/* roulang page: index */
:root {
      --primary-purple: #7B2FBE;
      --accent-cyan: #00F0B5;
      --dark-bg: #0D0B1A;
      --card-bg: #1A1726;
      --text-main: #EDEDF0;
      --text-muted: #9B97A8;
      --border-glow: rgba(123, 47, 190, 0.3);
      --shadow-card: 0 8px 32px rgba(123, 47, 190, 0.15);
      --shadow-hover: 0 12px 48px rgba(123, 47, 190, 0.3);
      --gradient-btn: linear-gradient(135deg, #7B2FBE 0%, #00F0B5 100%);
      --radius-lg: 16px;
      --radius-pill: 50px;
      --font-zh: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-en: 'Rajdhani', 'Orbitron', sans-serif;
      --spacing-section: 100px;
      --spacing-card-gap: 24px;
      --container-max: 1200px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-zh);
      background-color: var(--dark-bg);
      color: var(--text-main);
      line-height: 1.75;
      margin: 0;
      overflow-x: hidden;
    }

    a {
      text-decoration: none;
      color: var(--text-muted);
      transition: color 0.25s ease;
    }

    a:hover {
      color: var(--accent-cyan);
    }

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

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 导航栏 */
    .navbar-custom {
      background: var(--dark-bg);
      border-bottom: 1px solid var(--border-glow);
      height: 72px;
      display: flex;
      align-items: center;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      backdrop-filter: blur(8px);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
      position: relative;
    }

    .logo-center {
      font-family: var(--font-en);
      font-weight: 700;
      font-size: 28px;
      color: var(--accent-cyan);
      letter-spacing: 1px;
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      white-space: nowrap;
      text-shadow: 0 0 12px rgba(0, 240, 181, 0.6);
    }

    .nav-left, .nav-right {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-left {
      margin-right: auto;
      padding-right: 140px;
    }

    .nav-right {
      margin-left: auto;
      padding-left: 140px;
    }

    .nav-link-item {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-muted);
      letter-spacing: 0.5px;
      position: relative;
      padding-bottom: 6px;
      transition: 0.2s;
    }

    .nav-link-item:hover,
    .nav-link-item.active {
      color: var(--accent-cyan);
    }

    .nav-link-item.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-cyan);
      box-shadow: 0 0 10px var(--accent-cyan);
    }

    .navbar-toggler-icon {
      background-image: none;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent-cyan);
      font-size: 24px;
    }

    .navbar-toggler {
      border: 1px solid var(--border-glow);
      padding: 6px 12px;
      border-radius: 8px;
    }

    @media (max-width: 991px) {
      .nav-left, .nav-right {
        display: none;
      }
      .navbar-collapse {
        background: var(--dark-bg);
        padding: 20px;
        border-radius: 0 0 16px 16px;
        border: 1px solid var(--border-glow);
        margin-top: 12px;
      }
      .navbar-collapse .nav-link-item {
        display: block;
        padding: 10px 0;
        text-align: center;
        border-bottom: 1px solid rgba(123,47,190,0.2);
      }
    }

    @media (min-width: 992px) {
      .navbar-toggler, .navbar-collapse {
        display: none;
      }
    }

    /* 按钮系统 */
    .btn-primary-gradient {
      background: var(--gradient-btn);
      border: none;
      color: white;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-pill);
      transition: all 0.25s ease;
      box-shadow: 0 4px 15px rgba(123,47,190,0.4);
      letter-spacing: 0.8px;
    }

    .btn-primary-gradient:hover {
      box-shadow: 0 0 24px rgba(0,240,181,0.6);
      transform: scale(1.03);
      color: white;
    }

    .btn-outline-cyan {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      font-weight: 600;
      padding: 12px 34px;
      border-radius: var(--radius-pill);
      transition: 0.25s ease;
    }

    .btn-outline-cyan:hover {
      background: rgba(0,240,181,0.1);
      color: var(--accent-cyan);
      box-shadow: 0 0 16px rgba(0,240,181,0.4);
    }

    /* 区块标题 */
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 48px;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

    /* Hero */
    #hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 30%, #1a1430 0%, #0D0B1A 80%);
      position: relative;
      overflow: hidden;
      padding-top: 72px;
    }

    .hero-grid-bg {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: linear-gradient(rgba(123,47,190,0.1) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(123,47,190,0.1) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
    }

    .hero-content {
      position: relative;
      z-index: 2;
    }

    .hero-title {
      font-size: 48px;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: white;
      text-shadow: 0 0 25px rgba(123,47,190,0.7);
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      max-width: 560px;
      margin: 20px 0 32px;
    }

    .hero-image-wrapper {
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 0 60px rgba(123,47,190,0.4);
      background: rgba(0,0,0,0.3);
    }

    .hero-image-wrapper img {
      width: 100%;
      height: auto;
      mix-blend-mode: lighten;
    }

    /* 卡片通用 */
    .card-custom {
      background: var(--card-bg);
      border: 1px solid var(--border-glow);
      border-radius: var(--radius-lg);
      padding: 32px;
      transition: all 0.3s ease;
      box-shadow: var(--shadow-card);
      height: 100%;
    }

    .card-custom:hover {
      box-shadow: var(--shadow-hover);
      border-color: var(--accent-cyan);
      transform: translateY(-6px);
    }

    .icon-circle {
      width: 64px;
      height: 64px;
      background: rgba(0,240,181,0.15);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 28px;
      color: var(--accent-cyan);
      margin-bottom: 24px;
    }

    /* 数据徽章 */
    #stats {
      background: #0D0B1A;
      background-image: linear-gradient(rgba(123,47,190,0.05) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(123,47,190,0.05) 1px, transparent 1px);
      background-size: 50px 50px;
    }

    .stat-number {
      font-family: var(--font-en);
      font-size: 56px;
      font-weight: 800;
      color: var(--accent-cyan);
      line-height: 1.2;
    }

    .stat-label {
      color: var(--text-muted);
      font-size: 16px;
      margin-top: 8px;
    }

    .stat-divider {
      width: 1px;
      height: 60px;
      background: var(--border-glow);
    }

    /* 案例卡片 */
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      overflow: hidden;
      border: 1px solid var(--border-glow);
      transition: 0.3s;
    }

    .case-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
      border-color: var(--accent-cyan);
    }

    .case-img {
      height: 200px;
      object-fit: cover;
      width: 100%;
      border-bottom: 2px solid var(--border-glow);
    }

    .badge-cyan {
      background: var(--accent-cyan);
      color: #0D0B1A;
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 4px;
      font-size: 13px;
      letter-spacing: 1px;
    }

    /* 解决方案图文 */
    .solution-text h3 {
      font-size: 28px;
      font-weight: 700;
      color: white;
    }

    .feature-list {
      list-style: none;
      padding-left: 0;
    }

    .feature-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 12px;
      color: var(--text-muted);
    }

    .feature-list i {
      color: var(--accent-cyan);
      font-size: 18px;
    }

    /* FAQ */
    .accordion-button {
      background: var(--card-bg);
      color: var(--text-main);
      font-weight: 600;
      border: 1px solid var(--border-glow);
      border-radius: 12px !important;
      padding: 18px 24px;
      transition: 0.2s;
    }

    .accordion-button:not(.collapsed) {
      background: #2a2338;
      color: white;
      border-color: var(--accent-cyan);
      box-shadow: 0 0 12px rgba(0,240,181,0.25);
    }

    .accordion-button::after {
      filter: brightness(0) invert(1);
    }

    .accordion-item {
      background: transparent;
      border: none;
      margin-bottom: 16px;
    }

    .accordion-body {
      background: #1e1a2b;
      color: var(--text-muted);
      border-radius: 0 0 12px 12px;
    }

    /* CTA */
    #contact {
      background: #0A0815;
      border-top: 1px solid var(--border-glow);
    }

    .footer a {
      color: var(--text-muted);
    }

    .footer a:hover {
      color: var(--accent-cyan);
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 32px;
      }
      .section-title {
        font-size: 28px;
      }
      .stat-number {
        font-size: 42px;
      }
    }