/* roulang page: index */
:root {
      --primary-black: #0B0E14;
      --milan-gold: #C9A96E;
      --gold-hover: #B8934A;
      --travertine-white: #E8E3D9;
      --deep-gray-blue: #1C2128;
      --medium-gray: #6B7280;
      --soft-gray-bg: #F5F3EF;
      --border-subtle: rgba(201, 169, 110, 0.12);
      --border-light: #E5E7EB;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --font-mono: 'Inter', 'SF Mono', system-ui, monospace;
      --radius-card: 12px;
      --radius-btn: 8px;
      --spacing-section: 120px;
      --max-width: 1280px;
      --nav-height: 56px;
      --transition-fast: 0.25s ease-out;
      --transition-smooth: 0.35s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--primary-black);
      color: var(--travertine-white);
      line-height: 1.7;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

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

    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(11, 14, 20, 0.88);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 1000;
      border-bottom: 1px solid rgba(201, 169, 110, 0.15);
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo-area {
      display: flex;
      align-items: baseline;
      gap: 8px;
    }

    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--milan-gold);
      letter-spacing: -0.3px;
    }

    .domain-tag {
      font-size: 11px;
      color: var(--medium-gray);
      font-weight: 400;
    }

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

    .nav-links a {
      font-size: 14px;
      font-weight: 500;
      color: var(--travertine-white);
      position: relative;
      padding: 4px 0;
      transition: color var(--transition-fast);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0%;
      height: 2px;
      background-color: var(--milan-gold);
      transition: width var(--transition-smooth);
    }

    .nav-links a:hover {
      color: var(--milan-gold);
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .nav-cta {
      display: flex;
      align-items: center;
    }

    .btn-primary {
      background-color: var(--milan-gold);
      color: var(--primary-black);
      font-weight: 600;
      border: none;
      border-radius: var(--radius-btn);
      padding: 10px 22px;
      font-size: 14px;
      cursor: pointer;
      transition: background-color var(--transition-fast), transform var(--transition-fast);
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      background-color: var(--gold-hover);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--milan-gold);
      color: var(--milan-gold);
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 10px 22px;
      font-size: 14px;
      cursor: pointer;
      transition: all var(--transition-fast);
      display: inline-block;
    }

    .btn-outline:hover {
      background-color: rgba(201, 169, 110, 0.1);
      transform: translateY(-2px);
    }

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

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--milan-gold);
      transition: var(--transition-fast);
    }

    /* Hero 分屏 */
    .hero-section {
      display: flex;
      min-height: 100vh;
      padding-top: var(--nav-height);
      background-color: var(--primary-black);
    }

    .hero-left {
      width: 55%;
      display: flex;
      align-items: center;
      padding: 0 48px 0 24px;
    }

    .hero-content {
      max-width: 600px;
    }

    .hero-content h1 {
      font-size: 56px;
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--travertine-white);
      line-height: 1.2;
      margin-bottom: 24px;
    }

    .hero-sub {
      font-size: 18px;
      line-height: 1.6;
      color: rgba(232, 227, 217, 0.8);
      margin-bottom: 40px;
      max-width: 68ch;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-right {
      width: 45%;
      position: relative;
      overflow: hidden;
    }

    .hero-image {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .data-overlay {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 20% 30%, rgba(201,169,110,0.08) 0%, transparent 60%);
      pointer-events: none;
    }

    .particle-line {
      position: absolute;
      width: 1px;
      height: 60px;
      background: linear-gradient(to bottom, transparent, var(--milan-gold), transparent);
      opacity: 0.3;
      animation: drift 4s infinite alternate;
    }

    @keyframes drift {
      0% { transform: translateY(0); opacity: 0.2; }
      100% { transform: translateY(-30px); opacity: 0.6; }
    }

    /* 板块通用 */
    section {
      padding: var(--spacing-section) 0;
    }

    .section-title {
      font-size: 40px;
      font-weight: 600;
      letter-spacing: -0.01em;
      margin-bottom: 16px;
    }

    .gold-line {
      width: 40px;
      height: 2px;
      background-color: var(--milan-gold);
      margin: 0 auto 48px;
    }

    .bg-dark {
      background-color: var(--primary-black);
      color: var(--travertine-white);
    }

    .bg-soft {
      background-color: var(--soft-gray-bg);
      color: var(--primary-black);
    }

    .bg-soft .section-title {
      color: var(--primary-black);
    }

    /* 指标看板 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .metric-card {
      background: var(--deep-gray-blue);
      border-radius: var(--radius-card);
      padding: 32px;
      text-align: center;
      border: 1px solid transparent;
      transition: all var(--transition-fast);
    }

    .metric-card:hover {
      border-color: var(--milan-gold);
      transform: translateY(-4px);
    }

    .metric-number {
      font-family: var(--font-mono);
      font-size: 48px;
      font-weight: 700;
      color: var(--milan-gold);
      transition: transform 0.2s;
    }

    .metric-card:hover .metric-number {
      transform: scale(1.05);
    }

    .metric-label {
      font-size: 14px;
      color: var(--travertine-white);
      margin-top: 8px;
    }

    .trend {
      display: inline-block;
      margin-top: 6px;
      font-size: 14px;
    }

    /* 服务矩阵 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }

    .service-card {
      background: white;
      border-radius: var(--radius-card);
      display: flex;
      overflow: hidden;
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      transition: all var(--transition-fast);
      border: 1px solid transparent;
    }

    .service-card:hover {
      box-shadow: 0 12px 24px rgba(0,0,0,0.08);
      transform: translateX(4px);
      border-color: var(--milan-gold);
    }

    .service-text {
      padding: 32px;
      flex: 1;
    }

    .service-text h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--primary-black);
      margin-bottom: 12px;
    }

    .service-desc {
      color: var(--medium-gray);
      font-size: 16px;
      margin-bottom: 18px;
    }

    .service-link {
      color: var(--milan-gold);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    .service-img {
      width: 40%;
      object-fit: cover;
      filter: grayscale(40%);
      transition: filter var(--transition-fast);
    }

    .service-card:hover .service-img {
      filter: grayscale(0%);
    }

    /* 对比区 */
    .compare-wrapper {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 24px;
      flex-wrap: wrap;
    }

    .compare-card {
      background: var(--deep-gray-blue);
      border-radius: var(--radius-card);
      padding: 32px;
      flex: 1;
      min-width: 280px;
    }

    .compare-card.before {
      opacity: 0.8;
    }

    .compare-card.after {
      border: 1px solid var(--milan-gold);
    }

    .compare-list {
      list-style: none;
    }

    .compare-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
      font-size: 16px;
    }

    .vs-divider {
      font-size: 24px;
      font-weight: 700;
      color: var(--milan-gold);
      border: 1px solid var(--milan-gold);
      border-radius: 50%;
      width: 50px;
      height: 50px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .result-highlight {
      font-size: 24px;
      font-weight: 700;
      color: var(--milan-gold);
      text-align: center;
      margin-top: 32px;
    }

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

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
    }

    .faq-question {
      font-size: 18px;
      font-weight: 500;
      color: var(--primary-black);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      padding-left: 16px;
      border-left: 3px solid var(--milan-gold);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--medium-gray);
      font-size: 16px;
      padding-left: 20px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 16px;
    }

    .arrow {
      transition: transform 0.3s;
    }

    .faq-item.active .arrow {
      transform: rotate(180deg);
    }

    /* 表单 */
    .contact-form {
      max-width: 560px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .form-input {
      background: var(--deep-gray-blue);
      border: 1px solid #374151;
      border-radius: var(--radius-btn);
      padding: 14px 16px;
      color: var(--travertine-white);
      font-size: 16px;
      outline: none;
      transition: border var(--transition-fast);
    }

    .form-input:focus {
      border-color: var(--milan-gold);
    }

    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
    }

    .footer-brand p {
      color: var(--medium-gray);
      font-size: 14px;
    }

    .footer-links a {
      display: block;
      color: var(--medium-gray);
      margin-bottom: 8px;
      font-size: 14px;
    }

    @media (max-width: 1024px) {
      .hero-left { width: 50%; }
      .hero-right { width: 50%; }
    }

    @media (max-width: 768px) {
      .nav-links, .nav-cta { display: none; }
      .hamburger { display: flex; }
      .hero-section { flex-direction: column; }
      .hero-left, .hero-right { width: 100%; }
      .hero-left { padding: 48px 24px; }
      .hero-right { height: 50vh; }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
      .service-grid { grid-template-columns: 1fr; }
      .service-card { flex-direction: column; }
      .service-img { width: 100%; height: 200px; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      h1 { font-size: 36px !important; }
      .section-title { font-size: 28px; }
    }