gnu-social/public/assets/default_theme/css/pages/settings.css

.section-settings {
    background: var(--background-card);
    border: 2px solid var(--border);
    box-shadow: var(--shadow);
}

.section-settings,
.section-settings-details {
    margin-bottom: .6rem;
    border-radius: .6rem;
    padding: .6rem;
    box-sizing: border-box;
}
.section-settings-details {
    border: 2px solid var(--border);
}
.section-settings-details-title {
    display: block;
}
.section-settings-details[open] {
    border-left: 2px solid var(--foreground);
}

.section-settings-details[open] > summary:first-child {
    margin-bottom: var(--s);
}

.section-settings-details summary + form {
    padding-left: var(--s);
}

.section-settings hr {
    margin-top: .6rem;
    margin-bottom: .6rem;
}

.section-settings-details summary h3:first-letter ,.section-settings-details summary em:first-letter {
    text-transform: uppercase;
}

.section-settings-details summary:focus .icon-details-open,.section-settings-details summary:hover .icon-details-open {
    transition: all 200ms cubic-bezier(0,0.55,0.45,1);
}

.section-settings-details[open] svg {
    transform: rotate(180deg);
    animation: fadeOut 200ms cubic-bezier(0,0.55,0.45,1);
}

.section-settings-details[open] .set-nav li:last-of-type {
    margin-bottom: 0;
}

.section-settings-details:not([open]) svg {
    transform: initial;
    animation: fadeIn 200ms cubic-bezier(0,0.55,0.45,1);
}