:root {
      --primary: #1D4ED8;
      --primary-light: #3B82F6;
      --accent: #F97316;
      --accent-hover: #EA580C;
      --bg-dark: #0F172A;
      --bg-white: #FFFFFF;
      --bg-gray: #F8FAFC;
      --text-dark: #1E293B;
      --text-gray: #64748B;
      --text-light: #F8FAFC;
      --success: #10B981;
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      
      /* 新增的变量：用于统一控制背景和边框，便于切换暗黑模式 */
      --header-bg: rgba(255, 255, 255, 0.95);
      --hero-bg: linear-gradient(180deg, #EFF6FF 0%, #FFFFFF 100%);
      --card-bg: #FFFFFF;
      --border-color: #E2E8F0;
    }

    :root[data-theme="dark"] {
      /* 在暗色模式下反转颜色 */
      --bg-white: #0F172A;
      --bg-gray: #1E293B;
      --bg-dark: #020617; /* 原本深的背景变更深 */
      --text-dark: #F8FAFC;
      --text-gray: #94A3B8;
      --header-bg: rgba(15, 23, 42, 0.95);
      --hero-bg: linear-gradient(180deg, #1E293B 0%, #0F172A 100%);
      --card-bg: #1E293B;
      --border-color: #334155;
      --primary: #60A5FA; /* 蓝色在暗色背景下调亮一些以保持对比度 */
    }

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

    body {
      font-family: 'Inter', 'Noto Sans SC', sans-serif;
      color: var(--text-dark);
      background-color: var(--bg-white);
      line-height: 1.6;
      overflow-x: hidden;
      transition: background-color 0.3s ease, color 0.3s ease;
    }

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

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 工具类 */
    .text-accent {
      color: var(--accent);
    }

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

    .badge {
      background: rgba(249, 115, 22, 0.1);
      color: var(--accent);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 14px;
      font-weight: 700;
      display: inline-block;
      margin-bottom: 16px;
    }

    /* 辅助功能与SEO优化类 (对视觉隐藏，对爬虫可见) */
    .sr-only {
      position: absolute;
      width: 1px;
      height: 1px;
      padding: 0;
      margin: -1px;
      overflow: hidden;
      clip: rect(0, 0, 0, 0);
      white-space: nowrap;
      border-width: 0;
    }

    /* 导航 */
    header {
      position: fixed;
      top: 0;
      width: 100%;
      z-index: 100;
      background: var(--header-bg);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 10px rgba(0, 0, 0, 0.05);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 70px;
    }

    .logo {
      font-size: 22px;
      font-weight: 800;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .btn-cta {
      background: var(--accent);
      color: white;
      padding: 12px 28px;
      border-radius: 8px;
      font-weight: 700;
      font-size: 16px;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      box-shadow: 0 4px 15px rgba(249, 115, 22, 0.3);
    }

    .theme-toggle {
      background: transparent;
      border: none;
      color: var(--text-dark);
      font-size: 22px;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      width: 40px;
      height: 40px;
      border-radius: 50%;
      transition: var(--transition);
    }

    .theme-toggle:hover {
      background: rgba(100, 116, 139, 0.1);
    }

    .btn-cta:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 25px rgba(249, 115, 22, 0.4);
    }

    .pulse {
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0% {
        box-shadow: 0 0 0 0 rgba(249, 115, 22, 0.4);
      }

      70% {
        box-shadow: 0 0 0 10px rgba(249, 115, 22, 0);
      }

      100% {
        box-shadow: 0 0 0 0 rgba(249, 115, 22, 0);
      }
    }

    /* Hero 首屏 (痛点解决) */
    .hero {
      padding: 140px 0 80px;
      background: var(--hero-bg);
      position: relative;
    }

    .hero-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: 52px;
      font-weight: 900;
      line-height: 1.2;
      margin-bottom: 24px;
      color: var(--bg-dark);
    }

    .hero-content p {
      font-size: 20px;
      color: var(--text-gray);
      margin-bottom: 32px;
      font-weight: 500;
    }

    .hero-proof {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 30px;
      font-size: 14px;
      color: var(--text-gray);
      font-weight: 600;
    }

    .avatars {
      display: flex;
    }

    .avatars img {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      border: 2px solid white;
      margin-left: -10px;
      object-fit: cover;
    }

    .avatars img:first-child {
      margin-left: 0;
    }

    .hero-image-wrapper {
      position: relative;
      text-align: center;
    }

    .hero-image-wrapper img {
      width: 100%;
      max-width: 600px;
      animation: float 6s ease-in-out infinite;
    }

    .price-tag {
      position: absolute;
      bottom: 20px;
      right: 20px;
      background: var(--card-bg);
      padding: 15px 25px;
      border-radius: 12px;
      box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
      font-weight: 800;
      color: var(--text-dark);
      text-align: left;
      transform: rotate(-5deg);
      animation: float-delayed 5s ease-in-out infinite;
      border: 2px solid var(--accent);
    }

    .price-tag span {
      display: block;
      font-size: 12px;
      color: var(--text-gray);
      font-weight: 500;
      text-decoration: line-through;
    }

    .price-tag .price {
      font-size: 28px;
      color: var(--accent);
    }

    /* 痛点共鸣区 */
    .pain-points {
      padding: 80px 0;
      background: var(--bg-dark);
      color: white;
      text-align: center;
    }

    .pain-title {
      font-size: 32px;
      font-weight: 800;
      margin-bottom: 40px;
    }

    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .pain-card {
      background: rgba(255, 255, 255, 0.05);
      padding: 30px;
      border-radius: 16px;
      border: 1px solid rgba(255, 255, 255, 0.1);
    }

    .pain-card i {
      font-size: 40px;
      color: #EF4444;
      margin-bottom: 16px;
      display: block;
    }

    .pain-card h3 {
      font-size: 20px;
      margin-bottom: 12px;
    }

    .pain-card p {
      color: #94A3B8;
      font-size: 15px;
    }

    /* 权威保障 (价值展示) */
    .guarantee {
      padding: 100px 0;
      background: var(--bg-white);
    }

    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }

    .section-title h2 {
      font-size: 36px;
      font-weight: 800;
      margin-bottom: 16px;
    }

    .section-title p {
      font-size: 18px;
      color: var(--text-gray);
    }

    .g-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 40px;
    }

    .g-item {
      display: flex;
      gap: 20px;
      background: var(--bg-gray);
      padding: 30px;
      border-radius: 16px;
    }

    .g-icon {
      width: 50px;
      height: 50px;
      background: rgba(29, 78, 216, 0.1);
      color: var(--primary);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      flex-shrink: 0;
    }

    .g-content h3 {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 10px;
    }

    .g-content p {
      color: var(--text-gray);
    }

    /* 真实口碑墙 (Social Proof) */
    .testimonials {
      padding: 100px 0;
      background: var(--bg-gray);
    }

    .t-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .t-card {
      background: var(--card-bg);
      padding: 30px;
      border-radius: 16px;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.03);
      position: relative;
    }

    .t-card::before {
      content: '"';
      position: absolute;
      top: 10px;
      left: 20px;
      font-size: 60px;
      color: rgba(29, 78, 216, 0.1);
      font-family: serif;
    }

    .t-text {
      font-size: 16px;
      line-height: 1.7;
      color: var(--text-dark);
      margin-bottom: 20px;
      position: relative;
      z-index: 2;
      font-style: italic;
    }

    .t-author {
      display: flex;
      align-items: center;
      gap: 15px;
      border-top: 1px solid var(--border-color);
      padding-top: 20px;
    }

    .t-author img {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      object-fit: cover;
    }

    .t-info h4 {
      font-size: 16px;
      font-weight: 700;
    }

    .t-info p {
      font-size: 13px;
      color: var(--text-gray);
    }

    .stars {
      color: #FBBF24;
      font-size: 14px;
      margin-bottom: 5px;
    }

    /* 立即行动 (FOMO) */
    .cta-section {
      padding: 100px 0;
      background: var(--bg-dark);
      color: white;
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .cta-section::before {
      content: '';
      position: absolute;
      top: -50%;
      left: -50%;
      width: 200%;
      height: 200%;
      background: radial-gradient(circle, rgba(29, 78, 216, 0.2) 0%, transparent 50%);
      pointer-events: none;
    }

    .cta-content {
      position: relative;
      z-index: 2;
    }

    .cta-content h2 {
      font-size: 40px;
      font-weight: 900;
      margin-bottom: 20px;
    }

    .cta-content p {
      font-size: 20px;
      color: #94A3B8;
      margin-bottom: 40px;
    }

    .fomo-text {
      display: inline-block;
      background: rgba(239, 68, 68, 0.2);
      color: #FCA5A5;
      padding: 8px 16px;
      border-radius: 8px;
      font-size: 14px;
      font-weight: 600;
      margin-top: 20px;
    }

    /* Footer */
    footer {
      padding: 40px 0;
      text-align: center;
      color: var(--text-gray);
      font-size: 14px;
    }

    @keyframes float {
      0% {
        transform: translateY(0px);
      }

      50% {
        transform: translateY(-15px);
      }

      100% {
        transform: translateY(0px);
      }
    }

    @keyframes float-delayed {
      0% {
        transform: translateY(0px) rotate(-5deg);
      }

      50% {
        transform: translateY(10px) rotate(-3deg);
      }

      100% {
        transform: translateY(0px) rotate(-5deg);
      }
    }

    @media (max-width: 992px) {
      .hero-container,
      .g-grid,
      .t-grid,
      .pain-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }

      .hero-image-wrapper {
        margin-top: 40px;
      }

      .hero-content h1 {
        font-size: 40px;
      }

      .price-tag {
        right: 0;
        left: 0;
        margin: 0 auto;
        width: fit-content;
      }

      .g-item {
        text-align: left;
      }
    }

    /* 移动端深度适配 (<768px) */
    @media (max-width: 768px) {
      /* 缩小整体区块的上下内边距，让小屏幕显示更紧凑 */
      .hero {
        padding: 100px 0 50px;
      }
      
      .pain-points, 
      .guarantee, 
      .testimonials, 
      .cta-section {
        padding: 60px 0;
      }

      /* 缩小顶部导航栏的按钮 */
      .btn-cta {
        padding: 8px 16px;
        font-size: 14px;
      }

      /* 统一缩放各级标题和正文字体 */
      .hero-content h1 {
        font-size: 32px;
      }
      
      .hero-content p {
        font-size: 16px;
        margin-bottom: 24px;
      }

      .section-title h2, 
      .pain-title, 
      .cta-content h2 {
        font-size: 26px;
        line-height: 1.3;
      }

      .section-title {
        margin-bottom: 40px;
      }

      /* 优化信任背书区域 (头像+文字) 为上下排列 */
      .hero-proof {
        flex-direction: column;
        gap: 12px;
        text-align: center;
      }
      
      .hero-proof .avatars {
        justify-content: center;
      }

      /* 缩小卡片的内边距 */
      .g-item, 
      .t-card, 
      .pain-card {
        padding: 24px 20px;
      }

      /* 覆盖行内样式，让大按钮在手机端全宽且尺寸适中 */
      .hero-content .btn-cta,
      .cta-section .btn-cta {
        font-size: 16px !important;
        padding: 14px 24px !important;
        width: 100%;
        justify-content: center;
      }

      .fomo-text {
        font-size: 12px;
        padding: 6px 12px;
      }
      
      .price-tag {
        padding: 12px 18px;
      }
      
      .price-tag .price {
        font-size: 24px;
      }
    }