/* ══════════════════════════════════════════════════════
   TechDeep Blog — Global Styles
   设计语言：深色技术感 + 清晰信息层次
   ══════════════════════════════════════════════════════ */

/* ── 设计 Token ──────────────────────────────────────── */
:root {
  /* 颜色 - 亮色主题 */
  --color-bg:          #ffffff;
  --color-bg-secondary:#f8fafc;
  --color-bg-code:     #f1f5f9;
  --color-text:        #0f172a;
  --color-text-muted:  #64748b;
  --color-text-faint:  #94a3b8;
  --color-border:      #e2e8f0;
  --color-border-strong:#cbd5e1;
  --color-accent:      #2563eb;     /* 主蓝 */
  --color-accent-light:#dbeafe;
  --color-accent-dark: #1d4ed8;
  --color-bili:        #00a1d6;     /* B站蓝 */
  --color-bili-light:  #e0f4fc;
  --color-yt:          #ff0000;     /* YouTube 红 */
  --color-yt-light:    #ffe4e4;
  --color-success:     #16a34a;
  --color-key-border:  #3b82f6;
  --color-key-bg:      #eff6ff;

  /* 字体 */
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Cascadia Code", Consolas, monospace;

  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* 间距 */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
}

/* 暗色主题 */
[data-theme="dark"] {
  --color-bg:          #0f172a;
  --color-bg-secondary:#1e293b;
  --color-bg-code:     #1e293b;
  --color-text:        #f1f5f9;
  --color-text-muted:  #94a3b8;
  --color-text-faint:  #64748b;
  --color-border:      #1e293b;
  --color-border-strong:#334155;
  --color-accent:      #60a5fa;
  --color-accent-light:#1e3a5f;
  --color-accent-dark: #93c5fd;
  --color-bili-light:  #0c2a3d;
  --color-yt-light:    #3d0c0c;
  --color-key-bg:      #1e3a5f;
}

/* ── Reset & Base ────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  scroll-behavior: smooth;
}

a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }

/* ── 布局 ────────────────────────────────────────────── */
.site-wrapper {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── 导航 ────────────────────────────────────────────── */
.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.02em;
}
.nav-logo:hover { text-decoration: none; }

.nav-right { display: flex; align-items: center; gap: var(--space-md); }

.nav-link {
  font-size: 14px;
  color: var(--color-text-muted);
  transition: color .15s;
}
.nav-link:hover { color: var(--color-text); text-decoration: none; }

.theme-btn {
  background: none;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  padding: 5px 7px;
  cursor: pointer;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  transition: color .15s, border-color .15s;
}
.theme-btn:hover { color: var(--color-text); border-color: var(--color-accent); }

[data-theme="light"] .icon-moon { display: none; }
[data-theme="dark"]  .icon-sun  { display: none; }

/* ── Hero ────────────────────────────────────────────── */
.hero {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg) var(--space-lg);
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-lg);
}

.hero-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
}
.hero-desc { font-size: 15px; color: var(--color-text-muted); max-width: 520px; }

.hero-stat {
  text-align: right;
  flex-shrink: 0;
}
.hero-stat__num { display: block; font-size: 36px; font-weight: 700; line-height: 1; }
.hero-stat__label { font-size: 13px; color: var(--color-text-muted); }

/* ── 分类筛选 ────────────────────────────────────────── */
.category-filter {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--space-lg) var(--space-lg);
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.cat-btn {
  font-size: 13px;
  padding: 5px 14px;
  border-radius: 20px;
  border: 1px solid var(--color-border-strong);
  background: transparent;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all .15s;
  font-family: var(--font-sans);
}
.cat-btn:hover { border-color: var(--color-accent); color: var(--color-accent); }
.cat-btn--active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

/* ── 文章列表网格 ─────────────────────────────────────── */
.posts-grid {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--space-lg) var(--space-xl);
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-lg);
}

.no-results {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
  text-align: center;
  color: var(--color-text-muted);
}

/* ── PostCard ────────────────────────────────────────── */
.post-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-bg);
  transition: border-color .15s, transform .15s, box-shadow .15s;
}
.post-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.post-card__link {
  display: block;
  color: inherit;
  text-decoration: none;
}

/* 缩略图 */
.post-card__thumb {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--color-bg-secondary);
}
.post-card__cover {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.post-card__cover-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 100%);
  color: rgba(255,255,255,0.25);
}

.post-card__badges {
  position: absolute;
  top: 8px;
  left: 8px;
  display: flex;
  gap: 6px;
}
.post-card__platform-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}
.post-card__platform-badge--bili {
  background: var(--color-bili);
  color: #fff;
}
.post-card__platform-badge--yt {
  background: var(--color-yt);
  color: #fff;
}
.post-card__platform-badge--self {
  background: rgba(0,0,0,0.6);
  color: #fff;
}
.post-card__duration {
  font-size: 11px;
  font-weight: 500;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background: rgba(0,0,0,0.6);
  color: #fff;
}

.post-card__body { padding: var(--space-md); }
.post-card__title {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: var(--space-sm);
  color: var(--color-text);
}
.post-card__desc {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: var(--space-md);
}

.post-card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-sm);
}
.post-card__date { font-size: 12px; color: var(--color-text-faint); }
.post-card__tags { display: flex; gap: 6px; flex-wrap: wrap; }
.post-card__tag {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  background: var(--color-bg-secondary);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}

/* ── 文章详情 ────────────────────────────────────────── */
.main-content {
  max-width: 820px;
  margin: 0 auto;
  padding: var(--space-lg) var(--space-lg) var(--space-xl);
  flex: 1;
}

.breadcrumb {
  font-size: 13px;
  color: var(--color-text-faint);
  margin-bottom: var(--space-lg);
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-accent); text-decoration: none; }

.post-header { margin-bottom: var(--space-xl); }
.post-tags { display: flex; gap: var(--space-sm); margin-bottom: var(--space-md); flex-wrap: wrap; }
.post-tag {
  font-size: 12px;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  background: var(--color-accent-light);
  color: var(--color-accent);
  border: 1px solid transparent;
  transition: background .15s;
}
.post-tag:hover { background: var(--color-accent); color: #fff; text-decoration: none; }

.post-title {
  font-size: 30px;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-md);
}

.post-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  font-size: 13px;
  color: var(--color-text-muted);
}
.post-meta__item {
  display: flex;
  align-items: center;
  gap: 5px;
}

/* ── 视频嵌入组件样式 ─────────────────────────────────── */
.post-videos { margin-bottom: var(--space-xl); }
.post-video-item { margin-bottom: var(--space-lg); }
.post-video-item--secondary { margin-top: var(--space-lg); }

.video-embed {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-bg-secondary);
}

/* 平台标签栏 */
.video-embed__header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 10px var(--space-md);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}

.video-embed__platform {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-bili);
}
.video-embed__platform--youtube { color: var(--color-yt); }
.video-embed__platform--self { color: var(--color-text-muted); }

.video-embed__duration {
  font-size: 12px;
  padding: 1px 7px;
  border-radius: var(--radius-sm);
  background: var(--color-bg-code);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}

.video-embed__external {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: var(--color-text-faint);
  transition: color .15s;
}
.video-embed__external:hover { color: var(--color-accent); text-decoration: none; }

.video-embed__title {
  padding: var(--space-sm) var(--space-md) 0;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text);
}

/* 视频容器：16:9 自适应 */
.video-embed__container {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #000;
  cursor: pointer;
}

/* 点击前的封面占位层 */
.video-embed__placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.video-embed__cover {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.85;
  transition: opacity .2s;
}
.video-embed__placeholder:hover .video-embed__cover { opacity: 1; }

.video-embed__play-btn {
  position: relative;
  z-index: 1;
  background: none;
  border: none;
  cursor: pointer;
  transition: transform .15s;
}
.video-embed__play-btn:hover { transform: scale(1.1); }

/* 自托管原生播放器 */
.video-embed__container--native { aspect-ratio: unset; background: #000; }
.video-embed__native {
  width: 100%;
  max-height: 500px;
  display: block;
}

/* ── KeyPoints 卡片 ──────────────────────────────────── */
.key-points {
  border-left: 3px solid var(--color-key-border);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--color-key-bg);
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-xl);
}

.key-points__header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.key-points__list { list-style: none; }
.key-points__item {
  display: flex;
  gap: var(--space-md);
  padding: 6px 0;
  border-bottom: 1px solid rgba(59,130,246,0.1);
  align-items: flex-start;
}
.key-points__item:last-child { border-bottom: none; }

.key-points__num {
  font-size: 11px;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--color-accent);
  min-width: 22px;
  padding-top: 3px;
  opacity: 0.6;
}

.key-points__text {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text);
}

/* ── Prose（文章正文）────────────────────────────────── */
.prose { line-height: 1.8; }

.prose h1,
.prose h2,
.prose h3,
.prose h4 {
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-top: 2em;
  margin-bottom: 0.75em;
  color: var(--color-text);
}
.prose h2 { font-size: 22px; border-bottom: 1px solid var(--color-border); padding-bottom: 8px; }
.prose h3 { font-size: 18px; }
.prose h4 { font-size: 16px; }

.prose p { margin-bottom: 1.25em; }

.prose ul,
.prose ol {
  margin: 1em 0 1.25em;
  padding-left: 1.75em;
}
.prose li { margin-bottom: 0.4em; }

.prose blockquote {
  border-left: 3px solid var(--color-accent);
  margin: 1.5em 0;
  padding: var(--space-sm) var(--space-md);
  color: var(--color-text-muted);
  font-style: italic;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--color-bg-code);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  color: #e11d48;
}

.prose pre {
  background: #1e293b !important;
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  overflow-x: auto;
  margin: 1.5em 0;
}
.prose pre code {
  background: none;
  padding: 0;
  color: inherit;
  font-size: 14px;
}

.prose img {
  border-radius: var(--radius-md);
  margin: 1.5em 0;
  border: 1px solid var(--color-border);
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: 14px;
}
.prose th,
.prose td {
  border: 1px solid var(--color-border);
  padding: 8px 12px;
  text-align: left;
}
.prose th { background: var(--color-bg-secondary); font-weight: 600; }
.prose tr:hover td { background: var(--color-bg-secondary); }

.prose a { color: var(--color-accent); text-decoration: underline; text-underline-offset: 3px; }

/* ── 参考资料 ────────────────────────────────────────── */
.post-references {
  margin-top: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
}
.post-references h2 { font-size: 16px; font-weight: 600; margin-bottom: var(--space-md); }
.post-references ul { list-style: none; padding: 0; }
.post-references li { padding: 6px 0; }
.post-references a { font-size: 14px; color: var(--color-accent); }

/* ── Footer ──────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-border);
  text-align: center;
  padding: var(--space-lg);
  font-size: 13px;
  color: var(--color-text-faint);
}
.site-footer a { color: var(--color-text-muted); }

/* ── 响应式 ──────────────────────────────────────────── */
@media (max-width: 768px) {
  .hero { flex-direction: column; padding: var(--space-lg); }
  .hero-title { font-size: 22px; }
  .posts-grid {
    padding: 0 var(--space-md) var(--space-xl);
    grid-template-columns: 1fr;
  }
  .category-filter { padding: 0 var(--space-md) var(--space-md); }
  .main-content { padding: var(--space-md); }
  .post-title { font-size: 22px; }
  .nav { padding: 0 var(--space-md); }
  .nav-link { display: none; }
}