/* ============================================================
   LLM 工程手册 - 共享样式表
   主题：暗色技术文档（locked dark）
   规则：每页锁定单一 accent；圆角体系 = 面板 10px / 交互元素胶囊
   ============================================================ */

:root {
  /* 表面 */
  --bg: #0a0a0c;
  --bg-raised: #121217;
  --bg-inset: #17171d;
  --bg-code: #0d0d11;
  --border: #26262e;
  --border-soft: #1c1c22;
  --border-strong: #3a3a44;

  /* 文字 */
  --text: #ececf1;
  --text-2: #a6a6b0;
  --text-3: #74747e;

  /* 主题色（每页在 <style> 中覆盖） */
  --accent: #f4f4f5;
  --accent-rgb: 244, 244, 245;
  --on-accent: #0a0a0c;

  /* 字体 */
  --font-sans: "Segoe UI Variable Display", "Segoe UI", -apple-system,
    BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI",
    "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --font-mono: "Cascadia Code", "Cascadia Mono", "JetBrains Mono", "Fira Code",
    ui-monospace, "SF Mono", Consolas, "Courier New", monospace;

  /* 布局 */
  --content-max: 1240px;
  --nav-h: 60px;
  --radius: 10px;
  --radius-pill: 999px;
}

/* ---------------- reset ---------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 24px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 15.5px;
  line-height: 1.8;
  letter-spacing: 0.01em;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

img,
svg {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

code,
pre,
kbd {
  font-family: var(--font-mono);
  font-size: 0.86em;
}

::selection {
  background: rgba(var(--accent-rgb), 0.28);
  color: #fff;
}

/* 阅读进度条（scroll-driven，旧浏览器自动降级为不显示） */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 90;
  background: rgba(var(--accent-rgb), 0.9);
  transform-origin: 0 50%;
  transform: scaleX(0);
}

@supports (animation-timeline: scroll()) {
  .reading-progress {
    animation: progress-grow linear both;
    animation-timeline: scroll(root block);
  }
}

@keyframes progress-grow {
  from {
    transform: scaleX(0);
  }
  to {
    transform: scaleX(1);
  }
}

/* ---------------- 顶部导航 ---------------- */
.topnav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: 80;
  background: rgba(10, 10, 12, 0.82);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--border-soft);
}

.topnav-inner {
  max-width: var(--content-max);
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.brand-mark {
  width: 12px;
  height: 12px;
  border-radius: 3px;
  background: rgba(var(--accent-rgb), 0.9);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.18);
}

.brand-name {
  font-size: 14px;
  font-weight: 650;
  letter-spacing: 0.06em;
  color: var(--text);
}

.brand-name .brand-sub {
  color: var(--text-3);
  font-weight: 500;
  margin-left: 8px;
  font-size: 12.5px;
}

.topnav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.topnav-links::-webkit-scrollbar {
  display: none;
}

.topnav-links a {
  flex-shrink: 0;
  padding: 6px 12px;
  font-size: 13px;
  color: var(--text-2);
  border-radius: var(--radius-pill);
  transition: color 0.18s ease, background 0.18s ease;
  white-space: nowrap;
}

.topnav-links a:hover {
  color: var(--text);
  background: var(--bg-inset);
}

.topnav-links a[aria-current="page"] {
  color: rgba(var(--accent-rgb), 1);
  background: rgba(var(--accent-rgb), 0.1);
}

/* ---------------- Hero ---------------- */
.hero {
  padding: 92px 24px 56px;
  border-bottom: 1px solid var(--border-soft);
  background:
    radial-gradient(1100px 480px at 78% -10%,
      rgba(var(--accent-rgb), 0.09), transparent 60%),
    var(--bg);
}

.hero-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: 56px;
  align-items: start;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--text-3);
  margin: 0 0 20px;
}

.hero-eyebrow .eyebrow-accent {
  color: rgba(var(--accent-rgb), 1);
}

.hero h1 {
  margin: 0 0 18px;
  font-size: clamp(34px, 4.6vw, 52px);
  line-height: 1.12;
  font-weight: 750;
  letter-spacing: -0.015em;
}

.hero h1 .h1-accent {
  color: rgba(var(--accent-rgb), 1);
}

.hero-desc {
  margin: 0 0 26px;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--text-2);
  max-width: 34em;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 14px;
  font-size: 12.5px;
  color: var(--text-2);
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.chip b {
  color: var(--text);
  font-weight: 600;
}

.chip-cta {
  color: var(--on-accent);
  background: rgba(var(--accent-rgb), 0.96);
  border-color: transparent;
  font-weight: 600;
  transition: transform 0.15s ease, filter 0.15s ease;
}

.chip-cta:hover {
  filter: brightness(1.08);
}

.chip-cta:active {
  transform: scale(0.97);
}

/* hero 右侧要点面板 */
.hero-panel {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 26px 22px;
}

.hero-panel h2 {
  margin: 0 0 16px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--text-3);
  font-family: var(--font-mono);
}

.hero-panel ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.hero-panel li {
  display: flex;
  gap: 12px;
  font-size: 14px;
  line-height: 1.65;
  color: var(--text-2);
}

.hero-panel li::before {
  content: "";
  flex-shrink: 0;
  width: 6px;
  height: 6px;
  margin-top: 10px;
  border-radius: 50%;
  background: rgba(var(--accent-rgb), 0.85);
}

.hero-panel li b {
  color: var(--text);
  font-weight: 600;
}

/* ---------------- 主体布局 ---------------- */
.layout {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 48px 24px 96px;
  display: grid;
  grid-template-columns: 236px minmax(0, 1fr);
  gap: 56px;
  align-items: start;
}

/* 侧边目录 */
.toc {
  position: sticky;
  top: calc(var(--nav-h) + 28px);
  max-height: calc(100vh - var(--nav-h) - 56px);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
  padding-right: 8px;
}

.toc-title {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--text-3);
  margin: 0 0 14px;
  padding-left: 14px;
}

.toc ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
  counter-reset: toc;
}

.toc a {
  display: block;
  padding: 7px 14px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-3);
  border-left: 2px solid var(--border-soft);
  transition: color 0.15s ease, border-color 0.15s ease;
}

.toc a:hover {
  color: var(--text);
}

.toc a.active {
  color: rgba(var(--accent-rgb), 1);
  border-left-color: rgba(var(--accent-rgb), 1);
}

/* ---------------- 章节内容 ---------------- */
.content {
  min-width: 0;
}

.chapter {
  margin: 0 0 72px;
  scroll-margin-top: calc(var(--nav-h) + 24px);
}

.chapter-head {
  margin-bottom: 30px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border-soft);
}

.chapter-no {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: rgba(var(--accent-rgb), 0.9);
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 10px;
}

.chapter h2 {
  margin: 0 0 10px;
  font-size: clamp(24px, 2.6vw, 31px);
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.chapter .lead {
  margin: 0;
  font-size: 15.5px;
  color: var(--text-2);
  max-width: 62em;
}

h3.sub {
  margin: 42px 0 14px;
  font-size: 19px;
  font-weight: 650;
  letter-spacing: -0.005em;
}

h4.subsub {
  margin: 28px 0 10px;
  font-size: 15.5px;
  font-weight: 650;
  color: var(--text);
}

/* 正文排版 */
.content p {
  margin: 0 0 16px;
  color: var(--text-2);
  max-width: 74em;
}

.content p strong,
.content li strong {
  color: var(--text);
  font-weight: 620;
}

.content ul.plain,
.content ol.plain {
  margin: 0 0 18px;
  padding-left: 22px;
  color: var(--text-2);
  display: grid;
  gap: 8px;
  max-width: 72em;
}

.content ul.plain li::marker {
  color: rgba(var(--accent-rgb), 0.7);
}

.content ol.plain li::marker {
  color: rgba(var(--accent-rgb), 0.7);
  font-family: var(--font-mono);
  font-size: 0.85em;
}

.content a.inline-link {
  color: rgba(var(--accent-rgb), 1);
  border-bottom: 1px solid rgba(var(--accent-rgb), 0.35);
  transition: border-color 0.15s ease;
}

.content a.inline-link:hover {
  border-bottom-color: rgba(var(--accent-rgb), 0.9);
}

/* 行内代码 */
.content code.inline {
  padding: 2px 7px;
  margin: 0 1px;
  border-radius: 6px;
  background: var(--bg-inset);
  border: 1px solid var(--border-soft);
  color: #d3d3dd;
  font-size: 0.85em;
  white-space: nowrap;
}

kbd {
  padding: 2px 6px;
  border-radius: 5px;
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  background: var(--bg-inset);
  font-size: 11.5px;
  color: var(--text-2);
}

/* ---------------- 代码块 ---------------- */
figure.code {
  margin: 22px 0 26px;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

figure.code figcaption,
.code-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 9px 16px;
  border-bottom: 1px solid var(--border-soft);
  background: rgba(255, 255, 255, 0.015);
}

.code-lang {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--text-3);
  text-transform: uppercase;
}

.copy-btn {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--text-3);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 3px 12px;
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.copy-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

.copy-btn.copied {
  color: rgba(var(--accent-rgb), 1);
  border-color: rgba(var(--accent-rgb), 0.45);
}

figure.code pre {
  margin: 0;
  padding: 18px 20px;
  overflow-x: auto;
  line-height: 1.72;
  font-size: 13px;
  tab-size: 4;
}

figure.code code {
  font-family: var(--font-mono);
  background: none;
  color: #c8c8d2;
}

/* highlight.js 主题（tokyo-night 变体，适配本设计） */
.hljs-keyword,
.hljs-selector-tag,
.hljs-literal,
.hljs-doctag {
  color: #9d7cd8;
}

.hljs-string,
.hljs-regexp,
.hljs-addition {
  color: #9ece6a;
}

.hljs-number,
.hljs-symbol,
.hljs-bullet {
  color: #ff9e64;
}

.hljs-comment,
.hljs-quote {
  color: #565f89;
  font-style: italic;
}

.hljs-title,
.hljs-title.function_,
.hljs-section,
.hljs-name {
  color: #7aa2f7;
}

.hljs-title.class_,
.hljs-type,
.hljs-attr,
.hljs-attribute {
  color: #2ac3de;
}

.hljs-built_in,
.hljs-variable.language_ {
  color: #bb9af7;
}

.hljs-params {
  color: #c0caf5;
}

.hljs-meta,
.hljs-punctuation {
  color: #565f89;
}

.hljs-operator,
.hljs-property {
  color: #89ddff;
}

.hljs-variable,
.hljs-template-variable {
  color: #e0af68;
}

.hljs-emphasis {
  font-style: italic;
}

.hljs-strong {
  font-weight: 700;
}

/* ---------------- 提示框 ---------------- */
.callout {
  margin: 22px 0 26px;
  padding: 16px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  border-left: 3px solid var(--callout-color, var(--accent));
  background: var(--bg-raised);
}

.callout .callout-title {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--callout-color, var(--accent));
  margin-bottom: 8px;
}

.callout p {
  margin: 0 0 8px;
}

.callout p:last-child {
  margin-bottom: 0;
}

.callout.note {
  --callout-color: #7aa2f7;
}

.callout.tip {
  --callout-color: #9ece6a;
}

.callout.warn {
  --callout-color: #e0af68;
}

.callout.pitfall {
  --callout-color: #f7768e;
}

/* ---------------- 概念网格 ---------------- */
.grid-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 14px;
  margin: 24px 0 28px;
}

.grid-cards .card {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 20px 18px;
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.grid-cards .card:hover {
  border-color: var(--border-strong);
  transform: translateY(-2px);
}

.card .card-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: rgba(var(--accent-rgb), 1);
  margin-bottom: 10px;
}

.card h4,
.card .card-title {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 650;
  color: var(--text);
}

.card p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-3);
}

.card p code.inline {
  font-size: 0.86em;
}

/* 双栏对照 */
.split-2col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin: 24px 0 28px;
}

/* ---------------- 表格 ---------------- */
.table-wrap {
  margin: 24px 0 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow-x: auto;
  background: var(--bg-raised);
}

table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
  line-height: 1.65;
  min-width: 560px;
}

table.data th {
  text-align: left;
  padding: 12px 18px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-3);
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.015);
  white-space: nowrap;
}

table.data td {
  padding: 12px 18px;
  color: var(--text-2);
  border-bottom: 1px solid var(--border-soft);
  vertical-align: top;
}

table.data tr:last-child td {
  border-bottom: none;
}

table.data td:first-child {
  color: var(--text);
  font-weight: 550;
}

table.data code.inline {
  white-space: nowrap;
}

/* ---------------- 流程步骤 ---------------- */
.flow-steps {
  margin: 26px 0 30px;
  display: grid;
  gap: 0;
}

.flow-step {
  position: relative;
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  padding: 0 0 26px;
}

.flow-step::before {
  content: "";
  position: absolute;
  left: 19px;
  top: 42px;
  bottom: 0;
  width: 2px;
  background: linear-gradient(var(--border), var(--border-soft));
}

.flow-step:last-child::before {
  display: none;
}

.flow-step .step-dot {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: var(--bg-raised);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 13px;
  color: rgba(var(--accent-rgb), 1);
}

.flow-step .step-body h4 {
  margin: 6px 0 6px;
  font-size: 15.5px;
  font-weight: 650;
}

.flow-step .step-body p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-3);
  max-width: 60em;
}

/* ---------------- SVG 图示 ---------------- */
figure.diagram {
  margin: 26px 0 32px;
  padding: 24px;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

figure.diagram svg {
  margin: 0 auto;
  width: 100%;
  height: auto;
  max-width: 760px;
}

figure.diagram figcaption {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--border-soft);
  font-size: 13px;
  color: var(--text-3);
  text-align: center;
}

/* ---------------- 术语表 ---------------- */
.term-grid {
  margin: 24px 0 28px;
  display: grid;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-raised);
  overflow: hidden;
}

.term-grid .term {
  display: grid;
  grid-template-columns: 210px 1fr;
  gap: 18px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border-soft);
}

.term-grid .term:last-child {
  border-bottom: none;
}

.term-grid dt {
  font-family: var(--font-mono);
  font-size: 13px;
  color: rgba(var(--accent-rgb), 0.95);
  line-height: 1.6;
}

.term-grid dd {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-3);
}

.term-grid dd b {
  color: var(--text-2);
}

/* ---------------- Q&A 折叠 ---------------- */
.qa {
  margin: 24px 0 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-raised);
  overflow: hidden;
}

.qa summary {
  padding: 15px 20px;
  cursor: pointer;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: background 0.15s ease;
}

.qa summary::-webkit-details-marker {
  display: none;
}

.qa summary::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--text-3);
  font-size: 16px;
  flex-shrink: 0;
  transition: transform 0.2s ease, color 0.2s ease;
}

.qa[open] summary::after {
  transform: rotate(45deg);
  color: rgba(var(--accent-rgb), 1);
}

.qa summary:hover {
  background: rgba(255, 255, 255, 0.015);
}

.qa .qa-body {
  padding: 4px 20px 18px;
  border-top: 1px solid var(--border-soft);
}

.qa .qa-body p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-2);
}

/* ---------------- 练习清单 ---------------- */
.checklist {
  margin: 24px 0 28px;
  padding: 6px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-raised);
}

.checklist label {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 13px 0;
  border-bottom: 1px solid var(--border-soft);
  cursor: pointer;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-2);
}

.checklist label:last-child {
  border-bottom: none;
}

.checklist input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  margin-top: 4px;
  border: 1.5px solid var(--border-strong);
  border-radius: 5px;
  background: var(--bg-inset);
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
  position: relative;
}

.checklist input[type="checkbox"]:checked {
  border-color: rgba(var(--accent-rgb), 0.9);
  background: rgba(var(--accent-rgb), 0.9);
}

.checklist input[type="checkbox"]:checked::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 1.5px;
  width: 5px;
  height: 10px;
  border: solid var(--on-accent);
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checklist input[type="checkbox"]:checked + span {
  color: var(--text-3);
}

/* ---------------- 资源列表 ---------------- */
.resource-list {
  margin: 24px 0 28px;
  display: grid;
  gap: 10px;
}

.resource-list a {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 18px;
  padding: 14px 20px;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color 0.15s ease;
}

.resource-list a:hover {
  border-color: rgba(var(--accent-rgb), 0.45);
}

.resource-list .res-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.resource-list .res-desc {
  font-size: 12.5px;
  color: var(--text-3);
}

.resource-list .res-url {
  font-family: var(--font-mono);
  font-size: 12px;
  color: rgba(var(--accent-rgb), 0.85);
  white-space: nowrap;
}

/* ---------------- 页脚 ---------------- */
.pagefoot {
  border-top: 1px solid var(--border-soft);
  background: var(--bg-raised);
}

.pagefoot-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 44px 24px 40px;
}

.pager {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.pager-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  transition: border-color 0.16s ease, transform 0.16s ease;
}

.pager-card:hover {
  border-color: var(--border-strong);
  transform: translateY(-2px);
}

.pager-card.next {
  text-align: right;
  align-items: flex-end;
}

.pager-card .pager-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-3);
}

.pager-card .pager-title {
  font-size: 15.5px;
  font-weight: 650;
  color: var(--text);
}

.pager-card .pager-desc {
  font-size: 12.5px;
  color: var(--text-3);
}

.pagefoot-meta {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--border-soft);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 12.5px;
  color: var(--text-3);
}

/* ---------------- 首页专属 ---------------- */
.topic-list {
  display: grid;
  gap: 14px;
  margin: 32px 0;
}

.topic-card {
  display: grid;
  grid-template-columns: 84px 1fr auto;
  gap: 26px;
  align-items: center;
  padding: 24px 28px;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.topic-card:hover {
  transform: translateY(-2px);
}

.topic-card .topic-no {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 600;
  color: rgba(var(--topic-rgb, var(--accent-rgb)), 0.5);
  line-height: 1;
}

.topic-card .topic-body h3 {
  margin: 0 0 6px;
  font-size: 19px;
  font-weight: 680;
  letter-spacing: -0.005em;
}

.topic-card .topic-body h3 .topic-en {
  color: var(--text-3);
  font-weight: 500;
  font-size: 14px;
  margin-left: 8px;
}

.topic-card .topic-body p {
  margin: 0 0 8px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-3);
  max-width: 56em;
}

.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.topic-tags span {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 10px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border);
  color: var(--text-3);
}

.topic-card .topic-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-3);
  white-space: nowrap;
}

.topic-card .topic-go {
  color: rgba(var(--topic-rgb, var(--accent-rgb)), 1);
  font-size: 13px;
  font-weight: 600;
}

/* ---------------- 动效 ---------------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.55s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------------- 响应式 ---------------- */
@media (max-width: 1024px) {
  .layout {
    grid-template-columns: 1fr;
    gap: 0;
    padding-top: 28px;
  }

  .toc {
    position: static;
    max-height: none;
    overflow: visible;
    margin-bottom: 36px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-soft);
  }

  .hero-inner {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .topic-card {
    grid-template-columns: 56px 1fr;
  }

  .topic-card .topic-meta {
    display: none;
  }
}

@media (max-width: 768px) {
  body {
    font-size: 15px;
  }

  .hero {
    padding: 80px 18px 42px;
  }

  .layout {
    padding: 28px 18px 72px;
  }

  .hero h1 {
    font-size: clamp(30px, 8vw, 40px);
  }

  .split-2col {
    grid-template-columns: 1fr;
  }

  .term-grid .term {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .pager {
    grid-template-columns: 1fr;
  }

  .chapter {
    margin-bottom: 56px;
  }

  .topnav-inner {
    padding: 0 16px;
  }

  .brand-name .brand-sub {
    display: none;
  }

  .topic-card {
    grid-template-columns: 1fr;
    gap: 10px;
    padding: 20px;
  }

  .topic-card .topic-no {
    font-size: 22px;
  }
}