/* roulang page: index */
:root {
      --primary: #1A1A1A;
      --accent: #D4AF37;
      --bg: #FAFAFA;
      --card-bg: #FFFFFF;
      --border: #E8E8E8;
      --text-primary: #1A1A1A;
      --text-body: #4A4A4A;
      --text-muted: #8A8A8A;
      --white: #FFFFFF;
      --shadow-none: none;
      --radius: 4px;
      --transition: 0.3s ease;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --container-max: 1140px;
      --section-gap: 100px;
      --card-padding: 24px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      padding-top: 64px;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航 */
    .navbar {
      background: var(--white);
      height: 64px;
      border-bottom: 1px solid var(--border);
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1030;
      display: flex;
      align-items: center;
    }
    .navbar .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 2px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--accent);
      font-size: 24px;
    }
    .nav-links {
      display: flex;
      gap: 2rem;
      list-style: none;
      margin: 0;
      padding: 0;
    }
    .nav-links a {
      font-size: 14px;
      font-weight: 400;
      color: var(--text-body);
      padding: 0.5rem 0;
      position: relative;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--accent);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--primary);
      cursor: pointer;
    }
    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: var(--white);
      border-top: 1px solid var(--border);
      z-index: 1030;
      justify-content: space-around;
      align-items: center;
    }
    .mobile-tab {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 10px;
      color: var(--text-muted);
      transition: var(--transition);
    }
    .mobile-tab i {
      font-size: 20px;
      margin-bottom: 2px;
    }
    .mobile-tab.active {
      color: var(--accent);
      font-weight: 700;
    }
    /* Hero */
    .hero {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      min-height: 80vh;
      display: flex;
      align-items: center;
    }
    .hero::before {
      content: '';
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: linear-gradient(135deg, rgba(26,26,26,0.75) 0%, rgba(26,26,26,0.4) 100%);
    }
    .hero-content {
      position: relative;
      color: var(--white);
      max-width: 700px;
    }
    .hero h1 {
      font-size: 56px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1rem;
      color: white;
    }
    .hero .subtitle {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 2rem;
      max-width: 500px;
    }
    .btn-group-hero {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
      margin-bottom: 1.5rem;
    }
    .btn-primary-bb {
      background: var(--accent);
      color: var(--primary);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius);
      border: none;
      transition: var(--transition);
      font-size: 16px;
    }
    .btn-primary-bb:hover {
      background: var(--primary);
      color: var(--accent);
      border: 1px solid var(--accent);
    }
    .btn-outline-bb {
      background: transparent;
      border: 1px solid var(--white);
      color: var(--white);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius);
      transition: var(--transition);
      font-size: 16px;
    }
    .btn-outline-bb:hover {
      background: var(--white);
      color: var(--primary);
    }
    .trust-signal {
      font-size: 13px;
      color: rgba(255,255,255,0.7);
    }
    /* 通用区块 */
    section {
      padding: var(--section-gap) 0;
    }
    .section-title {
      font-size: 40px;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 1rem;
      line-height: 1.3;
    }
    .section-desc {
      font-size: 16px;
      color: var(--text-body);
      margin-bottom: 3rem;
      max-width: 600px;
    }
    /* 痛点卡片 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 2rem;
    }
    .pain-card {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: var(--card-padding);
      position: relative;
      transition: var(--transition);
    }
    .pain-card::before {
      content: '';
      position: absolute;
      left: 0;
      top: 10%;
      height: 30px;
      width: 2px;
      background: var(--accent);
    }
    .pain-card:hover {
      border-color: var(--accent);
    }
    .pain-icon {
      font-size: 32px;
      color: var(--accent);
      margin-bottom: 1rem;
    }
    .pain-card h3 {
      font-size: 18px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 0.5rem;
    }
    /* 解决方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 4rem;
      flex-wrap: wrap;
    }
    .solution-text, .solution-img {
      flex: 1 1 45%;
    }
    .solution-img img {
      border-radius: var(--radius);
      width: 100%;
      object-fit: cover;
    }
    .step-num {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1;
    }
    /* 成果数字 */
    .results-bg {
      background: #F5F5F5;
    }
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      text-align: center;
      gap: 2rem;
    }
    .stat-item .number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      font-family: 'Inter', sans-serif;
    }
    .stat-label {
      font-size: 14px;
      color: var(--text-body);
    }
    /* 证言轮播 */
    .testimonial-card {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 2rem;
      border-left: 4px solid var(--accent);
      margin: 0 10px;
    }
    .testimonial-text {
      font-style: italic;
      color: var(--text-body);
      margin-bottom: 1.5rem;
    }
    .avatar-placeholder {
      width: 40px;
      height: 40px;
      background: #E8E8E8;
      border-radius: 50%;
      display: inline-block;
      margin-right: 0.75rem;
    }
    /* FAQ */
    .accordion-item {
      border: none;
      border-bottom: 1px solid var(--border);
      background: transparent;
    }
    .accordion-button {
      font-weight: 700;
      color: var(--primary);
      background: transparent;
      box-shadow: none;
      font-size: 16px;
      padding: 16px 0;
    }
    .accordion-button:not(.collapsed) {
      color: var(--primary);
      background: transparent;
    }
    .accordion-button::after {
      display: none;
    }
    .accordion-button i {
      transition: transform 0.3s;
      color: var(--accent);
      margin-right: 12px;
    }
    .accordion-button:not(.collapsed) i {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-dark {
      background: var(--primary);
      color: var(--white);
      text-align: center;
      padding: 80px 0;
    }
    .cta-dark .section-title {
      color: white;
    }
    .footer {
      background: var(--primary);
      color: var(--text-muted);
      padding: 3rem 0 2rem;
    }
    .footer a:hover {
      color: var(--accent);
    }
    @media (max-width: 992px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .mobile-bottom-nav { display: flex; }
      .hero h1 { font-size: 40px; }
      .section-title { font-size: 32px; }
    }
    @media (max-width: 576px) {
      .hero { min-height: 60vh; }
      .hero h1 { font-size: 32px; }
      .pain-grid { grid-template-columns: 1fr; }
      .solution-row { flex-direction: column; }
      .stats-grid { flex-direction: column; }
    }
    .overlay-menu {
      position: fixed;
      top: 0; left: 0;
      width: 100%; height: 100%;
      background: rgba(26,26,26,0.95);
      display: none;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      z-index: 1050;
    }
    .overlay-menu a {
      color: white;
      font-size: 18px;
      margin: 1rem;
    }