a {
    color: #2ecc71;
    text-decoration: underline;
}


a:hover {
    color: #28cc28;
    text-decoration: none;
}


nav ul li a {
    color: #2ecc71;
    text-decoration: underline;
}

nav ul li a:hover {
    color: #28cc28;
}

body {
    background: black;
    color: #33ff33;
    font-family: 'Courier New', monospace;
    text-align: center;
}
nav ul {
    list-style: none;
    padding: 0;
    background: black;
    border-bottom: 3px solid #33ff33;
}
nav ul li {
    display: inline;
    margin-right: 20px;
}
nav ul li a {
    color: #33ff33;
    text-decoration: none;
}
.container {
    margin-top: 50px;
    font-size: 16px;
    width: 50%;
    margin: auto;
    text-align: center;
}
form {
    display: flex;
    flex-direction: column;
    align-items: center;
}
input {
    width: 200px;
    padding: 10px;
    margin: 5px 0;
    font-size: 18px;
    text-align: center;
    background: black;
    color: #33ff33;
    border: 1px solid #33ff33;
    font-family: 'Courier New', monospace;
}
input[type="number"] {
    -moz-appearance: textfield;
}
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}
button {
    width: 220px;
    padding: 10px;
    font-size: 18px;
    background-color: #33ff33;
    color: black;
    border: none;
    cursor: pointer;
    margin-top: 10px;
}
button:hover {
    background-color: #28cc28;
}