/* roulang page: index */
:root {
      --black-obsidian: #0B0C10;
      --energy-orange: #E8453C;
      --victory-gold: #C9A84C;
      --pure-white: #FFFFFF;
      --soft-gray: #F4F5F7;
      --text-muted: #8B949E;
      --border-light: rgba(0,0,0,0.06);
      --shadow-card: 0 8px 30px rgba(0,0,0,0.04);
      --shadow-hover: 0 18px 40px rgba(0,0,0,0.08);
      --orange-glow: 0 10px 25px rgba(232,69,60,0.25);
      --transition-smooth: 0.25s cubic-bezier(0.2, 0.0, 0, 1.0);
      --transition-bounce: 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
      --font-display: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-mono: 'DIN Alternate', 'Inter', 'SF Mono', monospace;
      --container-max: 1280px;
      --section-gap: 130px;
      --header-height: 76px;
    }

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

    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--pure-white);
      color: #1E1E1E;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 40px;
    }

    /* 科技感背景线条组件 */
    .geometric-bg {
      position: absolute;
      inset: 0;
      pointer-events: none;
      overflow: hidden;
    }
    .geometric-line {
      stroke: rgba(255,255,255,0.06);
      stroke-width: 1;
    }
    .gold-dot {
      fill: var(--victory-gold);
      filter: drop-shadow(0 0 6px rgba(201,168,76,0.7));
      animation: pulse-dot 2.4s infinite;
    }
    @keyframes pulse-dot {
      0% { opacity: 0.3; r: 2; }
      50% { opacity: 1; r: 3.5; }
      100% { opacity: 0.3; r: 2; }
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(255,255,255,0.8);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border-bottom: 1px solid transparent;
      transition: background 0.3s, box-shadow 0.3s, border-color 0.3s;
      z-index: 999;
      display: flex;
      align-items: center;
    }
    .header.scrolled {
      background: rgba(255,255,255,0.92);
      box-shadow: 0 10px 25px rgba(0,0,0,0.04);
      border-bottom: 1px solid rgba(0,0,0,0.04);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo-area {
      display: flex;
      align-items: baseline;
      gap: 8px;
      text-decoration: none;
    }
    .logo-text {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 26px;
      letter-spacing: -0.5px;
      color: var(--black-obsidian);
      line-height: 1;
    }
    .logo-domain {
      font-size: 12px;
      color: #6B7280;
      font-weight: 400;
      margin-left: 4px;
      letter-spacing: 0.3px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 36px;
      font-weight: 500;
      font-size: 15px;
    }
    .nav-links a {
      text-decoration: none;
      color: #2C2C2C;
      transition: color 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--energy-orange);
    }
    .btn-primary {
      background: var(--energy-orange);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: 10px;
      font-weight: 600;
      font-size: 15px;
      cursor: pointer;
      transition: all var(--transition-smooth);
      box-shadow: 0 8px 18px rgba(232,69,60,0.3);
      text-decoration: none;
      display: inline-block;
    }
    .btn-primary:hover {
      background: #F15A50;
      box-shadow: 0 12px 24px rgba(232,69,60,0.45);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--black-obsidian);
      color: var(--black-obsidian);
      padding: 12px 28px;
      border-radius: 10px;
      font-weight: 600;
      transition: 0.2s;
      text-decoration: none;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--black-obsidian);
      color: white;
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--black-obsidian);
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 20% 30%, #1F2128, #0B0C10);
      position: relative;
      padding-top: var(--header-height);
      overflow: hidden;
    }
    .hero-content {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 40px;
      align-items: center;
    }
    .hero-title {
      font-family: var(--font-display);
      font-size: 56px;
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 24px;
    }
    .hero-highlight {
      color: var(--energy-orange);
    }
    .dynamic-text {
      font-size: 24px;
      font-weight: 500;
      color: rgba(255,255,255,0.7);
      margin-bottom: 28px;
      min-height: 38px;
    }
    .hero-desc {
      color: rgba(255,255,255,0.7);
      margin-bottom: 40px;
      max-width: 500px;
    }
    .hero-actions {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .hero-visual {
      position: relative;
    }

    /* 区块标题 */
    .section-title {
      font-family: var(--font-display);
      font-size: 40px;
      font-weight: 700;
      margin-bottom: 20px;
      line-height: 1.3;
    }
    .section-sub {
      color: #555;
      margin-bottom: 48px;
    }

    /* 优势 cards */
    .advantages-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 2fr;
      gap: 28px;
    }
    .advantage-card {
      background: var(--pure-white);
      padding: 40px 32px;
      border-radius: 18px;
      box-shadow: var(--shadow-card);
      border-bottom: 4px solid transparent;
      transition: all var(--transition-smooth);
    }
    .advantage-card:nth-child(1) { border-bottom-color: var(--energy-orange); }
    .advantage-card:nth-child(2) { border-bottom-color: var(--victory-gold); }
    .advantage-card:nth-child(3) { border-bottom-color: var(--energy-orange); }
    .advantage-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    /* 服务网格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .service-card {
      background: white;
      padding: 40px 32px;
      border-radius: 16px;
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all var(--transition-smooth);
    }
    .service-number {
      font-size: 100px;
      font-weight: 700;
      color: #E5E7EB;
      position: absolute;
      right: -10px;
      top: -10px;
      transition: 0.3s;
    }
    .service-card:hover .service-number {
      color: var(--victory-gold);
      transform: translateX(-12px);
    }

    /* 数据深色区 */
    .data-strip {
      background: var(--black-obsidian);
      padding: 80px 0;
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
    }
    .data-number {
      font-family: var(--font-mono);
      font-size: 44px;
      color: var(--victory-gold);
      font-weight: 700;
    }

    /* 流程 */
    .process-step {
      display: flex;
      gap: 32px;
      align-items: flex-start;
      margin-bottom: 36px;
    }
    .process-node {
      width: 44px;
      height: 44px;
      background: white;
      border: 2px solid var(--energy-orange);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      box-shadow: 0 0 12px rgba(232,69,60,0.4);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid #e0e0e0;
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }

    /* CTA */
    .cta-dark {
      background: linear-gradient(135deg, #0B0C10, #1A1C23);
      border-radius: 24px;
      padding: 80px;
      text-align: center;
    }

    /* 页脚 */
    .footer {
      background: var(--black-obsidian);
      color: #b0b0b0;
      padding: 60px 0 30px;
      margin-top: 80px;
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
    }

    @media (max-width: 1024px) {
      .hero-content { grid-template-columns: 1fr; }
      .advantages-grid { grid-template-columns: 1fr; }
      .services-grid { grid-template-columns: 1fr 1fr; }
      .data-strip { grid-template-columns: 1fr 1fr; }
      .footer { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-menu-toggle { display: block; }
      .hero-title { font-size: 38px; }
      .services-grid { grid-template-columns: 1fr; }
    }