:root{
      --primary:#4f46e5;
      --secondary:#0f172a;
      --bg:#f8fafc;
    }

    body{
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      background: var(--bg);
      color:#1f2937;
    }

    .navbar{
      background:#fff;
      box-shadow:0 2px 10px rgba(0,0,0,.05);
    }

    .navbar-brand{
      font-weight:700;
      color:var(--primary);
    }

    .hero{
      padding:70px 0 40px;
      text-align:center;
    }

    .hero h1{
      font-weight:800;
      color:var(--secondary);
    }

    .calculator-card{
      border:none;
      border-radius:16px;
      transition:all .3s ease;
      height:100%;
    }

    .calculator-card:hover{
      transform:translateY(-6px);
      box-shadow:0 12px 30px rgba(0,0,0,.12);
    }

    .calculator-card h5{
      font-weight:700;
      color:var(--primary);
    }

    .calculator-card p{
      font-size:14px;
      color:#6b7280;
    }

    .about-section, .content-box{
      background:#fff;
      border-radius:20px;
      padding:40px;
      margin-top:40px;
    }

    footer{
      background:#0f172a;
      color:#cbd5f5;
      padding:30px 0;
      margin-top:50px;
    }

    footer a{
      color:#cbd5f5;
      text-decoration:none;
      margin:0 10px;
      font-size:14px;
    }

    footer a:hover{
      color:#fff;
    }

    footer p{
      margin-top:15px;
      font-size:13px;
    }