/* roulang page: index */
:root {
      --primary-orange: #E8452D;
      --primary-orange-hover: #C93A25;
      --deep-teal: #1B2A2E;
      --accent-cyan: #00C9A7;
      --bg-light: #F7F9FC;
      --text-dark: #1E2B32;
      --text-muted: #5F6B7A;
      --white: #FFFFFF;
      --border-light: rgba(0,0,0,0.05);
      --shadow-card: 0 8px 24px rgba(0,0,0,0.04);
      --shadow-hover: 0 18px 36px rgba(232,69,45,0.12);
      --radius-card: 24px;
      --radius-button: 50px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-number: 'Bebas Neue', 'DIN Alternate', 'PingFang SC', sans-serif;
      --transition: all 0.25s ease;
      --sidebar-width: 240px;
    }

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

    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.75;
      font-size: 16px;
      display: flex;
      min-height: 100vh;
      -webkit-font-smoothing: antialiased;
    }

    /* 左侧导航 App Shell */
    .app-sidebar {
      width: var(--sidebar-width);
      background: var(--deep-teal);
      color: white;
      display: flex;
      flex-direction: column;
      position: fixed;
      top: 0;
      left: 0;
      bottom: 0;
      z-index: 1000;
      padding: 2rem 1.5rem;
      box-shadow: 4px 0 20px rgba(0,0,0,0.08);
      transition: transform 0.3s ease;
    }

    .logo-area {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 3rem;
      text-decoration: none;
    }

    .logo-icon {
      width: 36px;
      height: 36px;
      background: var(--primary-orange);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
    }

    .logo-icon::before {
      content: "⚡";
      font-size: 22px;
      color: white;
      filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
    }

    .logo-text {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 1.5rem;
      letter-spacing: 1px;
      color: white;
      line-height: 1.2;
    }
    .logo-text span {
      color: var(--accent-cyan);
      font-weight: 800;
    }

    .nav-menu {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .nav-item {
      color: rgba(255,255,255,0.75);
      text-decoration: none;
      padding: 12px 16px;
      border-radius: 12px;
      font-weight: 500;
      display: flex;
      align-items: center;
      gap: 12px;
      transition: var(--transition);
      position: relative;
    }

    .nav-item i {
      font-size: 1.2rem;
      width: 24px;
      text-align: center;
    }

    .nav-item:hover {
      background: rgba(255,255,255,0.08);
      color: white;
    }

    .nav-item.active {
      background: rgba(232,69,45,0.2);
      color: white;
      border-left: 4px solid var(--primary-orange);
      padding-left: 12px;
      font-weight: 600;
    }

    .sidebar-contact {
      margin-top: auto;
      background: rgba(255,255,255,0.05);
      border-radius: 20px;
      padding: 20px;
      text-align: center;
    }

    .sidebar-contact p {
      font-size: 0.85rem;
      color: rgba(255,255,255,0.7);
      margin-bottom: 16px;
    }

    .btn-sidebar {
      background: var(--primary-orange);
      color: white;
      border: none;
      padding: 12px 20px;
      border-radius: var(--radius-button);
      font-weight: 600;
      width: 100%;
      cursor: pointer;
      transition: var(--transition);
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    .btn-sidebar:hover {
      background: var(--primary-orange-hover);
      transform: scale(1.02);
    }

    /* 主内容区 */
    .main-content {
      margin-left: var(--sidebar-width);
      flex: 1;
      width: calc(100% - var(--sidebar-width));
    }

    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      background: var(--deep-teal);
      color: white;
      padding: 1rem 1.5rem;
      z-index: 999;
      align-items: center;
      justify-content: space-between;
    }

    .hamburger {
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
      cursor: pointer;
    }

    /* 容器 */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 2rem;
    }

    section {
      padding: 5rem 0;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1B2A2E 0%, #2D3F3A 50%, #3A2A2A 100%);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
    }

    .hero-content {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 3rem;
    }

    .hero-text {
      flex: 1;
      color: white;
    }

    .hero h1 {
      font-family: var(--font-title);
      font-size: 3.5rem;
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      letter-spacing: -0.5px;
      color: white;
    }
    .hero h1 span {
      color: var(--primary-orange);
      border-bottom: 3px solid var(--accent-cyan);
    }

    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2.5rem;
      max-width: 500px;
    }

    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--primary-orange);
      border: none;
      color: white;
      padding: 1rem 2.5rem;
      border-radius: var(--radius-button);
      font-weight: 700;
      font-size: 1rem;
      cursor: pointer;
      transition: var(--transition);
      text-decoration: none;
      display: inline-block;
      box-shadow: 0 8px 18px rgba(232,69,45,0.3);
    }

    .btn-primary:hover {
      background: var(--primary-orange-hover);
      transform: scale(1.03);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 0.9rem 2.3rem;
      border-radius: var(--radius-button);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
      text-decoration: none;
      display: inline-block;
    }

    .btn-outline:hover {
      background: rgba(255,255,255,0.1);
    }

    .hero-graphic {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-graphic img {
      max-width: 100%;
      height: auto;
      filter: drop-shadow(0 20px 30px rgba(0,0,0,0.5));
    }

    /* 板块标题 */
    .section-title {
      font-family: var(--font-title);
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--text-dark);
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 3rem;
      font-size: 1.1rem;
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .advantage-card {
      background: var(--white);
      padding: 2.2rem 1.8rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      border: 1px solid transparent;
    }

    .advantage-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary-orange);
    }

    .advantage-icon {
      font-size: 2.4rem;
      color: var(--accent-cyan);
      margin-bottom: 1.4rem;
    }

    .services-grid {
      display: flex;
      flex-direction: column;
      gap: 2.5rem;
    }

    .service-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      background: white;
      border-radius: 28px;
      padding: 2rem;
      box-shadow: var(--shadow-card);
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }

    .service-img {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      height: auto;
      display: block;
      transition: 0.4s ease;
    }
    .service-row:hover .service-img img {
      transform: scale(1.03);
    }

    .data-section {
      background: var(--deep-teal);
      color: white;
      border-radius: 36px;
      padding: 3.5rem 2.5rem;
    }
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }
    .data-item {
      position: relative;
    }
    .data-number {
      font-family: var(--font-number);
      font-size: 3.4rem;
      font-weight: 700;
      color: var(--accent-cyan);
      letter-spacing: 2px;
    }
    .data-label {
      color: rgba(255,255,255,0.8);
    }
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 2rem;
    }
    .faq-item {
      background: white;
      border-radius: 16px;
      margin-bottom: 14px;
      padding: 1.2rem 1.8rem;
      cursor: pointer;
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }
    .faq-question {
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .cta-block {
      background: linear-gradient(135deg, #1B2A2E, #0F1A1E);
      border-radius: 40px;
      padding: 4rem 2rem;
      text-align: center;
      color: white;
    }
    footer {
      background: #122024;
      color: rgba(255,255,255,0.7);
      padding: 3rem 0 1.5rem;
    }

    @media (max-width: 1024px) {
      .app-sidebar { display: none; }
      .mobile-header { display: flex; }
      .main-content { margin-left: 0; width: 100%; }
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .data-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .hero-content { flex-direction: column; }
      .grid-3, .case-grid { grid-template-columns: 1fr; }
      .service-row, .service-row.reverse { flex-direction: column; }
    }