/* ==========================================================================
   Ink & Logic Blog — 全局样式
   纯 CSS，无任何框架依赖
   ========================================================================== */

/* ---------- 1. 设计令牌 (Design Tokens) ---------- */
:root {
  /* 明色主题 */
  --bg:          #f6f7f9;
  --bg-elev:     #ffffff;
  --bg-sub:      #eef0f4;
  --bg-inset:    #f2f4f7;
  --text:        #171a21;
  --text-2:      #4b5563;
  --text-3:      #8b93a3;
  --border:      #e4e7ee;
  --border-2:    #d5dae4;
  --accent:      #3d5af1;
  --accent-2:    #5b78f6;
  --accent-soft: #eef1ff;
  --accent-text: #2c43c9;
  --success:     #16a34a;
  --danger:      #dc2626;
  --warning:     #d97706;

  --shadow-xs: 0 1px 2px rgba(16, 24, 40, .05);
  --shadow-sm: 0 1px 3px rgba(16, 24, 40, .07), 0 1px 2px rgba(16, 24, 40, .04);
  --shadow-md: 0 8px 20px rgba(16, 24, 40, .08);
  --shadow-lg: 0 20px 48px rgba(16, 24, 40, .14);

  --radius-sm: 8px;
  --radius:    12px;
  --radius-lg: 18px;

  --maxw: 1140px;
  --header-h: 62px;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC",
               "Noto Sans CJK SC", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", Menlo, Consolas,
               "Liberation Mono", "Courier New", monospace;

  --code-bg:   #f6f8fb;
  --code-text: #24292f;

  color-scheme: light;
}

[data-theme="dark"] {
  --bg:          #0e1013;
  --bg-elev:     #16191f;
  --bg-sub:      #1c2027;
  --bg-inset:    #1c2027;
  --text:        #e8ebf0;
  --text-2:      #a8b0bd;
  --text-3:      #7a838f;
  --border:      #262b33;
  --border-2:    #333a45;
  --accent:      #7d92ff;
  --accent-2:    #97a8ff;
  --accent-soft: #1c2138;
  --accent-text: #a3b1ff;
  --success:     #4ade80;
  --danger:      #f87171;
  --warning:     #fbbf24;

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, .4);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, .45);
  --shadow-md: 0 8px 20px rgba(0, 0, 0, .5);
  --shadow-lg: 0 20px 48px rgba(0, 0, 0, .6);

  --code-bg:   #12151a;
  --code-text: #e6edf3;

  color-scheme: dark;
}

/* ---------- 2. 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color .25s ease, color .25s ease;
}

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

button, input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

::selection { background: var(--accent-soft); color: var(--accent-text); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 滚动条 */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--border-2);
  border-radius: 8px;
  border: 2px solid transparent;
  background-clip: content-box;
}
::-webkit-scrollbar-thumb:hover { background: var(--text-3); background-clip: content-box; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px;
}

/* ---------- 3. 顶栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: var(--bg);   /* 降级：不支持 color-mix 的浏览器 */
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}

.site-header .container {
  display: flex;
  align-items: center;
  gap: 18px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 16px;
  color: var(--text);
  letter-spacing: -.01em;
  text-decoration: none;
  white-space: nowrap;
}
.brand:hover { text-decoration: none; }

.brand-mark {
  width: 30px; height: 30px;
  flex: none;
  border-radius: 9px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  color: #fff;
  font-size: 15px;
  font-weight: 800;
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.nav a {
  padding: 7px 13px;
  border-radius: 8px;
  color: var(--text-2);
  font-size: 14.5px;
  font-weight: 500;
  transition: background .16s, color .16s;
}
.nav a:hover { background: var(--bg-sub); color: var(--text); text-decoration: none; }
.nav a.active { color: var(--accent-text); background: var(--accent-soft); }

.icon-btn {
  width: 36px; height: 36px;
  flex: none;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-elev);
  color: var(--text-2);
  cursor: pointer;
  transition: background .16s, color .16s, border-color .16s;
}
.icon-btn:hover { background: var(--bg-sub); color: var(--text); border-color: var(--border-2); }
.icon-btn svg { width: 17px; height: 17px; }

/* ---------- 4. 首页 Hero ---------- */
.hero {
  padding: 62px 0 40px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);   /* 降级 */
  background:
    radial-gradient(900px 340px at 12% -20%, color-mix(in srgb, var(--accent) 13%, transparent), transparent 70%),
    radial-gradient(700px 300px at 88% -10%, rgba(139, 92, 246, .12), transparent 70%);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid var(--border-2);
  background: var(--bg-elev);
  color: var(--text-2);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .02em;
  box-shadow: var(--shadow-xs);
}
.hero-badge .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--success) 20%, transparent);
}

.hero h1 {
  margin: 18px 0 12px;
  font-size: clamp(28px, 4.4vw, 44px);
  line-height: 1.22;
  letter-spacing: -.025em;
  font-weight: 800;
}
.hero h1 em {
  font-style: normal;
  background: linear-gradient(120deg, var(--accent), #8b5cf6 60%, #ec4899);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero p {
  max-width: 640px;
  margin: 0;
  color: var(--text-2);
  font-size: 16.5px;
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 26px;
  margin-top: 26px;
}
.hero-stat b {
  display: block;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -.02em;
}
.hero-stat span { font-size: 13px; color: var(--text-3); }

/* ---------- 5. 工具栏 ---------- */
.toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  padding: 26px 0 6px;
}

.search-box {
  position: relative;
  flex: 1 1 260px;
  max-width: 340px;
}
.search-box svg {
  position: absolute;
  left: 12px; top: 50%;
  transform: translateY(-50%);
  width: 16px; height: 16px;
  color: var(--text-3);
  pointer-events: none;
}
.search-box input {
  width: 100%;
  padding: 9px 12px 9px 36px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-elev);
  transition: border-color .16s, box-shadow .16s;
}
.search-box input::placeholder { color: var(--text-3); }
.search-box input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 16%, transparent);
}

.tag-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.tag-chip {
  padding: 5px 13px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
  color: var(--text-2);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all .16s;
}
.tag-chip:hover { border-color: var(--border-2); color: var(--text); }
.tag-chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.result-hint {
  padding: 6px 0 4px;
  font-size: 13.5px;
  color: var(--text-3);
}

/* ---------- 6. 文章卡片列表 ---------- */
.post-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
  padding: 16px 0 72px;
}

.post-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  box-shadow: var(--shadow-xs);
  overflow: hidden;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.post-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--border-2);
}

.post-cover {
  height: 8px;
  background: linear-gradient(90deg, var(--accent), #8b5cf6 50%, #ec4899);
  opacity: .9;
}

.post-card-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: 20px 20px 18px;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  font-size: 12.5px;
  color: var(--text-3);
}
.post-meta .sep { opacity: .5; }

.post-card h2 {
  margin: 10px 0 8px;
  font-size: 18.5px;
  line-height: 1.42;
  font-weight: 700;
  letter-spacing: -.012em;
}
.post-card h2 a { color: var(--text); }
.post-card h2 a:hover { color: var(--accent); text-decoration: none; }

.post-excerpt {
  margin: 0 0 16px;
  color: var(--text-2);
  font-size: 14.5px;
  line-height: 1.7;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px dashed var(--border);
}
.post-tags .tag {
  padding: 2px 9px;
  border-radius: 6px;
  background: var(--accent-soft);
  color: var(--accent-text);
  font-size: 12px;
  font-weight: 600;
}

.empty-state {
  grid-column: 1 / -1;
  padding: 64px 20px;
  text-align: center;
  color: var(--text-3);
  border: 1px dashed var(--border-2);
  border-radius: var(--radius-lg);
}
.empty-state strong { display: block; color: var(--text-2); font-size: 16px; margin-bottom: 6px; }

/* 骨架屏 */
.skeleton {
  height: 236px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: linear-gradient(100deg, var(--bg-elev) 30%, var(--bg-sub) 50%, var(--bg-elev) 70%);
  background-size: 220% 100%;
  animation: shimmer 1.3s infinite linear;
}
@keyframes shimmer { to { background-position: -120% 0; } }

/* ---------- 7. 文章详情页 ---------- */
.reading-progress {
  position: fixed;
  top: var(--header-h);
  left: 0;
  height: 2.5px;
  width: 0;
  z-index: 70;
  background: linear-gradient(90deg, var(--accent), #8b5cf6);
  transition: width .1s linear;
}

.post-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 250px;
  gap: 48px;
  padding: 40px 0 72px;
  align-items: start;
}

.article-header {
  padding-bottom: 26px;
  margin-bottom: 30px;
  border-bottom: 1px solid var(--border);
}
.article-header h1 {
  margin: 12px 0 14px;
  font-size: clamp(25px, 3.6vw, 38px);
  line-height: 1.28;
  letter-spacing: -.025em;
  font-weight: 800;
}
.article-header .post-meta { font-size: 13.5px; }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--text-2);
  font-weight: 500;
}
.back-link:hover { color: var(--accent); text-decoration: none; }

/* --- 正文排版 --- */
.article-body {
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--text);
  word-wrap: break-word;
}

.article-body > *:first-child { margin-top: 0; }

.article-body h2,
.article-body h3,
.article-body h4 {
  margin: 2.1em 0 .7em;
  line-height: 1.35;
  font-weight: 700;
  letter-spacing: -.018em;
  scroll-margin-top: calc(var(--header-h) + 18px);
}
.article-body h2 { font-size: 25px; padding-bottom: .32em; border-bottom: 1px solid var(--border); }
.article-body h3 { font-size: 20.5px; }
.article-body h4 { font-size: 17.5px; color: var(--text-2); }

.article-body .anchor {
  margin-left: 8px;
  font-size: .62em;
  color: var(--text-3);
  opacity: 0;
  transition: opacity .15s;
  text-decoration: none;
}
.article-body h2:hover .anchor,
.article-body h3:hover .anchor { opacity: 1; }

.article-body p { margin: 0 0 1.15em; }

.article-body ul,
.article-body ol { margin: 0 0 1.15em; padding-left: 1.5em; }
.article-body li { margin: .38em 0; }
.article-body li::marker { color: var(--text-3); }

.article-body a {
  color: var(--accent-text);
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 34%, transparent);
  text-decoration: none;
}
.article-body a:hover { border-bottom-color: var(--accent); }

.article-body strong { font-weight: 700; }

.article-body blockquote {
  margin: 1.5em 0;
  padding: 14px 20px;
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--bg-sub);
  color: var(--text-2);
}
.article-body blockquote p:last-child { margin-bottom: 0; }

.article-body hr {
  margin: 2.4em 0;
  border: 0;
  border-top: 1px solid var(--border);
}

.article-body code {
  font-family: var(--font-mono);
  font-size: .875em;
  padding: .18em .42em;
  border-radius: 5px;
  background: var(--bg-inset);
  border: 1px solid var(--border);
  color: var(--accent-text);
}

.article-body pre {
  position: relative;
  margin: 1.5em 0;
  padding: 18px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--code-bg);
  overflow-x: auto;
  line-height: 1.65;
}
.article-body pre code {
  padding: 0;
  border: 0;
  background: none;
  color: var(--code-text);
  font-size: 13.6px;
}

.code-lang {
  position: absolute;
  top: 9px; right: 74px;
  font-size: 11.5px;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text-3);
  font-family: var(--font-mono);
}

.copy-btn {
  position: absolute;
  top: 7px; right: 8px;
  padding: 3px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-elev);
  color: var(--text-3);
  font-size: 11.5px;
  cursor: pointer;
  opacity: 0;
  transition: opacity .16s, color .16s;
}
.article-body pre:hover .copy-btn { opacity: 1; }
.copy-btn:hover { color: var(--accent); }

.article-body table {
  width: 100%;
  margin: 1.5em 0;
  border-collapse: collapse;
  font-size: 15px;
  display: block;
  overflow-x: auto;
}
.article-body th, .article-body td {
  padding: 10px 14px;
  border: 1px solid var(--border);
  text-align: left;
}
.article-body th { background: var(--bg-sub); font-weight: 700; }

.article-body img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin: 1.5em auto;
}

.article-body .callout {
  margin: 1.5em 0;
  padding: 14px 18px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  font-size: 15.5px;
}
.article-body .callout p:last-child { margin-bottom: 0; }

/* --- 正文底部工具条 --- */
.article-footer {
  margin-top: 46px;
  padding-top: 26px;
  border-top: 1px solid var(--border);
}

.article-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 15px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-elev);
  color: var(--text-2);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all .16s;
}
.btn:hover { border-color: var(--border-2); color: var(--text); background: var(--bg-sub); }
.btn svg { width: 15px; height: 15px; }
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-2); border-color: var(--accent-2); color: #fff; }

.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 28px;
}
.post-nav a {
  padding: 15px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  transition: border-color .18s, transform .18s;
}
.post-nav a:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.post-nav .label { font-size: 12.5px; color: var(--text-3); }
.post-nav .title { display: block; margin-top: 5px; font-size: 15px; font-weight: 600; color: var(--text); line-height: 1.45; }
.post-nav .next { text-align: right; }
.post-nav .placeholder { visibility: hidden; }

/* --- 侧栏目录 --- */
.toc {
  position: sticky;
  top: calc(var(--header-h) + 24px);
  max-height: calc(100vh - var(--header-h) - 48px);
  overflow-y: auto;
  padding-left: 18px;
  border-left: 1px solid var(--border);
  font-size: 13.5px;
}
.toc-title {
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-3);
}
.toc ul { list-style: none; margin: 0; padding: 0; }
.toc li { margin: 0; }
.toc a {
  display: block;
  padding: 5px 0;
  color: var(--text-2);
  line-height: 1.5;
  border-left: 2px solid transparent;
  margin-left: -20px;
  padding-left: 16px;
  transition: color .16s, border-color .16s;
}
.toc a:hover { color: var(--text); text-decoration: none; }
.toc a.active { color: var(--accent-text); border-left-color: var(--accent); font-weight: 600; }
.toc .lvl-3 a { padding-left: 30px; font-size: 13px; }

/* ---------- 8. 评论区 ---------- */
.comments-section {
  margin-top: 56px;
  padding-top: 34px;
  border-top: 1px solid var(--border);
}
.section-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 22px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -.015em;
}
.section-title svg { width: 18px; height: 18px; color: var(--accent); }

.twikoo-tip {
  padding: 16px 20px;
  border: 1px dashed var(--border-2);
  border-radius: var(--radius);
  background: var(--bg-inset);
  font-size: 14.5px;
  color: var(--text-2);
}
.twikoo-tip code {
  font-family: var(--font-mono);
  font-size: .88em;
  padding: 2px 6px;
  border-radius: 5px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--accent-text);
}
.twikoo-tip ol { margin: 10px 0 0; padding-left: 1.3em; }
.twikoo-tip li { margin: 5px 0; }

/* ---------- 9. AI 问答 ---------- */
.ai-fab {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 90;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 18px 12px 15px;
  border: 0;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  color: #fff;
  font-size: 14.5px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  transition: transform .2s, box-shadow .2s;
}
.ai-fab:hover { transform: translateY(-2px) scale(1.02); }
.ai-fab svg { width: 18px; height: 18px; }
.ai-fab .ping {
  position: absolute;
  top: 6px; right: 8px;
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #4ade80;
  box-shadow: 0 0 0 3px rgba(74, 222, 128, .3);
}

.ai-drawer {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 95;
  width: min(430px, calc(100vw - 32px));
  height: min(640px, calc(100vh - 60px));
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  opacity: 0;
  transform: translateY(14px) scale(.98);
  pointer-events: none;
  transition: opacity .2s ease, transform .2s ease;
}
.ai-drawer.open { opacity: 1; transform: none; pointer-events: auto; }

.ai-head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 13px 14px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-sub);
}
.ai-head .ai-avatar {
  width: 30px; height: 30px;
  flex: none;
  border-radius: 9px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  color: #fff;
  font-size: 14px;
}
.ai-head-info { flex: 1; min-width: 0; }
.ai-head-info b { display: block; font-size: 14.5px; line-height: 1.3; }
.ai-head-info span { font-size: 12px; color: var(--text-3); }

.ai-head .icon-btn { width: 30px; height: 30px; border-radius: 8px; }
.ai-head .icon-btn svg { width: 15px; height: 15px; }

.ai-status {
  padding: 7px 14px;
  font-size: 12.5px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 7px;
}
.ai-status.ok  { color: var(--success); background: var(--bg-inset); background: color-mix(in srgb, var(--success) 8%, transparent); }
.ai-status.warn{ color: var(--warning); background: var(--bg-inset); background: color-mix(in srgb, var(--warning) 9%, transparent); }
.ai-status .tag {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 1px 6px;
  border-radius: 5px;
  background: var(--bg-inset);
  border: 1px solid var(--border);
}

.ai-messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.msg { display: flex; gap: 9px; max-width: 100%; }
.msg .bubble {
  padding: 10px 13px;
  border-radius: 12px;
  font-size: 14.2px;
  line-height: 1.72;
  word-wrap: break-word;
  overflow-wrap: anywhere;
}
.msg .bubble > *:first-child { margin-top: 0; }
.msg .bubble > *:last-child { margin-bottom: 0; }
.msg .bubble p { margin: 0 0 .7em; }
.msg .bubble ul, .msg .bubble ol { margin: .4em 0 .7em; padding-left: 1.3em; }
.msg .bubble h2, .msg .bubble h3, .msg .bubble h4 { margin: .9em 0 .45em; font-size: 15px; }
.msg .bubble pre {
  position: relative;              /* 供代码块内的复制按钮定位 */
  margin: .7em 0;
  padding: 11px 13px;
  border-radius: 9px;
  border: 1px solid var(--border);
  background: var(--code-bg);
  overflow-x: auto;
  font-size: 12.6px;
  line-height: 1.6;
}
.msg .bubble .code-lang { display: none; }
.msg .bubble .anchor { display: none; }   /* 对话气泡内不显示标题锚点 */
.msg .bubble .copy-btn { top: 5px; right: 6px; }
.msg .bubble code {
  font-family: var(--font-mono);
  font-size: .88em;
  padding: .12em .36em;
  border-radius: 4px;
  background: var(--bg-inset);
  border: 1px solid var(--border);
}
.msg .bubble pre code { border: 0; background: none; padding: 0; }
.msg .bubble table { width: 100%; border-collapse: collapse; font-size: 13px; }
.msg .bubble th, .msg .bubble td { border: 1px solid var(--border); padding: 6px 8px; }

.msg.user { flex-direction: row-reverse; }
.msg.user .bubble {
  background: var(--accent);
  color: #fff;
  border-bottom-right-radius: 4px;
}
.msg.user .bubble code { background: rgba(255,255,255,.18); border-color: transparent; color: #fff; }
.msg.assistant .bubble {
  background: var(--bg-sub);
  border: 1px solid var(--border);
  border-bottom-left-radius: 4px;
}
.msg .role-dot {
  width: 26px; height: 26px;
  flex: none;
  border-radius: 8px;
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 700;
}
.msg.assistant .role-dot { background: linear-gradient(135deg, var(--accent), #8b5cf6); color: #fff; }
.msg.user .role-dot { background: var(--bg-inset); border: 1px solid var(--border); color: var(--text-2); }

.typing-cursor {
  display: inline-block;
  width: 7px; height: 14px;
  vertical-align: -2px;
  margin-left: 2px;
  background: var(--accent);
  animation: blink 1s steps(2, start) infinite;
}
@keyframes blink { to { visibility: hidden; } }

.ai-quick {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  padding: 0 14px 12px;
}
.ai-quick button {
  padding: 5px 11px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
  color: var(--text-2);
  font-size: 12.5px;
  cursor: pointer;
  transition: all .16s;
}
.ai-quick button:hover { border-color: var(--accent); color: var(--accent-text); background: var(--accent-soft); }

.ai-input-wrap {
  border-top: 1px solid var(--border);
  padding: 11px 12px;
  background: var(--bg-elev);
}
.ai-input-row {
  display: flex;
  align-items: flex-end;
  gap: 9px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-inset);
  padding: 7px 7px 7px 12px;
  transition: border-color .16s, box-shadow .16s;
}
.ai-input-row:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 15%, transparent);
}
.ai-input-row textarea {
  flex: 1;
  border: 0;
  background: none;
  resize: none;
  outline: none;
  max-height: 130px;
  min-height: 24px;
  line-height: 1.6;
  font-size: 14.2px;
  padding: 4px 0;
}
.ai-input-row textarea::placeholder { color: var(--text-3); }
.ai-send {
  width: 32px; height: 32px;
  flex: none;
  display: grid;
  place-items: center;
  border: 0;
  border-radius: 9px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  transition: background .16s, opacity .16s;
}
.ai-send:hover:not(:disabled) { background: var(--accent-2); }
.ai-send:disabled { opacity: .45; cursor: not-allowed; }
.ai-send svg { width: 16px; height: 16px; }
.ai-foot-hint {
  margin-top: 7px;
  font-size: 11.5px;
  color: var(--text-3);
  display: flex;
  justify-content: space-between;
  gap: 10px;
}

/* AI 设置面板 */
.ai-settings {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: none;
  flex-direction: column;
  background: var(--bg-elev);
  overflow-y: auto;
  padding: 16px;
}
.ai-settings.open { display: flex; }
.ai-settings h4 { margin: 0 0 4px; font-size: 15.5px; }
.ai-settings .hint { margin: 0 0 16px; font-size: 12.8px; color: var(--text-3); line-height: 1.65; }
.field { margin-bottom: 14px; }
.field label {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
}
.field input, .field select, .field textarea {
  width: 100%;
  padding: 8px 11px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: var(--bg-inset);
  outline: none;
  font-size: 13.8px;
  transition: border-color .16s, box-shadow .16s;
}
.field input:focus, .field select:focus, .field textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 15%, transparent);
}
.field .sub { margin-top: 5px; font-size: 11.8px; color: var(--text-3); line-height: 1.55; }
.ai-settings-actions {
  display: flex;
  gap: 9px;
  margin-top: 4px;
}

/* ---------- 10. 页脚 ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-elev);
  padding: 34px 0;
  margin-top: auto;
}
.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  font-size: 13.5px;
  color: var(--text-3);
}
.site-footer a { color: var(--text-2); }
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
main { flex: 1; }

/* 离线提示条 */
.offline-banner {
  display: none;
  padding: 12px 18px;
  border: 1px solid color-mix(in srgb, var(--warning) 40%, var(--border));
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--warning) 9%, transparent);
  color: var(--text-2);
  font-size: 13.8px;
  line-height: 1.65;
  margin: 22px 0 -4px;
}
.offline-banner.show { display: block; }
.offline-banner code {
  font-family: var(--font-mono);
  font-size: .9em;
  padding: 2px 6px;
  border-radius: 5px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
}

/* ---------- 11. 响应式 ---------- */
@media (max-width: 1000px) {
  .post-layout { grid-template-columns: 1fr; gap: 0; }
  .toc {
    position: static;
    max-height: none;
    border-left: 0;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-elev);
    padding: 16px 18px;
    margin-bottom: 30px;
    order: -1;
  }
  .toc a { margin-left: 0; padding-left: 12px; }
  .toc .lvl-3 a { padding-left: 24px; }
}

@media (max-width: 700px) {
  .hero { padding: 40px 0 28px; }
  .post-grid { grid-template-columns: 1fr; gap: 16px; }
  .post-nav { grid-template-columns: 1fr; }
  .post-nav .next { text-align: left; }
  .post-nav .placeholder { display: none; }
  .ai-fab { right: 16px; bottom: 16px; padding: 12px; }
  .ai-fab span { display: none; }
  .ai-drawer {
    right: 0; bottom: 0;
    width: 100vw;
    height: 88vh;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  }
  .toolbar { gap: 10px; }
  .search-box { max-width: none; }
  .article-body { font-size: 16px; }
}

@media print {
  .site-header, .site-footer, .ai-fab, .ai-drawer, .toc, .comments-section { display: none !important; }
  .post-layout { grid-template-columns: 1fr; }
}