/* roulang page: index */
:root {
      --bg-deep: #0A0F1E;
      --bg-card: #141B2D;
      --cyan: #00E5FF;
      --cyan-dark: #00B8D4;
      --orange: #FF6D00;
      --orange-light: #FF8A00;
      --white: #FFFFFF;
      --gray-light: #B0C4DE;
      --gray-mid: #8A9BB5;
      --gray-dark: #6B7A90;
      --border-subtle: rgba(255,255,255,0.06);
      --glass-bg: rgba(255,255,255,0.03);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-glow: 0 0 20px rgba(255,109,0,0.5);
      --shadow-cyan: 0 12px 40px rgba(0,229,255,0.15);
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-inner: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "SF Pro Display", sans-serif;
      --transition: 0.3s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background: linear-gradient(135deg, #0A0F1E 0%, #141B2D 100%);
      color: var(--gray-mid);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      background-attachment: fixed;
    }

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

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

    a {
      text-decoration: none;
      color: var(--cyan);
      transition: var(--transition);
    }
    a:hover {
      color: var(--cyan-dark);
      text-decoration: underline;
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all 0.3s ease;
      cursor: pointer;
      border: none;
      font-family: var(--font-sans);
      letter-spacing: 0.5px;
    }
    .btn-primary {
      background: var(--orange);
      color: var(--white);
      padding: 14px 32px;
      box-shadow: var(--shadow-glow);
      font-size: 16px;
    }
    .btn-primary:hover {
      background: var(--orange-light);
      box-shadow: 0 0 30px rgba(255,109,0,0.7);
      transform: translateY(-2px);
      text-decoration: none;
      color: white;
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--cyan);
      color: var(--cyan);
      padding: 14px 32px;
    }
    .btn-secondary:hover {
      background: rgba(0,229,255,0.1);
      border-color: var(--cyan-dark);
      color: var(--cyan-dark);
      text-decoration: none;
    }
    .btn-large {
      font-size: 20px;
      padding: 18px 48px;
      box-shadow: 0 0 25px rgba(255,109,0,0.6);
    }

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(10,15,30,0.8);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-subtle);
      height: 72px;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      background: linear-gradient(to right, var(--cyan), var(--cyan-dark));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: 1px;
    }
    .logo i {
      font-size: 28px;
      color: var(--cyan);
      -webkit-text-fill-color: initial;
      background: none;
    }
    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-menu a {
      color: var(--gray-light);
      font-weight: 500;
      font-size: 16px;
      position: relative;
      padding: 8px 0;
      text-decoration: none;
    }
    .nav-menu a:hover, .nav-menu a.active {
      color: var(--cyan);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--cyan);
      transition: width 0.3s;
    }
    .nav-menu a:hover::after, .nav-menu a.active::after {
      width: 100%;
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      color: var(--cyan);
      font-size: 28px;
      cursor: pointer;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
      position: relative;
    }
    .section-title {
      font-size: 28px;
      font-weight: 600;
      color: var(--white);
      margin-bottom: 12px;
      text-align: center;
    }
    .section-subtitle {
      font-size: 18px;
      color: var(--gray-light);
      text-align: center;
      margin-bottom: 48px;
    }

    /* Hero */
    .hero {
      padding-top: 160px;
      padding-bottom: 100px;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,255,0.12) 0%, rgba(255,109,0,0.08) 80%, #0A0F1E 100%);
      position: relative;
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 42px;
      font-weight: 700;
      line-height: 1.2;
      background: linear-gradient(to right, #00E5FF, #00B8D4);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 20px;
    }
    .hero-text p {
      font-size: 18px;
      color: var(--gray-light);
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-card);
      min-height: 380px;
      box-shadow: var(--shadow-card);
      position: relative;
      overflow: hidden;
      border: 1px solid var(--border-subtle);
    }
    .hero-image::after {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(10,15,30,0.4);
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      border-color: var(--cyan);
      box-shadow: var(--shadow-cyan);
    }

    /* 优势卡片 */
    .feature-card {
      text-align: center;
    }
    .feature-icon {
      font-size: 48px;
      color: var(--cyan);
      margin-bottom: 16px;
    }
    .feature-card h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--white);
      margin-bottom: 12px;
    }
    .feature-card p {
      color: var(--gray-mid);
      font-size: 15px;
    }

    /* 方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-text h2 {
      font-size: 28px;
      color: var(--white);
      margin-bottom: 16px;
    }
    .solution-text p {
      margin-bottom: 20px;
    }
    .solution-img {
      flex: 1;
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-card);
      min-height: 300px;
      border: 1px solid var(--border-subtle);
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      text-align: center;
    }
    .step-item {
      flex: 1;
      position: relative;
    }
    .step-circle {
      width: 60px;
      height: 60px;
      border: 2px solid var(--cyan);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      font-size: 24px;
      font-weight: 700;
      color: var(--white);
      transition: 0.3s;
    }
    .step-item:hover .step-circle {
      background: var(--cyan);
      color: #0A0F1E;
      transform: scale(1.1);
    }
    .step-title {
      font-weight: 600;
      color: var(--white);
    }

    /* 证言 */
    .testimonial-card {
      display: flex;
      gap: 20px;
      align-items: center;
      border-left: 4px solid var(--orange);
    }
    .avatar {
      width: 60px;
      height: 60px;
      border-radius: 50%;
      background-size: cover;
      background-position: center;
      flex-shrink: 0;
    }

    /* FAQ */
    .faq-item {
      margin-bottom: 16px;
    }
    .faq-question {
      background: var(--glass-bg);
      backdrop-filter: blur(8px);
      border: 1px solid var(--border-subtle);
      padding: 18px 24px;
      border-radius: var(--radius-inner);
      font-weight: 600;
      color: var(--white);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      padding: 0 24px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: rgba(255,255,255,0.02);
      border-radius: 0 0 var(--radius-inner) var(--radius-inner);
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      padding: 16px 24px;
    }

    /* CTA */
    .cta-section {
      background: #080C18;
      text-align: center;
    }

    footer {
      background: #060A14;
      padding: 48px 0;
      color: var(--gray-dark);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .hero-content { flex-direction: column; }
      .steps { flex-wrap: wrap; gap: 24px; }
    }
    @media (max-width: 768px) {
      .site-header { height: auto; }
      .nav-menu { display: none; }
      .mobile-toggle { display: block; }
      .mobile-menu.active { display: flex; flex-direction: column; background: #0A0F1E; position: fixed; top: 72px; left:0; width:100%; padding:24px; }
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-text h1 { font-size: 30px; }
      section { padding: 60px 0; }
    }