Edit in JSFiddle

<h1>DBmast.ru</h1>

:root {
	background-color: #2980b9;
	background: -webkit-linear-gradient(235deg, #71b073 29.9%, #2776aa 80%), -webkit-linear-gradient(146deg, rgba(255, 101, 53, 0.4) 24.9%, #aa2743 91%), -webkit-linear-gradient(80deg, #b1c9d8 19.9%, #2776aa 50%), -webkit-linear-gradient(305deg, #f4df26 15.9%, #ff1b9a 40%);
	background: linear-gradient(215deg, #71b073 29.9%, #2776aa 80%), linear-gradient(304deg, rgba(255, 101, 53, 0.4) 24.9%, #aa2743 91%), linear-gradient(10deg, #b1c9d8 19.9%, #2776aa 50%), linear-gradient(145deg, #f4df26 15.9%, #ff1b9a 40%);
	background-repeat: no-repeat;
	background-blend-mode: hard-light;
	display: -webkit-box;
	display: -ms-flexbox;
	display: flex;
	-webkit-box-align: center;
	-ms-flex-align: center;
	align-items: center;
	-webkit-box-pack: center;
	-ms-flex-pack: center;
	justify-content: center;
	height: 100vh;
}
body {
	background: none;
	-webkit-box-flex: 1;
	-ms-flex-positive: 1;
	flex-grow: 1;
	padding: 2em;
}
h1 {
	color: rgba(255, 255, 255, 0.2);
	font-size: 15vw;
	font-family: "Segoe UI", "Helvetica Neue", sans-serif;
	text-align: center;
	text-shadow: 0.02em 0.02em 0.02em rgba(0, 0, 0, 0.08);
	filter: drop-shadow(0.045em 0.045em 0.04em rgba(0, 0, 0, 0.21));
}