* {
     box-sizing: border-box;
 }

 body {
     font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
     background: #f4f7fa;
     margin: 0;
     padding: 20px;
     display: flex;
     justify-content: center;
     align-items: center;
     min-height: 100vh;
     color: #333;
 }

 .container {
     background: white;
     max-width: 400px;
     width: 100%;
     padding: 30px 25px;
     border-radius: 12px;
     box-shadow: 0 12px 30px rgba(0, 123, 255, 0.15);
     text-align: center;
 }

 h1 {
     margin-bottom: 25px;
     color: #007bff;
 }

 label {
     display: block;
     text-align: left;
     font-weight: 600;
     margin-bottom: 6px;
     color: #555;
 }

 input[type="text"],
 select {
     width: 100%;
     padding: 12px 15px;
     margin-bottom: 20px;
     font-size: 16px;
     border: 2px solid #ddd;
     border-radius: 8px;
     transition: border-color 0.3s ease;
     outline: none;
 }

 input[type="text"]:focus,
 select:focus {
     border-color: #007bff;
     box-shadow: 0 0 8px rgba(0, 123, 255, 0.25);
 }

 button {
     background-color: #007bff;
     border: none;
     color: white;
     padding: 14px 20px;
     font-size: 18px;
     font-weight: 700;
     border-radius: 10px;
     cursor: pointer;
     width: 100%;
     transition: background-color 0.3s ease;
 }

 button:hover {
     background-color: #0056b3;
 }

 hr {
     margin: 30px 0;
     border: none;
     border-top: 1px solid #ddd;
 }

 #result {
     font-size: 20px;
     font-weight: 700;
     color: #28a745;
     margin-top: 15px;
 }

 /* Responsive */
 @media (max-width: 480px) {
     .container {
         padding: 25px 15px;
     }

     button {
         font-size: 16px;
         padding: 12px 15px;
     }
 }