/* roulang page: index */
:root {
      --primary-orange: #E85D04;
      --deep-gray: #1E1E24;
      --matte-white: #F8F9FA;
      --cool-silver: #CED4DA;
      --success-green: #2B9348;
      --alert-red: #D00000;
      --text-dark: #212529;
      --text-muted: #6C757D;
      --white: #FFFFFF;
      --border-light: #E9ECEF;
      --shadow-card: 0 8px 30px rgba(0,0,0,0.05);
      --shadow-hover: 0 14px 36px rgba(0,0,0,0.09);
      --radius-sm: 4px;
      --radius-md: 8px;
      --font-heading: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition: all 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--matte-white);
      color: var(--text-dark);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      font-weight: 600;
      border: none;
      outline: none;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    /* 导航系统 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      z-index: 1000;
      background: transparent;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
    }
    .main-header.scrolled {
      background: var(--deep-gray);
      border-bottom: 1px solid var(--cool-silver);
      box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 1.6rem;
      font-weight: 800;
      color: var(--white);
      letter-spacing: 0.5px;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--primary-orange);
      line-height: 1;
    }
    .desktop-nav {
      display: flex;
      gap: 36px;
      align-items: center;
    }
    .desktop-nav a {
      color: var(--white);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 4px 0;
    }
    .desktop-nav a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary-orange);
      transition: width 0.3s ease;
    }
    .desktop-nav a:hover::after,
    .desktop-nav a.active::after {
      width: 100%;
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      color: var(--white);
      font-size: 1.8rem;
    }
    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: var(--deep-gray);
      border-top: 1px solid var(--cool-silver);
      z-index: 999;
      padding: 8px 16px;
      justify-content: space-around;
      align-items: center;
    }
    .mobile-bottom-nav a {
      color: var(--cool-silver);
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 0.7rem;
      gap: 4px;
    }
    .mobile-bottom-nav i {
      font-size: 1.4rem;
    }
    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-color: var(--deep-gray);
      position: relative;
      display: flex;
      align-items: center;
      color: var(--white);
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 50%, rgba(30,30,36,0.4) 0%, rgba(30,30,36,0.9) 90%);
    }
    .hero-content {
      position: relative;
      max-width: 700px;
    }
    .hero h1 {
      font-size: clamp(2.8rem, 7vw, 4.5rem);
      font-weight: 900;
      color: var(--primary-orange);
      line-height: 1.15;
      margin-bottom: 1.5rem;
    }
    .hero-sub {
      font-size: 1.25rem;
      font-weight: 400;
      margin-bottom: 2.5rem;
      color: rgba(255,255,255,0.9);
    }
    .btn-group {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary-orange);
      color: var(--white);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      box-shadow: 0 6px 18px rgba(232,93,4,0.35);
    }
    .btn-primary:hover {
      background: #c94d03;
      transform: scale(1.03);
      box-shadow: 0 10px 24px rgba(232,93,4,0.5);
    }
    .btn-outline {
      background: transparent;
      color: var(--white);
      border: 2px solid var(--white);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
    }
    .btn-outline:hover {
      background: var(--white);
      color: var(--deep-gray);
      transform: scale(1.03);
    }
    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 800;
      margin-bottom: 16px;
      color: var(--deep-gray);
    }
    .section-desc {
      font-size: 1.1rem;
      color: var(--text-muted);
      max-width: 700px;
      margin-bottom: 48px;
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .service-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      display: flex;
      align-items: flex-start;
      gap: 20px;
      border-bottom: 2px solid transparent;
    }
    .service-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
      border-bottom-color: var(--primary-orange);
    }
    .service-number {
      font-size: 3.5rem;
      font-weight: 800;
      color: rgba(232,93,4,0.15);
      line-height: 1;
    }
    .service-info h3 {
      font-size: 1.5rem;
      margin-bottom: 8px;
    }
    .service-info p {
      color: var(--text-muted);
    }
    .arrow-icon {
      margin-left: auto;
      font-size: 1.4rem;
      transition: var(--transition);
    }
    .service-card:hover .arrow-icon {
      color: var(--primary-orange);
      transform: translateX(5px);
    }
    /* 优势数据 */
    .advantages {
      background: var(--deep-gray);
      color: var(--white);
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 36px;
      text-align: center;
    }
    .stat-number {
      font-size: 3.5rem;
      font-weight: 900;
      color: var(--primary-orange);
    }
    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 20px;
    }
    .case-main {
      background: url('/assets/images/coverpic/cover-1.webp') center/cover;
      border-radius: var(--radius-md);
      padding: 48px 32px;
      min-height: 320px;
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      position: relative;
      overflow: hidden;
    }
    .case-main::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(0deg, rgba(30,30,36,0.85) 20%, transparent);
    }
    .case-content {
      position: relative;
      color: white;
    }
    .case-side {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }
    .case-small {
      background: url('/assets/images/coverpic/cover-2.webp') center/cover;
      border-radius: var(--radius-md);
      padding: 32px;
      min-height: 140px;
      position: relative;
      display: flex;
      align-items: flex-end;
    }
    .case-small::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(30,30,36,0.7);
      border-radius: var(--radius-md);
    }
    .tag {
      background: var(--primary-orange);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 16px;
    }
    .faq-left-line {
      width: 4px;
      height: 24px;
      background: var(--primary-orange);
      border-radius: 2px;
    }
    .faq-question {
      font-weight: 700;
      flex: 1;
    }
    /* 页脚 */
    .footer {
      background: var(--deep-gray);
      color: var(--cool-silver);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: 1fr 1fr; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      .desktop-nav { display: none; }
      .mobile-menu-toggle { display: block; }
      .mobile-bottom-nav { display: flex; }
      .hero h1 { font-size: 2.5rem; }
      .services-grid { grid-template-columns: 1fr; }
      .cases-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }