Autoprefixer trick ?

style.css

@@ -1,3 +1,10 @@
+/*
+* Prefixed by https://autoprefixer.github.io
+* PostCSS: v8.3.6,
+* Autoprefixer: v10.3.1
+* Browsers: last 4 version
+*/
+
 :root {
 	--thickness: 1px;
 	--background: #9fd3a8;
@@ -18,37 +25,6 @@ body {
 	font-style: italic;
 }
 
-/* .container {
-	position: absolute;
-	left: 50%;
-	top: 50%;
-	width: 100%;
-	transform: translate(-50%, -50%);
-
-	display: flex;
-	flex-direction: column;
-	margin: 0 auto;
-
-	justify-content: start;
-	align-items: center;
-}
-
-.about-button {
-	width: 200px;
-	height: 200px;
-	border: var(--thickness) solid currentColor;
-	background-color: var(--background);
-	border-radius: 50%;
-	font-size: 48px;
-}
-
-.about-button:hover {
-	background-color: white;
-	cursor: pointer;
-} */
-
-/* .title, */
-
 .info {
 	display: inline-block;
 	padding: 8px;
@@ -69,9 +45,13 @@ body {
 
 .sticker {
 	position: absolute;
+	-webkit-user-select: none;
+	-moz-user-select: none;
+	-ms-user-select: none;
 	user-select: none;
 	border: var(--thickness) solid currentColor;
 	border-radius: 16px;
+	-webkit-box-shadow: 2px 2px 2px 1px rgba(0, 0, 0, 0.2);
 	box-shadow: 2px 2px 2px 1px rgba(0, 0, 0, 0.2);
 }