/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary: #6C3CF0;
      --primary-light: #A855F7;
      --gold: #FFD700;
      --gold-dark: #E6BE00;
      --deep-bg: #0A0E27;
      --surface-light: #F5F3FF;
      --card-white: #FFFFFF;
      --text-main: #1E1B4B;
      --text-secondary: #6B7280;
      --danger: #FF3366;
      --success: #10B981;
      --radius-card: 16px;
      --radius-inner: 12px;
      --radius-btn: 50px;
      --shadow-default: 0 4px 20px rgba(108, 60, 240, 0.06);
      --shadow-hover: 0 12px 32px rgba(108, 60, 240, 0.15);
      --brand-gradient: linear-gradient(135deg, #6C3CF0 0%, #A855F7 60%, #FFD700 100%);
      --card-micro-gradient: linear-gradient(180deg, rgba(108,60,240,0.03) 0%, rgba(255,215,0,0.03) 100%);
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-mono: 'JetBrains Mono', 'DIN Alternate', monospace;
      --transition-smooth: all 0.25s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--surface-light);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input {
      font-family: inherit;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* ----- 导航：卡片化控制面板 ----- */
    .main-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(10, 14, 39, 0.92);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      z-index: 100;
      border-bottom: 1px solid rgba(108, 60, 240, 0.3);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      padding: 12px 24px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: 24px;
      color: white;
      letter-spacing: 1px;
    }
    .logo-icon {
      font-size: 28px;
      color: var(--gold);
      filter: drop-shadow(0 0 6px rgba(255,215,0,0.6));
    }
    .nav-links {
      display: flex;
      gap: 8px;
      align-items: center;
    }
    .nav-card {
      display: flex;
      align-items: center;
      gap: 6px;
      padding: 8px 16px;
      border-radius: 10px;
      background: transparent;
      color: rgba(255,255,255,0.8);
      font-weight: 500;
      font-size: 15px;
      transition: var(--transition-smooth);
      border: 1px solid transparent;
    }
    .nav-card i {
      font-size: 16px;
      color: var(--primary-light);
    }
    .nav-card:hover {
      background: rgba(108, 60, 240, 0.3);
      color: white;
      border-color: rgba(255,215,0,0.3);
    }
    .nav-cta {
      background: var(--gold);
      color: #0A0E27;
      font-weight: 700;
      padding: 10px 22px;
      border-radius: 50px;
      margin-left: 16px;
      transition: var(--transition-smooth);
      border: none;
      font-size: 15px;
      cursor: pointer;
    }
    .nav-cta:hover {
      background: #FFE566;
      box-shadow: 0 0 14px rgba(255,215,0,0.5);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(10,14,39,0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        gap: 12px;
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .nav-card {
        width: 100%;
        justify-content: center;
        font-size: 18px;
        padding: 14px;
      }
      .nav-cta {
        margin-left: 0;
        width: 100%;
        text-align: center;
      }
    }

    /* ----- 首屏 Hero ----- */
    .hero {
      background: var(--deep-bg);
      background-image: radial-gradient(circle at 30% 40%, rgba(108,60,240,0.4) 0%, transparent 50%), 
                        linear-gradient(135deg, #0A0E27 0%, #1E1B4B 100%);
      padding: 140px 0 80px;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-content {
      flex: 1;
      color: white;
    }
    .hero h1 {
      font-family: var(--font-heading);
      font-size: 56px;
      font-weight: 800;
      line-height: 1.15;
      margin-bottom: 20px;
      background: linear-gradient(to right, #fff, #FFD700);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--brand-gradient);
      color: white;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: 50px;
      border: none;
      cursor: pointer;
      transition: var(--transition-smooth);
      font-size: 16px;
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      box-shadow: 0 8px 20px rgba(108,60,240,0.5);
      transform: scale(1.03);
    }
    .btn-ghost {
      background: transparent;
      border: 2px solid rgba(255,255,255,0.3);
      color: white;
      padding: 14px 32px;
      border-radius: 50px;
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition-smooth);
    }
    .btn-ghost:hover {
      background: rgba(255,255,255,0.1);
      border-color: white;
    }
    .hero-visual {
      flex: 1;
      text-align: center;
    }
    .hero-visual img {
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    }
    .data-badges {
      display: flex;
      gap: 20px;
      margin-top: 40px;
      flex-wrap: wrap;
    }
    .badge {
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(8px);
      padding: 16px 20px;
      border-radius: 12px;
      color: white;
      display: flex;
      align-items: center;
      gap: 12px;
      border: 1px solid rgba(255,215,0,0.25);
    }
    .badge-num {
      font-family: var(--font-mono);
      font-size: 28px;
      font-weight: 700;
      color: var(--gold);
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero h1 {
        font-size: 36px;
      }
      .data-badges {
        justify-content: center;
      }
    }

    /* 板块通用 */
    .section {
      padding: 80px 0;
    }
    .section h2 {
      font-family: var(--font-heading);
      font-size: 40px;
      font-weight: 700;
      text-align: center;
      margin-bottom: 48px;
    }
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-default);
      border: 1px solid rgba(108,60,240,0.08);
      transition: var(--transition-smooth);
      background: linear-gradient(180deg, #FFFFFF 0%, #FAF9FF 100%);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      background: var(--card-micro-gradient);
    }
    @media (max-width: 1024px) {
      .cards-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .cards-grid {
        grid-template-columns: 1fr;
      }
      .section h2 {
        font-size: 28px;
      }
    }

    /* 功能分组 tab 风格 */
    .features-panel {
      display: flex;
      gap: 32px;
    }
    .feature-tabs {
      display: flex;
      flex-direction: column;
      gap: 8px;
      min-width: 200px;
    }
    .tab-btn {
      background: transparent;
      border: none;
      padding: 14px 20px;
      border-radius: 12px;
      font-weight: 600;
      color: var(--text-secondary);
      cursor: pointer;
      transition: var(--transition-smooth);
      text-align: left;
    }
    .tab-btn.active {
      background: var(--primary);
      color: white;
    }
    .feature-content {
      flex: 1;
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
    }
    @media (max-width: 768px) {
      .features-panel {
        flex-direction: column;
      }
      .feature-tabs {
        flex-direction: row;
        overflow-x: auto;
      }
    }

    /* 场景双卡 */
    .scenario-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .scenario-card {
      background: #1A1F3A;
      border-radius: 24px;
      padding: 32px;
      color: white;
    }
    @media (max-width: 640px) {
      .scenario-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 12px;
      padding: 16px 24px;
      cursor: pointer;
      border: 1px solid rgba(108,60,240,0.1);
    }
    .faq-question {
      font-weight: 700;
      display: flex;
      justify-content: space-between;
    }

    /* CTA 深色区 */
    .cta-dark {
      background: var(--deep-bg);
      text-align: center;
      padding: 80px 24px;
      color: white;
    }
    .footer {
      background: #0A0E27;
      color: rgba(255,255,255,0.7);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(5,1fr);
      gap: 24px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }