/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --bg-deep: #0B0F1A;
      --accent-cyan: #00E5FF;
      --accent-red: #FF4D6A;
      --card-bg: rgba(255, 255, 255, 0.04);
      --card-border: rgba(255, 255, 255, 0.08);
      --text-primary: #FFFFFF;
      --text-secondary: rgba(255, 255, 255, 0.7);
      --text-muted: rgba(255, 255, 255, 0.5);
      --radius-sm: 12px;
      --radius-md: 16px;
      --radius-lg: 24px;
      --shadow-glow: 0 8px 32px rgba(0, 229, 255, 0.08);
      --shadow-hover: 0 16px 48px rgba(0, 229, 255, 0.15);
      --font-stack: 'Inter', 'SF Pro Display', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

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

    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }

    body {
      font-family: var(--font-stack);
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-stack);
      border: none;
      background: transparent;
      transition: all var(--transition-smooth);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    /* 容器与栅格 */
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

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

    /* ----- 导航 (沉浸式玻璃拟态) ----- */
    header.nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(11, 15, 26, 0.85);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border-bottom: 1px solid rgba(0, 229, 255, 0.15);
      transition: background var(--transition-smooth);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: 1px;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--accent-cyan);
      font-size: 2rem;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 1rem;
      color: var(--text-secondary);
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width var(--transition-smooth);
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--accent-cyan);
    }
    .nav-links a:hover::after, .nav-links a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--text-primary);
      background: none;
      border: none;
    }

    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(11, 15, 26, 0.96);
        backdrop-filter: blur(30px);
        flex-direction: column;
        gap: 24px;
        padding: 32px 24px;
        transform: translateY(-120%);
        opacity: 0;
        transition: transform 0.4s ease, opacity 0.3s ease;
        border-bottom: 1px solid var(--accent-cyan);
      }
      .nav-links.active {
        transform: translateY(0);
        opacity: 1;
      }
    }

    /* ----- 按钮系统 ----- */
    .btn-primary {
      background: var(--accent-red);
      color: #fff;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      box-shadow: 0 0 20px rgba(255, 77, 106, 0.4);
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      box-shadow: 0 0 40px rgba(255, 77, 106, 0.7);
      transform: scale(1.05);
    }

    .btn-outline {
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      background: transparent;
    }
    .btn-outline:hover {
      background: rgba(0, 229, 255, 0.08);
      box-shadow: 0 0 20px rgba(0, 229, 255, 0.3);
    }

    /* ----- Hero 首屏 ----- */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-color: var(--bg-deep);
      margin-top: 0;
      padding-top: 72px;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 20% 30%, rgba(0,229,255,0.12) 0%, rgba(11,15,26,0.85) 70%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
    }
    .hero h1 {
      font-size: 56px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 24px;
      text-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }
    .hero .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 40px;
      max-width: 600px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    @media (max-width: 768px) {
      .hero h1 {
        font-size: 36px;
      }
      .hero-buttons {
        flex-direction: column;
        width: 100%;
      }
      .btn-primary, .btn-outline {
        width: 100%;
        justify-content: center;
      }
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
      position: relative;
    }
    .section-title {
      font-size: 40px;
      font-weight: 700;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      color: var(--text-secondary);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 60px;
    }

    /* 痛点卡片 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .pain-card {
      background: var(--card-bg);
      backdrop-filter: blur(20px);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-md);
      padding: 32px;
      transition: all var(--transition-smooth);
    }
    .pain-card:hover {
      border-color: var(--accent-cyan);
      box-shadow: var(--shadow-hover);
      background: rgba(255,255,255,0.06);
    }

    /* 方案卡片网格 */
    .solution-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .solution-card {
      background: var(--card-bg);
      backdrop-filter: blur(20px);
      border-radius: var(--radius-md);
      padding: 40px 24px;
      text-align: center;
      border: 1px solid var(--card-border);
      transition: var(--transition-smooth);
    }
    .solution-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }
    .solution-icon {
      font-size: 2.8rem;
      color: var(--accent-cyan);
      margin-bottom: 20px;
    }

    /* 成果数据 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-cyan);
    }

    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .testimonial-card {
      background: var(--card-bg);
      backdrop-filter: blur(20px);
      border-left: 4px solid var(--accent-cyan);
      padding: 28px;
      border-radius: var(--radius-md);
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 24px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.2rem;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    /* CTA 区域 */
    .cta-section {
      background: radial-gradient(circle at center, #1a1f2e, #0B0F1A);
    }

    /* 页脚 */
    footer {
      padding: 60px 0 30px;
      border-top: 1px solid rgba(255,255,255,0.06);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .pain-grid, .solution-grid, .testimonial-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .pain-grid, .solution-grid, .testimonial-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
    }