body {
    font-family: "Courier New", Courier, monospace;
    margin: 0;
    padding: 20px;
    background-color: #1a1a1a;
    color: #00ff00;
    text-align: center;
}

.container {
    width: 90%;
    max-width: 450px;
    margin: 20px auto;
    padding: 20px;
    border: 2px solid #00cc00;
    background-color: #0d0d0d;
}

h1 {
    font-size: 1.8rem;
    margin-bottom: 25px;
    color: #ffff00;
    text-transform: uppercase;
    letter-spacing: 2px;
    border-bottom: 1px solid #00cc00;
    padding-bottom: 10px;
}

label {
    display: block;
    margin: 15px 0 5px 0;
    font-size: 1rem;
    text-align: left;
}

select, input[type="number"] {
    display: block;
    margin-bottom: 15px;
    padding: 8px;
    width: calc(100% - 18px);
    border: 1px solid #009900;
    border-radius: 0;
    background-color: #000000;
    color: #00ff00;
    font-family: inherit;
    font-size: 1rem;
    outline: none;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type="number"] {
    -moz-appearance: textfield;
}

select:focus, input[type="number"]:focus {
    background-color: #111111;
    border-color: #00ff00;
    box-shadow: 0 0 5px #00ff00;
}

.output {
    margin-top: 25px;
    padding: 15px;
    font-size: 1.1rem;
    background-color: #000000;
    border: 1px dashed #00cc00;
    min-height: 2em;
    line-height: 1.4;
    word-wrap: break-word;
}