/* roulang page: index */
:root {
      --primary: #0A1929;
      --accent: #00E5A0;
      --bg-white: #FFFFFF;
      --bg-light: #F7F8FA;
      --bg-dark: #0A1929;
      --text-primary: #1A1A1A;
      --text-secondary: #5A5A5A;
      --text-muted: #8A8A8A;
      --text-on-dark: #E0E0E0;
      --text-on-primary: #FFFFFF;
      --border-light: #F0F0F0;
      --border-default: #E5E7EB;
      --radius-card: 16px;
      --radius-btn: 8px;
      --shadow-xs: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.03);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --transition: 0.25s ease;
      --max-width: 1200px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-white);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

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

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

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

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      background: rgba(255,255,255,0.8);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      transition: background var(--transition), box-shadow var(--transition);
      border-bottom: 1px solid transparent;
    }

    .nav.scrolled {
      background: var(--bg-white);
      box-shadow: 0 1px 0 rgba(0,0,0,0.05);
    }

    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: -0.02em;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }

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

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-weight: 500;
      font-size: 1rem;
      color: var(--text-primary);
      transition: color var(--transition);
      position: relative;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition);
    }

    .nav-links a:hover {
      color: var(--primary);
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--primary);
      color: var(--text-on-primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      letter-spacing: 0.03em;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
      border: none;
      display: inline-block;
    }

    .btn-primary:hover {
      background: var(--accent);
      color: var(--primary);
      transform: scale(1.03);
      box-shadow: 0 10px 20px -8px rgba(0,229,160,0.4);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      transition: all var(--transition);
    }

    .btn-outline:hover {
      background: var(--primary);
      color: white;
      transform: scale(1.03);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      z-index: 1100;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: var(--transition);
    }

    @media (max-width: 768px) {
      .nav {
        height: 64px;
      }
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: rgba(10,25,41,0.95);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        transition: right 0.3s ease;
        z-index: 1050;
      }
      .nav-links.active {
        right: 0;
      }
      .nav-links a {
        color: white;
        font-size: 1.5rem;
        font-weight: 600;
      }
      .nav-links a::after {
        background: var(--accent);
      }
      .hamburger {
        display: flex;
      }
      .nav .btn-primary {
        display: none;
      }
      .mobile-cta {
        display: block;
        margin-top: 20px;
      }
    }

    @media (min-width: 769px) {
      .mobile-cta {
        display: none;
      }
    }

    /* 通用板块 */
    section {
      padding: 120px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 80px 0;
      }
    }

    .section-title {
      font-size: 2.8rem;
      font-weight: 700;
      letter-spacing: -0.01em;
      line-height: 1.2;
      margin-bottom: 24px;
      color: var(--text-primary);
    }

    @media (max-width: 768px) {
      .section-title {
        font-size: 2rem;
      }
    }

    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      display: flex;
      align-items: center;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      color: white;
    }

    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(10,25,41,0.85) 0%, rgba(2,12,20,0.65) 100%);
    }

    .hero .container {
      position: relative;
      z-index: 2;
    }

    .hero h1 {
      font-size: 3.8rem;
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.1;
      max-width: 700px;
      margin-bottom: 24px;
      color: white;
    }

    .hero .sub {
      font-size: 1.3rem;
      color: rgba(255,255,255,0.9);
      max-width: 550px;
      margin-bottom: 40px;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    @media (max-width: 768px) {
      .hero h1 {
        font-size: 2.5rem;
      }
      .hero .sub {
        font-size: 1.1rem;
      }
    }

    /* 痛点 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 48px;
    }

    .pain-card {
      background: var(--bg-white);
      border: 1px solid var(--border-default);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: all var(--transition);
    }

    .pain-card:hover {
      border-color: var(--primary);
      background: #fafbfc;
      transform: translateY(-4px);
      box-shadow: var(--shadow-sm);
    }

    .pain-icon {
      font-size: 2rem;
      margin-bottom: 20px;
      color: var(--primary);
    }

    @media (max-width: 768px) {
      .pain-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 解决方案非对称 */
    .solution-row {
      display: flex;
      gap: 48px;
      align-items: center;
      margin-top: 48px;
    }

    .solution-img {
      flex: 5;
      border-radius: 20px;
      overflow: hidden;
    }

    .solution-text {
      flex: 7;
    }

    .point {
      padding: 24px 0;
      border-bottom: 1px solid #f0f0f0;
      display: flex;
      gap: 16px;
    }

    .point-num {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
      transition: transform var(--transition);
    }

    .point:hover .point-num {
      transform: translateX(4px);
      color: var(--accent);
    }

    @media (max-width: 768px) {
      .solution-row {
        flex-direction: column;
      }
    }

    /* 成果数字 */
    .results-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 48px;
    }

    .stat-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 40px 24px;
      box-shadow: var(--shadow-sm);
      text-align: center;
    }

    .stat-number {
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 12px;
    }

    @media (max-width: 768px) {
      .results-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 48px;
    }

    .testimonial-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px;
      border-left: 4px solid var(--primary);
      transition: var(--transition);
    }

    .testimonial-card:hover {
      border-left-width: 8px;
      box-shadow: var(--shadow-md);
    }

    @media (max-width: 768px) {
      .testimonial-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid #eee;
      margin-bottom: 8px;
    }

    .faq-question {
      width: 100%;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 24px 0;
      font-weight: 600;
      font-size: 1.1rem;
      background: transparent;
      border: none;
      cursor: pointer;
      text-align: left;
    }

    .faq-icon {
      font-size: 1.5rem;
      transition: transform 0.3s;
    }

    .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;
      padding-bottom: 20px;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA */
    .cta-dark {
      background: var(--bg-dark);
      color: white;
      text-align: center;
    }

    .cta-dark .btn-primary {
      background: var(--accent);
      color: var(--primary);
      font-size: 1.2rem;
      padding: 16px 48px;
    }

    /* Footer */
    .footer {
      background: #020C14;
      color: #B0B0B0;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }