nextcloud-server/core/css/login/authpicker.css

.picker-window {
	display: inline-block;
	padding: 16px;
	margin: 20px;
	background-color: var(--color-main-background);
	color: var(--color-main-text);
	border-radius: var(--border-radius-large);
	box-shadow: 0 0 10px var(--color-box-shadow);
	cursor: default;
}

.picker-window.small {
    max-width: 400px;
}

.picker-window h2 {
    margin: 20px auto;
}

.apptoken-link {
	margin: 20px;
	display: block;
}