Шаблон:FlatCardWithHeader/Сollapsible/styles.css

.flat-card-with-header--сollapsible {
    border: 1px solid #3F3F46;
    border-radius: 4px;
    background-color: #1B1B1F !important;
    margin: 8px 0;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.flat-card-with-header--сollapsible__header {
    display: flex;
    align-items: center;
    background-color: #2A2A2E !important;
    padding: 8px 12px;
    border-bottom: 1px solid #3F3F46;
    color: #FFFFFF !important;
    font-size: 1.1em;
    font-weight: bold;
}

.flat-card-with-header--сollapsible__content {
    padding: 12px;
    background-color: #1B1B1F !important;
}

/* Чтобы кнопка развернуть была справа */
.flat-card-with-header--сollapsible > .mw-collapsible-toggle {
    position: absolute;
    right: 16px;
    top: 12px;
    color: #6699FF;
}