/* roulang page: index */
:root {
      --primary: #6C3CE1;
      --primary-soft: rgba(108, 60, 225, 0.25);
      --accent: #FF6B35;
      --accent-light: #FF8255;
      --bg-deep: #0F0A1A;
      --bg-card: rgba(255, 255, 255, 0.03);
      --bg-section: #1A1525;
      --text-white: #FFFFFF;
      --text-body: #CBC3E3;
      --text-muted: #9A8FB8;
      --border-purple: rgba(108, 60, 225, 0.35);
      --border-accent: #FF6B35;
      --shadow-card: 0 12px 32px rgba(0, 0, 0, 0.55);
      --radius-card: 14px;
      --radius-btn: 10px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "Poppins", "Montserrat", "PingFang SC", sans-serif;
      --transition: 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    h1, h2, h3, h4 {
      font-family: var(--font-mono);
      font-weight: 600;
      letter-spacing: -0.3px;
    }

    h1 {
      font-size: clamp(44px, 7vw, 64px);
      font-weight: 700;
      color: var(--text-white);
      line-height: 1.2;
    }
    h2 {
      font-size: clamp(32px, 5vw, 44px);
      color: var(--text-white);
    }
    h3 {
      font-size: 22px;
      color: var(--primary);
      font-weight: 600;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      font-weight: 600;
      border: none;
      transition: var(--transition);
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(15, 10, 26, 0.8);
      backdrop-filter: blur(18px);
      border-bottom: 1px solid rgba(108, 60, 225, 0.5);
      padding: 0 24px;
    }
    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: -0.5px;
    }
    .logo i {
      color: var(--primary);
      font-size: 2rem;
    }
    .logo span {
      background: linear-gradient(135deg, var(--primary), var(--accent));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 36px;
      list-style: none;
    }
    .nav-menu a {
      color: var(--text-body);
      font-weight: 500;
      position: relative;
      padding: 6px 0;
      transition: color 0.2s;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--accent);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2.5px;
      background: var(--accent);
      transition: width 0.3s ease;
    }
    .nav-menu a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      letter-spacing: 0.3px;
      box-shadow: 0 8px 18px rgba(255, 107, 53, 0.3);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--accent-light);
      box-shadow: 0 12px 24px rgba(255, 107, 53, 0.5);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--primary);
      border-radius: 4px;
      transition: 0.3s;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, rgba(108,60,225,0.25) 0%, #0F0A1A 80%);
      position: relative;
      overflow: hidden;
      padding-top: 80px;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 120" preserveAspectRatio="none"><path d="M0,60 C200,120 400,0 600,60 C800,120 1000,0 1200,60 L1200,120 L0,120 Z" fill="rgba(108,60,225,0.06)"/></svg>');
      background-repeat: repeat-x;
      background-position: bottom;
      opacity: 0.5;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      margin: 0 auto;
      text-align: center;
    }
    .hero h1 .highlight {
      color: var(--accent);
      background: linear-gradient(135deg, #FF6B35, #FFA06B);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero p {
      font-size: 1.3rem;
      color: var(--text-body);
      margin: 24px 0 36px;
      max-width: 620px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }

    /* 区块通用 */
    section {
      padding: 90px 0;
    }
    .section-title {
      margin-bottom: 56px;
      text-align: center;
    }
    .section-title h2 {
      margin-bottom: 16px;
    }
    .divider {
      width: 70px;
      height: 4px;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      margin: 16px auto 0;
      border-radius: 4px;
    }

    /* 核心优势 非对称 */
    .features-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.9fr;
      gap: 28px;
    }
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-purple);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      backdrop-filter: blur(6px);
      transition: var(--transition);
      border-left: 5px solid var(--primary);
    }
    .feature-card:hover {
      border-color: var(--accent);
      border-left-color: var(--accent);
      transform: translateY(-6px);
      box-shadow: 0 20px 30px rgba(108,60,225,0.25);
    }
    .feature-card i {
      font-size: 2.2rem;
      color: var(--primary);
      margin-bottom: 18px;
    }
    .feature-card h3 {
      color: white;
      font-size: 1.5rem;
      margin-bottom: 12px;
    }

    /* 服务区 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 50px;
      margin-bottom: 70px;
      flex-wrap: wrap;
    }
    .service-img {
      flex: 1 1 45%;
      background: #1e1630;
      border-radius: 18px;
      overflow: hidden;
      border: 1px solid rgba(108,60,225,0.3);
    }
    .service-text {
      flex: 1 1 45%;
    }

    /* 解决方案 手风琴风格 */
    .solution-tabs {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
      justify-content: center;
      margin-bottom: 36px;
    }
    .tab-btn {
      background: transparent;
      border: 1px solid var(--border-purple);
      color: var(--text-body);
      padding: 12px 28px;
      border-radius: 30px;
      font-weight: 600;
      transition: 0.3s;
    }
    .tab-btn.active {
      background: var(--primary);
      border-color: var(--primary);
      color: white;
    }
    .solution-panel {
      display: none;
      background: rgba(255,255,255,0.02);
      padding: 36px;
      border-radius: 20px;
      border: 1px solid var(--border-purple);
    }
    .solution-panel.active {
      display: flex;
      gap: 36px;
      flex-wrap: wrap;
    }

    /* 案例卡片 */
    .cases-scroll {
      display: flex;
      gap: 28px;
      overflow-x: auto;
      padding-bottom: 20px;
      scroll-snap-type: x mandatory;
    }
    .case-card {
      flex: 0 0 300px;
      background: var(--bg-card);
      border-radius: var(--radius-card);
      border: 1px solid var(--border-purple);
      padding: 24px;
      scroll-snap-align: start;
      transition: var(--transition);
    }
    .case-card:hover {
      border-color: var(--accent);
      transform: translateY(-5px);
    }
    .case-stat {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--accent);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(108,60,225,0.25);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 1.2rem;
      color: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-body);
    }

    /* CTA */
    .cta-band {
      background: linear-gradient(135deg, #1A1230, #0F0A1A);
      border-top: 2px solid var(--primary);
      border-bottom: 2px solid var(--accent);
      text-align: center;
    }

    /* 页脚 */
    .footer {
      background: #0A0612;
      border-top: 2px solid var(--primary);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 36px;
    }
    .footer h4 {
      color: var(--accent);
      margin-bottom: 18px;
    }
    .copyright {
      text-align: center;
      margin-top: 48px;
      color: var(--text-muted);
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: 1fr; }
      .service-row { flex-direction: column; }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 2.8rem; }
      .footer-grid { grid-template-columns: 1fr; }
    }