/* roulang page: index */
:root {
      --bg-deep: #0A0E27;
      --bg-section: #0F1535;
      --bg-footer: #060B1F;
      --cyan: #00E5FF;
      --purple: #7B2FBE;
      --white-strong: rgba(255,255,255,0.92);
      --white-muted: rgba(255,255,255,0.65);
      --white-weak: rgba(255,255,255,0.4);
      --card-bg: rgba(255,255,255,0.04);
      --card-border: rgba(255,255,255,0.08);
      --card-hover-border: rgba(0,229,255,0.4);
      --glass-blur: blur(20px) saturate(180%);
      --radius-card: 20px;
      --radius-btn: 50px;
      --radius-faq: 14px;
      --shadow-card: 0 12px 32px rgba(0,0,0,0.45);
      --shadow-glow: 0 0 35px rgba(0,229,255,0.2);
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-mono: "Inter", "SF Pro Display", -apple-system, monospace;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      background-color: var(--bg-deep);
      color: var(--white-muted);
      font-family: var(--font-sans);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3 {
      color: var(--white-strong);
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    h2 {
      font-size: clamp(2rem, 5vw, 2.8rem);
      margin-bottom: 1.2rem;
      position: relative;
      display: inline-block;
    }
    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 60%;
      height: 3px;
      background: linear-gradient(90deg, var(--cyan), transparent);
      border-radius: 4px;
    }
    .section-title-center {
      text-align: center;
    }
    .section-title-center h2::after {
      left: 50%;
      transform: translateX(-50%);
      width: 80px;
    }
    a {
      text-decoration: none;
      color: var(--cyan);
      transition: var(--transition-smooth);
    }
    img {
      max-width: 100%;
      display: block;
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 39, 0.7);
      backdrop-filter: blur(25px);
      border-bottom: 1px solid rgba(0, 229, 255, 0.2);
      transition: background 0.3s, box-shadow 0.3s;
    }
    .navbar.scrolled {
      background: rgba(10, 14, 39, 0.92);
      box-shadow: 0 4px 25px rgba(0,0,0,0.6);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      background: linear-gradient(135deg, #FFFFFF 0%, var(--cyan) 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.5px;
    }
    .nav-links {
      display: flex;
      gap: 2.2rem;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      color: var(--white-muted);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 6px 0;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--cyan);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--cyan);
      transition: width 0.3s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .btn-primary {
      background: linear-gradient(135deg, #00E5FF 0%, #7B2FBE 100%);
      color: #fff;
      border: none;
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      box-shadow: 0 4px 18px rgba(0, 229, 255, 0.4);
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      box-shadow: 0 8px 30px rgba(0, 229, 255, 0.7);
      transform: translateY(-2px);
      filter: brightness(1.1);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid rgba(0, 229, 255, 0.5);
      color: var(--cyan);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-smooth);
    }
    .btn-outline:hover {
      background: rgba(0, 229, 255, 0.08);
      border-color: var(--cyan);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: var(--white-strong);
      border-radius: 2px;
      transition: 0.3s;
    }
    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(10, 14, 39, 0.96);
        backdrop-filter: blur(30px);
        flex-direction: column;
        padding: 2rem 1.5rem;
        gap: 1.8rem;
        transform: translateY(-150%);
        transition: transform 0.4s ease;
        border-bottom: 1px solid var(--cyan);
      }
      .nav-links.active {
        transform: translateY(0);
      }
      .hamburger {
        display: flex;
      }
      .btn-primary.nav-cta {
        display: none;
      }
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,255,0.08) 0%, transparent 50%), 
                  url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: rgba(10,14,39,0.75);
      backdrop-filter: blur(4px);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 750px;
      padding: 2rem 0;
    }
    .hero h1 {
      font-size: clamp(2.8rem, 7vw, 4.5rem);
      font-weight: 800;
      line-height: 1.2;
      background: linear-gradient(to right, #fff, var(--cyan));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      margin-bottom: 1.5rem;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.7);
      margin-bottom: 2.5rem;
      max-width: 600px;
    }
    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
    }
    /* 解决方案 */
    .solutions-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 28px;
      margin-top: 3rem;
    }
    .solution-card {
      background: rgba(255,255,255,0.03);
      backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      padding: 2.2rem;
      transition: var(--transition-smooth);
      position: relative;
      overflow: hidden;
    }
    .solution-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 3px;
      background: linear-gradient(90deg, var(--cyan), var(--purple));
      opacity: 0;
      transition: opacity 0.4s;
    }
    .solution-card:hover {
      transform: translateY(-8px);
      border-color: var(--card-hover-border);
      box-shadow: var(--shadow-glow);
    }
    .solution-card:hover::before {
      opacity: 1;
    }
    .solution-icon {
      font-size: 2.2rem;
      color: var(--cyan);
      margin-bottom: 1.2rem;
    }
    .solution-card h3 {
      font-size: 1.5rem;
      margin-bottom: 0.8rem;
    }
    /* 成果数据 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      margin-top: 2.5rem;
    }
    .stat-item {
      text-align: center;
      padding: 1.8rem;
      background: rgba(255,255,255,0.02);
      border-radius: 24px;
      border: 1px solid rgba(255,255,255,0.05);
    }
    .stat-number {
      font-size: 3.2rem;
      font-weight: 800;
      background: linear-gradient(180deg, #fff, var(--cyan));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      font-family: var(--font-mono);
    }
    .stat-label {
      color: var(--white-muted);
      margin-top: 0.4rem;
    }
    @media (max-width: 768px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    /* 客户证言 */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
      margin-top: 2.8rem;
    }
    .testimonial-card {
      background: rgba(255,255,255,0.05);
      backdrop-filter: blur(18px);
      padding: 2.5rem;
      border-radius: 24px;
      border-left: 4px solid var(--cyan);
      border: 1px solid rgba(255,255,255,0.08);
    }
    .testimonial-text {
      font-size: 1.1rem;
      font-style: italic;
      color: var(--white-strong);
      margin-bottom: 1.8rem;
    }
    .client-info {
      display: flex;
      align-items: center;
      gap: 1rem;
    }
    .client-avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: url('/assets/images/backpic/back-2.webp') center/cover;
      border: 2px solid var(--cyan);
    }
    @media (max-width: 768px) {
      .testimonials-grid {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-container {
      max-width: 800px;
      margin: 2.5rem auto 0;
    }
    .faq-item {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(15px);
      border: 1px solid rgba(255,255,255,0.06);
      border-radius: var(--radius-faq);
      margin-bottom: 14px;
      overflow: hidden;
      transition: 0.3s;
    }
    .faq-question {
      padding: 1.2rem 1.8rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--white-strong);
      cursor: pointer;
      background: transparent;
      border: none;
      width: 100%;
      text-align: left;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease-in-out;
      background: rgba(0,229,255,0.02);
      padding: 0 1.8rem;
      color: var(--white-muted);
    }
    .faq-item.active .faq-answer {
      max-height: 220px;
      padding: 1rem 1.8rem 1.5rem;
    }
    .faq-icon {
      color: var(--cyan);
      font-size: 1.4rem;
      transition: transform 0.3s;
    }
    /* 最终CTA */
    .cta-section {
      background: #0F1535;
      text-align: center;
      padding: 90px 0;
    }
    .cta-form {
      display: flex;
      justify-content: center;
      gap: 1rem;
      margin-top: 2.2rem;
      flex-wrap: wrap;
    }
    .cta-input {
      background: rgba(255,255,255,0.06);
      border: 1px solid rgba(255,255,255,0.12);
      padding: 14px 20px;
      border-radius: 50px;
      color: white;
      width: 300px;
      outline: none;
      transition: 0.3s;
    }
    .cta-input:focus {
      border-color: var(--cyan);
      box-shadow: 0 0 15px rgba(0,229,255,0.4);
    }
    /* 页脚 */
    .footer {
      background: #060B1F;
      border-top: 1px solid rgba(0,229,255,0.25);
      padding: 60px 0 25px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2.5rem;
    }
    .footer-logo {
      font-size: 1.7rem;
      font-weight: 800;
      color: white;
    }
    .footer a {
      color: var(--white-muted);
    }
    .copyright {
      text-align: center;
      margin-top: 3rem;
      color: rgba(255,255,255,0.3);
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }