/* roulang page: index */
:root {
      --color-obsidian: #0B0C0E;
      --color-flame: #FF4F00;
      --color-track: #E5E5E7;
      --color-cyan-data: #00C2BA;
      --color-white: #FFFFFF;
      --color-gray-dark: #2C2D30;
      --color-gray-soft: #F5F5F7;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "Inter", "DIN Alternate", "Arial", sans-serif;
      --shadow-neo: 8px 8px 0px rgba(0,0,0,0.04);
      --shadow-hover: 12px 12px 0px rgba(0,0,0,0.08);
      --border-thin: 1px solid rgba(0,0,0,0.06);
      --radius-none: 0px;
      --radius-sm: 2px;
      --transition-burst: 0.2s cubic-bezier(0.25, 0.8, 0.25, 1);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--color-white);
      color: var(--color-obsidian);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input {
      font-family: var(--font-sans);
      outline: none;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,0,0,0.05);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 800;
      font-size: 1.7rem;
      color: var(--color-obsidian);
      letter-spacing: -0.02em;
    }
    .logo-dot {
      display: inline-block;
      width: 8px;
      height: 8px;
      background: var(--color-flame);
    }
    .nav-links {
      display: flex;
      gap: 2.5rem;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      color: #1A1A1A;
      transition: color var(--transition-burst);
      position: relative;
      padding: 4px 0;
    }
    .nav-links a:hover {
      color: var(--color-flame);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--color-flame);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-cta {
      background: var(--color-flame);
      color: white;
      padding: 12px 26px;
      font-weight: 700;
      border: none;
      cursor: pointer;
      transition: all var(--transition-burst);
      font-size: 0.95rem;
      letter-spacing: 0.5px;
    }
    .btn-cta:hover {
      background: var(--color-obsidian);
      color: white;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger div {
      width: 25px;
      height: 2px;
      background: var(--color-obsidian);
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
      flex-direction: column;
      background: white;
      padding: 1.5rem 2rem;
      border-top: 1px solid #eee;
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-tag {
      display: flex;
      align-items: center;
      gap: 14px;
      margin-bottom: 1.5rem;
    }
    .orange-short-line {
      width: 40px;
      height: 3px;
      background: var(--color-flame);
    }
    h2 {
      font-size: 2.6rem;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.02em;
      margin-bottom: 1.2rem;
    }
    /* 首屏 */
    .hero-grid {
      display: grid;
      grid-template-columns: 5fr 7fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-title {
      font-size: 3.6rem;
      font-weight: 900;
      line-height: 1.15;
      letter-spacing: -0.035em;
      margin-bottom: 1.5rem;
    }
    .hero-highlight {
      color: var(--color-flame);
      position: relative;
    }
    .metrics-row {
      display: flex;
      gap: 2.5rem;
      margin: 2rem 0;
    }
    .metric-item {
      text-align: left;
    }
    .metric-number {
      font-family: var(--font-mono);
      font-weight: 800;
      font-size: 2.8rem;
      color: var(--color-obsidian);
      line-height: 1;
    }
    .metric-line {
      width: 24px;
      height: 2px;
      background: var(--color-flame);
      margin: 6px 0;
    }
    .hero-image-wrapper {
      position: relative;
      border-radius: 2px;
      overflow: hidden;
      background: #dcdcdc;
    }
    .hero-image-wrapper img {
      width: 100%;
      height: auto;
      object-fit: cover;
      filter: grayscale(40%) contrast(1.1);
    }
    .data-overlay {
      position: absolute;
      top: 20px;
      right: 20px;
      background: rgba(255,79,0,0.9);
      padding: 10px 18px;
      font-family: var(--font-mono);
      font-weight: 700;
      color: white;
    }
    /* 按钮组 */
    .btn-group {
      display: flex;
      gap: 1.2rem;
      margin-top: 2.2rem;
      flex-wrap: wrap;
    }
    .btn-outline {
      border: 1.5px solid var(--color-obsidian);
      background: transparent;
      padding: 12px 28px;
      font-weight: 600;
      color: var(--color-obsidian);
      display: flex;
      align-items: center;
      gap: 8px;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: var(--color-obsidian);
      color: white;
    }
    /* 数据看板深色区域 */
    .dark-dashboard {
      background: var(--color-obsidian);
      color: white;
      padding: 80px 0;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2px;
      background: rgba(255,255,255,0.15);
    }
    .data-card {
      background: var(--color-obsidian);
      padding: 2.2rem 1.8rem;
      border: none;
    }
    .big-number {
      font-family: var(--font-mono);
      font-size: 3.5rem;
      font-weight: 800;
      color: var(--color-cyan-data);
    }
    .trend-green {
      color: var(--color-cyan-data);
      font-weight: 700;
    }
    /* 交错服务 */
    .service-row {
      display: grid;
      grid-template-columns: 5fr 7fr;
      gap: 3rem;
      align-items: center;
      margin-bottom: 90px;
    }
    .service-row.reverse {
      grid-template-columns: 7fr 5fr;
    }
    .service-text h3 {
      font-size: 2rem;
      font-weight: 700;
      margin-bottom: 1rem;
    }
    .vertical-line {
      width: 4px;
      height: 48px;
      background: var(--color-flame);
      margin-bottom: 1.4rem;
    }
    .service-img {
      width: 100%;
      height: 360px;
      object-fit: cover;
      position: relative;
    }
    .color-wash {
      position: relative;
      display: inline-block;
      width: 100%;
    }
    .color-wash::after {
      content: '';
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: rgba(255,79,0,0.09);
      pointer-events: none;
    }
    /* 对比案例 */
    .compare-cards {
      display: grid;
      grid-template-columns: 1fr 60px 1fr;
      align-items: center;
    }
    .case-card {
      background: white;
      padding: 2.2rem;
      box-shadow: var(--shadow-neo);
      transition: 0.2s;
      border: 1px solid #eee;
    }
    .case-card.old {
      filter: grayscale(0.3);
      opacity: 0.85;
    }
    .vs-icon {
      background: var(--color-flame);
      color: white;
      font-weight: 900;
      width: 60px;
      height: 60px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      font-family: var(--font-mono);
    }
    /* FAQ */
    .faq-layout {
      display: grid;
      grid-template-columns: 3fr 9fr;
      gap: 50px;
    }
    .faq-categories {
      display: flex;
      flex-direction: column;
      gap: 0.8rem;
    }
    .faq-cat {
      font-weight: 600;
      padding: 12px 14px;
      cursor: pointer;
      border-left: 3px solid transparent;
      transition: 0.2s;
    }
    .faq-cat.active {
      border-left-color: var(--color-flame);
      color: var(--color-flame);
      background: #f9f9f9;
    }
    .accordion-item {
      border-bottom: 1px solid #e0e0e0;
      padding: 1.2rem 0;
    }
    .accordion-question {
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    /* 表单深色 */
    .cta-dark {
      background: var(--color-obsidian);
      color: white;
      text-align: center;
    }
    .form-line {
      display: flex;
      flex-wrap: wrap;
      gap: 18px;
      justify-content: center;
      margin-top: 2rem;
    }
    .form-line input {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.4);
      padding: 14px 18px;
      color: white;
      width: 240px;
    }
    .form-line input:focus {
      border-color: var(--color-flame);
    }
    .submit-btn {
      background: var(--color-flame);
      border: none;
      color: white;
      font-weight: 800;
      padding: 14px 34px;
      cursor: pointer;
    }
    /* 页脚 */
    .footer {
      background: #1a1a1a;
      color: #aaa;
      padding: 60px 0 25px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 1024px) {
      .hero-grid, .service-row, .service-row.reverse {
        grid-template-columns: 1fr;
      }
      .faq-layout {
        grid-template-columns: 1fr;
      }
      .compare-cards {
        grid-template-columns: 1fr;
        gap: 1rem;
      }
      .vs-icon {
        width: 100%;
      }
      .grid-4 {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-title { font-size: 2.4rem; }
      h2 { font-size: 2rem; }
      .metrics-row { flex-wrap: wrap; }
    }