tmpl-flask/static/css/style.css

body {
    height: 100vh;
    padding: 0;
    margin: 0;
    font-family: sans-serif;

    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;

    --bg: #fff;
    --fg: #000;

    background: var(--bg);
    color: var(--fg);
}

@media (prefers-color-scheme: dark) {
    body {
        --bg: #202023;
        --fg: #eee;
    }
}

header { margin-top: 5px; }
footer { margin-bottom: 5px; }

a {
    color: #5b8a55;
}
a:hover {
    filter: brightness(120%);
}

form {
    display: flex;
    flex-direction: column;
}
form > div {
    margin-top: 5px;
    display: flex;
    flex-direction: row;
    justify-content: end;
}
form > div > label {
    width: 50%;
    margin-right: 10px;
}
form > div > input {
    width: 50%;
    border: 1px solid var(--fg);
    outline: none;
    background: var(--bg);
    color: var(--fg);
}
form > div > input:hover,
form > div > input:focus {
    filter: brightness(130%);
}