/* roulang page: index */
:root {
      --black: #0B0E14;
      --silver: #C0C5CE;
      --purple: #6B5B95;
      --purple-deep: #5A4A7A;
      --gold: #D4AF37;
      --gray-dark: #1C212B;
      --silver-10: rgba(192, 197, 206, 0.1);
      --silver-20: rgba(192, 197, 206, 0.2);
      --silver-30: rgba(192, 197, 206, 0.3);
      --purple-10: rgba(107, 91, 149, 0.1);
      --purple-30: rgba(107, 91, 149, 0.3);
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Inter', sans-serif;
      --font-number: 'Inter', 'SF Pro Display', sans-serif;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-chip: 20px;
      --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.4);
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

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

    body {
      background-color: var(--black);
      color: var(--silver);
      font-family: var(--font-body);
      font-size: 16px;
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.3s, backdrop-filter 0.3s, box-shadow 0.3s;
      background: transparent;
      backdrop-filter: blur(0px);
    }

    .header.scrolled {
      background: rgba(28, 33, 43, 0.95);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 var(--silver-10);
    }

    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .logo {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 24px;
      color: var(--purple);
      letter-spacing: 0.02em;
    }
    .logo span {
      color: var(--gold);
    }

    .nav-chips {
      display: flex;
      align-items: center;
      gap: 8px;
      flex-wrap: wrap;
    }

    .chip {
      padding: 8px 18px;
      border-radius: var(--radius-chip);
      background: transparent;
      color: var(--silver);
      font-size: 14px;
      font-weight: 500;
      transition: background 0.2s, color 0.2s;
      white-space: nowrap;
      background: transparent;
      border: none;
      cursor: pointer;
    }

    .chip:hover {
      background: var(--purple-10);
      color: white;
    }

    .chip.active {
      background: var(--purple);
      color: white;
    }

    .btn-primary {
      background: var(--purple);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      border: none;
      transition: background 0.25s, transform 0.2s, box-shadow 0.25s;
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      background: var(--purple-deep);
      transform: scale(1.03);
      box-shadow: 0 0 18px rgba(107, 91, 149, 0.5);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--silver);
      color: var(--silver);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      transition: all 0.2s;
      display: inline-block;
      text-align: center;
    }

    .btn-outline:hover {
      border-color: var(--purple);
      color: var(--purple);
      background: var(--purple-10);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--silver);
      border-radius: 2px;
      transition: 0.3s;
    }

    /* 移动端导航 */
    @media (max-width: 1023px) {
      .nav-chips {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(28, 33, 43, 0.98);
        backdrop-filter: blur(16px);
        flex-direction: column;
        padding: 24px;
        gap: 12px;
        border-bottom: 1px solid var(--silver-10);
      }
      .nav-chips.open {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .header .btn-primary {
        display: none;
      }
      .nav-chips .btn-primary {
        display: block;
        width: 100%;
        margin-top: 8px;
      }
    }

    @media (min-width: 1024px) {
      .hamburger {
        display: none;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      background-attachment: fixed;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at center, transparent 20%, var(--black) 85%);
      background-color: rgba(11, 14, 20, 0.65);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 720px;
      margin-top: 40px;
    }
    .hero h1 {
      font-family: var(--font-heading);
      font-size: 56px;
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 20px;
    }
    .hero .sub {
      font-size: 18px;
      color: var(--silver);
      margin-bottom: 36px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      color: var(--silver);
      font-size: 28px;
      animation: float 2s infinite;
      z-index: 2;
    }
    @keyframes float {
      0%, 100% { transform: translateX(-50%) translateY(0); }
      50% { transform: translateX(-50%) translateY(8px); }
    }

    /* 通用板块 */
    section {
      padding: 120px 0;
    }
    .section-title {
      font-family: var(--font-heading);
      font-size: 40px;
      font-weight: 600;
      margin-bottom: 16px;
      color: white;
      line-height: 1.3;
    }
    .section-desc {
      color: var(--silver);
      max-width: 68ch;
      margin-bottom: 48px;
    }

    /* 痛点区 */
    .problem-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .pain-item {
      display: flex;
      gap: 16px;
      margin-bottom: 32px;
    }
    .pain-item .line {
      width: 4px;
      background: var(--purple);
      border-radius: 4px;
    }
    .pain-item h3 {
      font-size: 22px;
      font-weight: 600;
      color: white;
      margin-bottom: 8px;
    }
    .cover-img {
      border-radius: var(--radius-card);
      border: 1px solid var(--silver-20);
      width: 100%;
    }

    /* 解决方案卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }
    .solution-card {
      background: rgba(28, 33, 43, 0.8);
      border: 1px solid var(--silver-10);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
    }
    .solution-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: var(--purple-30);
    }
    .solution-icon {
      font-size: 32px;
      color: var(--purple);
      margin-bottom: 20px;
    }
    .solution-card h3 {
      font-size: 22px;
      font-weight: 600;
      color: white;
      margin-bottom: 12px;
    }

    /* 数据区 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--gold);
      line-height: 1.2;
    }
    .stat-label {
      font-size: 14px;
      color: var(--silver);
      margin-top: 8px;
    }

    /* 证言 */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }
    .testimonial-card {
      background: rgba(28, 33, 43, 0.7);
      border: 1px solid var(--silver-10);
      border-radius: var(--radius-card);
      padding: 28px;
      transition: 0.3s;
    }
    .testimonial-card:hover {
      border-color: var(--purple-30);
      transform: translateY(-3px);
    }
    .quote-icon {
      color: var(--purple);
      font-size: 28px;
      margin-bottom: 12px;
    }
    .testimonial-text {
      font-style: italic;
      margin-bottom: 20px;
    }
    .stars {
      color: var(--gold);
      margin-bottom: 8px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--silver-10);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 20px;
      font-weight: 600;
      color: white;
      transition: color 0.2s;
    }
    .faq-question:hover {
      color: var(--purple);
    }
    .faq-icon {
      font-size: 24px;
      color: var(--purple);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--silver);
      padding-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 16px;
    }

    /* CTA 区 */
    .cta-section {
      background: linear-gradient(135deg, #6B5B95 0%, #0B0E14 100%);
      text-align: center;
      padding: 100px 0;
    }
    .cta-section h2 {
      color: white;
    }

    /* 页脚 */
    .footer {
      background: var(--black);
      padding: 60px 0 30px;
      border-top: 1px solid var(--silver-10);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer a {
      color: var(--silver);
    }
    .footer a:hover {
      color: var(--purple);
    }
    .copyright {
      font-size: 12px;
      color: var(--silver);
      opacity: 0.7;
      text-align: center;
    }

    @media (max-width: 1024px) {
      .hero h1 { font-size: 44px; }
      .section-title { font-size: 36px; }
      .problem-grid { grid-template-columns: 1fr; }
      .stats-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      section { padding: 80px 0; }
      .hero h1 { font-size: 32px; }
      .hero-actions { flex-direction: column; }
      .btn-primary, .btn-outline { width: 100%; text-align: center; }
      .footer-grid { grid-template-columns: 1fr; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 520px) {
      .stats-grid { grid-template-columns: 1fr; }
    }
    .fade-up {
      opacity: 0;
      transform: translateY(30px);
      transition: opacity 0.8s ease, transform 0.8s ease;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }