Simplify CSS by migrating to Flexbox

src/shareon.css

@@ -1,76 +1,53 @@
 :root {
-  --button-size: 36px;
-  --icon-size: 20px;
-
-  --padding-ver: calc(0.3 * var(--icon-size));
-  --padding-hor: calc(var(--icon-size) / 2);
-  --padding-icon: calc((var(--button-size) - var(--icon-size)) / 2);
-
-  --height: calc(var(--button-size) - 2 * var(--padding-ver));
-  --width: calc(var(--button-size) - 2 * var(--padding-hor));
+  --shareon-size: 36px;
+  --shareon-icon-size: 20px;
+  --shareon-radius: 4px;
 }
 
 .shareon {
-  font-size: 0 !important;
+  display: flex;
+  flex-wrap: wrap;
+  align-items: flex-start;
+  gap: 5px;
 }
 
 .shareon > * {
-  display: inline-block;
-  position: relative;
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+  justify-content: space-evenly;
+  gap: calc((var(--shareon-size) - var(--shareon-icon-size)) / 2);
 
-  height: var(--height);
-  min-width: var(--width);
+  box-sizing: border-box;
+  height: var(--shareon-size);
+  min-width: var(--shareon-size);
+  padding: calc((var(--shareon-size) - var(--shareon-icon-size)) / 2);
 
-  margin: calc(var(--padding-ver) / 2);
-  padding: var(--padding-ver) var(--padding-hor);
+  border: none;
+  border-radius: var(--shareon-radius);
 
   background-color: #333;
-  border-radius: calc(var(--icon-size) / 6);
-  border: none;
-  box-sizing: content-box;
   color: white;
-  line-height: 1.5;
   transition: opacity 300ms ease;
-  vertical-align: middle;
 }
 
 .shareon > *:hover {
-  border: none;
   cursor: pointer;
   opacity: 0.7;
 }
 
 .shareon > *:not(:empty) {
-  font-size: calc(0.8 * var(--icon-size));
+  font-size: calc(0.8 * var(--shareon-icon-size));
   text-decoration: none;
 }
 
-.shareon > *:not(:empty)::before {
-  position: relative;
-
-  height: 100%;
-  width: calc(var(--icon-size) + var(--padding-icon));
-
-  top: 0;
-  left: 0;
-
-  background-position: 0 50%;
-}
-
 .shareon > *::before {
-  display: inline-block;
-  position: absolute;
-
-  height: var(--icon-size);
-  width: var(--icon-size);
-
-  top: var(--padding-icon);
-  left: var(--padding-icon);
+  height: var(--shareon-icon-size);
+  width: var(--shareon-icon-size);
 
   background-repeat: no-repeat;
-  background-size: var(--icon-size) var(--icon-size);
+  background-size: contain;
   content: "";
-  vertical-align: bottom;
 }
 
 .shareon > .copy-url:before {