style.css

html {
    box-sizing: border-box;
}

*,
*:before,
*:after {
    box-sizing: inherit;
}

body {
    max-width: 1000px;
}

a {
    cursor: pointer;
}


.container {
    margin: 20px auto;
    padding: 20px;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.popup {
    margin-left: 5px;
}

form input[type="text"] {
    min-width: 100%;
    /* margin-right: 0; */
}

form {
    display: flex;
    flex-direction: column;
}

fieldset {
    display: flex;
    flex-direction: column;
}

label:has(> #show-advanced:checked)~.section-advanced {
    display: block;
}

.section-advanced {
    display: none;
}

.side-by-side {
    gap: 1em;
    display: flex;
    align-items: center;
    justify-content: flex-start;
}

.side-by-side span {
    margin: 0;
    padding: 0;
    font-size: .9rem;
    transform: translateY(-4px);
    opacity: 0;
}

details:not([open]) summary {
    background-color: white;
}

.note {
    margin-top: 0;
}