/* roulang page: index */
:root {
      --primary: #2563EB;
      --primary-dark: #1D4ED8;
      --primary-light: #DBEAFE;
      --accent-orange: #F97316;
      --accent-orange-dark: #EA580C;
      --accent-green: #10B981;
      --white: #FFFFFF;
      --gray-bg: #F8FAFC;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --border: #E2E8F0;
      --radius-card: 16px;
      --radius-button: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 10px 25px -8px rgba(0,0,0,0.04), 0 2px 5px rgba(0,0,0,0.02);
      --shadow-hover: 0 20px 30px -10px rgba(0,0,0,0.1), 0 8px 12px rgba(0,0,0,0.04);
      --max-width: 1200px;
      --header-height: 76px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background: var(--white);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.25s;
    }
    h1, h2, h3 {
      font-weight: 600;
      letter-spacing: -0.3px;
    }
    h2 {
      font-size: 2.25rem;
      margin-bottom: 0.5rem;
      color: #0F172A;
    }
    @media (max-width: 640px) {
      h2 {
        font-size: 1.8rem;
      }
      .container {
        padding: 0 16px;
      }
    }
    /* Header & Nav */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 10px rgba(0,0,0,0.02);
      z-index: 99;
      height: var(--header-height);
      border-bottom: 1px solid rgba(0,0,0,0.03);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: var(--header-height);
    }
    .logo {
      font-size: 1.9rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .logo span {
      color: #0F172A;
      font-weight: 500;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2.5rem;
      font-weight: 500;
      color: #334155;
    }
    .nav-menu a {
      color: #1E293B;
      font-size: 0.95rem;
    }
    .nav-menu a:hover {
      color: var(--primary);
    }
    .nav-cta {
      background: var(--primary);
      color: white !important;
      padding: 10px 20px;
      border-radius: 40px;
      font-weight: 600;
      font-size: 0.9rem;
      transition: all 0.25s;
      box-shadow: 0 8px 14px -8px rgba(37,99,235,0.3);
      margin-left: 0.8rem;
      display: inline-block;
    }
    .nav-cta:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--text-main);
      cursor: pointer;
    }
    @media (max-width: 1024px) {
      .nav-menu {
        gap: 1.5rem;
      }
    }
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 30px 20px;
        gap: 1.8rem;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        display: none;
        border-bottom: 1px solid var(--border);
      }
      .nav-menu.active {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .nav-cta {
        margin-left: 0;
        width: fit-content;
      }
    }
    /* Hero */
    .hero {
      padding: 160px 0 100px;
      background: linear-gradient(135deg, #F8FAFC 0%, #EFF6FF 100%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      color: #0B1E3D;
    }
    .hero h1 span {
      color: var(--primary);
    }
    .hero-sub {
      font-size: 1.2rem;
      color: #475569;
      margin-bottom: 2.5rem;
    }
    .button-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 15px 34px;
      border-radius: 40px;
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: 0.25s;
      font-size: 1.05rem;
      box-shadow: 0 12px 18px -10px rgba(37,99,235,0.35);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 13px 32px;
      border-radius: 40px;
      font-weight: 600;
      cursor: pointer;
      transition: 0.25s;
      font-size: 1.05rem;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-orange {
      background: var(--accent-orange);
      color: white;
      border: none;
      box-shadow: 0 10px 15px -8px rgba(249,115,22,0.4);
    }
    .btn-orange:hover {
      background: var(--accent-orange-dark);
    }
    .hero-image {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 32px;
      height: 400px;
      box-shadow: 0 25px 35px -12px rgba(0,0,0,0.15);
    }
    @media (max-width: 900px) {
      .hero-grid {
        flex-direction: column;
        gap: 40px;
      }
      .hero h1 {
        font-size: 2.3rem;
      }
      .hero-image {
        width: 100%;
        height: 280px;
        order: -1;
      }
    }
    /* Sections */
    section {
      padding: 90px 0;
    }
    .section-header {
      text-align: center;
      max-width: 720px;
      margin: 0 auto 60px;
    }
    .pain-grid, .advantage-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .pain-card {
      background: white;
      padding: 28px;
      border-radius: var(--radius-card);
      border: 1px solid var(--border);
      border-left: 5px solid var(--accent-orange);
      transition: 0.2s;
    }
    .pain-card h3 {
      font-size: 1.25rem;
      margin-bottom: 10px;
    }
    .solution-steps {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 20px;
      flex-wrap: wrap;
    }
    .step {
      flex: 1;
      min-width: 160px;
      text-align: center;
    }
    .step-circle {
      width: 56px;
      height: 56px;
      border-radius: 50%;
      background: var(--primary);
      color: white;
      font-weight: 700;
      line-height: 56px;
      font-size: 1.5rem;
      margin: 0 auto 16px;
    }
    .advantage-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 34px 26px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border);
      transition: all 0.27s;
      text-align: center;
    }
    .advantage-card:hover {
      transform: translateY(-7px);
      box-shadow: var(--shadow-hover);
    }
    .advantage-card img {
      width: 70px;
      height: 70px;
      border-radius: 20px;
      object-fit: cover;
      margin: 0 auto 20px;
      background: #F1F5F9;
    }
    .stats-block {
      display: flex;
      justify-content: space-around;
      text-align: center;
      background: #F0F4FF;
      border-radius: 40px;
      padding: 50px 30px;
      margin-top: 20px;
    }
    .stat-number {
      font-size: 3.3rem;
      font-weight: 700;
      color: var(--primary);
    }
    .testimonial-grid {
      display: flex;
      gap: 30px;
      overflow-x: auto;
      padding-bottom: 15px;
    }
    .testimonial-card {
      min-width: 300px;
      background: white;
      padding: 30px;
      border-radius: var(--radius-card);
      border-left: 6px solid var(--accent-orange);
      box-shadow: var(--shadow-card);
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      font-size: 1.1rem;
    }
    .faq-answer {
      margin-top: 12px;
      color: #475569;
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .cta-section {
      background: var(--primary);
      text-align: center;
      padding: 100px 0;
      border-radius: 48px 48px 0 0;
      margin-bottom: 0;
    }
    .cta-section h2 {
      color: white;
    }
    .footer {
      background: #0F172A;
      color: #CBD5E1;
      padding: 60px 0 40px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 35px;
    }
    @media (max-width: 768px) {
      .pain-grid, .advantage-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero {
        padding: 130px 0 70px;
      }
    }