/* roulang page: index */
:root {
      --deep-space: #0A0E17;
      --surface: #141A26;
      --input-bg: #1E2535;
      --neon-lime: #D4FF00;
      --purple-spark: #7B2FFF;
      --text-primary: #FFFFFF;
      --text-body: #B0B8CC;
      --text-muted: #7B8AA6;
      --border-glow: rgba(212, 255, 0, 0.25);
      --card-border: rgba(212, 255, 0, 0.08);
      --radius-xl: 24px;
      --radius-lg: 20px;
      --radius-md: 16px;
      --radius-full: 50px;
      --shadow-card: 0 12px 32px rgba(0, 0, 0, 0.5);
      --font-mono: 'Inter', 'SF Mono', 'Menlo', monospace;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition-smooth: 0.25s 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(--deep-space);
    }

    body {
      font-family: var(--font-sans);
      background: var(--deep-space);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

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

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

    /* 导航栏 */
    .nav-bar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(10, 14, 23, 0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      z-index: 1000;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: border 0.3s, background 0.3s;
    }

    .nav-bar.scrolled {
      border-bottom: 1px solid rgba(212, 255, 0, 0.35);
      background: rgba(10, 14, 23, 0.9);
    }

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

    .logo {
      font-weight: 700;
      font-size: 1.6rem;
      letter-spacing: -0.5px;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo span {
      background: linear-gradient(135deg, var(--neon-lime), var(--purple-spark));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-links a {
      color: var(--text-body);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 6px 0;
    }

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

    .nav-cta {
      background: linear-gradient(135deg, var(--neon-lime), var(--purple-spark));
      color: #0A0E17;
      font-weight: 700;
      padding: 10px 24px;
      border-radius: var(--radius-full);
      margin-left: 0.5rem;
      font-size: 0.9rem;
      letter-spacing: 0.3px;
      box-shadow: 0 4px 14px rgba(212, 255, 0, 0.3);
    }

    .nav-cta:hover {
      transform: scale(1.05);
      box-shadow: 0 0 24px rgba(212, 255, 0, 0.6);
    }

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

    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--neon-lime);
      border-radius: 3px;
      transition: var(--transition-smooth);
    }

    .mobile-menu {
      display: none;
    }

    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }

    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(10,14,23,0.9) 40%, rgba(10,14,23,0.5) 100%);
    }

    .hero .container {
      position: relative;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      background: rgba(123, 47, 255, 0.2);
      border: 1px solid rgba(212, 255, 0, 0.3);
      color: var(--neon-lime);
      padding: 6px 18px;
      border-radius: 30px;
      font-size: 0.85rem;
      font-weight: 600;
      margin-bottom: 24px;
      backdrop-filter: blur(8px);
    }

    h1 {
      font-size: 3.2rem;
      font-weight: 700;
      letter-spacing: -1px;
      line-height: 1.2;
      background: linear-gradient(135deg, var(--neon-lime), var(--purple-spark));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 1.5rem;
    }

    .hero-sub {
      font-size: 1.125rem;
      color: var(--text-body);
      max-width: 460px;
      margin-bottom: 2rem;
      line-height: 1.6;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--neon-lime), var(--purple-spark));
      color: #0A0E17;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-full);
      border: none;
      font-size: 1rem;
      letter-spacing: 0.4px;
      cursor: pointer;
      transition: var(--transition-smooth);
      box-shadow: 0 6px 18px rgba(123, 47, 255, 0.3);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-primary:hover {
      filter: brightness(1.15);
      box-shadow: 0 0 28px rgba(212, 255, 0, 0.6);
      transform: scale(1.03);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--neon-lime);
      color: var(--neon-lime);
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-full);
      transition: var(--transition-smooth);
    }

    .btn-outline:hover {
      background: rgba(212, 255, 0, 0.1);
      border-color: #fff;
      color: #fff;
    }

    .hero-image {
      background: url('/assets/images/backpic/back-2.webp') center/cover no-repeat;
      border-radius: 32px;
      height: 380px;
      box-shadow: 0 0 0 2px rgba(123, 47, 255, 0.4), 0 20px 40px rgba(0,0,0,0.6);
    }

    /* 通用板块 */
    section {
      padding: 90px 0;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 14px;
    }

    .section-title::before {
      content: '';
      width: 4px;
      height: 36px;
      background: var(--neon-lime);
      border-radius: 4px;
    }

    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 40px;
    }

    .feature-card {
      background: var(--surface);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-xl);
      padding: 32px;
      transition: var(--transition-smooth);
      box-shadow: var(--shadow-card);
    }

    .feature-card:hover {
      transform: translateY(-10px);
      box-shadow: 0 20px 36px rgba(123, 47, 255, 0.25);
      border-color: rgba(212, 255, 0, 0.25);
    }

    .icon-box {
      width: 56px;
      height: 56px;
      border-radius: 16px;
      background: linear-gradient(135deg, var(--purple-spark), var(--neon-lime));
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      font-size: 24px;
      color: white;
    }

    .feature-card h3 {
      font-size: 1.4rem;
      font-weight: 600;
      color: #fff;
      margin-bottom: 12px;
    }

    .service-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      margin-top: 40px;
    }

    .service-card {
      background: var(--surface);
      border-radius: var(--radius-xl);
      padding: 36px;
      border: 1px solid rgba(123, 47, 255, 0.2);
    }

    .steps {
      display: flex;
      justify-content: space-between;
      margin-top: 48px;
    }

    .step-item {
      text-align: center;
      flex: 1;
    }

    .step-num {
      font-family: var(--font-mono);
      font-size: 3.2rem;
      font-weight: 800;
      background: linear-gradient(135deg, var(--neon-lime), var(--purple-spark));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .stats {
      display: flex;
      justify-content: center;
      gap: 3rem;
      margin: 40px 0;
    }

    .stat-badge {
      background: #0f131f;
      border: 1px solid rgba(212,255,0,0.2);
      border-radius: 24px;
      padding: 18px 32px;
      text-align: center;
    }

    .faq-item {
      background: var(--surface);
      border-radius: 16px;
      margin-bottom: 16px;
      padding: 18px 24px;
      border-left: 4px solid transparent;
      transition: 0.2s;
      cursor: pointer;
    }

    .faq-item.active {
      border-left-color: var(--purple-spark);
      background: #1b1f2d;
    }

    .cta-section {
      background: #0b0f18;
      padding: 100px 0;
      text-align: center;
    }

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

    @media (max-width: 1024px) {
      .card-grid { grid-template-columns: repeat(2,1fr); }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu.active { display: flex; flex-direction: column; background: #0a0e17; position: fixed; top:72px; left:0; width:100%; padding:24px; gap:20px; }
      .hero .container { grid-template-columns: 1fr; }
      h1 { font-size: 2.4rem; }
      .card-grid, .service-grid, .footer-grid { grid-template-columns: 1fr; }
      .steps { flex-direction: column; gap: 30px; }
      .stats { flex-wrap: wrap; }
    }