/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary-purple: #7B2FF7;
      --primary-magenta: #E9007A;
      --accent-gold: #FFB800;
      --bg-deep: #0A0E17;
      --card-surface: #141B2D;
      --text-primary: #F0F2F5;
      --text-secondary: #8892A8;
      --border-subtle: rgba(255, 255, 255, 0.06);
      --border-hover: rgba(255, 255, 255, 0.15);
      --radius-card: 20px;
      --radius-btn: 50px;
      --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.4);
      --shadow-hover: 0 12px 32px rgba(123, 47, 247, 0.25);
      --font-sans: 'Inter', 'PingFang SC', 'MiSans', 'HarmonyOS Sans', system-ui, -apple-system, sans-serif;
      --font-mono: 'Space Grotesk', 'Inter', monospace;
      --transition-smooth: all 0.25s ease;
      --container-max: 1280px;
    }

    /* ----- 基础重置 ----- */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    ul {
      list-style: none;
    }

    /* ----- 容器与布局 ----- */
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }
    section {
      padding: 100px 0;
      position: relative;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    /* ----- 导航栏 (沉浸式固定) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 23, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.08);
      transition: var(--transition-smooth);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.8rem;
      background: linear-gradient(135deg, var(--primary-purple), var(--primary-magenta));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 2px;
    }
    .logo i {
      font-size: 2rem;
      background: none;
      -webkit-text-fill-color: var(--primary-magenta);
      text-shadow: 0 0 8px rgba(233,0,122,0.5);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 8px 0;
      letter-spacing: 0.5px;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-gold);
      transition: width 0.2s ease;
    }
    .nav-link:hover {
      color: var(--accent-gold);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--text-primary);
      background: none;
      border: none;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: #0A0E17;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        transition: right 0.3s ease;
        box-shadow: -5px 0 25px rgba(0,0,0,0.5);
        backdrop-filter: blur(20px);
        background: rgba(10, 14, 23, 0.95);
      }
      .nav-menu.active {
        right: 0;
      }
      .hamburger {
        display: block;
      }
      .close-menu {
        position: absolute;
        top: 25px;
        right: 25px;
        font-size: 2rem;
        color: white;
        background: none;
        border: none;
      }
    }

    /* ----- 按钮体系 ----- */
    .btn-primary {
      background: linear-gradient(135deg, var(--primary-purple), var(--primary-magenta));
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: all 0.3s ease;
      border: none;
      box-shadow: 0 4px 15px rgba(123,47,247,0.3);
    }
    .btn-primary:hover {
      background: linear-gradient(155deg, var(--primary-purple), var(--primary-magenta));
      box-shadow: 0 0 24px rgba(233,0,122,0.5);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 12px 30px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.3s ease;
    }
    .btn-outline:hover {
      border-color: var(--primary-purple);
      background: rgba(123,47,247,0.15);
      color: white;
      box-shadow: 0 0 15px rgba(123,47,247,0.3);
    }
    .btn-gold {
      background: var(--accent-gold);
      color: #0A0E17;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: 0.3s;
    }
    .btn-gold:hover {
      background: #ffc933;
      box-shadow: 0 0 20px rgba(255,184,0,0.5);
    }

    /* ----- Hero 区域 ----- */
    .hero {
      padding-top: 140px;
      padding-bottom: 100px;
      background: radial-gradient(circle at 30% 20%, rgba(123,47,247,0.18), transparent 50%),
                  radial-gradient(circle at 80% 40%, rgba(233,0,122,0.12), transparent 60%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 60px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 24px;
      background: linear-gradient(to right, #fff, #e0e0ff);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 36px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .hero-right {
      position: relative;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }
    .hero-image {
      width: 100%;
      border-radius: 32px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.6);
      border: 1px solid rgba(255,255,255,0.1);
    }
    .data-badge-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 14px;
    }
    .data-badge {
      background: rgba(20,27,45,0.8);
      backdrop-filter: blur(8px);
      border-radius: 16px;
      padding: 16px 10px;
      text-align: center;
      border: 1px solid var(--border-subtle);
    }
    .badge-number {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--accent-gold);
      font-family: var(--font-mono);
    }
    .badge-label {
      font-size: 0.8rem;
      color: var(--text-secondary);
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      .hero-left h1 {
        font-size: 2.4rem;
      }
    }

    /* 亮点网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 28px;
    }
    .feature-card {
      background: var(--card-surface);
      border-radius: var(--radius-card);
      padding: 32px;
      border: 1px solid var(--border-subtle);
      transition: var(--transition-smooth);
      position: relative;
      overflow: hidden;
    }
    .feature-card:hover {
      border-color: var(--border-hover);
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      font-size: 2.5rem;
      color: var(--primary-purple);
      margin-bottom: 20px;
    }
    .feature-title {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 10px;
    }
    .feature-stat {
      font-size: 2rem;
      font-weight: 700;
      color: var(--accent-gold);
      margin: 12px 0 8px;
    }
    .feature-desc {
      color: var(--text-secondary);
      font-size: 0.95rem;
    }

    /* 案例瀑布流 */
    .waterfall {
      columns: 3;
      column-gap: 24px;
    }
    .case-card {
      break-inside: avoid;
      margin-bottom: 24px;
      background: var(--card-surface);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-subtle);
      transition: 0.2s;
    }
    .case-card:hover {
      border-color: var(--border-hover);
    }
    .case-img {
      position: relative;
    }
    .case-img img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
    }
    .case-tag {
      position: absolute;
      top: 12px;
      left: 12px;
      background: var(--primary-magenta);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
    }
    .case-body {
      padding: 20px;
    }
    .case-title {
      font-weight: 600;
      font-size: 1.1rem;
      margin-bottom: 12px;
    }
    .case-meta {
      display: flex;
      justify-content: space-between;
      color: var(--text-secondary);
      font-size: 0.85rem;
    }
    .win-badge {
      color: var(--accent-gold);
      font-weight: 700;
    }
    @media (max-width: 768px) {
      .waterfall {
        columns: 1;
      }
    }

    /* 方案对比 */
    .compare-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
    }
    .plan-card {
      background: var(--card-surface);
      border-radius: var(--radius-card);
      padding: 36px 28px;
      border-top: 5px solid var(--primary-purple);
    }
    .plan-card.premium {
      border-top-color: var(--primary-magenta);
    }
    .plan-header {
      font-size: 1.8rem;
      font-weight: 700;
    }
    .plan-price {
      color: var(--accent-gold);
      margin: 12px 0 24px;
    }
    .feature-list li {
      padding: 10px 0;
      border-bottom: 1px solid var(--border-subtle);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .gold-star {
      color: var(--accent-gold);
    }
    @media (max-width: 768px) {
      .compare-row {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1.2fr;
      gap: 60px;
    }
    .accordion-item {
      border-bottom: 1px solid var(--border-subtle);
      padding: 18px 0;
    }
    .accordion-question {
      width: 100%;
      text-align: left;
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      background: none;
      border: none;
      color: white;
      cursor: pointer;
    }
    .accordion-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      padding-right: 15px;
    }
    .accordion-answer.open {
      max-height: 200px;
      margin-top: 12px;
    }
    @media (max-width: 768px) {
      .faq-grid {
        grid-template-columns: 1fr;
      }
    }

    /* CTA 横幅 */
    .cta-band {
      background: linear-gradient(150deg, #7B2FF7, #E9007A);
      border-radius: 40px;
      padding: 70px 40px;
      text-align: center;
      margin: 0 24px;
      position: relative;
    }
    .cta-band h2 {
      font-size: 2.4rem;
      margin-bottom: 20px;
    }
    .cta-buttons {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
      margin-top: 30px;
    }
    @media (max-width: 768px) {
      .cta-band {
        margin: 0 16px;
        padding: 50px 20px;
      }
    }

    /* 页脚 */
    .footer {
      background: #080C14;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .social-icons i {
      font-size: 1.5rem;
      margin-right: 16px;
      color: var(--text-secondary);
      transition: 0.3s;
    }
    .social-icons i:hover {
      color: var(--accent-gold);
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    .copyright {
      border-top: 1px solid var(--border-subtle);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      color: var(--text-secondary);
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      margin-bottom: 16px;
    }