/* =========================================================
   夜语AI · 全站共享样式
   配色：浅色底 + 靛紫高光（Indigo），柔和阴影，圆角卡片
   ========================================================= */

/* ---------- CSS 变量 ---------- */
:root {
  /* 品牌主色 */
  --color-primary: #6366F1;
  --color-primary-light: #818CF8;
  --color-primary-lighter: #A5B4FC;
  --color-primary-dark: #4F46E5;
  --color-accent: #8B5CF6;
  --color-accent-soft: #A78BFA;
  --color-violet-text: #7C3AED;

  /* 提示色 */
  --color-tag-bg: #DCE7FB;
  --color-tag-text: #3B82F6;
  --color-heart: #EF4444;
  --color-fire: #F97316;
  --color-success: #10B981;
  --color-warning: #F59E0B;

  /* 背景层 */
  --bg-page: #F4F5F7;
  --bg-card: #FFFFFF;
  --bg-input: #F1F5F9;
  --bg-soft: #F8FAFC;

  /* 文本 */
  --text-primary: #0F172A;
  --text-secondary: #64748B;
  --text-tertiary: #94A3B8;
  --text-on-primary: #FFFFFF;

  /* 描边 */
  --border-color: #E2E8F0;
  --border-strong: #CBD5E1;

  /* 阴影 */
  --shadow-card: 0 1px 3px rgba(15, 23, 42, .05);
  --shadow-hover: 0 8px 24px rgba(99, 102, 241, .12);
  --shadow-button: 0 8px 24px rgba(99, 102, 241, .35);
  --shadow-lg: 0 20px 48px rgba(15, 23, 42, .08);

  /* 圆角 */
  --radius-card: 16px;
  --radius-card-sm: 12px;
  --radius-pill: 9999px;
  --radius-btn: 12px;

  /* 渐变 */
  --gradient-primary: linear-gradient(135deg, #6366F1, #8B5CF6);
  --gradient-soft: linear-gradient(135deg, #EEF2FF, #F5F3FF);
  --gradient-hero: linear-gradient(135deg, #EEF2FF 0%, #F5F3FF 50%, #FCE7F3 100%);

  /* 容器 */
  --container-max: 1200px;
  --container-padding: 24px;

  /* 动画 */
  --transition-fast: .2s ease;
  --transition-base: .3s ease;
  --transition-slow: .5s ease;
}

/* 深色模式 */
[data-theme="dark"] {
  --bg-page: #0F172A;
  --bg-card: #1E293B;
  --bg-input: #334155;
  --bg-soft: #1E293B;

  --text-primary: #F1F5F9;
  --text-secondary: #CBD5E1;
  --text-tertiary: #94A3B8;

  --border-color: #334155;
  --border-strong: #475569;

  --color-tag-bg: #312E81;
  --color-tag-text: #A5B4FC;

  --shadow-card: 0 1px 3px rgba(0, 0, 0, .3);
  --shadow-hover: 0 8px 24px rgba(99, 102, 241, .25);
  --shadow-lg: 0 20px 48px rgba(0, 0, 0, .4);

  --gradient-soft: linear-gradient(135deg, #1E1B4B, #312E81);
  --gradient-hero: linear-gradient(135deg, #1E1B4B 0%, #312E81 50%, #4C1D95 100%);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-page);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-base), color var(--transition-base);
}

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

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul,
ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  color: var(--text-primary);
  font-weight: 700;
}

/* ---------- 通用容器 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

.section {
  padding: 80px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 12px;
  font-size: clamp(28px, 4vw, 40px);
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 56px;
  font-size: 16px;
}

.section-title .accent {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  padding: 0 4px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-btn);
  cursor: pointer;
  transition: all var(--transition-base);
  white-space: nowrap;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--gradient-primary);
  color: #fff;
  box-shadow: 0 4px 12px rgba(99, 102, 241, .25);
}

.btn-primary:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-button);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--color-primary);
  border-color: var(--color-primary-lighter);
}

.btn-secondary:hover {
  background: var(--color-tag-bg);
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
  transform: translateY(-2px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-primary);
  padding: 8px 16px;
}

.btn-ghost:hover {
  color: var(--color-primary);
  background: var(--bg-input);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 16px;
}

/* ---------- 头部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, .85);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-base);
}

[data-theme="dark"] .site-header {
  background: rgba(15, 23, 42, .85);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  color: var(--text-primary);
  flex-shrink: 0;
}

.logo:hover {
  color: var(--color-primary);
}

.logo img {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

.logo .logo-text .accent {
  color: var(--color-primary);
}

/* 主菜单 */
.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
  justify-content: center;
}

.main-nav a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 15px;
  transition: all var(--transition-fast);
}

.main-nav a:hover {
  color: var(--color-primary);
  background: var(--bg-input);
}

.main-nav a i {
  font-size: 14px;
}

/* 右侧操作 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.theme-toggle,
.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  background: var(--bg-input);
  transition: all var(--transition-fast);
}

.theme-toggle:hover,
.menu-toggle:hover {
  color: var(--color-primary);
  background: var(--color-tag-bg);
}

.menu-toggle {
  display: none;
}

/* 语言切换 */
.lang-switcher {
  position: relative;
}

.lang-trigger {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  background: var(--bg-input);
  font-weight: 500;
  font-size: 14px;
  transition: all var(--transition-fast);
}

.lang-trigger:hover {
  color: var(--color-primary);
  background: var(--color-tag-bg);
}

.lang-trigger i.fa-chevron-down {
  font-size: 11px;
  transition: transform var(--transition-fast);
}

.lang-switcher.open .lang-trigger i.fa-chevron-down {
  transform: rotate(180deg);
}

.lang-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  min-width: 180px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-card-sm);
  box-shadow: var(--shadow-lg);
  padding: 6px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: all var(--transition-fast);
  z-index: 200;
}

.lang-switcher.open .lang-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-menu a {
  display: block;
  padding: 9px 12px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.lang-menu a:hover {
  background: var(--bg-input);
  color: var(--color-primary);
}

.lang-menu a.active {
  background: var(--color-tag-bg);
  color: var(--color-primary);
  font-weight: 600;
}

/* ---------- Hero 区（单列居中版） ---------- */
.hero {
  position: relative;
  padding: 72px 0 80px;
  background: var(--gradient-hero);
  overflow: hidden;
  text-align: center;
}

.hero::before,
.hero::after {
  content: '';
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: .5;
  pointer-events: none;
  z-index: 1;
}

.hero::before {
  width: 460px;
  height: 460px;
  background: rgba(165, 180, 252, .55);
  top: -160px;
  left: 50%;
  transform: translateX(-90%);
}

.hero::after {
  width: 520px;
  height: 520px;
  background: rgba(196, 181, 253, .45);
  bottom: -200px;
  right: 50%;
  transform: translateX(80%);
}

.hero-inner {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 840px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  border-radius: var(--radius-pill);
  background: rgba(99, 102, 241, .12);
  color: var(--color-primary-dark);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 20px;
  border: 1px solid rgba(99, 102, 241, .15);
  backdrop-filter: blur(6px);
}

.hero-badge .pulse {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-primary);
  position: relative;
}

.hero-badge .pulse::after {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: 50%;
  background: var(--color-primary);
  opacity: .35;
  animation: heroPulse 2s ease-out infinite;
}

@keyframes heroPulse {
  0% { transform: scale(.6); opacity: .55; }
  100% { transform: scale(1.8); opacity: 0; }
}

[data-theme="dark"] .hero-badge {
  background: rgba(99, 102, 241, .25);
  color: var(--color-primary-lighter);
  border-color: rgba(165, 180, 252, .25);
}

.hero-title {
  font-size: clamp(32px, 5.2vw, 56px);
  line-height: 1.12;
  margin-bottom: 18px;
  letter-spacing: -.02em;
  max-width: 800px;
}

.hero-title .accent {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  padding: 0 6px;
}

.hero-subtitle {
  font-size: clamp(15px, 1.5vw, 18px);
  color: var(--text-secondary);
  margin: 0 auto 28px;
  line-height: 1.65;
  max-width: 640px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  margin-bottom: 24px;
}

.hero-actions .btn-lg {
  padding: 14px 32px;
  font-size: 15px;
}

.hero-trust {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--text-secondary);
}

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

.hero-trust .trust-item i {
  color: var(--color-primary);
  font-size: 13px;
}

/* Hero mini-stats 数据横条 */
.hero-mini-stats {
  margin-top: 40px;
  padding-top: 32px;
  border-top: 1px solid rgba(99, 102, 241, .15);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  width: 100%;
  max-width: 720px;
}

[data-theme="dark"] .hero-mini-stats {
  border-top-color: rgba(165, 180, 252, .2);
}

.hero-mini-stat-num {
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.1;
  letter-spacing: -.02em;
}

.hero-mini-stat-label {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ---------- 通用卡片 ---------- */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-card);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-card);
  transition: all var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--color-primary-lighter);
}

/* ---------- 特色 Features ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  padding: 32px 28px;
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  color: #fff;
  background: var(--gradient-primary);
  margin-bottom: 20px;
  box-shadow: 0 6px 16px rgba(99, 102, 241, .2);
}

.feature-card:nth-child(2) .feature-icon { background: linear-gradient(135deg, #F472B6, #A855F7); }
.feature-card:nth-child(3) .feature-icon { background: linear-gradient(135deg, #34D399, #6366F1); }
.feature-card:nth-child(4) .feature-icon { background: linear-gradient(135deg, #FB923C, #EF4444); }
.feature-card:nth-child(5) .feature-icon { background: linear-gradient(135deg, #38BDF8, #6366F1); }
.feature-card:nth-child(6) .feature-icon { background: linear-gradient(135deg, #FBBF24, #F472B6); }

.feature-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.7;
}

/* ---------- Rankings 榜单 ---------- */
.rankings-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
}

.rankings-tab {
  padding: 10px 22px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-pill);
  transition: all var(--transition-fast);
}

.rankings-tab:hover {
  color: var(--color-primary);
  border-color: var(--color-primary-lighter);
}

.rankings-tab.active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
  box-shadow: 0 4px 10px rgba(99, 102, 241, .25);
}

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

.ranking-card {
  padding: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.ranking-cover {
  position: relative;
  height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 56px;
  color: #fff;
  background: var(--gradient-primary);
}

.ranking-card:nth-child(2) .ranking-cover { background: linear-gradient(135deg, #F472B6, #A855F7); }
.ranking-card:nth-child(3) .ranking-cover { background: linear-gradient(135deg, #34D399, #6366F1); }
.ranking-card:nth-child(4) .ranking-cover { background: linear-gradient(135deg, #FB923C, #EF4444); }
.ranking-card:nth-child(5) .ranking-cover { background: linear-gradient(135deg, #38BDF8, #6366F1); }
.ranking-card:nth-child(6) .ranking-cover { background: linear-gradient(135deg, #FBBF24, #EC4899); }

.ranking-rank {
  position: absolute;
  top: 12px;
  left: 12px;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: rgba(255, 255, 255, .85);
  color: var(--color-primary-dark);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 800;
  backdrop-filter: blur(6px);
}

.ranking-rank.top {
  background: linear-gradient(135deg, #FBBF24, #F59E0B);
  color: #fff;
}

.ranking-tags {
  position: absolute;
  top: 12px;
  right: 12px;
  display: flex;
  gap: 6px;
}

.ranking-tags .tag {
  padding: 4px 10px;
  font-size: 11px;
  font-weight: 600;
  background: rgba(255, 255, 255, .85);
  color: var(--color-primary-dark);
  border-radius: var(--radius-pill);
  backdrop-filter: blur(6px);
}

.ranking-body {
  padding: 18px 20px 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.ranking-body h4 {
  font-size: 17px;
  margin: 0;
}

.ranking-body p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.ranking-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 4px;
  font-size: 13px;
  color: var(--text-tertiary);
}

.ranking-meta .heat {
  color: var(--color-fire);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.ranking-meta .heart {
  color: var(--color-heart);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* ---------- Categories 分区 ---------- */
.categories-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.category-card {
  padding: 28px 22px;
  text-align: center;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-soft);
  opacity: 0;
  transition: opacity var(--transition-base);
  z-index: 0;
}

.category-card:hover::before {
  opacity: 1;
}

.category-card > * {
  position: relative;
  z-index: 1;
}

.category-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-pill);
  background: var(--color-tag-bg);
  color: var(--color-primary-dark);
  margin: 0 auto 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  transition: all var(--transition-base);
}

.category-card:hover .category-icon {
  background: var(--gradient-primary);
  color: #fff;
  transform: scale(1.05);
}

.category-card h4 {
  font-size: 16px;
  margin-bottom: 4px;
}

.category-card span {
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ---------- Scenes 使用场景 ---------- */
.scenes-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.scene-card {
  padding: 36px 32px;
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.scene-icon {
  flex-shrink: 0;
  width: 64px;
  height: 64px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  color: #fff;
  background: var(--gradient-primary);
}

.scene-card:nth-child(2) .scene-icon { background: linear-gradient(135deg, #F472B6, #A855F7); }
.scene-card:nth-child(3) .scene-icon { background: linear-gradient(135deg, #34D399, #6366F1); }
.scene-card:nth-child(4) .scene-icon { background: linear-gradient(135deg, #38BDF8, #A855F7); }

.scene-card h3 {
  font-size: 19px;
  margin-bottom: 8px;
}

.scene-card p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 12px;
}

.scene-card .scene-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.scene-tags .tag {
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  font-size: 12px;
  font-weight: 500;
}

/* ---------- Stats 平台数据 ---------- */
.stats-section {
  background: var(--gradient-soft);
}

[data-theme="dark"] .stats-section {
  background: var(--bg-soft);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.stat-card {
  text-align: center;
  padding: 36px 20px;
  background: var(--bg-card);
  border-radius: var(--radius-card);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-card);
}

.stat-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-pill);
  background: var(--color-tag-bg);
  color: var(--color-primary-dark);
  margin: 0 auto 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
}

.stat-number {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.1;
  margin-bottom: 4px;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 14px;
}

/* ---------- Testimonials 用户评价 ---------- */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.testimonial-rating {
  color: var(--color-warning);
  font-size: 15px;
  letter-spacing: 2px;
}

.testimonial-quote {
  color: var(--text-primary);
  font-size: 15px;
  line-height: 1.75;
  flex: 1;
  font-style: italic;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.testimonial-avatar {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-pill);
  background: var(--gradient-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
}

.testimonial-card:nth-child(2) .testimonial-avatar { background: linear-gradient(135deg, #F472B6, #A855F7); }
.testimonial-card:nth-child(3) .testimonial-avatar { background: linear-gradient(135deg, #34D399, #6366F1); }
.testimonial-card:nth-child(4) .testimonial-avatar { background: linear-gradient(135deg, #FB923C, #EC4899); }

.testimonial-author-info h5 {
  font-size: 14px;
  margin: 0 0 2px;
}

.testimonial-author-info span {
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ---------- FAQ ---------- */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius-card-sm);
  border: 1px solid var(--border-color);
  overflow: hidden;
  transition: all var(--transition-base);
}

.faq-item:hover {
  border-color: var(--color-primary-lighter);
}

.faq-question {
  width: 100%;
  padding: 22px 26px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  text-align: left;
  background: transparent;
  transition: color var(--transition-fast);
}

.faq-question:hover {
  color: var(--color-primary);
}

.faq-question .faq-icon {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  background: var(--color-tag-bg);
  color: var(--color-primary-dark);
  font-size: 12px;
  transition: transform var(--transition-base);
}

.faq-item.open .faq-question .faq-icon {
  transform: rotate(180deg);
  background: var(--color-primary);
  color: #fff;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
}

.faq-item.open .faq-answer {
  max-height: 400px;
}

.faq-answer-inner {
  padding: 0 26px 22px;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.75;
}

/* ---------- CTA 区 ---------- */
.cta-section {
  position: relative;
  padding: 90px 0;
  overflow: hidden;
  background: var(--gradient-primary);
  color: #fff;
}

.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(255, 255, 255, .25), transparent 40%),
    radial-gradient(circle at 80% 80%, rgba(255, 255, 255, .15), transparent 40%);
  pointer-events: none;
}

.cta-inner {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 720px;
  margin: 0 auto;
}

.cta-inner h2 {
  color: #fff;
  font-size: clamp(28px, 4vw, 42px);
  margin-bottom: 16px;
}

.cta-inner p {
  color: rgba(255, 255, 255, .9);
  font-size: 17px;
  margin-bottom: 32px;
}

.cta-inner .btn-primary {
  background: #fff;
  color: var(--color-primary-dark);
  font-weight: 700;
}

.cta-inner .btn-primary:hover {
  background: #fff;
  color: var(--color-primary-dark);
  box-shadow: 0 12px 28px rgba(0, 0, 0, .2);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border-color);
  padding-top: 64px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand .logo {
  margin-bottom: 16px;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: 18px;
  max-width: 320px;
}

.footer-social {
  display: flex;
  gap: 10px;
}

.footer-social a {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-pill);
  background: var(--bg-input);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  background: var(--gradient-primary);
  color: #fff;
  transform: translateY(-2px);
}

.footer-col h5 {
  font-size: 15px;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col a {
  color: var(--text-secondary);
  font-size: 14px;
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-primary);
}

.footer-bottom {
  padding: 24px 0;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--text-tertiary);
}

.footer-bottom-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

/* ---------- 返回顶部按钮 ---------- */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-pill);
  background: var(--gradient-primary);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-button);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition-base);
  z-index: 90;
  cursor: pointer;
}

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

.back-to-top:hover {
  transform: translateY(-4px);
}

/* ---------- 移动端响应 ---------- */
@media (max-width: 1024px) {
  .features-grid,
  .rankings-grid,
  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .categories-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .hero-mini-stats {
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
  }
}

@media (max-width: 768px) {
  .section {
    padding: 60px 0;
  }

  /* ---- 移动端头部修复 ---- */
  .header-inner {
    height: 60px;
    gap: 8px;
    flex-wrap: nowrap;
    min-width: 0;
  }

  .logo {
    font-size: 17px;
    gap: 8px;
    flex-shrink: 1;
    min-width: 0;
  }

  .logo img {
    width: 30px;
    height: 30px;
  }

  .header-actions {
    gap: 6px;
    flex-shrink: 0;
  }

  /* 顶部 CTA 按钮在移动端隐藏，避免挤占空间；
     用户可通过 Hero 区与 CTA 区的大按钮进入 */
  .header-actions > .btn-primary {
    display: none;
  }

  .lang-trigger {
    padding: 7px 10px;
  }

  .theme-toggle,
  .menu-toggle {
    width: 36px;
    height: 36px;
  }

  /* 移动菜单 */
  .menu-toggle {
    display: inline-flex;
  }

  .main-nav {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    padding: 12px;
    box-shadow: var(--shadow-card);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    max-height: calc(100vh - 60px);
    overflow-y: auto;
  }

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

  .main-nav a {
    padding: 12px 16px;
    border-radius: 10px;
    width: 100%;
  }

  .features-grid,
  .rankings-grid,
  .scenes-grid,
  .testimonials-grid,
  .categories-grid,
  .stats-grid {
    grid-template-columns: 1fr;
  }

  .categories-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .hero {
    padding: 48px 0 56px;
  }

  .hero-badge {
    font-size: 12px;
    padding: 5px 12px;
    margin-bottom: 16px;
  }

  .hero-mini-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 32px;
    padding-top: 24px;
  }

  .hero-trust {
    gap: 14px;
    font-size: 12px;
  }

  .scene-card {
    flex-direction: column;
    gap: 16px;
    padding: 28px 24px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .lang-trigger span.lang-text {
    display: none;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn {
    width: 100%;
  }

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

  /* 超小屏：进一步收紧头部 */
  .header-inner {
    gap: 6px;
  }

  .logo {
    font-size: 16px;
    gap: 6px;
  }

  .logo img {
    width: 28px;
    height: 28px;
  }

  .header-actions {
    gap: 4px;
  }

  .lang-trigger {
    padding: 6px 8px;
    font-size: 13px;
  }

  .theme-toggle,
  .menu-toggle {
    width: 34px;
    height: 34px;
    font-size: 14px;
  }
}


/* =========================================================
   内页通用样式（FAQ / 用户手册 / 法律 / 支持 / 反馈）
   ========================================================= */

/* ---------- 内页 Hero（紧凑型） ---------- */
.page-hero {
  position: relative;
  padding: 110px 0 56px;
  background: var(--gradient-hero);
  text-align: center;
  overflow: hidden;
}

[data-theme="dark"] .page-hero {
  background: linear-gradient(135deg,
              rgba(99, 102, 241, .12) 0%,
              rgba(139, 92, 246, .10) 50%,
              rgba(236, 72, 153, .06) 100%);
}

.page-hero::before,
.page-hero::after {
  content: "";
  position: absolute;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  filter: blur(80px);
  opacity: .4;
  pointer-events: none;
}

.page-hero::before {
  top: -120px;
  left: -80px;
  background: radial-gradient(circle, var(--color-primary), transparent 65%);
}

.page-hero::after {
  bottom: -160px;
  right: -80px;
  background: radial-gradient(circle, var(--color-accent), transparent 65%);
}

.page-hero-inner {
  position: relative;
  z-index: 1;
  max-width: 820px;
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.page-hero .hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(255, 255, 255, .85);
  border: 1px solid rgba(99, 102, 241, .25);
  border-radius: var(--radius-pill);
  font-size: 13px;
  color: var(--color-primary-dark);
  font-weight: 600;
  backdrop-filter: blur(10px);
  margin-bottom: 16px;
}

[data-theme="dark"] .page-hero .hero-badge {
  background: rgba(30, 41, 59, .8);
  color: var(--color-primary-lighter);
}

.page-hero h1 {
  font-size: clamp(28px, 4vw, 40px);
  margin: 0 0 14px;
  line-height: 1.2;
  font-weight: 800;
}

.page-hero h1 .accent {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.page-hero p {
  font-size: clamp(15px, 1.4vw, 17px);
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto 8px;
  line-height: 1.7;
}

.page-hero .breadcrumb {
  margin-top: 18px;
  font-size: 13px;
  color: var(--text-tertiary);
}

.page-hero .breadcrumb a {
  color: var(--color-primary-dark);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.page-hero .breadcrumb a:hover {
  color: var(--color-accent);
}

.page-hero .breadcrumb .sep {
  margin: 0 8px;
  opacity: .5;
}

/* ---------- 内页主体两栏（目录 + 内容） ---------- */
.page-section {
  padding: 64px 0 80px;
}

.page-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 40px;
  align-items: start;
}

/* 目录（左侧吸顶） */
.page-toc {
  position: sticky;
  top: 96px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-card);
  padding: 20px;
  box-shadow: var(--shadow-card);
  max-height: calc(100vh - 120px);
  overflow-y: auto;
}

.page-toc h4 {
  font-size: 14px;
  font-weight: 700;
  margin: 0 0 12px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-toc h4 i {
  color: var(--color-primary);
}

.page-toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.page-toc li + li {
  margin-top: 4px;
}

.page-toc a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  border-left: 2px solid transparent;
  border-radius: 0 6px 6px 0;
  transition: all var(--transition-fast);
}

.page-toc a:hover,
.page-toc a.active {
  color: var(--color-primary-dark);
  background: rgba(99, 102, 241, .08);
  border-left-color: var(--color-primary);
}

/* 内容区 */
.page-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-card);
  padding: 40px 44px;
  box-shadow: var(--shadow-card);
}

.page-content article + article {
  margin-top: 40px;
  padding-top: 36px;
  border-top: 1px solid var(--border-color);
}

.page-content h2 {
  font-size: clamp(20px, 2vw, 24px);
  font-weight: 700;
  margin: 0 0 16px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
  scroll-margin-top: 96px;
}

.page-content h2 i {
  color: var(--color-primary);
}

.page-content h3 {
  font-size: 17px;
  font-weight: 600;
  margin: 24px 0 10px;
  color: var(--text-primary);
}

.page-content p {
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-secondary);
  margin: 0 0 14px;
}

.page-content strong {
  color: var(--text-primary);
  font-weight: 600;
}

.page-content ul,
.page-content ol {
  padding-left: 22px;
  margin: 0 0 16px;
}

.page-content li {
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.page-content li::marker {
  color: var(--color-primary);
}

.page-content a {
  color: var(--color-primary-dark);
  text-decoration: none;
  border-bottom: 1px dashed var(--color-primary-lighter);
  transition: color var(--transition-fast);
}

.page-content a:hover {
  color: var(--color-accent);
}

.page-content .last-updated {
  display: inline-block;
  padding: 4px 12px;
  background: var(--bg-input);
  border-radius: var(--radius-pill);
  font-size: 13px;
  color: var(--text-secondary);
  margin: 0 0 28px;
}

.page-content .callout {
  display: flex;
  gap: 12px;
  padding: 16px 18px;
  background: rgba(99, 102, 241, .08);
  border-left: 3px solid var(--color-primary);
  border-radius: 0 var(--radius-card-sm) var(--radius-card-sm) 0;
  margin: 16px 0;
}

.page-content .callout i {
  color: var(--color-primary);
  font-size: 18px;
  flex-shrink: 0;
  margin-top: 2px;
}

.page-content .callout p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-secondary);
}

/* ---------- FAQ 内页（分组 + 复用 .faq-item） ---------- */
.faq-group {
  margin-bottom: 32px;
}

.faq-group-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
}

.faq-group-title i {
  color: var(--color-primary);
}

/* ---------- 技术支持卡片 ---------- */
.support-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin: 24px 0;
}

.support-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  padding: 24px;
  background: var(--bg-soft);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-card);
  transition: all var(--transition-base);
}

.support-card:hover {
  transform: translateY(-3px);
  border-color: var(--color-primary-lighter);
  box-shadow: var(--shadow-hover);
}

.support-card .support-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  color: var(--text-on-primary);
  border-radius: var(--radius-card-sm);
  font-size: 18px;
}

.support-card h4 {
  font-size: 16px;
  font-weight: 700;
  margin: 0;
  color: var(--text-primary);
}

.support-card p {
  font-size: 13px;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.6;
}

.support-card .support-value {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary-dark);
  word-break: break-all;
  border-bottom: 0;
}

/* ---------- 反馈表单 ---------- */
.feedback-form {
  display: grid;
  gap: 18px;
  margin-top: 16px;
}

.feedback-form .form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.feedback-form label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.feedback-form input,
.feedback-form select,
.feedback-form textarea {
  width: 100%;
  padding: 12px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-card-sm);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 14px;
  transition: all var(--transition-fast);
}

.feedback-form input:focus,
.feedback-form select:focus,
.feedback-form textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  background: var(--bg-card);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, .15);
}

.feedback-form textarea {
  min-height: 140px;
  resize: vertical;
  line-height: 1.6;
}

.feedback-form .form-actions {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}

.feedback-form .form-hint {
  font-size: 13px;
  color: var(--text-tertiary);
}

/* ---------- 页脚新增的"法律信息"列已被原 .footer-col 复用，无需新增样式 ---------- */

/* ---------- 内页响应式 ---------- */
@media (max-width: 960px) {
  .page-layout {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .page-toc {
    position: static;
    max-height: none;
  }

  .page-content {
    padding: 28px 22px;
  }
}

@media (max-width: 768px) {
  .page-hero {
    padding: 90px 0 40px;
  }

  .feedback-form .form-row {
    grid-template-columns: 1fr;
  }

  .page-content {
    padding: 24px 18px;
  }

  .page-content h2 {
    font-size: 19px;
  }
}