/* roulang page: index */
/* 基础设计变量 */
    :root {
      --red-orange: #E8453C;
      --red-orange-hover: #D03A32;
      --deep-black: #1A1D23;
      --warm-white: #F9F7F2;
      --card-white: #FFFFFF;
      --card-border: #E8E5DF;
      --track-gray: #5F6368;
      --track-green: #1F9A5E;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 6px 20px rgba(0,0,0,0.08);
      --shadow-nav: 0 1px 8px rgba(0,0,0,0.06);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-img: 8px;
      --container-max: 1200px;
      --section-gap: 80px;
      --gap-mobile: 48px;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
      background-color: var(--warm-white);
      color: var(--deep-black);
      line-height: 1.7;
      font-size: 16px;
      font-weight: 400;
      min-height: 100vh;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

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

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

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

    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 rgba(0,0,0,0.05);
      z-index: 100;
      display: flex;
      align-items: center;
      transition: background 0.2s, box-shadow 0.2s;
    }

    #nav.scrolled {
      background: #FFFFFF;
      box-shadow: var(--shadow-nav);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-weight: 700;
      font-size: 20px;
      color: var(--deep-black);
      letter-spacing: -0.3px;
      display: flex;
      align-items: baseline;
      gap: 6px;
    }

    .logo-domain {
      font-size: 11px;
      font-weight: 400;
      color: var(--track-gray);
      letter-spacing: 0;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-links a {
      font-weight: 500;
      font-size: 15px;
      color: var(--deep-black);
      transition: color 0.2s;
    }

    .nav-links a:hover {
      color: var(--red-orange);
    }

    .btn-primary {
      background: var(--red-orange);
      color: white;
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-size: 14px;
      transition: background 0.2s, transform 0.1s;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    .btn-primary:hover {
      background: var(--red-orange-hover);
      transform: translateY(-1px);
    }

    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--deep-black);
      color: var(--deep-black);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-size: 15px;
      transition: all 0.2s;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    .btn-secondary:hover {
      background: var(--deep-black);
      color: white;
    }

    .download-btn {
      background: var(--deep-black);
      color: white;
      padding: 12px 28px;
      border-radius: 10px;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 10px;
      transition: all 0.2s;
    }

    .download-btn:hover {
      background: #2a2d33;
      box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--deep-black);
      border-radius: 2px;
      transition: 0.2s;
    }

    .mobile-menu {
      display: none;
    }

    /* 首屏 Hero */
    #hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: var(--warm-white);
      position: relative;
      overflow: hidden;
      padding-top: 64px;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }

    .hero-text {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    h1 {
      font-size: 36px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.3;
      color: var(--deep-black);
    }

    .hero-sub {
      font-size: 16px;
      color: var(--track-gray);
      line-height: 1.6;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-top: 8px;
    }

    .hero-image {
      position: relative;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.12);
      transform: rotate(1deg);
    }

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

    .speed-lines {
      position: absolute;
      bottom: 0;
      right: 0;
      width: 300px;
      height: 200px;
      background: radial-gradient(circle at 30% 70%, rgba(232,69,60,0.03) 0%, transparent 70%);
      pointer-events: none;
    }

    /* 版块通用 */
    section {
      padding: var(--section-gap) 0;
    }

    h2 {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .section-intro {
      color: var(--track-gray);
      max-width: 640px;
      margin-bottom: 40px;
      font-size: 16px;
    }

    /* 痛点卡片 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .pain-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      border-bottom: 2px solid transparent;
      transition: all 0.3s ease;
      box-shadow: var(--shadow-card);
    }

    .pain-card:hover {
      border-bottom-color: var(--red-orange);
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }

    .pain-icon {
      width: 44px;
      height: 44px;
      background: #f1f0eb;
      border-radius: 50%;
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--track-gray);
      font-size: 18px;
    }

    /* 解决方案左右交替 */
    .solution-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
      margin-bottom: 64px;
    }

    .solution-row.reverse {
      direction: rtl;
    }

    .solution-row.reverse .solution-text {
      direction: ltr;
    }

    .solution-img {
      border-radius: var(--radius-img);
      overflow: hidden;
      background: #E8E5DF;
      aspect-ratio: 16 / 9;
    }

    .solution-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .tag {
      display: inline-block;
      background: #fbeae9;
      color: var(--red-orange);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: 20px;
      margin-bottom: 12px;
    }

    /* 数据成果 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      text-align: center;
    }

    .stat-number {
      font-family: 'Roboto', sans-serif;
      font-size: 48px;
      font-weight: 700;
      color: var(--red-orange);
      line-height: 1.2;
    }

    .stat-label {
      color: var(--track-gray);
      margin-top: 8px;
      font-size: 15px;
    }

    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .testimonial-card {
      background: var(--card-white);
      border-left: 3px solid var(--red-orange);
      padding: 24px;
      border-radius: 8px;
      box-shadow: var(--shadow-card);
      transition: all 0.25s;
    }

    .testimonial-card:hover {
      border-left-width: 5px;
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }

    .user-info {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
    }

    .avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #E8E5DF;
      overflow: hidden;
    }

    .avatar img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: var(--card-white);
      border-radius: var(--radius-card);
      border: 1px solid var(--card-border);
      padding: 18px 24px;
      cursor: pointer;
      transition: background 0.2s;
    }

    .faq-item.active {
      background: #Fdf8f6;
      border-color: #f0d7d5;
    }

    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 16px;
    }

    .faq-answer {
      margin-top: 12px;
      color: var(--track-gray);
      display: none;
      line-height: 1.6;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    .faq-icon {
      font-size: 20px;
      font-weight: 400;
      color: var(--red-orange);
    }

    /* CTA 区域 */
    #cta {
      background: var(--deep-black);
      color: white;
      text-align: center;
    }

    .cta-title {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    .cta-buttons {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
      margin-top: 24px;
    }

    /* 页脚 */
    #footer {
      background: var(--deep-black);
      color: #cccccc;
      padding: 48px 0 24px;
      font-size: 14px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 32px;
    }

    .footer-brand {
      font-weight: 700;
      color: white;
      font-size: 18px;
    }

    .footer-links a {
      color: #cccccc;
      display: block;
      margin-bottom: 6px;
    }

    .copyright {
      border-top: 1px solid #2f3238;
      margin-top: 32px;
      padding-top: 16px;
      text-align: center;
      font-size: 13px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid, .solution-row {
        grid-template-columns: 1fr;
        gap: 32px;
      }
      .solution-row.reverse {
        direction: ltr;
      }
      .hero-image {
        order: -1;
      }
    }

    @media (max-width: 768px) {
      :root {
        --section-gap: 48px;
      }
      h1 { font-size: 28px; }
      h2 { font-size: 24px; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .pain-grid, .stats-grid, .testimonial-grid {
        grid-template-columns: 1fr;
        gap: 20px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .mobile-menu {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        height: calc(100vh - 64px);
        background: var(--deep-black);
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 32px;
        z-index: 99;
        transform: translateX(100%);
        transition: transform 0.3s ease;
      }
      .mobile-menu.open {
        transform: translateX(0);
        display: flex;
      }
      .mobile-menu a {
        color: white;
        font-size: 20px;
        font-weight: 500;
      }
      .hero-buttons .btn-secondary,
      .hero-buttons .btn-primary {
        width: 100%;
      }
      #nav .btn-primary.desktop-cta {
        display: none;
      }
    }

    @media (max-width: 520px) {
      .container { padding: 0 16px; }
      .hero-buttons { flex-direction: column; }
    }