/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary-deep: #0B0E2F;
      --accent-purple: #4A3AFF;
      --glow-cyan: #00E5FF;
      --spark-gold: #FFB800;
      --surface-dark: #0F133A;
      --card-bg: rgba(22, 27, 75, 0.65);
      --card-border: rgba(74, 58, 255, 0.35);
      --text-white: #FFFFFF;
      --text-body: #B0B8D6;
      --text-muted: #7B82A8;
      --radius-card: 16px;
      --radius-btn: 50px;
      --shadow-card: 0 12px 32px rgba(0,0,0,0.5), 0 0 0 1px rgba(74,58,255,0.25);
      --shadow-glow: 0 0 25px rgba(0,229,255,0.5);
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition-smooth: all 0.3s cubic-bezier(0.23, 1, 0.32, 1);
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--primary-deep);
      color: var(--text-body);
      line-height: 1.7;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 自定义背景粒子效果 (星空微光) */
    .starfield-bg {
      position: relative;
      background: radial-gradient(circle at 20% 30%, #1A1F5C 0%, #0B0E2F 85%);
      overflow: hidden;
    }
    .starfield-bg::before {
      content: "";
      position: absolute;
      inset: 0;
      background-image: radial-gradient(1px 1px at 10% 20%, rgba(255,255,255,0.4), transparent),
                        radial-gradient(1px 1px at 80% 60%, rgba(255,255,255,0.3), transparent),
                        radial-gradient(2px 2px at 45% 70%, rgba(0,229,255,0.5), transparent),
                        radial-gradient(2px 2px at 90% 15%, rgba(74,58,255,0.6), transparent);
      background-size: 200px 200px, 300px 300px, 250px 250px, 180px 180px;
      background-repeat: no-repeat;
      pointer-events: none;
      z-index: 0;
      opacity: 0.7;
    }

    /* 导航栏：分段标签风格 + 粘性模糊 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 40;
      background: rgba(11, 14, 47, 0.8);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(74, 58, 255, 0.25);
      padding: 12px 0;
    }

    .nav-wrapper {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }

    .logo-area {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--text-white);
      letter-spacing: 0.5px;
    }

    .logo-icon {
      width: 32px;
      height: 32px;
      background: radial-gradient(circle, var(--glow-cyan), var(--accent-purple));
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 800;
      font-size: 18px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 8px;
      background: rgba(15, 19, 58, 0.7);
      backdrop-filter: blur(8px);
      border-radius: 50px;
      padding: 5px 12px;
      border: 1px solid rgba(74,58,255,0.3);
    }

    .nav-chip {
      padding: 8px 18px;
      border-radius: 30px;
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-muted);
      transition: var(--transition-smooth);
      white-space: nowrap;
    }

    .nav-chip:hover {
      color: var(--glow-cyan);
      background: rgba(74,58,255,0.2);
    }

    .nav-chip.active {
      background: var(--accent-purple);
      color: white;
      box-shadow: 0 0 15px rgba(0,229,255,0.5);
      font-weight: 600;
    }

    .header-cta {
      margin-left: 16px;
      background: var(--accent-purple);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      letter-spacing: 0.03em;
      box-shadow: 0 0 20px rgba(0,229,255,0.5);
      transition: var(--transition-smooth);
      white-space: nowrap;
    }
    .header-cta:hover {
      background: var(--glow-cyan);
      color: var(--primary-deep);
      box-shadow: 0 0 32px rgba(0,229,255,0.85);
    }

    /* 汉堡菜单基础隐藏，Foundation 控制显示 */
    .menu-icon {
      color: white;
      font-size: 1.8rem;
    }

    /* Hero 双栏 */
    .hero-section {
      padding: 80px 0 100px;
      position: relative;
      z-index: 2;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .hero-left {
      flex: 1 1 400px;
    }
    .hero-right {
      flex: 1 1 400px;
      position: relative;
    }

    .hero-image {
      width: 100%;
      border-radius: 32px;
      box-shadow: 0 20px 40px rgba(0,229,255,0.25);
      animation: floatGlow 6s infinite alternate ease-in-out;
    }

    @keyframes floatGlow {
      0% { filter: drop-shadow(0 0 15px rgba(0,229,255,0.4)); transform: translateY(0); }
      100% { filter: drop-shadow(0 0 30px rgba(74,58,255,0.7)); transform: translateY(-8px); }
    }

    .hero-title {
      font-size: clamp(2.5rem, 5vw, 3.8rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      color: white;
      margin-bottom: 20px;
      line-height: 1.2;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-body);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-purple);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      letter-spacing: 0.04em;
      box-shadow: var(--shadow-glow);
      border: none;
      cursor: pointer;
      transition: var(--transition-smooth);
      display: inline-block;
    }
    .btn-primary:hover {
      background: var(--glow-cyan);
      color: #0B0E2F;
      box-shadow: 0 0 35px rgba(0,229,255,0.9);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-purple);
      color: var(--accent-purple);
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      transition: var(--transition-smooth);
    }
    .btn-outline:hover {
      background: var(--accent-purple);
      color: white;
    }

    /* 通用区块 */
    .section {
      padding: 80px 0;
      position: relative;
      z-index: 2;
    }
    .section-title {
      font-size: clamp(1.8rem, 3vw, 2.5rem);
      font-weight: 700;
      color: white;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      text-align: center;
      color: var(--text-muted);
      max-width: 700px;
      margin: 0 auto 48px;
    }

    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 28px;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      border: 1px solid var(--card-border);
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
      color: var(--text-body);
    }
    .glass-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 18px 40px rgba(0,229,255,0.3);
      border-color: var(--glow-cyan);
    }
    .highlight-icon {
      font-size: 2.4rem;
      margin-bottom: 16px;
      color: var(--glow-cyan);
    }
    .highlight-number {
      font-size: 2rem;
      font-weight: 700;
      color: white;
      margin-bottom: 8px;
    }

    /* 案例瀑布 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
      gap: 28px;
      grid-auto-rows: auto;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--card-border);
      transition: var(--transition-smooth);
      backdrop-filter: blur(10px);
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: 0 16px 35px rgba(0,229,255,0.3);
    }
    .case-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      border-bottom: 1px solid rgba(74,58,255,0.4);
    }
    .case-content {
      padding: 20px;
    }
    .case-tag {
      background: rgba(74,58,255,0.25);
      color: var(--glow-cyan);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      display: inline-block;
      margin-bottom: 10px;
    }

    /* 方案对比 */
    .comparison-row {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
      justify-content: center;
    }
    .plan-card {
      flex: 1 1 280px;
      background: rgba(15,19,58,0.8);
      backdrop-filter: blur(8px);
      border-radius: 20px;
      padding: 32px 24px;
      border: 1px solid rgba(74,58,255,0.2);
      transition: var(--transition-smooth);
    }
    .plan-card.recommended {
      border: 2px solid var(--spark-gold);
      box-shadow: 0 0 28px rgba(255,184,0,0.35);
      position: relative;
    }
    .badge-gold {
      background: var(--spark-gold);
      color: #0B0E2F;
      font-weight: 700;
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 0.8rem;
      display: inline-block;
      margin-bottom: 12px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid rgba(74,58,255,0.25);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.2rem;
      color: white;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      margin-top: 12px;
      color: var(--text-body);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-item.active .faq-question {
      color: var(--glow-cyan);
    }

    /* CTA 深色全宽 */
    .cta-dark {
      background: #0B0E2F;
      text-align: center;
      padding: 80px 24px;
      border-top: 1px solid rgba(74,58,255,0.3);
    }

    /* 页脚 */
    .footer {
      background: #080B24;
      padding: 60px 0 30px;
      border-top: 1px solid rgba(74,58,255,0.3);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(160px,1fr));
      gap: 40px;
    }
    .footer-links a {
      display: block;
      color: var(--text-muted);
      margin-bottom: 8px;
    }
    .footer-links a:hover {
      color: var(--glow-cyan);
    }

    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .btn-group {
        justify-content: center;
      }
      .nav-links {
        display: none;
      }
      .menu-icon {
        display: block;
      }
    }