/* ==========================================================================
   大哥云 (daggeyun.homes) - 极简现代化高精度样式表
   Design System: Pure Porcelain White & Deep Slate Typography
   Strict Constraint: Zero icons, zero clipart, zero background gradients.
   Focus: Razor-sharp alignment, micro-elevation shifts, ultra-soft shadows.
   ========================================================================== */

:root {
  /* 排版字体 */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --line-height: 1.6;

  /* 基础调色板 - 白天模式 (默认) */
  --bg-body: #ffffff;             /* 纯净瓷白 */
  --bg-surface: #ffffff;
  --bg-subtle: #f4f5f7;           /* 雅致冷灰分界 */
  --bg-card: #ffffff;
  --bg-hover: #f8fafc;
  
  /* 边框体系 (细线微边框) */
  --border-hairline: #e5e7eb;
  --border-subtle: #f1f5f9;
  --border-focus: #2563eb;

  /* 文字排版深度 */
  --text-primary: #0f172a;        /* 深石板灰 */
  --text-secondary: #475569;      /* 次级阅读灰 */
  --text-muted: #64748b;          /* 弱化标注 */
  --text-dim: #94a3b8;

  /* 核心交互色 (钴蓝 - 严格限定于核心可交互状态) */
  --brand-cobalt: #2563eb;
  --brand-cobalt-hover: #1d4ed8;
  --brand-cobalt-light: #eff6ff;

  /* 状态指标色 (微饱和度) */
  --status-online: #10b981;
  --status-online-bg: #ecfdf5;

  /* 阴影层级体系 (Multi-layered ultra-soft ambient shadows) */
  --shadow-flat: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-elevation: 0 4px 6px -1px rgba(15, 23, 42, 0.04), 0 10px 24px -3px rgba(15, 23, 42, 0.07);
  --shadow-floating: 0 12px 32px -4px rgba(15, 23, 42, 0.08), 0 4px 12px rgba(15, 23, 42, 0.03);

  /* 头部与定位 */
  --header-bg: rgba(255, 255, 255, 0.94);
  --header-height: 70px;
}

/* 调色板 - 夜间模式 (Dark Mode) */
[data-theme="dark"] {
  --bg-body: #0b0f19;
  --bg-surface: #111827;
  --bg-subtle: #0f1523;
  --bg-card: #111827;
  --bg-hover: #1e293b;

  --border-hairline: #1f293d;
  --border-subtle: #192231;
  --border-focus: #3b82f6;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-dim: #475569;

  --brand-cobalt: #3b82f6;
  --brand-cobalt-hover: #60a5fa;
  --brand-cobalt-light: rgba(59, 130, 246, 0.12);

  --status-online: #34d399;
  --status-online-bg: rgba(16, 185, 129, 0.15);

  --shadow-flat: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-elevation: 0 6px 16px -2px rgba(0, 0, 0, 0.5), 0 2px 6px rgba(0, 0, 0, 0.4);
  --shadow-floating: 0 16px 36px -4px rgba(0, 0, 0, 0.7);

  --header-bg: rgba(11, 15, 25, 0.94);
}

/* ==========================================================================
   全局重置与排版
   ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: var(--line-height);
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 20px);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--bg-body);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.18s ease;
}

button, input {
  font-family: inherit;
}

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 28px;
}

.section {
  padding: 96px 0;
  position: relative;
}

.section-divider {
  background-color: var(--bg-subtle);
  border-top: 1px solid var(--border-hairline);
  border-bottom: 1px solid var(--border-hairline);
}

/* ==========================================================================
   顶部导航栏 (Navbar)
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: var(--header-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-hairline);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

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

.brand-title-wrap {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.brand-text {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--brand-cobalt);
  background: var(--brand-cobalt-light);
  border: 1px solid var(--border-hairline);
  padding: 2px 6px;
  border-radius: 4px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 22px;
  list-style: none;
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 6px 4px;
  position: relative;
  transition: color 0.18s ease;
}

.nav-link:hover, .nav-link.active {
  color: var(--brand-cobalt);
}

.nav-link.highlight {
  color: var(--brand-cobalt);
  font-weight: 600;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* 昼夜模式切换按钮 - 图2圆形太阳/月亮微拟物设计 */
.theme-toggle-btn {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: #ffffff;
  border: 1px solid var(--border-hairline);
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.06), 0 1px 2px rgba(15, 23, 42, 0.04);
  color: #334155;
  cursor: pointer;
  padding: 0;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  flex-shrink: 0;
}

.theme-toggle-btn:hover {
  border-color: #cbd5e1;
  transform: scale(1.05);
  box-shadow: 0 3px 8px rgba(15, 23, 42, 0.08);
  color: var(--brand-cobalt);
}

.theme-toggle-btn svg {
  width: 19px;
  height: 19px;
  stroke: currentColor;
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.2s ease;
}

.sun-icon {
  display: block;
}

.moon-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle-btn {
  background: #1e293b;
  border-color: #334155;
  color: #f1f5f9;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .theme-toggle-btn:hover {
  border-color: #475569;
  color: #60a5fa;
}

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

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

/* 通用按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 42px;
  padding: 0 20px;
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--brand-cobalt);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--brand-cobalt-hover);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.btn-secondary {
  background-color: var(--bg-surface);
  border-color: var(--border-hairline);
  color: var(--text-primary);
}

.btn-secondary:hover {
  border-color: var(--border-focus);
  background-color: var(--bg-hover);
  color: var(--brand-cobalt);
}

.btn-sm {
  height: 36px;
  padding: 0 14px;
  font-size: 0.85rem;
}

/* ==========================================================================
   Hero 主视觉区 (Asymmetric Two-Column Layout)
   ========================================================================== */

.hero-section {
  padding: 80px 0 90px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 56px;
}

.hero-badge-row {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.live-indicator {
  width: 6px;
  height: 6px;
  background-color: var(--status-online);
  border-radius: 50%;
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.035em;
  color: var(--text-primary);
  margin-bottom: 20px;
}

.hero-title .brand-highlight {
  color: var(--brand-cobalt);
}

.hero-subtitle {
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 34px;
  max-width: 580px;
}

/* 输入框式快捷注册入口 (Clean input-style quick-start button) */
.quick-start-box {
  display: flex;
  align-items: center;
  max-width: 500px;
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: 8px;
  padding: 5px;
  box-shadow: var(--shadow-flat);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  margin-bottom: 36px;
}

.quick-start-box:focus-within {
  border-color: var(--brand-cobalt);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.quick-start-input {
  flex: 1;
  border: none;
  background: transparent;
  padding: 10px 14px;
  font-size: 0.92rem;
  color: var(--text-primary);
  outline: none;
}

.quick-start-input::placeholder {
  color: var(--text-dim);
}

.hero-meta-stats {
  display: flex;
  align-items: center;
  gap: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border-hairline);
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ==========================================================================
   右栏：实时节点监控卡片 (Interactive Server Status Table)
   ========================================================================== */

.server-status-card {
  background: var(--bg-card);
  border: 1px solid var(--border-hairline);
  border-radius: 12px;
  box-shadow: var(--shadow-floating);
  overflow: hidden;
  transition: border-color 0.25s ease;
}

.server-status-header {
  padding: 18px 22px;
  border-bottom: 1px solid var(--border-hairline);
  background: var(--bg-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.server-status-title {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.server-status-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--status-online);
  background: var(--status-online-bg);
  padding: 3px 8px;
  border-radius: 4px;
}

.server-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.server-table th {
  padding: 12px 20px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  border-bottom: 1px solid var(--border-hairline);
  background: var(--bg-surface);
}

.server-row {
  cursor: pointer;
  border-bottom: 1px solid var(--border-hairline);
  transition: background-color 0.15s ease;
}

.server-row:last-child {
  border-bottom: none;
}

.server-row:hover {
  background-color: var(--bg-hover);
}

.server-row td {
  padding: 14px 20px;
  font-size: 0.88rem;
  color: var(--text-primary);
}

.node-name-cell {
  font-weight: 600;
}

.node-route-cell {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.node-ping-cell {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--status-online);
}

.node-status-cell {
  text-align: right;
}

.status-pill {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 4px;
  background: var(--status-online-bg);
  color: var(--status-online);
}

/* 展开的 24h 稳定性微曲线 (Inline Sparkline Container) */
.sparkline-row {
  display: none;
  background-color: var(--bg-hover);
  border-bottom: 1px solid var(--border-hairline);
}

.sparkline-row.active {
  display: table-row;
}

.sparkline-container {
  padding: 12px 20px 16px;
}

.sparkline-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 6px;
  font-family: var(--font-mono);
}

.sparkline-svg {
  width: 100%;
  height: 38px;
  display: block;
}

.server-status-footer {
  padding: 12px 20px;
  background: var(--bg-subtle);
  border-top: 1px solid var(--border-hairline);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ==========================================================================
   通用 Section 标头与排版
   ========================================================================== */

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--brand-cobalt);
  letter-spacing: 0.06em;
  margin-bottom: 10px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Micro-Elevated Cards (微仰角卡片规范)
   Rest flat with 1px border; smoothly elevate by 4px on hover
   ========================================================================== */

.micro-card {
  background: var(--bg-card);
  border: 1px solid var(--border-hairline);
  border-radius: 8px;
  box-shadow: var(--shadow-flat);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.25s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.25s ease;
}

.micro-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-focus);
  box-shadow: var(--shadow-elevation);
}

/* 三大核心优势卡片 */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-box {
  padding: 34px 28px;
  display: flex;
  flex-direction: column;
}

.feature-index {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--brand-cobalt);
  margin-bottom: 18px;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.feature-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 24px;
  flex-grow: 1;
}

.feature-metrics-table {
  border-top: 1px solid var(--border-hairline);
  padding-top: 18px;
  width: 100%;
}

.metric-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.82rem;
  padding: 5px 0;
}

.metric-label {
  color: var(--text-muted);
}

.metric-value {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-primary);
}

/* ==========================================================================
   流媒体 & AI 模型支持专区 (数据指标卡片)
   ========================================================================== */

.ecosystem-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.showcase-block {
  padding: 36px 32px;
}

.showcase-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 14px;
}

.showcase-title {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-primary);
}

.showcase-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--brand-cobalt);
  background: var(--brand-cobalt-light);
  padding: 2px 8px;
  border-radius: 4px;
}

.showcase-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.6;
}

.data-specs-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  margin-bottom: 24px;
}

.data-specs-table th {
  text-align: left;
  padding: 8px 12px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 600;
}

.data-specs-table td {
  padding: 10px 12px;
  border: 1px solid var(--border-hairline);
  color: var(--text-primary);
}

.data-specs-table td.code-cell {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--brand-cobalt);
  font-weight: 600;
}

.notice-strip {
  padding: 12px 16px;
  border-radius: 6px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ==========================================================================
   价格表与 Spring-Physics 弹簧阻尼切换开关 (高紧凑度优化，确保首屏完整露出“立即购买”按钮)
   ========================================================================== */

#pricing {
  padding: 32px 0 48px;
  scroll-margin-top: calc(var(--header-height) + 6px);
}

#pricing .section-header {
  margin: 0 auto 16px;
  max-width: 620px;
}

#pricing .section-tag {
  margin-bottom: 4px;
}

#pricing .section-title {
  font-size: 1.85rem;
  margin-bottom: 6px;
}

#pricing .section-desc {
  font-size: 0.92rem;
}

.pricing-controls {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  margin-bottom: 22px;
}

.pricing-toggle-wrap {
  display: inline-flex;
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  border-radius: 8px;
  padding: 3px;
}

.pricing-toggle-btn {
  padding: 6px 18px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.pricing-toggle-btn.active {
  background: var(--bg-surface);
  color: var(--brand-cobalt);
  box-shadow: var(--shadow-flat);
}

.discount-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--brand-cobalt);
  padding: 1px 5px;
  border-radius: 4px;
  margin-left: 4px;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  align-items: stretch;
}

.pricing-card {
  padding: 24px 24px 20px;
  display: flex;
  flex-direction: column;
  position: relative;
}

.pricing-card.featured {
  border-color: var(--brand-cobalt);
  box-shadow: var(--shadow-elevation);
}

.pricing-tag-featured {
  position: absolute;
  top: 12px;
  right: 14px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--brand-cobalt);
  background: var(--brand-cobalt-light);
  border: 1px solid var(--border-hairline);
  padding: 1px 6px;
  border-radius: 4px;
}

.pricing-plan-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.pricing-plan-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  min-height: unset;
  margin-bottom: 14px;
  line-height: 1.45;
}

.pricing-figure {
  display: flex;
  align-items: baseline;
  gap: 3px;
  margin-bottom: 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-hairline);
}

.pricing-curr {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
}

/* Odometer-style number transition */
.pricing-num {
  font-family: var(--font-mono);
  font-size: 2.3rem;
  font-weight: 800;
  line-height: 1;
  color: var(--text-primary);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.2s ease;
}

.pricing-num.animating {
  transform: translateY(-8px);
  opacity: 0.4;
}

.pricing-cycle {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.pricing-checklist {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 7px;
  margin-bottom: 18px;
  flex-grow: 1;
}

.pricing-checklist li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.pricing-checklist li .spec-value {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-primary);
}

.pricing-card .btn {
  width: 100%;
  height: 40px;
  font-size: 0.92rem;
  font-weight: 700;
}

/* ==========================================================================
   用户口碑 (Testimonials)
   ========================================================================== */

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-box {
  padding: 30px 26px;
  display: flex;
  flex-direction: column;
}

.review-quote {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 24px;
  flex-grow: 1;
}

.review-profile {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-top: 1px solid var(--border-hairline);
  padding-top: 16px;
}

.reviewer-name {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-primary);
}

.reviewer-role {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ==========================================================================
   常见问题解答 (FAQ) - 原生 Details
   ========================================================================== */

.faq-stack {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-card {
  background: var(--bg-card);
  border: 1px solid var(--border-hairline);
  border-radius: 8px;
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-card[open] {
  border-color: var(--border-focus);
}

.faq-summary {
  padding: 18px 24px;
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

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

.faq-indicator {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--text-muted);
  transition: transform 0.2s ease, color 0.2s ease;
}

.faq-card[open] .faq-indicator {
  transform: rotate(45deg);
  color: var(--brand-cobalt);
}

.faq-body {
  padding: 0 24px 20px 24px;
  font-size: 0.94rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

/* ==========================================================================
   规范页脚 (Footer) - 严格只保留四个链接标题，均在新标签页中打开
   ========================================================================== */

.site-footer {
  margin-top: auto;
  background-color: var(--bg-subtle);
  border-top: 1px solid var(--border-hairline);
  padding: 56px 0 40px;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 48px;
  list-style: none;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-link {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: 4px;
  transition: color 0.18s ease;
}

.footer-link:hover {
  color: var(--brand-cobalt);
}

.footer-bottom {
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-muted);
  padding-top: 24px;
  border-top: 1px solid var(--border-hairline);
  max-width: 640px;
  margin: 0 auto;
}

/* ==========================================================================
   独立子页面通用排版规范 (about, terms, privacy, sitemap, insights)
   ========================================================================== */

.page-hero {
  padding: 64px 0 44px;
  text-align: center;
  background: var(--bg-subtle);
  border-bottom: 1px solid var(--border-hairline);
  margin-bottom: 56px;
}

.page-title {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.page-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto;
}

.content-box {
  max-width: 860px;
  margin: 0 auto 80px;
  background: var(--bg-card);
  border: 1px solid var(--border-hairline);
  border-radius: 8px;
  padding: 48px;
  box-shadow: var(--shadow-flat);
}

.prose h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin: 36px 0 14px;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-hairline);
  padding-bottom: 8px;
}

.prose h2:first-child {
  margin-top: 0;
}

.prose p {
  font-size: 0.96rem;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 18px;
}

.prose ul, .prose ol {
  margin: 0 0 24px 20px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.prose li {
  margin-bottom: 8px;
}

.callout-box {
  padding: 18px 22px;
  border-radius: 6px;
  margin: 22px 0;
  border: 1px solid var(--border-hairline);
  background: var(--bg-subtle);
  font-size: 0.92rem;
  line-height: 1.7;
}

.callout-box.highlight {
  border-color: var(--brand-cobalt);
  background: var(--brand-cobalt-light);
}

.callout-box.alert {
  border-color: #ef4444;
  background: rgba(239, 68, 68, 0.06);
}

/* 资讯列表卡片 */
.article-card {
  padding: 26px 28px;
  border-bottom: 1px solid var(--border-hairline);
}

.article-card:last-child {
  border-bottom: none;
}

.article-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--brand-cobalt);
  margin-bottom: 8px;
}

.article-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.article-excerpt {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 14px;
}

.read-more-link {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--brand-cobalt);
}

/* ==========================================================================
   长篇深度 SEO 文章专属排版系统 (Breadcrumbs, TOC, FAQ, Related)
   ========================================================================== */

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.84rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

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

.breadcrumbs a:hover {
  color: var(--brand-cobalt);
}

.article-header {
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border-hairline);
  padding-bottom: 24px;
}

.article-header-title {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.25;
  color: var(--text-primary);
  margin-bottom: 14px;
}

.article-header-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.article-header-meta span {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 目录盒子 (Table of Contents) */
.article-toc {
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  border-radius: 8px;
  padding: 20px 24px;
  margin: 28px 0 36px;
}

.article-toc-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.article-toc ol {
  margin: 0;
  padding-left: 20px;
  list-style-type: decimal;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.92rem;
}

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

.article-toc a:hover {
  color: var(--brand-cobalt);
  text-decoration: underline;
}

/* 文章正文增强 */
.article-prose {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.article-prose h2 {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-primary);
  margin: 42px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-hairline);
}

.article-prose h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 26px 0 12px;
}

.article-prose p {
  margin-bottom: 18px;
}

.article-prose strong {
  color: var(--text-primary);
}

.article-prose code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--brand-cobalt);
}

.article-prose pre {
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  border-radius: 6px;
  padding: 16px 20px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.6;
  margin: 20px 0;
  color: var(--text-primary);
}

.article-prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 0.9rem;
}

.article-prose th {
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  padding: 10px 14px;
  font-weight: 700;
  color: var(--text-primary);
  text-align: left;
}

.article-prose td {
  border: 1px solid var(--border-hairline);
  padding: 10px 14px;
  color: var(--text-secondary);
}

/* FAQ 模块 */
.article-faq-section {
  margin: 48px 0 36px;
  padding-top: 32px;
  border-top: 1px solid var(--border-hairline);
}

.article-faq-section h2 {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 20px;
  color: var(--text-primary);
}

/* 相关阅读模块 */
.article-related-section {
  margin: 48px 0 20px;
  padding-top: 32px;
  border-top: 1px solid var(--border-hairline);
}

.article-related-section h2 {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.related-card {
  padding: 18px 20px;
  border: 1px solid var(--border-hairline);
  border-radius: 6px;
  background: var(--bg-surface);
  transition: all 0.2s ease;
}

.related-card:hover {
  border-color: var(--brand-cobalt);
  transform: translateY(-2px);
  box-shadow: var(--shadow-elevation);
}

.related-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
  line-height: 1.4;
}

.related-card p {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin: 0;
}

/* 文章正文内链高亮 */
.internal-link {
  color: var(--brand-cobalt);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.internal-link:hover {
  color: var(--brand-cobalt-hover);
}

/* ==========================================================================
   移动端响应式断点 (@media 媒体查询)
   ========================================================================== */

@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  .grid-3 {
    grid-template-columns: 1fr;
  }
  .ecosystem-grid {
    grid-template-columns: 1fr;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 500px;
    margin: 0 auto;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .hero-section {
    padding: 50px 0 60px;
  }
  .hero-title {
    font-size: 2.2rem;
  }
  .nav-menu {
    display: none;
  }
  .hero-meta-stats {
    flex-wrap: wrap;
    gap: 20px;
  }
  .quick-start-box {
    flex-direction: column;
    padding: 8px;
    gap: 8px;
  }
  .quick-start-box .btn {
    width: 100%;
  }
  .content-box {
    padding: 28px 20px;
  }
  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }
}