style.css

:root {
    --red: #ff9393;
    --green: #93ffa9;
    --blue: #93adff;
}

* {
    padding: 0px;
    margin: 0px;
    box-sizing: border-box;
    font-family: Verdana, serif;
}

body {
    background-color: #222222;
    color: white;
    padding: 50px 5%;
    text-align: center;
}

input {
    width: 700px;
    display: block;
    border: 5px solid var(--blue);
    padding: 15px 20px;
    margin: 5px auto;
    font-size: 25px;
    font-family: monospace;
    background-color: inherit;
    color: inherit;
    border-radius: 10px;
    transition: border-color 250ms;
}

input:focus {
    border-color: var(--green);
    outline: none;
}

button {
    width: 700px;
    background-color: var(--blue);
    color: #222222;
    font-size: 20px;
    padding: 30px;
    border: none;
    border-radius: 10px;
    text-decoration: none;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 250ms;
}

button:hover {
    background-color: var(--green);
}

p {
    margin: 20px 0px;
}

a {
    color: var(--red);
}

a:hover {
    text-decoration: none;
}