[Design] Setup page background.

scss/index.scss

@@ -0,0 +1,49 @@
+$cloud_width: 200px;
+
+body {
+	margin: 0;
+	padding: 0;
+	.top {
+		background-image: linear-gradient(#24d3ff, #aaeeff);
+		height: 70vh;
+	}
+
+	.bottom {
+		background-image: linear-gradient(#26a4c4, #afdde9);
+		height: 30vh;
+	}
+	.clouds {
+		position: absolute;
+		width: $cloud_width;
+		animation-name: move_right;
+		animation-direction: alternate;
+		animation-iteration-count: infinite;
+		animation-timing-function: linear;
+	}
+	#cloud1 {
+		top: $cloud_width / 466 * 70; // 1 cloud worth of gap
+		left: 0;
+		animation-duration: 17s;
+	}
+
+	#cloud2 {
+		top: $cloud_width / 466 * 70 * 4; // 4 clouds worth of gap
+		left: 0;
+		animation-delay: -2s;
+		animation-duration: 15s;
+		transform: rotateY(180deg);
+	}
+}
+
+
+
+@keyframes move_right {
+	from {left: 0}
+	to {left: calc(100vw - #{$cloud_width})}
+}
+
+
+@keyframes move_left {
+	from {right: 0}
+	to {right: calc(100vw - #{$cloud_width})}
+}