body {
    margin: 0;
}

.popup {
	position: absolute;
    display: flex;
    justify-content: center;
    align-items: center;
	top: 0;
	bottom: 0;
	left: 0;
	right: 0;
	background: rgba(0, 0, 0, 0.7);
	transition: opacity 500ms;
	visibility: hidden;
	opacity: 0;
}
.popup--visible {
	visibility: visible;
	opacity: 1;
}
.popup__box {
	width: 100%;
	min-width: 320px;
	max-width: 30rem;
	padding: 20px;
	background: #fff;
	border-radius: 5px;
}
.popup__close {
    float: right;
    font-size: 20px;
    cursor: pointer;
}
.popup__title {
    margin-top: 0;
}