badge[href*="一人公司"] { background: var(--cat-一人公司); }
.cat-badge[href*="心屿"] { background: var(--cat-心屿); }

/* Tag pills */
.tag {
  display: inline-block;
  padding: 2px 8px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  text-decoration: none;
  margin-right: 4px;
}
.tag:hover { background: var(--color-primary); color: #fff; text-decoration: none; }
.tag-sm {
  display: inline-block;
  padding: 1px 6px;
  background: var(--color-border-light);
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
}

/* ═══ Article ═══ */
article { line-height: 1.9; }
article h1 { font-size: 1.9rem; margin: 0 0 var(--space-sm); }
article .meta {
  color: var(--color-text-muted);
  font-size: 0.88rem;
  margin-bottom: var(--space-xl);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}
.article-body { margin-top: var(--space-lg); }
.article-body h2 { font-size: 1.4rem; margin: 2rem 0 0.8rem; padding-top: 1rem; }
.article-body h3 { font-size: 1.15rem; margin: 1.5rem 0 0.6rem; }
.article-body h2:first-child { margin-top: 0; }
.article-body p { margin: 1rem 0; }
.article-body ul, .article-body ol { margin: 0.8rem 0; padding-left: 1.5rem; }
.article-body li { margin: 0.3rem 0; }

/* ═══ TOC Sidebar ═══ */
.toc-sidebar {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-xl);
}
.toc-title { font-size: 0.9rem; margin: 0 0 var(--space-sm); color: var(--color-text); }
.toc-list { list-style: none; padding: 0; margin: 0; }
.toc-item { padding: 3px 0; font-size: 0.88rem; }
.toc-item a { color: var(--color-text-secondary); }
.toc-item a:hover { color: var(--color-primary); text-decoration: none; }
.toc-sub { padding-left: var(--space-lg); font-size: 0.84rem; }

/* ═══ Post Tags ═══ */
.post-tags { margin-top: var(--space-xl); padding-top: var(--space-lg); border-top: 1px solid var(--color-border-light); }

/* ═══ Prev/Next Nav ═══ */
.post-nav {
  display: flex;
  justify-content: space-between;
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border-light);
  gap: var(--space-md);
  flex-wrap: wrap;
}
.prev-link, .next-link {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  max-width: 48%;
}
.prev-link:hover, .next-link:hover { color: var(--color-primary); text-decoration: none; }
.next-link { text-align: right; margin-left: auto; }

/* ═══ Blockquote, Code ═══ */
blockquote {
  border-left: 3px solid var(--color-primary);
  padding: var(--space-sm) var(--space-lg);
  margin: var(--space-lg) 0;
  color: var(--color-text-secondary);
  background: var(--color-primary-light);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
blockquote p { margin: 0.5rem 0; }
code {
  background: var(--color-code-bg);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.88em;
  color: var(--color-primary);
}
pre {
  background: var(--color-pre-bg);
  color: var(--color-pre-text);
  padding: var(--space-lg);
  border-radius: var(--radius);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88em;
  line-height: 1.6;
  margin: var(--space-lg) 0;
}
pre code { background: transparent; color: inherit; padding: 0; }

/* ═══ CTA ═══ */
.cta {
  display: inline-block;
  margin: var(--space-xl) 0;
  padding: 14px 36px;
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 1.1rem;
}
.cta:hover { background: var(--color-primary-hover); text-decoration: none; color: #fff; }

/* ═══ Tag Cloud Header ═══ */
.tag-cloud-header {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: var(--space-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-2xl);
  justify-content: center;
  align-items: baseline;
}
.tag-cloud-header .tag-cloud-item {
  padding: 4px 12px;
  border-radius: var(--radius);
  background: var(--color-bg);
}
.tag-cloud-header .tag-cloud-item:hover {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

/* ═══ Tag Section (tags.html) ═══ */
.tag-section {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-border-light);
}
.tag-section-title {
  font-size: 1.3rem;
  margin: 0 0 var(--space-md);
  display: flex;
  align-items: baseline;
  gap: var(--space-sm);
}
.tag-post-list {
  list-style: none; padding: 0; margin: 0;
}
.tag-post-list li {
  padding: 4px 0;
  font-size: 0.92rem;
}
.tag-post-list li a { color: var(--color-text); }
.tag-post-list li a:hover { color: var(--color-primary); }

.meta-sm {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  margin-left: var(--space-sm);
}

/* ═══ Archive ═══ */
.archive-year-section { margin-bottom: var(--space-2xl); }
.archive-year-section h2 {
  font-size: 1.5rem;
  margin: 0 0 var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border);
}
.archive-month { margin-bottom: var(--space-lg); }
.archive-month h3 {
  font-size: 1.1rem;
  margin: 0 0 var(--space-sm);
  color: var(--color-text-secondary);
}
.archive-post-list {
  list-style: none; padding: 0; margin: 0;
}
.archive-post-list li {
  padding: 3px 0;
  font-size: 0.92rem;
}
.archive-post-list li a { color: var(--color-text); }
.archive-post-list li a:hover { color: var(--color-primary); }

/* ═══ Footer ═══ */
footer {
  margin-top: var(--space-3xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border-light);
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* ═══ Breadcrumb ═══ */
.breadcrumb { margin-bottom: var(--space-xl); font-size: 0.88rem; }
.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-primary); }

/* ═══ Misc ═══ */
hr {
  border: none;
  border-top: 1px solid var(--color-border-light);
  margin: var(--space-xl) 0;
}

/* ═══ Responsive ═══ */
@media (max-width: 768px) {
  .layout {
    grid-template-columns: 1fr;
  }
  .sidebar {
    display: none;
    position: static;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-md);
  }
  .sidebar.open { display: block; }
  .main-content {
    padding: var(--space-md);
  }
  .card {
    padding: var(--space-md);
  }
  .page-header h1 { font-size: 1.5rem; }
  article h1 { font-size: 1.5rem; }
  .post-nav { flex-direction: column; }
  .prev-link, .next-link { max-width: 100%; }
  .next-link { text-align: left; margin-left: 0; }
}

/* ═══ Dark Mode (ready) ═══ */
@media (prefers-color-scheme: dark) {
  /* Uncomment and adjust when ready:
  :root {
    --color-bg: #1a202c;
    --color-surface: #2d3748;
    --color-text: #e2e8f0;
    --color-text-secondary: #a0aec0;
    --color-text-muted: #718096;
    --color-border: #4a5568;
    --color-border-light: #2d3748;
    --color-code-bg: #2d3748;
    --color-pre-bg: #171923;
    --color-pre-text: #e2e8f0;
    --color-shadow: rgba(0,0,0,0.3);
    --color-shadow-hover: rgba(0,0,0,0.5);
    --color-primary-light: #553c3c;
  }
  */
}