/* roulang page: index */
/* 设计变量 */
    :root {
      --primary-deep: #0B0C0E;
      --accent-red: #E10600;
      --titanium: #C0C0C0;
      --matte-white: #F5F5F7;
      --glass-bg: rgba(255, 255, 255, 0.03);
      --glass-border: rgba(255, 255, 255, 0.06);
      --font-head: "PingFang SC", "Microsoft YaHei", sans-serif;
      --font-data: "Inter", "DIN Alternate", sans-serif;
      --radius-lg: 16px;
      --radius-pill: 40px;
      --section-padding: 120px;
      --card-gap: 24px;
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--primary-deep);
      color: #E0E0E0;
      line-height: 1.7;
      font-weight: 400;
      overflow-x: hidden;
      background-image: radial-gradient(rgba(255,255,255,0.02) 1px, transparent 1px);
      background-size: 40px 40px;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    h1, h2, h3, .data-number, .hero-title {
      font-family: var(--font-head);
      font-weight: 700;
      letter-spacing: -0.02em;
      color: #FFFFFF;
    }

    h1 {
      font-size: 4.5rem;
      line-height: 1.1;
    }

    h2 {
      font-size: 3rem;
      margin-bottom: 16px;
    }

    .section-title {
      font-size: 3rem;
      font-weight: 700;
      color: #FFFFFF;
      margin-bottom: 12px;
      position: relative;
    }
    .section-subtitle {
      color: var(--titanium);
      font-size: 1.2rem;
      margin-bottom: 48px;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-head);
      font-weight: 600;
      transition: all 0.25s ease;
      border: none;
      outline: none;
    }

    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: transparent;
      transition: background 0.4s ease, backdrop-filter 0.4s ease;
      padding: 16px 0;
    }
    .main-header.scrolled {
      background: rgba(11, 12, 14, 0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.04);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 900;
      font-size: 1.8rem;
      color: #FFFFFF;
      letter-spacing: -0.5px;
    }
    .logo-icon {
      font-size: 2.2rem;
      color: var(--accent-red);
      transform: rotate(-5deg);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-menu a {
      color: var(--titanium);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding-bottom: 6px;
    }
    .nav-menu a.active, .nav-menu a:hover {
      color: #FFFFFF;
    }
    .nav-menu a.active::after, .nav-menu a:hover::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-red);
    }
    .cta-btn-nav {
      background: transparent;
      border: 1px solid var(--titanium);
      color: #FFFFFF;
      padding: 10px 24px;
      border-radius: 40px;
      font-weight: 600;
      font-size: 0.9rem;
    }
    .cta-btn-nav:hover {
      background: rgba(255,255,255,0.1);
      border-color: #FFFFFF;
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      color: #FFFFFF;
      font-size: 1.8rem;
    }

    /* Hero */
    .hero {
      padding: 180px 0 120px;
      display: flex;
      align-items: center;
      min-height: 100vh;
      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: radial-gradient(circle at 20% 30%, rgba(225,6,0,0.15) 0%, rgba(11,12,14,0.7) 70%);
    }
    .hero .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      position: relative;
      z-index: 2;
    }
    .hero-left {
      flex: 1;
    }
    .hero-title {
      font-size: 4.8rem;
      font-weight: 900;
      line-height: 1.15;
      margin-bottom: 24px;
      color: #FFFFFF;
      text-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }
    .hero-dynamic {
      font-size: 1.8rem;
      font-weight: 600;
      color: var(--titanium);
      margin-bottom: 40px;
    }
    .btn-primary {
      background: var(--accent-red);
      color: #FFFFFF;
      padding: 16px 40px;
      border-radius: 40px;
      font-size: 1.1rem;
      font-weight: 700;
      display: inline-block;
      box-shadow: 0 0 20px rgba(225,6,0,0.5);
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      background: #ff1a12;
      box-shadow: 0 0 30px rgba(225,6,0,0.8);
      transform: translateY(-2px);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--titanium);
      color: #FFFFFF;
      padding: 14px 36px;
      border-radius: 40px;
      font-weight: 600;
      margin-left: 16px;
    }
    .btn-secondary:hover {
      background: rgba(255,255,255,0.08);
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .data-dashboard {
      background: rgba(11,12,14,0.7);
      backdrop-filter: blur(16px);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: 24px;
      padding: 32px;
      width: 100%;
      max-width: 380px;
    }
    .live-data {
      display: flex;
      justify-content: space-between;
      margin-bottom: 20px;
    }
    .live-number {
      font-family: var(--font-data);
      font-weight: 800;
      font-size: 2.4rem;
      color: var(--accent-red);
    }

    /* 数据看板 */
    .data-section {
      padding: var(--section-padding) 0;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--glass-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-data);
      font-weight: 800;
      font-size: 3rem;
      color: var(--accent-red);
    }

    /* 服务矩阵 1+2 */
    .services-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .service-main {
      grid-row: span 2;
      background: url('/assets/images/coverpic/cover-1.webp') center/cover no-repeat;
      border-radius: var(--radius-lg);
      padding: 40px;
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      min-height: 480px;
      position: relative;
      overflow: hidden;
    }
    .service-main::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(0deg, rgba(11,12,14,0.9) 10%, transparent 60%);
    }
    .service-main h3, .service-card h3 {
      position: relative;
      z-index: 2;
      font-size: 2rem;
      color: #FFFFFF;
    }
    .service-card {
      background: rgba(255,255,255,0.02);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255,255,255,0.05);
      border-radius: var(--radius-lg);
      padding: 32px;
      display: flex;
      flex-direction: column;
      justify-content: center;
      background-size: cover;
      position: relative;
      overflow: hidden;
    }
    .service-card::before {
      content: '';
      position: absolute;
      top:0;left:0;right:0;bottom:0;
      background: radial-gradient(circle at top right, rgba(225,6,0,0.1), transparent 70%);
    }

    /* 案例对比滑块 */
    .compare-slider {
      position: relative;
      width: 100%;
      height: 400px;
      border-radius: 24px;
      overflow: hidden;
      margin-top: 32px;
    }
    .img-before, .img-after {
      position: absolute;
      top:0; left:0; width:100%; height:100%;
      background-size: cover;
      background-position: center;
    }
    .img-before { background-image: url('/assets/images/coverpic/cover-2.webp'); filter: grayscale(0.8); }
    .img-after { background-image: url('/assets/images/coverpic/cover-3.webp'); clip-path: inset(0 50% 0 0); }
    .handle {
      position: absolute;
      left: 50%;
      top:0; bottom:0; width:4px;
      background: var(--accent-red);
      cursor: ew-resize;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 700;
      font-size: 1.2rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }

    /* 表单 */
    .contact-form input, .contact-form textarea {
      background: transparent;
      border: none;
      border-bottom: 1px solid #444;
      padding: 14px 0;
      width: 100%;
      color: white;
      margin-bottom: 24px;
    }
    .contact-form input:focus {
      border-bottom-color: var(--accent-red);
      outline: none;
    }
    .submit-btn {
      background: var(--accent-red);
      width: 100%;
      padding: 16px;
      border-radius: 40px;
      font-weight: 700;
      color: white;
    }

    footer {
      text-align: center;
      padding: 40px;
      color: var(--titanium);
    }

    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .services-grid { grid-template-columns: 1fr; }
      .hero .container { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .mobile-toggle { display: block; }
      h1 { font-size: 2.8rem; }
      .section-title { font-size: 2.2rem; }
    }