Simplify some style nesting and remove leftover styles

sass/_buttons.scss

@@ -27,8 +27,6 @@
 	}
 
 	&.colored {
-		-webkit-backdrop-filter: unset;
-		backdrop-filter: unset;
 		background-color: transparent;
 		box-shadow: none;
 		color: var(--primary-color);

sass/_main.scss

@@ -11,14 +11,12 @@ html {
 	accent-color: var(--primary-color);
 	overflow-wrap: break-word;
 	overflow: hidden; // Disable scroll of html, scroll body instead
-}
 
-// Smaller font size on mobile
-// @media only screen and (max-width: 480px) {
-//   html {
-//     font-size: 14px;
-//   }
-// }
+	// Smaller font size on mobile
+	// @media only screen and (max-width: 480px) {
+	//     font-size: 14px;
+	// }
+}
 
 html,
 body {
@@ -177,11 +175,9 @@ aside {
 	width: 30%;
 
 	@media only screen and (max-width: 720px) {
-		& {
-			width: 100%;
-			float: none;
-			margin-inline-start: 0;
-		}
+		width: 100%;
+		float: none;
+		margin-inline-start: 0;
 	}
 }
 

sass/_qrcode.scss

@@ -7,8 +7,6 @@
 	width: 150px;
 
 	@media only screen and (max-width: 720px) {
-		& {
-			display: none;
-		}
+		display: none;
 	}
 }