/* roulang page: index */
:root {
      --primary: #F04E23;
      --primary-hover: #D03C1A;
      --secondary: #1A1A1A;
      --accent: #00C2BA;
      --bg-warm: #F7F5F2;
      --card-bg: #FFFFFF;
      --text-main: #1A1A1A;
      --text-body: #4A4A4A;
      --text-muted: #8A8A8A;
      --border-light: #E8E5E0;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-card: 16px;
      --radius-btn: 40px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-numbers: "Inter", "Roboto", sans-serif;
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --container-max: 1280px;
      --section-gap: 100px;
      --nav-height: 72px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 17px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      transition: box-shadow 0.2s;
    }
    .header.scrolled {
      box-shadow: 0 6px 20px rgba(0,0,0,0.04);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      white-space: nowrap;
      display: flex;
      align-items: center;
    }
    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-link {
      font-weight: 500;
      color: var(--text-body);
      font-size: 16px;
      position: relative;
      padding: 8px 0;
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--primary);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transform: translateY(6px);
    }
    .btn-nav {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.03em;
      transition: var(--transition-smooth);
      white-space: nowrap;
    }
    .btn-nav:hover {
      background: var(--primary-hover);
      transform: scale(1.03);
      box-shadow: 0 8px 18px rgba(240,78,35,0.3);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: var(--secondary);
      border-radius: 4px;
      transition: var(--transition-smooth);
    }
    .mobile-nav {
      display: none;
    }

    /* 区块间距 */
    section {
      padding: var(--section-gap) 0;
    }

    /* 首屏 Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: var(--secondary);
      position: relative;
      overflow: hidden;
      padding-top: var(--nav-height);
    }
    .hero-bg {
      position: absolute;
      inset: 0;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.38;
      z-index: 0;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 20% 30%, rgba(240,78,35,0.22) 0%, transparent 60%);
      z-index: 1;
    }
    .hero .container {
      position: relative;
      z-index: 2;
      color: white;
    }
    .hero-title {
      font-size: 56px;
      font-weight: 800;
      line-height: 1.15;
      letter-spacing: -0.02em;
      max-width: 700px;
      color: white;
      margin-bottom: 24px;
    }
    .hero-highlight {
      color: var(--primary);
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      max-width: 560px;
      margin-bottom: 36px;
    }
    .hero-actions {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
      align-items: center;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      letter-spacing: 0.03em;
      transition: var(--transition-smooth);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: scale(1.03);
      box-shadow: 0 14px 28px rgba(240,78,35,0.4);
    }
    .btn-ghost {
      border: 1.5px solid white;
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-smooth);
    }
    .btn-ghost:hover {
      background: white;
      color: var(--primary);
    }
    .hero-stats {
      display: flex;
      gap: 48px;
      margin-top: 48px;
      flex-wrap: wrap;
    }
    .stat-number {
      font-family: var(--font-numbers);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
    }
    .stat-label {
      color: rgba(255,255,255,0.7);
      font-size: 15px;
    }

    /* 痛点卡片 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .pain-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition-smooth);
      border: 1px solid transparent;
    }
    .pain-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }
    .pain-icon {
      width: 48px;
      height: 48px;
      color: var(--accent);
      margin-bottom: 20px;
    }
    .section-title {
      font-size: 40px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
    }
    .section-desc {
      color: var(--text-muted);
      max-width: 680px;
      margin-bottom: 48px;
    }

    /* 解决方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .solution-text {
      flex: 1;
    }
    .check-list {
      list-style: none;
      margin-top: 20px;
    }
    .check-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
      color: var(--text-body);
    }
    .check-icon {
      color: var(--accent);
      font-weight: 700;
    }

    /* 数据指标 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 24px;
    }
    .metric-number {
      font-family: var(--font-numbers);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
    }
    .metric-label {
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .testimonial-card {
      background: #FAF9F7;
      border-radius: var(--radius-card);
      padding: 28px;
      position: relative;
    }
    .testimonial-quote {
      font-size: 40px;
      color: #ddd;
      line-height: 1;
    }
    .testimonial-text {
      font-style: italic;
      margin: 12px 0 20px;
    }
    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      object-fit: cover;
      background: #ccc;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-body);
    }
    .faq-item.open .faq-answer {
      max-height: 300px;
      padding-top: 12px;
    }
    .arrow {
      transition: transform 0.3s;
    }
    .faq-item.open .arrow {
      transform: rotate(180deg);
    }

    /* CTA 深色横幅 */
    .cta-banner {
      background: var(--secondary);
      padding: 80px 0;
      text-align: center;
    }
    .cta-title {
      color: white;
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 28px;
    }

    /* 页脚 */
    .footer {
      background: #F0EDE8;
      border-top: 1px solid var(--border-light);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-logo {
      font-weight: 700;
      color: var(--primary);
      font-size: 22px;
    }

    @media (max-width: 1024px) {
      .pain-grid, .testimonial-grid { grid-template-columns: repeat(2,1fr); }
      .metrics-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .mobile-nav {
        display: block;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: rgba(255,255,255,0.98);
        z-index: 999;
        padding: 24px;
        transform: translateX(100%);
        transition: transform 0.3s;
      }
      .mobile-nav.open {
        transform: translateX(0);
      }
      .hero-title { font-size: 36px; }
      .section-title { font-size: 28px; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .pain-grid, .testimonial-grid, .metrics-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
    }