/* ============================================================
   ~/blog · 个人技术博客样式
   纯手写 CSS，无任何框架依赖。深色为默认主题，可切换浅色。
   ============================================================ */

/* ---------- 1. 设计变量 ---------- */
:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;

  --container: 1100px;
  --header-h: 64px;

  --transition: 0.2s ease;
}

/* 深色主题（默认） */
:root[data-theme="dark"] {
  --bg: #0b0f17;
  --bg-soft: #0e1420;
  --surface: #121a29;
  --card: #141d2f;
  --card-hover: #17223a;
  --border: #233049;
  --border-strong: #31415f;
  --text: #e8ecf4;
  --text-secondary: #aab6c8;
  --text-muted: #74839b;
  --accent: #2dd4bf;
  --accent-soft: rgba(45, 212, 191, 0.12);
  --accent-2: #818cf8;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
  --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.25);
  --code-bg: #0a0e16;
  --code-header: #101726;
  --hero-grid: rgba(148, 163, 198, 0.07);
  --hero-glow-1: rgba(45, 212, 191, 0.13);
  --hero-glow-2: rgba(129, 140, 248, 0.12);
  color-scheme: dark;
}

/* 浅色主题 */
:root[data-theme="light"] {
  --bg: #f6f8fb;
  --bg-soft: #eef2f7;
  --surface: #ffffff;
  --card: #ffffff;
  --card-hover: #f4f8ff;
  --border: #e2e8f2;
  --border-strong: #cbd5e5;
  --text: #1b2434;
  --text-secondary: #45536a;
  --text-muted: #71809a;
  --accent: #0d9488;
  --accent-soft: rgba(13, 148, 136, 0.1);
  --accent-2: #6366f1;
  --shadow: 0 10px 32px rgba(30, 45, 80, 0.1);
  --shadow-sm: 0 2px 8px rgba(30, 45, 80, 0.07);
  --code-bg: #0d1117; /* 代码块在浅色主题下依然保持深色，阅读体验更好 */
  --code-header: #161d2a;
  --hero-grid: rgba(60, 80, 120, 0.08);
  --hero-glow-1: rgba(13, 148, 136, 0.1);
  --hero-glow-2: rgba(99, 102, 241, 0.1);
  color-scheme: light;
}

/* ---------- 2. 基础与重置 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.25s ease, color 0.25s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  text-decoration: underline;
}

::selection {
  background: var(--accent);
  color: #04211d;
}

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

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.mono {
  font-family: var(--font-mono);
}

/* ---------- 3. 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

@supports not (backdrop-filter: blur(12px)) {
  .site-header {
    background: var(--bg);
  }
}

.nav-wrap {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.5px;
}

.brand:hover {
  text-decoration: none;
  color: var(--accent);
}

.brand .brand-path {
  color: var(--accent);
}

.brand .brand-cursor {
  display: inline-block;
  width: 0.55em;
  color: var(--accent);
  animation: blink 1.1s steps(1) infinite;
}

@keyframes blink {
  50% {
    opacity: 0;
  }
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  color: var(--text-secondary);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  transition: color var(--transition), background-color var(--transition);
}

.nav-link:hover {
  color: var(--text);
  background: var(--accent-soft);
  text-decoration: none;
}

.nav-link.active {
  color: var(--accent);
  background: var(--accent-soft);
  font-weight: 600;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1.05rem;
  transition: all var(--transition);
}

.icon-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
}

/* 主题按钮的日月图标随主题切换 */
.icon-btn .icon-sun,
.icon-btn .icon-moon {
  display: none;
  font-size: 1rem;
  line-height: 1;
}

:root[data-theme="dark"] .icon-btn .icon-sun {
  display: block;
}

:root[data-theme="light"] .icon-btn .icon-moon {
  display: block;
}

/* 移动端菜单按钮（桌面隐藏） */
.menu-toggle {
  display: none;
}

@media (max-width: 720px) {
  .menu-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px 16px;
    gap: 4px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
    box-shadow: var(--shadow);
  }

  .site-nav.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    padding: 12px 14px;
    font-size: 1rem;
  }
}

/* ---------- 4. 首页 Hero ---------- */
.hero {
  position: relative;
  padding: 96px 0 72px;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
  background-image:
    radial-gradient(600px 300px at 15% 0%, var(--hero-glow-1), transparent 70%),
    radial-gradient(600px 320px at 85% 20%, var(--hero-glow-2), transparent 70%),
    linear-gradient(var(--hero-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--hero-grid) 1px, transparent 1px);
  background-size: auto, auto, 32px 32px, 32px 32px;
}

.hero-inner {
  position: relative;
  max-width: 760px;
  margin: 0 auto;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  border-radius: 999px;
  padding: 5px 14px;
  margin-bottom: 28px;
}

.hero-badge::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%,
  100% {
    box-shadow: 0 0 0 0 var(--accent-soft);
  }
  50% {
    box-shadow: 0 0 0 6px transparent;
  }
}

.hero h1 {
  font-size: clamp(2rem, 5.5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -1px;
  margin-bottom: 20px;
}

.hero h1 .gradient-text {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 28px;
}

.hero-typing {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 36px;
  min-height: 1.8em;
}

.hero-typing .prompt-sign {
  color: var(--accent);
  margin-right: 8px;
}

.hero-typing #typingText {
  color: var(--accent);
}

.hero-typing .typing-cursor {
  display: inline-block;
  width: 0.55em;
  color: var(--accent);
  animation: blink 1s steps(1) infinite;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-top: 52px;
  flex-wrap: wrap;
}

.stat {
  text-align: center;
}

.stat .stat-num {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--accent);
}

.stat .stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 26px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: var(--accent);
  color: #052e2a;
}

.btn-primary:hover {
  box-shadow: 0 6px 20px var(--accent-soft), 0 0 0 1px var(--accent);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border-strong);
}

.btn-ghost:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
}

/* ---------- 6. 区块通用 ---------- */
.section {
  padding: 72px 0;
}

.section-alt {
  background: var(--bg-soft);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 36px;
}

.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-title::before {
  content: "";
  width: 4px;
  height: 1.15em;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--accent), var(--accent-2));
}

.section-more {
  font-size: 0.92rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.section-more:hover {
  color: var(--accent);
}

/* ---------- 7. 文章卡片 ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 22px;
}

.card {
  display: flex;
  flex-direction: column;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.card::after {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  opacity: 0;
  transition: opacity var(--transition);
}

.card:hover {
  background: var(--card-hover);
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  text-decoration: none;
}

.card:hover::after {
  opacity: 1;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid transparent;
  transition: all var(--transition);
}

.card-title {
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
  margin-bottom: 10px;
}

.card-summary {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.7;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
}

.card-meta .meta-item {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

/* ---------- 8. 文章列表页 ---------- */
.page-header {
  padding: 56px 0 8px;
}

.page-title {
  font-size: clamp(1.7rem, 4vw, 2.3rem);
  font-weight: 800;
  letter-spacing: -0.5px;
}

.page-sub {
  color: var(--text-muted);
  margin-top: 8px;
}

.article-toolbar {
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 28px 0 8px;
}

.search-box {
  position: relative;
  max-width: 460px;
}

.search-box .search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
  font-size: 0.95rem;
}

.search-box input {
  width: 100%;
  padding: 11px 16px 11px 40px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: all var(--transition);
}

.search-box input::placeholder {
  color: var(--text-muted);
}

.search-box input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.tag-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag-pill {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  padding: 5px 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
}

.tag-pill:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.tag-pill.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #052e2a;
  font-weight: 600;
}

.article-count {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  padding: 18px 0;
}

.empty-state {
  text-align: center;
  padding: 72px 24px;
  color: var(--text-muted);
}

.empty-state .empty-icon {
  font-size: 2.4rem;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  color: var(--accent);
}

/* ---------- 9. 文章详情页 ---------- */

/* 顶部阅读进度条 */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  z-index: 200;
  transition: width 0.1s linear;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: 48px;
  padding: 48px 0 72px;
  align-items: start;
}

@media (max-width: 960px) {
  .article-layout {
    grid-template-columns: 1fr;
  }
}

.article-header {
  margin-bottom: 36px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border);
}

.back-link {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 22px;
}

.back-link:hover {
  color: var(--accent);
}

.article-title {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 800;
  line-height: 1.4;
  letter-spacing: -0.5px;
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.article-meta .meta-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* 正文排版 */
.post-content {
  font-size: 1.02rem;
  line-height: 1.9;
  color: var(--text);
  word-break: break-word;
}

.post-content h2 {
  font-size: 1.45rem;
  font-weight: 700;
  margin: 2.2em 0 0.9em;
  padding-left: 14px;
  border-left: 4px solid var(--accent);
  line-height: 1.4;
  scroll-margin-top: calc(var(--header-h) + 20px);
}

.post-content h3 {
  font-size: 1.18rem;
  font-weight: 700;
  margin: 1.8em 0 0.7em;
}

.post-content p {
  margin: 1em 0;
}

.post-content ul,
.post-content ol {
  margin: 1em 0;
  padding-left: 1.6em;
}

.post-content li {
  margin: 0.4em 0;
}

.post-content blockquote {
  margin: 1.5em 0;
  padding: 14px 20px;
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-secondary);
}

.post-content blockquote p {
  margin: 0.3em 0;
}

.post-content :not(pre) > code {
  font-family: var(--font-mono);
  font-size: 0.87em;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 2px 7px;
  border-radius: 5px;
}

.post-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: 0.92rem;
  display: block;
  overflow-x: auto;
}

.post-content th,
.post-content td {
  border: 1px solid var(--border);
  padding: 9px 14px;
  text-align: left;
}

.post-content th {
  background: var(--surface);
  font-weight: 700;
}

.post-content tr:nth-child(even) td {
  background: var(--bg-soft);
}

.post-content hr {
  border: none;
  border-top: 1px dashed var(--border-strong);
  margin: 2.4em 0;
}

.post-content img {
  border-radius: var(--radius-md);
  margin: 1.5em auto;
}

/* ---------- 10. 代码块 ---------- */
.code-block {
  margin: 1.6em 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--code-bg);
}

.code-block-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 16px;
  background: var(--code-header);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.code-lang {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: #8b98ab;
  letter-spacing: 0.5px;
  text-transform: lowercase;
}

.copy-btn {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: #8b98ab;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 6px;
  padding: 3px 10px;
  cursor: pointer;
  transition: all var(--transition);
}

.copy-btn:hover {
  color: var(--code-bg);
  background: var(--accent);
  border-color: var(--accent);
}

.copy-btn.copied {
  color: var(--accent);
  border-color: var(--accent);
}

.code-block pre {
  margin: 0;
  padding: 18px 20px;
  overflow-x: auto;
}

.code-block code {
  font-family: var(--font-mono);
  font-size: 0.87rem;
  line-height: 1.75;
  color: #dbe4f0;
}

/* 代码高亮配色（两种主题一致，基于深色代码底色） */
.tok-com {
  color: #6a7f95;
  font-style: italic;
}

.tok-str {
  color: #9ae6b4;
}

.tok-kw {
  color: #f0a5c8;
}

.tok-num {
  color: #fbd38d;
}

.tok-tag {
  color: #7cc7ff;
}

.tok-attr {
  color: #c3b6ff;
}

/* ---------- 11. 文章目录（TOC） ---------- */
.toc {
  position: sticky;
  top: calc(var(--header-h) + 28px);
  border-left: 2px solid var(--border);
  padding-left: 18px;
  font-size: 0.87rem;
}

.toc-title {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 12px;
}

.toc a {
  display: block;
  color: var(--text-muted);
  padding: 5px 0;
  border-left: 2px solid transparent;
  margin-left: -20px;
  padding-left: 18px;
  line-height: 1.5;
  transition: all var(--transition);
}

.toc a:hover {
  color: var(--accent);
  text-decoration: none;
}

.toc a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  font-weight: 600;
}

@media (max-width: 960px) {
  .toc {
    display: none;
  }
}

/* ---------- 12. 上下篇 / 相关文章 ---------- */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 56px;
}

@media (max-width: 640px) {
  .post-nav {
    grid-template-columns: 1fr;
  }
}

.post-nav-link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--card);
  transition: all var(--transition);
}

.post-nav-link:hover {
  border-color: var(--accent);
  background: var(--card-hover);
  text-decoration: none;
}

.post-nav-link .nav-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.post-nav-link .nav-title {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
}

.post-nav-link.next {
  text-align: right;
}

.related-section {
  margin-top: 64px;
}

.related-section .section-title {
  font-size: 1.2rem;
  margin-bottom: 22px;
}

/* ---------- 13. 关于页 ---------- */
.about-hero {
  display: flex;
  align-items: center;
  gap: 28px;
  padding: 64px 0 40px;
  flex-wrap: wrap;
}

.avatar {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  font-weight: 800;
  color: #fff;
  flex-shrink: 0;
  box-shadow: var(--shadow);
}

.about-intro h1 {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.about-intro p {
  color: var(--text-secondary);
  max-width: 640px;
}

.about-body {
  padding-bottom: 72px;
  display: grid;
  gap: 48px;
}

.skill-group h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.skill-group h3 .skill-icon {
  font-family: var(--font-mono);
  color: var(--accent);
}

.skill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.skill-item {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 6px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  transition: all var(--transition);
}

.skill-item:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}

.contact-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.contact-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--card);
  transition: all var(--transition);
}

.contact-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
  text-decoration: none;
}

.contact-card .contact-icon {
  font-size: 1.3rem;
}

.contact-card .contact-name {
  font-weight: 600;
  color: var(--text);
  font-size: 0.95rem;
}

.contact-card .contact-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* ---------- 14. 404 页 ---------- */
.not-found {
  text-align: center;
  padding: 110px 24px;
}

.not-found .nf-code {
  font-family: var(--font-mono);
  font-size: clamp(4rem, 14vw, 7rem);
  font-weight: 800;
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.1;
}

.not-found .nf-msg {
  font-family: var(--font-mono);
  color: var(--text-muted);
  margin: 16px 0 32px;
}

/* ---------- 15. 页脚 ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  margin-top: auto;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-align: center;
  font-size: 0.87rem;
  color: var(--text-muted);
}

.footer-inner a {
  color: var(--text-secondary);
}

.footer-inner a:hover {
  color: var(--accent);
}

.footer-mono {
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

/* ---------- 16. 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  right: 28px;
  bottom: 28px;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition);
  z-index: 90;
  box-shadow: var(--shadow-sm);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* ---------- 17. 入场动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }

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