/* roulang page: index */
:root {
      --primary: #C2004A;
      --primary-dark: #8A0030;
      --accent: #00E5FF;
      --bg: #F8F8FA;
      --card-bg: #FFFFFF;
      --dark: #1A1A1E;
      --text: #1A1A1E;
      --text-secondary: #5A5A6E;
      --border: #E8E8EC;
      --testimonial-bg: #F0F0F4;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", sans-serif;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 17px;
      -webkit-font-smoothing: antialiased;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      transition: all var(--transition);
      border-radius: var(--radius-btn);
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* HEADER / NAV */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.2s, box-shadow 0.2s;
      background: transparent;
    }
    .site-header.scrolled {
      background: rgba(255,255,255,0.97);
      box-shadow: 0 1px 8px rgba(0,0,0,0.08);
      backdrop-filter: blur(12px);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: white;
      white-space: nowrap;
    }
    .scrolled .logo {
      color: var(--dark);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-weight: 600;
      font-size: 16px;
      opacity: 0.9;
      color: white;
    }
    .scrolled .nav-links a {
      color: var(--dark);
    }
    .nav-links a:hover {
      opacity: 1;
      color: var(--accent);
    }
    .scrolled .nav-links a:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      font-size: 16px;
      border-radius: var(--radius-btn);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.03);
      box-shadow: 0 4px 12px rgba(194,0,74,0.4);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--dark);
      color: var(--dark);
      padding: 12px 28px;
      font-size: 16px;
    }
    .btn-outline:hover {
      background: var(--dark);
      color: white;
    }
    .btn-large {
      padding: 18px 40px;
      font-size: 18px;
    }
    .hamburger {
      display: none;
      background: transparent;
      border: none;
      flex-direction: column;
      gap: 5px;
      width: 28px;
    }
    .hamburger span {
      display: block;
      height: 2px;
      background: white;
      transition: 0.2s;
    }
    .scrolled .hamburger span {
      background: var(--dark);
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu {
        position: fixed;
        top: 0;
        right: 0;
        width: 280px;
        height: 100vh;
        background: var(--dark);
        flex-direction: column;
        padding: 80px 24px;
        gap: 24px;
        transform: translateX(100%);
        transition: transform 0.3s ease;
        z-index: 999;
      }
      .mobile-menu.active {
        transform: translateX(0);
      }
      .mobile-menu a {
        color: white;
        font-size: 20px;
        font-weight: 600;
      }
      .mobile-menu .btn-primary {
        width: 100%;
        justify-content: center;
      }
    }

    /* HERO */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #1A1A1E 0%, #2D1A24 100%);
      padding-top: 72px;
      color: white;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero h1 {
      font-size: 56px;
      line-height: 1.1;
      font-weight: 800;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
    }
    .hero-subtitle {
      font-size: 20px;
      opacity: 0.85;
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 16px;
      height: 400px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero h1 {
        font-size: 38px;
      }
      .hero-image {
        height: 280px;
      }
    }

    /* SECTIONS */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    h2 {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 16px;
      color: var(--dark);
    }
    .section-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

    /* PAIN POINTS */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 32px;
    }
    .pain-card {
      background: transparent;
      padding: 16px 0;
      border-bottom: 2px solid #E8E8EC;
      transition: border 0.2s;
    }
    .pain-card:hover {
      border-bottom: 4px solid var(--primary);
    }
    .pain-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .pain-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    @media (max-width: 768px) {
      .pain-grid {
        grid-template-columns: 1fr;
      }
    }

    /* SOLUTIONS (非对称) */
    .solutions-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 32px;
    }
    .solution-wide {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      border: 1px solid var(--border);
      display: flex;
      flex-direction: column;
    }
    .solution-img {
      background: url('/assets/images/coverpic/cover-1.webp') center/cover;
      height: 240px;
      border-radius: 8px;
      margin-bottom: 20px;
    }
    .solution-narrow {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .solution-card {
      background: var(--card-bg);
      padding: 28px;
      border-radius: var(--radius-card);
      border: 1px solid var(--border);
    }
    @media (max-width: 768px) {
      .solutions-grid {
        grid-template-columns: 1fr;
      }
    }

    /* DATA COUNTERS */
    .counters {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 32px;
      text-align: center;
    }
    .counter-number {
      font-size: 64px;
      font-weight: 900;
      font-feature-settings: "tnum";
      color: var(--primary);
      line-height: 1;
    }
    .counter-label {
      font-size: 16px;
      color: var(--text-secondary);
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .counters {
        grid-template-columns: 1fr 1fr;
      }
      .counter-number {
        font-size: 48px;
      }
    }

    /* TESTIMONIALS */
    .testimonial-bg {
      background: var(--testimonial-bg);
    }
    .testimonial-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }
    .testimonial-card {
      background: white;
      padding: 32px;
      border-radius: var(--radius-card);
      position: relative;
    }
    .testimonial-quote {
      font-size: 48px;
      color: var(--accent);
      opacity: 0.3;
      line-height: 1;
      margin-bottom: 16px;
    }
    .testimonial-text {
      font-style: italic;
      font-size: 18px;
      margin-bottom: 20px;
    }
    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .author-avatar {
      width: 48px;
      height: 48px;
      background: #ccc;
      border-radius: 50%;
      background-image: url('/assets/images/coverpic/cover-2.webp');
      background-size: cover;
    }
    @media (max-width: 768px) {
      .testimonial-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-list {
      max-width: 760px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      font-size: 18px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      font-size: 16px;
      color: var(--text-secondary);
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* FINAL CTA */
    .cta-dark {
      background: var(--dark);
      color: white;
      text-align: center;
    }
    .cta-dark h2 {
      color: white;
    }

    /* FOOTER */
    .footer {
      background: var(--dark);
      color: #ccc;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer a {
      color: #aaa;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }