/* roulang page: index */
:root {
      --deep-space: #0F0A2A;
      --cosmic-purple: #1A0A3E;
      --starlight-silver: #C0C8E0;
      --energy-orange: #FF6B35;
      --energy-orange-light: #FF8255;
      --deep-blue: #0D1B3E;
      --card-bg: #1E1A2F;
      --dark-glass: rgba(15, 10, 42, 0.65);
      --white-mist: #F0F2FA;
      --text-primary: #E8ECF4;
      --text-secondary: #B0B8D0;
      --border-glow: rgba(192, 200, 224, 0.18);
      --shadow-glow: 0 12px 32px rgba(100, 80, 255, 0.15);
      --shadow-hover: 0 20px 40px rgba(255, 107, 53, 0.25);
      --radius-card: 16px;
      --radius-btn: 8px;
      --font-mono: 'Orbitron', monospace;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      background: radial-gradient(ellipse at 20% 20%, #1A0A3E 0%, #0F0A2A 65%, #0D1B3E 100%);
      background-attachment: fixed;
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      border: none;
      background: transparent;
    }

    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 8, 24, 0.7);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border-bottom: 1px solid rgba(192, 200, 224, 0.1);
      transition: background 0.4s ease;
    }

    .main-header.scrolled {
      background: rgba(10, 5, 26, 0.88);
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.6rem;
      letter-spacing: 1px;
      color: var(--starlight-silver);
    }
    .logo i {
      color: var(--energy-orange);
      font-size: 2rem;
      filter: drop-shadow(0 0 6px var(--energy-orange));
    }

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

    .nav-link {
      font-weight: 500;
      font-size: 1rem;
      color: var(--starlight-silver);
      padding: 8px 0;
      position: relative;
      letter-spacing: 0.3px;
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--energy-orange);
      box-shadow: 0 0 12px var(--energy-orange);
      transition: width 0.3s ease;
    }

    .nav-link:hover {
      color: var(--energy-orange);
    }
    .nav-link:hover::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--starlight-silver);
      background: transparent;
      border: none;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      padding-top: 72px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      background-color: rgba(10, 6, 30, 0.55);
    }

    .hero-content {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 48px;
      width: 100%;
    }

    .hero-text {
      flex: 1 1 500px;
    }
    .hero-text h1 {
      font-size: clamp(2.8rem, 6vw, 4.4rem);
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 24px;
      background: linear-gradient(to right, #F0F2FA, #C0C8E0);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .hero-text .highlight {
      color: var(--energy-orange);
      -webkit-text-fill-color: var(--energy-orange);
    }
    .hero-desc {
      font-size: 1.15rem;
      color: var(--text-secondary);
      margin-bottom: 36px;
      max-width: 560px;
    }
    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }
    .btn-primary {
      background: var(--energy-orange);
      color: #fff;
      font-weight: 700;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      box-shadow: 0 8px 24px rgba(255,107,53,0.35);
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }
    .btn-primary:hover {
      background: #FF8255;
      box-shadow: 0 12px 28px rgba(255,107,53,0.6);
      transform: translateY(-2px);
    }
    .btn-outline {
      border: 1px solid var(--starlight-silver);
      color: var(--starlight-silver);
      font-weight: 600;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      backdrop-filter: blur(8px);
      background: rgba(192,200,224,0.05);
    }
    .btn-outline:hover {
      border-color: var(--energy-orange);
      color: var(--energy-orange);
      background: rgba(255,107,53,0.08);
    }
    .hero-visual {
      flex: 1 1 400px;
      display: flex;
      justify-content: center;
    }
    .hero-visual img {
      border-radius: 32px;
      box-shadow: var(--shadow-glow);
      max-height: 450px;
      object-fit: cover;
    }

    /* 通用区块 */
    section {
      padding: 120px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      text-align: center;
      margin-bottom: 16px;
      color: var(--white-mist);
      letter-spacing: 1px;
    }
    .section-sub {
      text-align: center;
      color: var(--text-secondary);
      max-width: 680px;
      margin: 0 auto 56px;
    }

    /* 痛点 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 32px;
    }
    .pain-card {
      background: rgba(30,26,47,0.7);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-glow);
      border-radius: var(--radius-card);
      padding: 36px 24px;
      transition: var(--transition);
    }
    .pain-card:hover {
      border-color: var(--energy-orange);
      box-shadow: var(--shadow-hover);
    }
    .pain-icon {
      font-size: 2.4rem;
      color: var(--energy-orange);
      margin-bottom: 18px;
    }

    /* 解决方案卡片 */
    .solution-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 36px;
    }
    .solution-card {
      background: rgba(20, 16, 36, 0.7);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-glow);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      transition: all 0.25s;
    }
    .solution-card:hover {
      transform: translateY(-6px);
      border-color: var(--energy-orange);
      box-shadow: 0 20px 40px rgba(255,107,53,0.2);
    }
    .solution-card img {
      border-radius: 16px;
      margin-bottom: 20px;
      height: 200px;
      object-fit: cover;
    }

    /* 数据成果 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 28px;
    }
    .stat-card {
      background: rgba(30,26,47,0.65);
      backdrop-filter: blur(10px);
      border-radius: var(--radius-card);
      padding: 32px 16px;
      text-align: center;
      border: 1px solid var(--border-glow);
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 700;
      background: linear-gradient(135deg, #C0C8E0, #FF6B35);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
      gap: 36px;
    }
    .testimonial-card {
      display: flex;
      gap: 20px;
      background: rgba(30,26,47,0.55);
      backdrop-filter: blur(12px);
      border-radius: var(--radius-card);
      padding: 28px;
      border: 1px solid var(--border-glow);
    }
    .avatar {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      object-fit: cover;
      border: 2px solid var(--energy-orange);
    }

    /* FAQ */
    .faq-list {
      max-width: 860px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid rgba(192,200,224,0.15);
      padding: 18px 0;
    }
    .faq-question {
      width: 100%;
      text-align: left;
      font-weight: 600;
      font-size: 1.15rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: transparent;
      border: none;
      color: var(--text-primary);
      padding: 12px 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
    }

    /* CTA */
    .cta-section {
      text-align: center;
      background: radial-gradient(circle at center, #1E1A2F, #0F0A2A);
    }

    /* Footer */
    .footer {
      background: #0B0B0F;
      padding: 48px 0 28px;
      border-top: 2px solid rgba(192,200,224,0.1);
      text-align: center;
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(10,6,25,0.96);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        backdrop-filter: blur(20px);
      }
      .nav-menu.active {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-content {
        flex-direction: column;
      }
    }