/* ============================================================
   博客系统 CSS 样式表
   风格：现代简约 · 灰色系 · 留白通透
   包含：设计令牌、基础重置、排版、组件、工具类、页面样式
   ============================================================ */

/* ---------- 1. 设计令牌（浅色主题） ---------- */
:root {
  /* 主色：中性近黑，承担强调与反转按钮 */
  --color-primary: #18181b;
  --color-primary-hover: #000000;
  --color-primary-light: #f4f4f5;
  --color-primary-dark: #09090b;

  /* 辅助色 */
  --color-secondary: #71717a;
  --color-secondary-hover: #52525b;
  --color-secondary-light: #f4f4f5;

  /* 状态色 */
  --color-success: #16a34a;
  --color-success-bg: #f0fdf4;
  --color-warning: #ca8a04;
  --color-warning-bg: #fefce8;
  --color-danger: #dc2626;
  --color-danger-bg: #fef2f2;
  --color-info: #0891b2;
  --color-info-bg: #ecfeff;

  /* 中性色（背景 / 边框 / 文字） */
  --color-bg-body: #fafafa;
  --color-bg-card: #ffffff;
  --color-bg-muted: #f4f4f5;
  --color-bg-hover: #f4f4f5;

  --color-border: #e4e4e7;
  --color-border-light: #f0f0f1;
  --color-border-dark: #d4d4d8;

  --color-text-primary: #18181b;
  --color-text-secondary: #52525b;
  --color-text-muted: #a1a1aa;
  --color-text-inverse: #ffffff;
  --color-text-link: var(--color-text-primary);

  /* 代码块专用 */
  --color-code-bg: #18181b;
  --color-code-text: #e4e4e7;
  --color-code-inline-bg: #f4f4f5;
  --color-code-inline-text: #18181b;

  /* 阴影：极轻，靠层级而非重投影 */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.04);
  --shadow-md: 0 1px 3px 0 rgb(0 0 0 / 0.06), 0 1px 2px -1px rgb(0 0 0 / 0.06);
  --shadow-lg: 0 4px 16px -2px rgb(0 0 0 / 0.08), 0 2px 6px -2px rgb(0 0 0 / 0.05);
  --shadow-xl: 0 12px 32px -6px rgb(0 0 0 / 0.12), 0 4px 12px -4px rgb(0 0 0 / 0.08);

  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  --radius-full: 9999px;

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

  /* 字体 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", Roboto,
    "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --font-serif: Georgia, Cambria, "Songti SC", "SimSun", "Times New Roman", Times, serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  /* 过渡 */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);

  /* 焦点环 */
  --color-focus-ring: rgba(24, 24, 27, 0.14);

  /* 布局 */
  --container-max: 1140px;
  --reading-max: 1140px;
  --header-height: 64px;
}

/* ---------- 2. 深色主题 ---------- */
[data-theme="dark"] {
  --color-primary: #fafafa;
  --color-primary-hover: #ffffff;
  --color-primary-light: #262626;
  --color-primary-dark: #ffffff;

  --color-secondary: #a1a1aa;
  --color-secondary-hover: #d4d4d8;
  --color-secondary-light: #1f1f1f;

  --color-success-bg: #0f1f16;
  --color-warning-bg: #241f0d;
  --color-danger-bg: #2a1414;
  --color-info-bg: #0b2229;

  --color-bg-body: #0a0a0a;
  --color-bg-card: #141414;
  --color-bg-muted: #1f1f1f;
  --color-bg-hover: #1f1f1f;

  --color-border: #262626;
  --color-border-light: #1f1f1f;
  --color-border-dark: #3f3f46;

  --color-text-primary: #fafafa;
  --color-text-secondary: #a1a1aa;
  --color-text-muted: #71717a;
  --color-text-inverse: #18181b;

  --color-code-bg: #000000;
  --color-code-inline-bg: #262626;
  --color-code-inline-text: #e4e4e7;

  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.4);
  --shadow-md: 0 1px 3px 0 rgb(0 0 0 / 0.5), 0 1px 2px -1px rgb(0 0 0 / 0.5);
  --shadow-lg: 0 4px 16px -2px rgb(0 0 0 / 0.6), 0 2px 6px -2px rgb(0 0 0 / 0.5);
  --shadow-xl: 0 12px 32px -6px rgb(0 0 0 / 0.7), 0 4px 12px -4px rgb(0 0 0 / 0.6);

  --color-focus-ring: rgba(250, 250, 250, 0.2);
}

/* ---------- 3. 基础重置 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg-body);
  color: var(--color-text-primary);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-base), color var(--transition-base);
}

::selection {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

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

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

a {
  color: var(--color-text-link);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover {
  text-decoration: underline;
  text-underline-offset: 2px;
}

ul,
ol {
  list-style: none;
}

/* 细滚动条 */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-dark) transparent;
}
*::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
*::-webkit-scrollbar-thumb {
  background-color: var(--color-border-dark);
  border: 3px solid transparent;
  background-clip: content-box;
  border-radius: var(--radius-full);
}
*::-webkit-scrollbar-thumb:hover {
  background-color: var(--color-text-muted);
  background-clip: content-box;
}

/* ---------- 4. 排版 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
  color: var(--color-text-secondary);
}

small {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

strong, b { font-weight: 700; }
em, i { font-style: italic; }

hr {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin: var(--space-xl) 0;
}

blockquote {
  border-left: 2px solid var(--color-text-primary);
  padding: var(--space-sm) var(--space-lg);
  margin: var(--space-lg) 0;
  background-color: var(--color-bg-muted);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--color-text-secondary);
}
blockquote p:last-child {
  margin-bottom: 0;
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background-color: var(--color-code-inline-bg);
  color: var(--color-code-inline-text);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
}

pre {
  background-color: var(--color-code-bg);
  color: var(--color-code-text);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  overflow-x: auto;
  margin: var(--space-lg) 0;
  font-size: 0.875rem;
  line-height: 1.7;
}
pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-size: inherit;
}

/* ---------- 5. 布局组件 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container-narrow {
  max-width: var(--reading-max);
}

.grid {
  display: grid;
  gap: var(--space-lg);
}
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-xs { gap: var(--space-xs); }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.gap-xl { gap: var(--space-xl); }

/* ---------- 6. 头部 / 导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  background-color: rgba(250, 250, 250, 0.8);
}
[data-theme="dark"] .site-header {
  background-color: rgba(10, 10, 10, 0.8);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.site-logo {
  font-size: 1.125rem;
  font-weight: 800;
  color: var(--color-text-primary);
  letter-spacing: -0.03em;
}
.site-logo:hover {
  text-decoration: none;
  color: var(--color-text-primary);
  opacity: 0.7;
}

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

.nav-link {
  position: relative;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-muted);
  padding: var(--space-xs) 0;
  transition: color var(--transition-fast);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background-color: var(--color-text-primary);
  border-radius: var(--radius-full);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}
.nav-link:hover,
.nav-link.active {
  color: var(--color-text-primary);
  text-decoration: none;
}
.nav-link:hover::after,
.nav-link.active::after {
  transform: scaleX(1);
}

/* ---------- 7. 卡片 ---------- */
.card {
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-base), box-shadow var(--transition-base),
    transform var(--transition-base);
}
.card:hover {
  box-shadow: var(--shadow-md);
}
.card-clickable:hover {
  transform: translateY(-3px);
  border-color: var(--color-border-dark);
  box-shadow: var(--shadow-lg);
}

.card-header {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.card-body {
  padding: var(--space-lg);
}

.card-footer {
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--color-border-light);
  background-color: var(--color-bg-muted);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.post-card .card-body {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.post-card .post-title {
  font-size: 1.1875rem;
  font-weight: 700;
  margin-bottom: 0;
  letter-spacing: -0.01em;
  text-wrap: balance;
}
.post-card .post-title a {
  color: var(--color-text-primary);
}
.post-card .post-title a:hover {
  color: var(--color-text-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
.post-card .post-meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.5rem 1rem;
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1.5;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: background-color var(--transition-fast), border-color var(--transition-fast),
    color var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
  user-select: none;
}
.btn:hover {
  text-decoration: none;
}
.btn:active {
  transform: translateY(1px);
}
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}
.btn:focus-visible {
  outline: 2px solid var(--color-text-primary);
  outline-offset: 2px;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}
.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
  color: var(--color-text-inverse);
}

.btn-secondary {
  background-color: var(--color-secondary-light);
  color: var(--color-text-secondary);
  border-color: var(--color-border);
}
.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-border);
  color: var(--color-text-primary);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-text-primary);
  border-color: var(--color-border-dark);
}
.btn-outline:hover:not(:disabled) {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.btn-danger {
  background-color: var(--color-danger);
  color: #ffffff;
}
.btn-danger:hover:not(:disabled) {
  background-color: #b91c1c;
}

.btn-success {
  background-color: var(--color-success);
  color: #ffffff;
}
.btn-success:hover:not(:disabled) {
  background-color: #15803d;
}

.btn-sm {
  padding: 0.3rem 0.75rem;
  font-size: 0.8125rem;
}
.btn-lg {
  padding: 0.75rem 1.5rem;
  font-size: 1.0625rem;
}
.btn-block {
  width: 100%;
}

/* ---------- 9. 表单 ---------- */
.form-group {
  margin-bottom: var(--space-lg);
}
.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}
.form-hint {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-top: var(--space-xs);
}
.form-error {
  font-size: 0.8125rem;
  color: var(--color-danger);
  margin-top: var(--space-xs);
}

.form-control {
  display: block;
  width: 100%;
  padding: 0.5rem 0.75rem;
  font-size: 0.9375rem;
  line-height: 1.5;
  color: var(--color-text-primary);
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.form-control::placeholder {
  color: var(--color-text-muted);
}
.form-control:focus {
  outline: none;
  border-color: var(--color-text-primary);
  box-shadow: 0 0 0 3px var(--color-focus-ring);
}
.form-control:disabled {
  background-color: var(--color-bg-muted);
  cursor: not-allowed;
}

textarea.form-control {
  resize: vertical;
  min-height: 120px;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2371717a' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2.25rem;
}

.form-check {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}
.form-check input[type="checkbox"],
.form-check input[type="radio"] {
  width: 1rem;
  height: 1rem;
  accent-color: var(--color-text-primary);
  cursor: pointer;
}
.form-check label {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  cursor: pointer;
}

/* ---------- 10. 徽章 / 标签 ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.125rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.5;
  border-radius: var(--radius-full);
  white-space: nowrap;
}
.badge-primary { background-color: var(--color-primary-light); color: var(--color-text-primary); }
.badge-secondary { background-color: var(--color-secondary-light); color: var(--color-text-secondary); }
.badge-success { background-color: var(--color-success-bg); color: var(--color-success); }
.badge-warning { background-color: var(--color-warning-bg); color: var(--color-warning); }
.badge-danger { background-color: var(--color-danger-bg); color: var(--color-danger); }
.badge-info { background-color: var(--color-info-bg); color: var(--color-info); }

.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.15rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1.6;
  color: var(--color-text-secondary);
  background-color: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  transition: background-color var(--transition-fast), border-color var(--transition-fast),
    color var(--transition-fast);
}
.tag:hover {
  color: var(--color-text-inverse);
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  text-decoration: none;
}

.pin-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.1rem 0.5rem;
  font-size: 0.6875rem;
  font-weight: 600;
  line-height: 1.6;
  color: #fff;
  background-color: var(--color-primary);
  border-radius: var(--radius-full);
}

/* ---------- 11. 警告 / 提示 ---------- */
.alert {
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  border-left-width: 3px;
  margin-bottom: var(--space-lg);
  font-size: 0.9375rem;
}
.alert-success {
  background-color: var(--color-success-bg);
  border-color: var(--color-success);
  color: var(--color-success);
}
.alert-warning {
  background-color: var(--color-warning-bg);
  border-color: var(--color-warning);
  color: var(--color-warning);
}
.alert-danger {
  background-color: var(--color-danger-bg);
  border-color: var(--color-danger);
  color: var(--color-danger);
}
.alert-info {
  background-color: var(--color-info-bg);
  border-color: var(--color-info);
  color: var(--color-info);
}

/* ---------- 12. 头像 ---------- */
.avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-full);
  background-color: var(--color-bg-muted);
  color: var(--color-text-primary);
  font-weight: 700;
  font-size: 0.9375rem;
  overflow: hidden;
  flex-shrink: 0;
}
.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.avatar-sm { width: 2rem; height: 2rem; font-size: 0.8125rem; }
.avatar-lg { width: 3.5rem; height: 3.5rem; font-size: 1.25rem; }

/* ---------- 13. 分页 ---------- */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  margin: var(--space-xl) 0;
}
.pagination a,
.pagination span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.25rem;
  height: 2.25rem;
  padding: 0 var(--space-sm);
  font-size: 0.875rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background-color: var(--color-bg-card);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}
.pagination a:hover {
  border-color: var(--color-text-primary);
  color: var(--color-text-primary);
  text-decoration: none;
}
.pagination .active {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-inverse);
}
.pagination .disabled {
  opacity: 0.5;
  pointer-events: none;
}

/* ---------- 14. 表格 ---------- */
.table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}
.table th,
.table td {
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}
.table th {
  font-weight: 600;
  color: var(--color-text-secondary);
  background-color: var(--color-bg-muted);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.table tbody tr:hover {
  background-color: var(--color-bg-hover);
}

/* ---------- 15. 模态框 ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(2px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: var(--space-md);
  animation: fadeIn var(--transition-base);
}
.modal {
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
  animation: slideUp var(--transition-base);
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
}
.modal-header h3 {
  margin-bottom: 0;
  font-size: 1.125rem;
}
.modal-body {
  padding: var(--space-lg);
}
.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--color-border);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}
@keyframes slideUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- 16. 下拉菜单 ---------- */
.dropdown {
  position: relative;
  display: inline-block;
}
.dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  min-width: 180px;
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: var(--space-xs) 0;
  z-index: 50;
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: all var(--transition-fast);
}
.dropdown.open .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.dropdown-item {
  display: block;
  padding: var(--space-sm) var(--space-md);
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  transition: background-color var(--transition-fast);
}
.dropdown-item:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text-primary);
  text-decoration: none;
}
.dropdown-divider {
  height: 1px;
  background-color: var(--color-border);
  margin: var(--space-xs) 0;
}

/* ---------- 17. 加载动画 ---------- */
.spinner {
  display: inline-block;
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-text-primary);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ---------- 18. 工具类 ---------- */
.text-primary { color: var(--color-text-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-muted { color: var(--color-text-muted); }
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-sm { font-size: 0.875rem; }
.text-xs { font-size: 0.75rem; }
.text-lg { font-size: 1.125rem; }
.font-bold { font-weight: 700; }
.font-medium { font-weight: 500; }

.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--space-xs); }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--space-xs); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.ml-auto { margin-left: auto; }
.mr-auto { margin-right: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }

.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.px-md { padding-left: var(--space-md); padding-right: var(--space-md); }
.py-md { padding-top: var(--space-md); padding-bottom: var(--space-md); }

.w-full { width: 100%; }
.h-full { height: 100%; }

.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }

.border { border: 1px solid var(--color-border); }
.border-top { border-top: 1px solid var(--color-border); }
.border-bottom { border-bottom: 1px solid var(--color-border); }

.bg-card { background-color: var(--color-bg-card); }
.bg-muted { background-color: var(--color-bg-muted); }

.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }

.truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 19. 页脚 ---------- */
.site-footer {
  margin-top: var(--space-2xl);
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
  background-color: var(--color-bg-card);
  color: var(--color-text-muted);
  font-size: 0.875rem;
}
.site-footer a {
  color: var(--color-text-secondary);
}
.site-footer a:hover {
  color: var(--color-text-primary);
}

/* ---------- 20. 响应式调整 ---------- */
@media (max-width: 640px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }

  .container {
    padding: 0 var(--space-md);
  }

  .nav {
    gap: var(--space-md);
  }

  .card-header,
  .card-body {
    padding: var(--space-md);
  }

  .modal {
    max-width: 100%;
  }
}

/* ---------- 21. 首页 ---------- */
.hero-section {
  padding: var(--space-2xl) 0;
  border-bottom: 1px solid var(--color-border);
  background:
    radial-gradient(60% 120% at 50% 0%, var(--color-bg-muted) 0%, transparent 70%),
    var(--color-bg-body);
  margin-bottom: var(--space-xl);
}
.hero-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1.1;
  margin-bottom: var(--space-sm);
  text-wrap: balance;
}
.hero-sub {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin-bottom: 0;
}

.main-grid {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  gap: var(--space-xl);
  align-items: start;
}

@media (min-width: 769px) {
  .main-grid > aside {
    position: sticky;
    top: calc(var(--header-height) + var(--space-lg));
  }
}

.sidebar-widget-title {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border-light);
}
.sidebar-list li { margin-bottom: var(--space-sm); }
.sidebar-list li:last-child { margin-bottom: 0; }
.sidebar-list a {
  display: block;
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  line-height: 1.5;
}
.sidebar-list a:hover {
  color: var(--color-text-primary);
  text-decoration: none;
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-md);
}
.footer-links { display: flex; gap: var(--space-lg); }

.classify-filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}
.classify-btn {
  padding: 0.375rem 1rem;
  font-size: 0.8125rem;
  font-weight: 500;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-bg-card);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: background-color var(--transition-fast), border-color var(--transition-fast),
    color var(--transition-fast);
}
.classify-btn:hover {
  border-color: var(--color-border-dark);
  color: var(--color-text-primary);
}
.classify-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-inverse);
}
.classify-btn:focus-visible {
  outline: 2px solid var(--color-text-primary);
  outline-offset: 2px;
}

#articleList {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.empty-state {
  padding: var(--space-2xl) var(--space-xl);
  text-align: center;
  color: var(--color-text-muted);
  background: var(--color-bg-card);
  border: 1px dashed var(--color-border-dark);
  border-radius: var(--radius-lg);
}

.load-more-wrap {
  display: flex;
  justify-content: center;
  padding: var(--space-lg) 0 var(--space-md);
}
.load-more-wrap[hidden] {
  display: none;
}

#tagCloud {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}
.tag-button {
  font-family: inherit;
  cursor: pointer;
}
.tag-button.active {
  color: var(--color-text-inverse);
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}
.tag-button:focus-visible {
  outline: 2px solid var(--color-text-primary);
  outline-offset: 2px;
}

@media (max-width: 768px) {
  .main-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .hero-section { padding: var(--space-xl) 0; }
  .hero-title { font-size: 1.75rem; }
  .hero-sub { font-size: 1rem; }
}

/* ---------- 22. 文章阅读页 ---------- */
.reading-page {
  max-width: var(--reading-max);
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}
.article-header { margin-bottom: var(--space-xl); }
.article-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-md);
  line-height: 1.2;
  text-wrap: balance;
}
.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  padding-bottom: var(--space-lg);
  margin-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border-light);
}
.article-meta span {
  color: var(--color-text-muted);
}
.article-meta span[id] {
  color: var(--color-text-secondary);
}

.article-content {
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--color-text-secondary);
}
.article-content h1,
.article-content h2,
.article-content h3,
.article-content h4 {
  margin-top: var(--space-xl);
  margin-bottom: var(--space-md);
  color: var(--color-text-primary);
}
.article-content h2 {
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border-light);
}
.article-content p {
  margin-bottom: var(--space-lg);
}
.article-content img {
  border-radius: var(--radius-lg);
  margin: var(--space-lg) auto;
  border: 1px solid var(--color-border);
}
.article-content blockquote {
  margin: var(--space-lg) 0;
}
.article-content pre {
  margin: var(--space-lg) 0;
}
.article-content ul,
.article-content ol {
  margin: var(--space-md) 0 var(--space-lg) var(--space-lg);
  color: var(--color-text-secondary);
}
.article-content ul li,
.article-content ol li {
  margin-bottom: var(--space-xs);
}
.article-content ul li::marker,
.article-content ol li::marker {
  color: var(--color-text-muted);
}
.article-content ul { list-style: disc; }
.article-content ol { list-style: decimal; }
.article-content a {
  color: var(--color-text-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
  text-decoration-color: var(--color-border-dark);
  transition: text-decoration-color var(--transition-fast);
}
.article-content a:hover {
  text-decoration-color: var(--color-text-primary);
}
.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-lg) 0;
  font-size: 0.9375rem;
}
.article-content th,
.article-content td {
  border: 1px solid var(--color-border);
  padding: var(--space-sm) var(--space-md);
  text-align: left;
}
.article-content th {
  background-color: var(--color-bg-muted);
  font-weight: 600;
}
.article-content hr {
  margin: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-xl);
  transition: color var(--transition-fast);
}
.back-link:hover {
  color: var(--color-text-primary);
  text-decoration: none;
}
.loading-spinner {
  display: flex;
  justify-content: center;
  padding: var(--space-2xl) 0;
}
.error-message {
  padding: var(--space-xl);
  text-align: center;
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text-secondary);
}
.article-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border-light);
}

/* ---------- 22b. 文章目录侧栏 ---------- */
.reading-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-xl);
  align-items: start;
}
.reading-layout.with-toc {
  grid-template-columns: minmax(0, 1fr) 240px;
}
.toc-aside {
  display: none;
  align-self: stretch;
}
.toc-card {
  position: sticky;
  top: calc(var(--header-height) + var(--space-lg));
}
.toc-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  max-height: calc(100vh - var(--header-height) - 6rem);
  overflow-y: auto;
}
.toc-link {
  display: block;
  padding: 4px 10px;
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--color-text-muted);
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  transition: background-color var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast);
}
.toc-link:hover {
  color: var(--color-text-primary);
  background-color: var(--color-bg-muted);
  text-decoration: none;
}
.toc-link.active {
  color: var(--color-text-primary);
  font-weight: 600;
  background-color: var(--color-bg-muted);
  border-left-color: var(--color-text-primary);
}
.toc-h3 {
  padding-left: 1.5rem;
  font-size: 0.8125rem;
}
.article-content h2,
.article-content h3 {
  scroll-margin-top: calc(var(--header-height) + 1rem);
}

@media (max-width: 1000px) {
  .reading-layout.with-toc {
    grid-template-columns: minmax(0, 1fr);
  }
  .toc-aside {
    order: -1;
  }
  .toc-card {
    position: static;
  }
  .toc-nav {
    max-height: 260px;
  }
}

@media (max-width: 640px) {
  .reading-page { padding-top: var(--space-xl); }
  .article-title { font-size: 1.625rem; }
  .article-content { font-size: 1rem; }
}

/* ---------- 23. 说说 ---------- */
.moments-page {
  max-width: 760px;
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}
.moments-header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-border-light);
}
.moments-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-xs);
}
.moments-sub {
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

.moments-timeline {
  position: relative;
  padding-left: var(--space-xl);
}
.moments-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background-color: var(--color-border);
}
.moment-item {
  position: relative;
  padding-bottom: var(--space-xl);
}
.moment-item:last-child {
  padding-bottom: 0;
}
.moment-item::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 5px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-bg-body);
  border: 2px solid var(--color-text-primary);
  box-sizing: border-box;
}
.moment-time {
  display: block;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-xs);
}
.moment-content {
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--color-text-secondary);
  white-space: pre-wrap;
  word-break: break-word;
}

.widget-more {
  float: right;
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: none;
  letter-spacing: 0;
  color: var(--color-text-muted);
}
.widget-more:hover {
  color: var(--color-text-primary);
  text-decoration: none;
}

.moment-mini {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.moment-mini-time {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}
.moment-mini-text {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
  white-space: pre-wrap;
  word-break: break-word;
}

@media (max-width: 640px) {
  .moments-page { padding-top: var(--space-xl); }
  .moment-content { font-size: 1rem; }
}

/* ---------- 24. 页面加载与进入动画 ---------- */
body.is-loading {
  overflow: hidden;
}

.page-loader {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  background-color: var(--color-bg-body);
  transition: opacity var(--transition-slow), visibility var(--transition-slow);
}
.page-loader.is-hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.page-loader-logo {
  font-size: 2.75rem;
  line-height: 1;
  animation: loaderPulse 1.6s ease-in-out infinite;
}
.page-loader-dots {
  display: flex;
  gap: 6px;
}
.page-loader-dots span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-text-muted);
  animation: loaderBounce 1.2s ease-in-out infinite;
}
.page-loader-dots span:nth-child(2) { animation-delay: 0.15s; }
.page-loader-dots span:nth-child(3) { animation-delay: 0.3s; }
.page-loader-text {
  margin: 0;
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
}

@keyframes loaderPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(0.86); opacity: 0.6; }
}
@keyframes loaderBounce {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.5; }
  40% { transform: translateY(-6px); opacity: 1; }
}

/* 加载完成前不展示页面内容 */
body:not(.is-ready) .site-header,
body:not(.is-ready) main,
body:not(.is-ready) .site-footer {
  opacity: 0;
}

body.is-ready .site-header {
  animation: pageEnter 0.5s cubic-bezier(0.22, 1, 0.36, 1) both;
}
body.is-ready main {
  animation: pageEnter 0.55s cubic-bezier(0.22, 1, 0.36, 1) 0.05s both;
}
body.is-ready .site-footer {
  animation: pageEnter 0.55s cubic-bezier(0.22, 1, 0.36, 1) 0.1s both;
}

@keyframes pageEnter {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 25. 动效减弱偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}