body {
    margin: 20px;
}
h1 {
    color: #333;
}
input[type="number"] {
    width: 60px;
}
select {
    margin-left: 10px;
}
table {
    border-collapse: collapse;
    margin-top: 20px;
    width: 100%;
    overflow-x: auto;
}
th, td {
    border: 1px solid #999;
    padding: 8px;
    text-align: center;
}
th {
    background-color: #eee;
}
.matrix {
    margin-bottom: 20px;
}