/* roulang page: index */
:root {
      --color-bg-deep: #0B0C10;
      --color-accent: #FF4C1E;
      --color-accent-glow: rgba(255,76,30,0.4);
      --color-card: #1A1D23;
      --color-text-dim: #A9B4C2;
      --color-text-white: #FFFFFF;
      --color-success: #00C9A7;
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition-default: 0.25s ease-out;
      --container-max: 1280px;
      --font-sans: 'Inter', 'Noto Sans SC', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--color-bg-deep);
      color: var(--color-text-dim);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease, border-color 0.2s ease;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      transition: all 0.2s ease;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      z-index: 100;
      display: flex;
      align-items: center;
      background: transparent;
      backdrop-filter: blur(0px);
      transition: background 0.3s ease, backdrop-filter 0.3s ease;
    }

    .site-header.scrolled {
      background: rgba(26, 29, 35, 0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.2);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-weight: 700;
      font-size: 20px;
      letter-spacing: -0.5px;
      color: var(--color-text-white);
    }
    .logo span {
      color: var(--color-accent);
    }

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

    .nav-links a {
      font-weight: 400;
      color: var(--color-text-dim);
      font-size: 0.95rem;
      position: relative;
      padding: 4px 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--color-accent);
      transition: width 0.2s ease;
    }

    .nav-links a:hover {
      color: var(--color-accent);
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .header-actions {
      display: flex;
      align-items: center;
      gap: 20px;
    }

    .btn-primary {
      background: var(--color-accent);
      color: white;
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-size: 0.9rem;
      box-shadow: 0 0 0 0 var(--color-accent-glow);
      transition: background 0.2s, box-shadow 0.2s;
    }

    .btn-primary:hover {
      background: #ff5e2e;
      box-shadow: 0 0 16px var(--color-accent-glow);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--color-text-dim);
      color: var(--color-text-dim);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
    }
    .btn-outline:hover {
      border-color: var(--color-accent);
      color: white;
      background: var(--color-card);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--color-text-white);
      transition: 0.2s;
    }

    /* 移动端导航面板 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--color-card);
      backdrop-filter: blur(20px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 40px;
      z-index: 99;
      transform: translateY(-100%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.open {
      transform: translateY(0);
    }
    .mobile-menu a {
      font-size: 1.8rem;
      color: var(--color-text-white);
      font-weight: 500;
    }

    /* Hero 分屏 */
    .hero {
      display: flex;
      min-height: 100vh;
      align-items: center;
    }
    .hero-left {
      width: 50%;
      padding: 0 24px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .hero-right {
      width: 50%;
      min-height: 100vh;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-right::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(11,12,16,0.4);
      backdrop-filter: blur(0.5px);
    }
    .hero-grid-overlay {
      position: absolute;
      width: 100%;
      height: 100%;
      background-image: linear-gradient(rgba(169,180,194,0.08) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(169,180,194,0.08) 1px, transparent 1px);
      background-size: 40px 40px;
    }

    .hero-title {
      font-size: clamp(2.8rem, 6vw, 4.2rem);
      font-weight: 700;
      color: white;
      line-height: 1.1;
      letter-spacing: -0.02em;
      margin-bottom: 24px;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--color-text-dim);
      max-width: 480px;
      margin-bottom: 40px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 通用区块 */
    section {
      padding: 120px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 600;
      color: white;
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .section-sub {
      color: var(--color-text-dim);
      font-size: 1.1rem;
      margin-bottom: 48px;
    }

    .grid-3, .grid-4 {
      display: grid;
      gap: 24px;
    }
    .grid-3 { grid-template-columns: repeat(3,1fr); }
    .grid-4 { grid-template-columns: repeat(4,1fr); }

    .card {
      background: var(--color-card);
      border-radius: var(--radius-card);
      border: 1px solid rgba(169,180,194,0.15);
      padding: 32px;
      transition: transform 0.25s ease, border-color 0.2s;
    }
    .card:hover {
      transform: translateY(-4px);
      border-color: var(--color-accent);
    }

    .value-icon {
      font-size: 2rem;
      color: var(--color-accent);
      margin-bottom: 20px;
    }

    /* 产品卡片 */
    .product-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      border-radius: 8px;
      margin-bottom: 20px;
    }
    .tags {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      margin: 16px 0;
    }
    .tag {
      border: 1px solid var(--color-text-dim);
      color: var(--color-text-dim);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
    }

    .case-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
      gap: 20px;
    }
    .case-item {
      position: relative;
      overflow: hidden;
      border-radius: var(--radius-card);
      aspect-ratio: 4/3;
      background: var(--color-card);
    }
    .case-item img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .case-item:hover img {
      transform: scale(1.03);
    }
    .case-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      background: rgba(26,29,35,0.85);
      padding: 16px;
      transform: translateY(100%);
      transition: 0.25s;
    }
    .case-item:hover .case-overlay {
      transform: translateY(0);
    }

    .compare-table {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .compare-card {
      background: var(--color-card);
      border-radius: var(--radius-card);
      padding: 32px;
      border: 1px solid rgba(169,180,194,0.15);
      text-align: center;
    }
    .compare-card.featured {
      border: 2px solid var(--color-accent);
      position: relative;
    }
    .badge {
      background: var(--color-accent);
      color: white;
      font-size: 0.8rem;
      padding: 4px 14px;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
    }

    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid rgba(169,180,194,0.2);
      padding: 24px 0;
    }
    .faq-question {
      font-weight: 600;
      color: white;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--color-text-dim);
    }

    .cta-section {
      background: var(--color-card);
      text-align: center;
      border-radius: 24px;
    }
    .input-group {
      display: flex;
      max-width: 500px;
      margin: 24px auto 0;
    }
    .input-group input {
      flex:1;
      background: var(--color-bg-deep);
      border: 1px solid var(--color-text-dim);
      border-radius: var(--radius-btn) 0 0 var(--radius-btn);
      padding: 14px;
      color: white;
    }
    .input-group button {
      border-radius: 0 var(--radius-btn) var(--radius-btn) 0;
      background: var(--color-accent);
      color: white;
      font-weight: 600;
      padding: 0 24px;
    }

    footer {
      background: var(--color-card);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .social-icons span {
      margin-right: 12px;
      font-size: 1.4rem;
      color: var(--color-text-dim);
    }

    @media (max-width: 1024px) {
      .hero { flex-direction: column; }
      .hero-left, .hero-right { width: 100%; }
      .hero-right { min-height: 60vh; }
      .grid-3, .compare-table { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links, .header-actions .btn-primary { display: none; }
      .hamburger { display: flex; }
      .grid-4 { grid-template-columns: 1fr 1fr; }
      .hero-title { font-size: 2.4rem; }
    }