/* roulang page: index */
:root {
      --primary-dark: #0B0E14;
      --primary-bg: #1A1E28;
      --accent-red: #FF4655;
      --accent-gold: #FFD166;
      --card-bg: rgba(30, 35, 48, 0.9);
      --card-border: rgba(255, 70, 85, 0.25);
      --text-primary: #FFFFFF;
      --text-secondary: #B0B8C5;
      --text-muted: #7A8291;
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --radius-badge: 24px;
      --shadow-card: 0 4px 24px rgba(255, 70, 85, 0.08);
      --shadow-card-hover: 0 8px 32px rgba(255, 70, 85, 0.2);
      --transition: all 0.25s ease;
      --font-title: 'Inter', 'Rajdhani', 'Noto Sans SC', system-ui, sans-serif;
      --font-body: 'Inter', 'Noto Sans SC', system-ui, sans-serif;
    }

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

    body {
      background: radial-gradient(circle at 20% 10%, #1A1E28 0%, #0B0E14 85%);
      color: var(--text-primary);
      font-family: var(--font-body);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
      position: relative;
      overflow-x: hidden;
    }

    body::before {
      content: "";
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200" opacity="0.03"><path d="M20 20h160v160H20z" fill="none" stroke="%23FF4655" stroke-width="0.8"/><circle cx="60" cy="60" r="4" fill="%23FFD166"/><circle cx="140" cy="140" r="6" fill="%23FF4655"/><path d="M80 80l40 40M120 80L80 120" stroke="%23FFD166" stroke-width="0.5"/></svg>');
      background-size: 220px 220px;
      pointer-events: none;
      z-index: 0;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
      position: relative;
      z-index: 2;
    }

    h1, h2, h3, .h1, .h2, .h3 {
      font-family: var(--font-title);
      font-weight: 700;
      letter-spacing: -0.02em;
    }

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

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

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

    button, .button {
      background: var(--accent-red);
      color: white;
      border: none;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      border: 1px solid transparent;
      background: linear-gradient(135deg, #FF4655 0%, #E03B4A 100%);
      box-shadow: 0 0 12px rgba(255, 70, 85, 0.3);
    }

    .button:hover {
      background: linear-gradient(135deg, #FFD166 0%, #FF4655 100%);
      box-shadow: 0 0 20px rgba(255, 70, 85, 0.6);
      transform: translateY(-2px);
      color: #0B0E14;
      border-color: var(--accent-gold);
    }

    .button.secondary {
      background: transparent;
      border: 1px solid rgba(255, 255, 255, 0.5);
      color: white;
      box-shadow: none;
    }

    .button.secondary:hover {
      border-color: var(--accent-red);
      background: rgba(255, 70, 85, 0.1);
      color: white;
      box-shadow: 0 0 12px rgba(255, 70, 85, 0.3);
    }

    /* 导航 */
    .site-header {
      background: rgba(11, 14, 20, 0.8);
      backdrop-filter: blur(16px);
      padding: 1rem 0;
      position: sticky;
      top: 0;
      z-index: 100;
      border-bottom: 1px solid rgba(255, 70, 85, 0.15);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: white;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      text-decoration: none;
      letter-spacing: -0.5px;
      background: linear-gradient(to right, #fff, #FFD166);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .logo i {
      font-size: 2rem;
      color: var(--accent-red);
      background: none;
      -webkit-text-fill-color: initial;
    }

    .nav-desktop {
      display: flex;
      gap: 2.5rem;
      align-items: center;
    }

    .nav-desktop a {
      color: var(--text-secondary);
      font-weight: 500;
      font-size: 0.95rem;
      letter-spacing: 0.3px;
      text-transform: uppercase;
      transition: color 0.2s;
    }

    .nav-desktop a:hover {
      color: var(--accent-gold);
    }

    .nav-right {
      display: flex;
      gap: 1.5rem;
    }

    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
    }

    /* 汉堡菜单 */
    @media (max-width: 768px) {
      .nav-desktop {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(11, 14, 20, 0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 2rem;
        gap: 1.8rem;
        border-bottom: 1px solid var(--accent-red);
      }
      .nav-desktop.active {
        display: flex;
      }
      .mobile-toggle {
        display: block;
      }
      .header-inner {
        flex-wrap: wrap;
      }
    }

    /* Hero */
    .hero {
      padding: 3rem 0 4rem;
      display: flex;
      align-items: center;
      gap: 3rem;
      min-height: 80vh;
    }

    .hero-left {
      flex: 1;
    }

    .hero-right {
      flex: 1;
      position: relative;
      display: flex;
      justify-content: center;
    }

    .hero h1 {
      font-size: 3.5rem;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      background: linear-gradient(to right, #fff, #FFD166);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .hero .subtitle {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 2.5rem;
    }

    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }

    .card-stack {
      position: relative;
      width: 320px;
      height: 380px;
    }

    .float-card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: 20px;
      padding: 1.5rem;
      position: absolute;
      backdrop-filter: blur(12px);
      box-shadow: var(--shadow-card);
      transition: 0.2s;
    }

    .card1 {
      top: 10px;
      right: 20px;
      width: 240px;
      z-index: 3;
      transform: rotate(2deg);
    }

    .card2 {
      top: 80px;
      right: 120px;
      width: 200px;
      z-index: 2;
      transform: rotate(-3deg);
    }

    .card3 {
      top: 160px;
      right: 30px;
      width: 220px;
      z-index: 1;
      transform: rotate(1deg);
    }

    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        text-align: center;
        padding: 2rem 0;
      }
      .hero h1 {
        font-size: 2.5rem;
      }
      .card-stack {
        width: 260px;
        height: 300px;
        margin-top: 2rem;
      }
    }

    /* 通用板块 */
    section {
      padding: 4rem 0;
      position: relative;
      z-index: 2;
    }

    .section-title {
      font-size: 2.2rem;
      margin-bottom: 0.5rem;
      text-align: center;
      color: white;
    }

    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      margin-bottom: 3rem;
    }

    /* 服务卡片 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.8rem;
    }

    .service-card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      transition: var(--transition);
      backdrop-filter: blur(8px);
    }

    .service-card:hover {
      box-shadow: var(--shadow-card-hover);
      border-color: var(--accent-red);
    }

    .service-icon {
      font-size: 2.2rem;
      color: var(--accent-gold);
      margin-bottom: 1.2rem;
    }

    .service-card h3 {
      font-size: 1.4rem;
      margin-bottom: 0.8rem;
    }

    @media (max-width: 1024px) {
      .service-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 数据徽章 */
    .stats-row {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 2rem;
      margin: 2rem 0;
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-family: 'Rajdhani', sans-serif;
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--accent-gold);
      line-height: 1;
    }

    .stat-label {
      color: var(--text-secondary);
      margin-top: 0.2rem;
    }

    /* 案例网格 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 2rem;
    }

    .case-card {
      position: relative;
      border-radius: var(--radius-card);
      overflow: hidden;
      background: #1e2330;
    }

    .case-img {
      width: 100%;
      height: 260px;
      object-fit: cover;
    }

    .case-overlay {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(255, 70, 85, 0.15);
      transition: 0.3s;
      display: flex;
      align-items: flex-end;
      padding: 1.5rem;
    }

    .case-card:hover .case-overlay {
      background: rgba(255, 70, 85, 0.5);
    }

    @media (max-width: 640px) {
      .case-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-item {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      margin-bottom: 1rem;
      padding: 1.2rem 1.8rem;
      cursor: pointer;
      transition: 0.2s;
    }

    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }

    .faq-item.active .faq-answer {
      max-height: 180px;
      margin-top: 1rem;
    }

    /* CTA 表单 */
    .cta-section {
      background: linear-gradient(135deg, #1A1E28, #0B0E14);
      border-radius: 24px;
      padding: 3rem;
      border: 1px solid var(--accent-red);
    }

    .form-input {
      background: rgba(255,255,255,0.08);
      border: 1px solid rgba(255,255,255,0.2);
      border-radius: var(--radius-input);
      padding: 0.8rem 1rem;
      color: white;
      width: 100%;
      margin-bottom: 1rem;
    }

    .form-input:focus {
      border-color: var(--accent-red);
      outline: none;
    }

    footer {
      text-align: center;
      padding: 2rem 0;
      border-top: 1px solid rgba(255,70,85,0.2);
      color: var(--text-muted);
    }