body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 5px;
    margin-top: 30px;
}

h1 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 30px;
}

h2 {
    color: #3498db;
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
    margin-top: 20px;
}

.form-group {
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

input[type="number"] {
    width: 100%;
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box;
}

.submit-btn, .back-btn {
    display: block;
    width: 100%;
    padding: 10px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    margin-top: 20px;
    text-align: center;
    text-decoration: none;
}

.submit-btn:hover, .back-btn:hover {
    background-color: #2980b9;
}

.result-section {
    margin-top: 20px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

table, th, td {
    border: 1px solid #ddd;
}

th, td {
    padding: 12px;
    text-align: left;
}

th {
    background-color: #f2f2f2;
}

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

tr.total {
    font-weight: bold;
    background-color: #e6f7ff;
}