body, html {
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f6f6f6, #e0e0e0);
    color: #333;
    height: 100%;
}

.container {
    max-width: 600px;
    margin: 50px auto;
    background: #fff;
    padding: 30px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    text-align: center;
    border: 1px solid #f1f1f1;
}

h1 {
    font-size: 26px;
    color: #333;
    margin-bottom: 25px;
    letter-spacing: 1px;
}

label {
    display: block;
    font-size: 16px;
    font-weight: 500;
    margin-top: 15px;
    text-align: left;
}

input[type="number"] {
    width: calc(100% - 20px);
    max-width: 100%;
    padding: 12px;
    border: 1px solid #ccc;
    border-radius: 8px;
    margin-top: 5px;
    font-size: 16px;
    transition: border 0.3s ease-in-out;
    box-sizing: border-box;
}

.error-message {
    color: red;
    font-size: 14px;
    margin-top: 5px;
    display: block;
    text-align: left;
}

input[type="number"]:focus {
    border-color: #28a745;
    outline: none;
}

select {
    width: calc(100% - 20px);
    max-width: 100%;
    padding: 12px;
    border: 1px solid #ccc;
    border-radius: 8px;
    margin-top: 5px;
    font-size: 16px;
    transition: border 0.3s ease-in-out;
    box-sizing: border-box;
}

.error-message {
    color: red;
    font-size: 14px;
    margin-top: 5px;
    display: block;
}

select:focus {
    outline: none;
    border-color: #28a745;
}


button {
    display: block;
    width: 100%;
    padding: 15px;
    background: #28a745;
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 18px;
    margin-top: 20px;
    transition: background 0.3s, transform 0.2s;
}

button:hover {
    background: #218838;
}

.result {
    margin-top: 30px;
    padding: 20px;
    background: #f8f9fa;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    text-align: left;
}

.result h3, .result h4 {
    margin: 10px 0;
    color: #495057;
}

.result p {
    font-size: 16px;
    margin: 10px 0;
}

.result-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    font-size: 15px;
}

.result-table th, .result-table td {
    border: 1px solid #ddd;
    padding: 12px;
    text-align: center;
}

.result-table th {
    background: #f1f1f1;
    font-weight: 600;
}

.result-table tr:nth-child(even) {
    background-color: #f9f9f9;
}

/* Responsive design for smaller devices */
@media (max-width: 768px) {
    .container {
        padding: 20px;
    }

    h1 {
        font-size: 22px;
    }

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

    .result-table th, .result-table td {
        font-size: 14px;
        padding: 10px;
    }
}