/* roulang page: index */
:root {
      --red: #C8102E;
      --red-dark: #A50D25;
      --black: #1A1A1A;
      --gray-light: #F4F4F4;
      --gold: #FFD700;
      --white: #FFFFFF;
      --text-secondary: #555555;
      --border-light: #E2E2E2;
      --shadow-card: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 24px rgba(0,0,0,0.08);
      --radius-card: 8px;
      --radius-button: 4px;
      --font-title: "Montserrat", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
      --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--white);
      color: var(--black);
      line-height: 1.7;
      font-weight: 400;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(10px);
      z-index: 1000;
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
      transition: box-shadow 0.3s;
    }
    .header.scrolled {
      box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    }
    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 1.6rem;
      color: var(--red);
      letter-spacing: -0.02em;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      font-size: 1.8rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      text-decoration: none;
      font-weight: 500;
      color: var(--black);
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
      padding-bottom: 4px;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--red);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--red);
      transition: width 0.25s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--red);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-button);
      font-weight: 600;
      font-family: var(--font-body);
      cursor: pointer;
      transition: background var(--transition), transform 0.2s;
      text-decoration: none;
      display: inline-block;
      font-size: 0.95rem;
    }
    .btn-primary:hover {
      background: var(--red-dark);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--red);
      color: var(--red);
      padding: 12px 28px;
      border-radius: var(--radius-button);
      font-weight: 600;
      cursor: pointer;
      transition: all var(--transition);
      text-decoration: none;
      display: inline-block;
      font-size: 0.95rem;
    }
    .btn-outline:hover {
      background: var(--red);
      color: white;
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--black);
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-links {
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        flex-direction: column;
        background: white;
        padding: 24px;
        gap: 20px;
        box-shadow: 0 20px 25px rgba(0,0,0,0.05);
        display: none;
      }
      .nav-links.open {
        display: flex;
      }
      .nav-cta {
        display: none;
      }
    }
    /* Hero */
    .hero {
      padding: 120px 0 80px;
      background: linear-gradient(135deg, #f9f9f9 0%, #ffffff 70%);
      display: flex;
      align-items: center;
      min-height: 90vh;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-family: var(--font-title);
      font-size: 3.4rem;
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--black);
      margin-bottom: 20px;
    }
    .hero-content h1 span {
      color: var(--red);
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 24px;
      height: 420px;
      box-shadow: 0 25px 40px rgba(0,0,0,0.15);
      position: relative;
      overflow: hidden;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-content h1 {
        font-size: 2.5rem;
      }
      .hero-image {
        height: 280px;
        order: -1;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    /* 板块通用 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-family: var(--font-title);
      font-size: 2.4rem;
      font-weight: 700;
      letter-spacing: -0.02em;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      max-width: 650px;
      margin: 0 auto 48px;
      font-size: 1.1rem;
    }
    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .feature-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      border: 1px solid var(--border-light);
    }
    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--red);
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-family: var(--font-title);
      font-size: 1.4rem;
      margin-bottom: 12px;
    }
    @media (max-width: 900px) {
      .features-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 600px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      height: 320px;
      background-size: cover;
      background-position: center;
      border-radius: 16px;
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-text h3 {
      font-family: var(--font-title);
      font-size: 1.8rem;
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
      .scenario-img {
        width: 100%;
      }
    }
    /* 数据卡片 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .stat-item {
      text-align: center;
      background: var(--gray-light);
      padding: 32px;
      border-radius: var(--radius-card);
    }
    .stat-number {
      font-family: var(--font-title);
      font-size: 2.6rem;
      font-weight: 800;
      color: var(--red);
    }
    /* 价格卡片 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .pricing-card {
      background: white;
      border-radius: 12px;
      padding: 32px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-light);
      transition: all 0.25s;
      position: relative;
    }
    .pricing-card.featured {
      border: 2px solid var(--red);
      transform: scale(1.02);
      box-shadow: 0 20px 30px rgba(0,0,0,0.08);
    }
    .pricing-card h4 {
      font-size: 1.6rem;
    }
    .price {
      font-size: 2.2rem;
      font-weight: 800;
      color: var(--black);
      margin: 20px 0;
    }
    .badge-gold {
      background: var(--gold);
      color: var(--black);
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      position: absolute;
      top: -12px;
      right: 20px;
    }
    @media (max-width: 900px) {
      .pricing-grid, .stats-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 600px) {
      .pricing-grid, .stats-grid {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 700;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      margin-top: 8px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
    }
    /* CTA band */
    .cta-band {
      background: var(--red);
      color: white;
      text-align: center;
      padding: 70px 20px;
      border-radius: 0;
    }
    .cta-band h2 {
      font-size: 2.2rem;
      font-weight: 700;
    }
    .footer {
      background: var(--black);
      color: #ccc;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    .footer a {
      color: #ccc;
      text-decoration: none;
    }
    .footer a:hover {
      color: white;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }