/* roulang page: index */
/* ===== CSS 变量与全局重置 ===== */
    :root {
      --primary-red: #E63946;
      --primary-red-hover: #C1121F;
      --deep-black: #1A1A2E;
      --data-cyan: #00B4D8;
      --metal-gray: #6C757D;
      --light-bg: #F8F9FA;
      --white: #FFFFFF;
      --gold-accent: #F4A261;
      
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-mono: 'DIN Alternate', 'Roboto Mono', 'Courier New', monospace;
      
      --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.25);
      --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.4);
      --shadow-card-light: 0 4px 15px rgba(0, 0, 0, 0.08);
      --border-radius-card: 12px;
      --border-radius-btn: 8px;
      --border-radius-input: 6px;
      --border-radius-badge: 20px;
      --transition-smooth: all 0.25s ease;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--deep-black);
      color: #e0e0e0;
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    a, button, input, textarea {
      font-family: inherit;
    }

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* ===== 导航 (沉浸式毛玻璃) ===== */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(26, 26, 46, 0.75);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      transition: background 0.3s ease;
    }

    .navbar.scrolled {
      background: rgba(26, 26, 46, 0.95);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 70px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      text-decoration: none;
      color: var(--white);
      font-weight: 700;
      font-size: 24px;
      letter-spacing: -0.02em;
    }

    .logo-icon {
      font-size: 28px;
      color: var(--primary-red);
      display: flex;
      align-items: center;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      color: #cccccc;
      text-decoration: none;
      font-weight: 500;
      font-size: 16px;
      position: relative;
      padding: 8px 0;
      transition: var(--transition-smooth);
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--primary-red);
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-red);
      transition: width 0.25s ease;
    }

    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }

    .btn-nav-cta {
      background: var(--primary-red);
      color: white;
      border: none;
      padding: 10px 24px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition-smooth);
      text-decoration: none;
      display: inline-block;
    }

    .btn-nav-cta:hover {
      background: var(--primary-red-hover);
      transform: scale(1.03);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      cursor: pointer;
      gap: 5px;
    }

    .hamburger span {
      width: 25px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }

    /* 移动端抽屉 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: -100%;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: var(--deep-black);
      z-index: 1001;
      padding: 80px 32px;
      transition: right 0.3s ease;
      box-shadow: -5px 0 25px rgba(0,0,0,0.5);
      display: flex;
      flex-direction: column;
      gap: 28px;
    }

    .mobile-drawer.open {
      right: 0;
    }

    .mobile-drawer .nav-link {
      font-size: 20px;
      display: block;
    }

    .drawer-close {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }

    /* ===== 区块通用间距 ===== */
    section {
      padding: 80px 0;
    }

    /* ===== 首屏/数据看板 (Hero) ===== */
    .hero-dashboard {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 20% 30%, #2a2a4a, var(--deep-black) 80%);
      position: relative;
      overflow: hidden;
    }

    .hero-bg-grid {
      position: absolute;
      top:0;
      left:0;
      width:100%;
      height:100%;
      background-image: 
        linear-gradient(rgba(0,180,216,0.08) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,180,216,0.08) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
    }

    .hero-content {
      text-align: center;
      position: relative;
      z-index: 2;
      width: 100%;
    }

    .hero-title {
      font-family: var(--font-title);
      font-size: clamp(40px, 8vw, 56px);
      font-weight: 700;
      letter-spacing: -0.02em;
      color: white;
      margin-bottom: 16px;
      line-height: 1.2;
    }

    .hero-title span {
      color: var(--primary-red);
    }

    .hero-subtitle {
      font-size: 20px;
      color: #b0b0c0;
      max-width: 700px;
      margin: 0 auto 48px;
    }

    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin: 40px 0 48px;
    }

    .metric-card {
      background: rgba(255,255,255,0.05);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255,255,255,0.08);
      border-radius: var(--border-radius-card);
      padding: 28px 16px;
      text-align: center;
    }

    .metric-number {
      font-family: var(--font-mono);
      font-size: 42px;
      font-weight: 700;
      color: var(--data-cyan);
      line-height: 1.2;
      margin-bottom: 8px;
    }

    .metric-number.red {
      color: var(--primary-red);
    }

    .metric-label {
      font-size: 15px;
      color: var(--metal-gray);
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .hero-cta-group {
      display: flex;
      justify-content: center;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--primary-red);
      color: white;
      border: none;
      padding: 14px 40px;
      border-radius: var(--border-radius-btn);
      font-weight: 700;
      font-size: 18px;
      cursor: pointer;
      transition: var(--transition-smooth);
      text-decoration: none;
      display: inline-block;
    }

    .btn-primary:hover {
      background: var(--primary-red-hover);
      transform: scale(1.03);
      box-shadow: 0 8px 20px rgba(230,57,70,0.4);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-red);
      color: white;
      padding: 12px 38px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition-smooth);
      text-decoration: none;
    }

    .btn-outline:hover {
      background: rgba(230,57,70,0.15);
    }

    /* ===== 服务矩阵 (非对称) ===== */
    .services-section {
      background: var(--light-bg);
      color: #1e1e2e;
    }

    .section-title {
      font-family: var(--font-title);
      font-size: clamp(32px, 6vw, 40px);
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--deep-black);
      text-align: center;
    }

    .section-subtitle {
      color: var(--metal-gray);
      text-align: center;
      margin-bottom: 56px;
    }

    .services-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 24px;
    }

    .service-card {
      background: var(--white);
      border-radius: var(--border-radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card-light);
      transition: var(--transition-smooth);
      display: flex;
      flex-direction: column;
    }

    .service-card:first-child {
      grid-row: span 2;
    }

    .service-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }

    .service-icon {
      font-size: 36px;
      color: var(--primary-red);
      margin-bottom: 20px;
    }

    .service-title {
      font-size: 24px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    .service-desc {
      color: #555;
      margin-bottom: 20px;
      flex:1;
    }

    .service-link {
      color: var(--primary-red);
      text-decoration: none;
      font-weight: 600;
      align-self: flex-start;
    }

    .right-col {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    /* ===== 对比区 (分屏) ===== */
    .compare-section {
      background: var(--deep-black);
    }

    .compare-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      margin-top: 40px;
    }

    .compare-panel {
      padding: 40px 28px;
      border-radius: var(--border-radius-card);
    }

    .compare-panel.left {
      background: #2a2a3a;
      border: 1px solid #444;
      color: #aaa;
    }

    .compare-panel.right {
      background: rgba(0,180,216,0.08);
      border: 1px solid var(--data-cyan);
      color: white;
    }

    .compare-item {
      display: flex;
      justify-content: space-between;
      padding: 14px 0;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    .compare-value {
      font-weight: 700;
    }

    .right .compare-value {
      color: var(--data-cyan);
    }

    /* ===== 案例卡片横向滚动 ===== */
    .cases-section {
      background: var(--light-bg);
    }

    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding: 20px 0 30px;
      scroll-snap-type: x mandatory;
    }

    .case-card {
      min-width: 300px;
      max-width: 320px;
      background: white;
      border-radius: var(--border-radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card-light);
      scroll-snap-align: start;
      flex-shrink: 0;
      transition: var(--transition-smooth);
    }

    .case-card:hover {
      transform: translateY(-6px);
    }

    .case-img {
      height: 180px;
      background: #ddd;
    }

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

    .case-info {
      padding: 20px;
      color: #222;
    }

    .case-tags {
      display: flex;
      gap: 8px;
      margin-top: 10px;
    }

    .badge {
      background: var(--gold-accent);
      color: #000;
      padding: 4px 12px;
      border-radius: var(--border-radius-badge);
      font-size: 12px;
      font-weight: 600;
    }

    /* ===== FAQ ===== */
    .faq-section {
      background: var(--deep-black);
    }

    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: rgba(255,255,255,0.06);
      border-radius: 12px;
      margin-bottom: 16px;
      overflow: hidden;
    }

    .faq-question {
      padding: 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: white;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: rgba(0,0,0,0.3);
      color: #ccc;
      padding: 0 24px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 24px;
    }

    /* ===== 表单 ===== */
    .contact-section {
      background: radial-gradient(circle at 80% 50%, #2a2a4a, #1a1a2e);
    }

    .form-card {
      background: white;
      border-radius: var(--border-radius-card);
      padding: 48px;
      max-width: 700px;
      margin: 0 auto;
      color: #333;
    }

    .form-group {
      margin-bottom: 20px;
    }

    .form-group input,
    .form-group textarea {
      width: 100%;
      padding: 14px;
      border: 1px solid #ddd;
      border-radius: var(--border-radius-input);
      font-size: 16px;
    }

    .btn-submit {
      background: var(--primary-red);
      color: white;
      width: 100%;
      padding: 16px;
      border: none;
      border-radius: var(--border-radius-btn);
      font-weight: 700;
      cursor: pointer;
    }

    /* ===== 页脚 ===== */
    .footer {
      background: #0f0f1a;
      padding: 48px 0 24px;
      color: var(--metal-gray);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 32px;
    }

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

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .compare-wrapper { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .metrics-grid { grid-template-columns: 1fr; }
    }