/* roulang page: index */
/* ========== 设计变量与重置 ========== */
    :root {
      --primary: #E94057;
      --primary-dark: #D12F45;
      --secondary: #00E5FF;
      --accent: #FFB800;
      --bg-deep: #0A0E17;
      --bg-card: #131A25;
      --bg-light: #F0F2F5;
      --text-main: #FFFFFF;
      --text-body: #B0B8C5;
      --text-muted: #6B7280;
      --border-dim: rgba(0, 229, 255, 0.08);
      --border-glow: rgba(0, 229, 255, 0.4);
      --radius-sm: 8px;
      --radius-md: 12px;
      --shadow-card: 0 16px 32px rgba(0,0,0,0.4);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, sans-serif;
      --font-data: "DIN Alternate", "Arial", sans-serif;
      --max-width: 1200px;
      --section-gap: 100px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-body);
      line-height: 1.8;
      margin: 0;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: var(--secondary);
      transition: color 0.2s;
    }

    a:hover {
      color: var(--primary);
    }

    h1, h2, h3, h4 {
      color: var(--text-main);
      font-weight: 700;
      letter-spacing: -0.02em;
      margin-top: 0;
    }

    h1 {
      font-size: 3.5rem;
      line-height: 1.2;
    }

    h2 {
      font-size: 2.5rem;
      margin-bottom: 1.5rem;
    }

    h3 {
      font-size: 1.5rem;
      margin-bottom: 0.75rem;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    /* 按钮组件 */
    .btn {
      display: inline-block;
      padding: 0.85rem 2.2rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
      text-align: center;
      transition: all 0.3s ease;
      cursor: pointer;
      border: none;
      font-size: 1rem;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      box-shadow: 0 4px 12px rgba(233, 64, 87, 0.3);
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      color: white;
      box-shadow: 0 0 20px rgba(233, 64, 87, 0.6);
      transform: translateY(-2px);
    }

    .btn-secondary {
      background: transparent;
      border: 2px solid var(--secondary);
      color: var(--secondary);
    }

    .btn-secondary:hover {
      background: rgba(0, 229, 255, 0.1);
      color: var(--secondary);
      border-color: var(--secondary);
    }

    /* 导航栏 */
    .sticky-header {
      background: rgba(10, 14, 23, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.05);
      position: sticky;
      top: 0;
      z-index: 100;
      padding: 0.8rem 0;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: 0.5px;
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      white-space: nowrap;
    }

    .logo span {
      color: var(--primary);
    }

    .nav-left, .nav-right {
      display: flex;
      gap: 2rem;
      align-items: center;
    }

    .nav-left a, .nav-right a {
      color: var(--text-body);
      font-weight: 500;
      transition: color 0.2s, text-shadow 0.2s;
    }

    .nav-left a:hover, .nav-right a:hover,
    .nav-left a.active, .nav-right a.active {
      color: var(--primary);
      text-shadow: 0 0 8px rgba(233,64,87,0.5);
    }

    .mobile-toggle {
      display: none;
      font-size: 1.8rem;
      color: white;
      cursor: pointer;
    }

    /* 英雄区 */
    .hero {
      background: linear-gradient(135deg, #0A0E17 0%, #1a1f2e 100%);
      padding: 6rem 0 5rem;
      position: relative;
      overflow: hidden;
    }

    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.2;
      z-index: 0;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 3rem;
    }

    .hero-text {
      flex: 1;
    }

    .hero-text h1 {
      margin-bottom: 1.5rem;
      color: white;
    }

    .hero-text p {
      font-size: 1.25rem;
      color: var(--text-body);
      margin-bottom: 2.5rem;
      max-width: 550px;
    }

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

    .hero-visual {
      flex: 1;
      display: flex;
      justify-content: center;
      animation: float 4s ease-in-out infinite;
    }

    .hero-visual img {
      max-height: 380px;
      filter: drop-shadow(0 20px 30px rgba(0,229,255,0.2));
    }

    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-15px); }
      100% { transform: translateY(0); }
    }

    /* 通用区块 */
    section {
      padding: var(--section-gap) 0;
    }

    .section-header {
      text-align: center;
      margin-bottom: 3.5rem;
    }

    .section-header h2 {
      display: inline-block;
      position: relative;
    }

    .section-header h2::after {
      content: '';
      position: absolute;
      bottom: -10px;
      left: 50%;
      transform: translateX(-50%);
      width: 60px;
      height: 3px;
      background: var(--primary);
      border-radius: 2px;
    }

    /* 卡片组件 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 2rem;
    }

    .card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      padding: 2rem 1.8rem;
      border: 1px solid var(--border-dim);
      transition: all 0.3s ease;
    }

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

    .card-icon {
      font-size: 2.4rem;
      color: var(--secondary);
      margin-bottom: 1.5rem;
    }

    /* 痛点区左侧竖线 */
    .pain-card {
      border-left: 4px solid var(--primary);
    }

    /* 数据统计 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }

    .stat-number {
      font-family: var(--font-data);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }

    .stat-label {
      color: var(--text-body);
      margin-top: 0.5rem;
    }

    /* 证言区 */
    .testimonial-card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      padding: 2.5rem;
      border: 1px solid var(--border-dim);
    }

    .testimonial-quote {
      font-size: 2.5rem;
      color: rgba(255,184,0,0.4);
      line-height: 1;
      margin-bottom: 1rem;
    }

    .testimonial-text {
      font-size: 1.1rem;
      color: #E0E5EC;
      margin-bottom: 2rem;
    }

    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 1rem;
    }

    .testimonial-author img {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      border: 2px solid var(--primary);
    }

    /* FAQ 手风琴 */
    .accordion-item {
      background: var(--bg-card);
      border-radius: var(--radius-sm);
      margin-bottom: 1rem;
      border: 1px solid var(--border-dim);
    }

    .accordion-title {
      padding: 1.2rem 1.8rem;
      font-weight: 600;
      color: white;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      border-left: 3px solid var(--secondary);
    }

    .accordion-content {
      padding: 0 1.8rem 1.5rem;
      display: none;
      color: var(--text-body);
    }

    .accordion-item.active .accordion-content {
      display: block;
    }

    /* CTA 区 */
    .cta-section {
      background: radial-gradient(circle at center, #2a1a2e, #0A0E17);
      padding: 5rem 0;
      text-align: center;
    }

    .cta-section h2 {
      color: white;
      margin-bottom: 1rem;
    }

    /* 页脚 */
    .footer {
      background: #0A0E17;
      border-top: 1px solid rgba(255,255,255,0.08);
      padding: 4rem 0 2rem;
      color: var(--text-muted);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
    }

    .footer a {
      color: var(--text-muted);
      display: block;
      margin-bottom: 0.6rem;
    }

    .footer a:hover {
      color: var(--secondary);
    }

    .copyright {
      text-align: center;
      margin-top: 3rem;
      padding-top: 2rem;
      border-top: 1px solid rgba(255,255,255,0.1);
      font-size: 0.9rem;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      h1 { font-size: 2.8rem; }
      .stats-grid { grid-template-columns: repeat(2, 1fr); }
      .hero-content { flex-direction: column; text-align: center; }
      .hero-text p { margin-left: auto; margin-right: auto; }
      .hero-buttons { justify-content: center; }
    }

    @media (max-width: 768px) {
      .nav-left, .nav-right { display: none; }
      .mobile-toggle { display: block; position: absolute; right: 1.5rem; }
      .logo { position: static; transform: none; margin: 0 auto; }
      .nav-container { justify-content: center; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      section { padding: 70px 0; }
    }

    @media (max-width: 520px) {
      h1 { font-size: 2.2rem; }
      h2 { font-size: 1.9rem; }
      .card-grid { grid-template-columns: 1fr; }
      .stats-grid { grid-template-columns: 1fr; }
      .hero-buttons { flex-direction: column; align-items: center; }
    }