/* roulang page: index */
:root {
      --primary: #E85D04;
      --primary-dark: #D35400;
      --primary-light: #FF8C42;
      --secondary: #1A1A2E;
      --warm-bg: #F5F0E8;
      --accent: #FFB347;
      --text-body: #2D2D2D;
      --text-heading: #1A1A2E;
      --border-soft: #E8E0D5;
      --white: #FFFFFF;
      --gray-light: #B0B0C0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-large: 24px;
      --shadow-card: 0 2px 12px rgba(26, 26, 46, 0.06);
      --shadow-hover: 0 8px 32px rgba(26, 26, 46, 0.10);
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --font-heading: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --font-body: 'Inter', 'Noto Sans SC', system-ui, sans-serif;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--warm-bg);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 17px;
      display: flex;
      min-height: 100vh;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }

    /* 容器与主布局 */
    .app-wrapper {
      display: flex;
      width: 100%;
      min-height: 100vh;
      position: relative;
    }

    .main-content {
      flex: 1;
      margin-left: 72px;
      transition: margin-left 0.3s ease;
      background-color: var(--warm-bg);
      overflow-x: hidden;
    }

    /* 左侧竖向导航 */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      height: 100vh;
      width: 72px;
      background-color: var(--secondary);
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 24px 0;
      z-index: 1000;
      transition: width 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      overflow: hidden;
      box-shadow: 4px 0 20px rgba(0,0,0,0.08);
    }

    .side-nav:hover {
      width: 220px;
    }

    .nav-brand {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 48px;
      padding: 0 16px;
      width: 100%;
      text-decoration: none;
      color: white;
    }

    .brand-icon {
      width: 40px;
      height: 40px;
      min-width: 40px;
      background: radial-gradient(circle at 30% 30%, var(--accent), var(--primary));
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 900;
      font-size: 22px;
      color: white;
      font-family: var(--font-heading);
    }

    .brand-text {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 18px;
      white-space: nowrap;
      opacity: 0;
      transition: opacity 0.2s ease;
      color: white;
    }

    .side-nav:hover .brand-text {
      opacity: 1;
    }

    .nav-menu {
      list-style: none;
      width: 100%;
      display: flex;
      flex-direction: column;
      gap: 8px;
      padding: 0 8px;
      flex: 1;
    }

    .nav-item a {
      display: flex;
      align-items: center;
      gap: 16px;
      padding: 12px 16px;
      border-radius: 8px;
      color: #B0B0C0;
      text-decoration: none;
      transition: var(--transition-smooth);
      font-weight: 500;
      font-size: 16px;
      white-space: nowrap;
      border-left: 3px solid transparent;
    }

    .nav-item a:hover {
      background-color: rgba(255,255,255,0.05);
      color: white;
    }

    .nav-item a.active {
      background-color: rgba(232, 93, 4, 0.15);
      color: white;
      border-left: 3px solid var(--primary);
      font-weight: 600;
    }

    .nav-icon {
      font-size: 20px;
      min-width: 20px;
      text-align: center;
    }

    .nav-label {
      opacity: 0;
      transition: opacity 0.2s ease;
    }

    .side-nav:hover .nav-label {
      opacity: 1;
    }

    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background-color: var(--secondary);
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      z-index: 1001;
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }

    .mobile-logo {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 20px;
      color: white;
      text-decoration: none;
    }

    .hamburger {
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
      display: flex;
      align-items: center;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background-color: var(--secondary);
      flex-direction: column;
      padding: 24px;
      gap: 12px;
      z-index: 999;
    }

    .mobile-menu a {
      color: #B0B0C0;
      text-decoration: none;
      font-size: 18px;
      font-weight: 500;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    /* 通用容器 */
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    section {
      padding: 140px 0;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      color: var(--text-heading);
    }

    h1 {
      font-size: 56px;
      line-height: 1.15;
      letter-spacing: -0.02em;
      font-weight: 900;
    }

    h2 {
      font-size: 42px;
      line-height: 1.25;
      letter-spacing: -0.01em;
      font-weight: 700;
    }

    h3 {
      font-size: 24px;
      line-height: 1.35;
      font-weight: 600;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 17px;
      cursor: pointer;
      transition: var(--transition-smooth);
      text-decoration: none;
      border: none;
      outline: none;
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
    }

    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(232,93,4,0.3);
    }

    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
    }

    .btn-outline:hover {
      background-color: rgba(232,93,4,0.1);
      transform: translateY(-2px);
    }

    .btn-white {
      background: white;
      color: var(--primary);
    }

    .btn-white:hover {
      background: #f0f0f0;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1A1A2E 0%, #16213E 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }

    .hero-glow {
      position: absolute;
      top: -20%;
      right: -10%;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, rgba(255,179,71,0.15) 0%, transparent 70%);
      border-radius: 50%;
      animation: slowRotate 20s infinite linear;
    }

    @keyframes slowRotate {
      from { transform: rotate(0deg); }
      to { transform: rotate(360deg); }
    }

    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }

    .hero-text {
      flex: 1 1 60%;
      color: white;
    }

    .hero-text h1 {
      color: white;
      margin-bottom: 24px;
      animation: fadeUp 0.8s ease;
    }

    .hero-sub {
      font-size: 20px;
      line-height: 1.6;
      color: rgba(255,255,255,0.85);
      margin-bottom: 40px;
      max-width: 550px;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .hero-visual {
      flex: 1 1 40%;
      position: relative;
    }

    .hero-image {
      width: 100%;
      height: auto;
      border-radius: var(--radius-large);
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
      object-fit: cover;
      background: #2a2a3a;
    }

    @keyframes fadeUp {
      0% { opacity: 0; transform: translateY(20px); }
      100% { opacity: 1; transform: translateY(0); }
    }

    /* 优势错层 */
    .advantages-grid {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }

    .adv-row {
      display: flex;
      gap: 40px;
      align-items: center;
    }

    .adv-row.reverse {
      flex-direction: row-reverse;
    }

    .adv-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      border-left: 4px solid var(--primary);
      flex: 1;
      transition: var(--transition-smooth);
    }

    .adv-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .adv-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 16px;
    }

    .adv-meta {
      color: var(--primary);
      font-weight: 600;
      margin-top: 12px;
    }

    /* 服务横向滚动 */
    .services-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 20px;
      scroll-snap-type: x mandatory;
    }

    .service-card {
      min-width: 300px;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      scroll-snap-align: start;
      transition: var(--transition-smooth);
    }

    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }

    .service-body {
      padding: 24px;
    }

    /* 数据 */
    .data-row {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
    }

    .data-item {
      flex: 1;
      min-width: 150px;
    }

    .data-number {
      font-size: 56px;
      font-weight: 800;
      color: var(--primary);
      font-family: var(--font-heading);
    }

    /* 案例交替 */
    .case-block {
      display: flex;
      gap: 60px;
      align-items: center;
      margin-bottom: 80px;
    }

    .case-block.reverse {
      flex-direction: row-reverse;
    }

    .case-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

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

    /* 时间轴 */
    .timeline {
      position: relative;
      padding-left: 40px;
    }

    .timeline::before {
      content: '';
      position: absolute;
      left: 15px;
      top: 0;
      bottom: 0;
      width: 2px;
      background: linear-gradient(to bottom, var(--primary), var(--accent));
    }

    .timeline-item {
      margin-bottom: 40px;
      position: relative;
    }

    .timeline-dot {
      position: absolute;
      left: -31px;
      top: 8px;
      width: 12px;
      height: 12px;
      background: var(--primary);
      border-radius: 50%;
    }

    /* FAQ */
    .faq-group {
      margin-bottom: 32px;
    }

    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      box-shadow: var(--shadow-card);
    }

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 24px;
      font-size: 18px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--text-heading);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding: 0 24px;
    }

    .faq-answer.open {
      max-height: 300px;
      padding-bottom: 20px;
    }

    /* CTA横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #E85D04, #FF8C42);
      padding: 80px 0;
      text-align: center;
      color: white;
    }

    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: #B0B0C0;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1023px) {
      .side-nav { display: none; }
      .mobile-header { display: flex; }
      .main-content { margin-left: 0; }
      .hero-content { flex-direction: column; }
      h1 { font-size: 42px; }
      h2 { font-size: 32px; }
      .adv-row, .case-block { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 767px) {
      section { padding: 80px 0; }
      .container { padding: 0 20px; }
      h1 { font-size: 36px; }
      .data-row { gap: 20px; }
      .footer-grid { grid-template-columns: 1fr; }
    }