/* roulang page: index */
:root {
      --primary: #E10600;
      --primary-dark: #C80500;
      --secondary: #1A1A2E;
      --accent: #FFB800;
      --white: #FFFFFF;
      --gray-bg: #F8F9FA;
      --gray-light: #E9ECEF;
      --gray-mid: #6C757D;
      --text-main: #1A1A2E;
      --text-secondary: #6C757D;
      --border-color: #E9ECEF;
      --radius-sm: 8px;
      --radius-md: 12px;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.2s ease;
      --nav-height: 64px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--white);
      color: var(--text-main);
      line-height: 1.8;
      font-size: 16px;
      padding-top: var(--nav-height);
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }
    h1 {
      font-size: 40px;
      font-weight: 900;
    }
    h2 {
      font-size: 32px;
      margin-bottom: 16px;
    }
    h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: var(--transition);
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }
    .btn-primary {
      background-color: var(--primary);
      color: var(--white);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      box-shadow: 0 4px 10px rgba(225,6,0,0.2);
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
    }
    .btn-outline:hover {
      background-color: #FFF0F0;
    }
    .btn-white {
      background: var(--white);
      color: var(--primary);
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-sm);
    }
    .btn-white:hover {
      background: #f1f1f1;
      transform: translateY(-2px);
    }
    section {
      padding: 80px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 48px 0;
      }
      h1 {
        font-size: 28px;
      }
      h2 {
        font-size: 24px;
      }
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--white);
      border-bottom: 1px solid var(--border-color);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      color: var(--secondary);
      font-weight: 900;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      font-weight: 500;
      color: var(--text-main);
    }
    .nav-links a {
      padding: 8px 0;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--secondary);
      transition: var(--transition);
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu {
        display: none;
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: var(--secondary);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        z-index: 999;
      }
      .mobile-menu.active {
        display: flex;
      }
      .mobile-menu a {
        color: white;
        font-size: 18px;
      }
    }
    /* Hero */
    .hero {
      background: var(--secondary);
      background-image: radial-gradient(circle at 80% 30%, rgba(225,6,0,0.15) 0%, transparent 45%);
      color: white;
      display: flex;
      align-items: center;
      min-height: 85vh;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      margin-bottom: 24px;
      color: white;
    }
    .hero-text p {
      font-size: 18px;
      color: #ccc;
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 320px;
      border-radius: var(--radius-md);
      box-shadow: 0 15px 30px rgba(0,0,0,0.3);
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-visual {
        width: 100%;
        min-height: 240px;
      }
    }
    /* 卡片通用 */
    .card {
      background: white;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .grid-4, .grid-3, .grid-2 {
      display: grid;
      gap: 24px;
    }
    .grid-4 { grid-template-columns: repeat(4,1fr); }
    .grid-3 { grid-template-columns: repeat(3,1fr); }
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 640px) {
      .grid-4, .grid-3 { grid-template-columns: 1fr; }
    }
    .icon-red {
      color: var(--primary);
      font-size: 28px;
      margin-bottom: 16px;
    }
    .feature-card h3 {
      margin: 8px 0;
    }
    .accent-text {
      color: var(--accent);
      font-weight: 700;
    }
    /* 场景卡片 */
    .scenario-row {
      display: flex;
      gap: 40px;
      align-items: center;
      margin-bottom: 48px;
    }
    .scenario-img {
      flex: 1;
      background: #f0f0f0;
      border-radius: var(--radius-md);
      min-height: 220px;
      background-size: cover;
    }
    .scenario-content {
      flex: 1;
    }
    @media (max-width: 768px) {
      .scenario-row {
        flex-direction: column;
      }
    }
    /* 价格卡 */
    .pricing-card {
      text-align: center;
      position: relative;
    }
    .pricing-card.recommended {
      border: 2px solid var(--primary);
      box-shadow: 0 12px 24px rgba(225,6,0,0.08);
    }
    .badge {
      background: var(--accent);
      color: #1A1A2E;
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
    }
    .price {
      font-size: 36px;
      font-weight: 800;
      color: var(--primary);
      margin: 16px 0;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-color);
      padding: 16px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .cta-banner {
      background: var(--primary);
      text-align: center;
      color: white;
      padding: 60px 24px;
    }
    footer {
      background: var(--secondary);
      color: #ccc;
      padding: 40px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }