Add focus effects to inputs

Provides better keyboard accessibility for:
* Checkboxes
* Range Inputs
* Copy-over Buttons
* Option-reveal Elements
Along with some minor design improvements

src/client/lazy-app/Compress/Options/Checkbox/style.css

@@ -2,6 +2,26 @@
   display: inline-block;
   position: relative;
   --size: 17px;
+
+  &::before {
+    content: '';
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    width: 200%;
+    height: 200%;
+    background-color: var(--main-theme-color);
+    border-radius: 999px;
+    opacity: 0.25;
+
+    transform: translate(-50%, -50%) scale(0);
+    transition-property: transform;
+    transition-duration: 250ms;
+  }
+
+  &:focus-within::before {
+    transform: translate(-50%, -50%) scale(1);
+  }
 }
 
 .real-checkbox {

src/client/lazy-app/Compress/Options/Range/custom-els/RangeInput/style.css

@@ -47,6 +47,10 @@ range-input::before {
   height: 12px;
 }
 
+range-input:focus-within .thumb {
+  outline: white solid 2px;
+}
+
 .thumb-wrapper {
   position: absolute;
   left: 6px;

src/client/lazy-app/Compress/Options/Toggle/style.css

@@ -11,6 +11,10 @@
   padding: 3px calc(var(--thumb-size) / 2 + 3px);
 }
 
+.checkbox:focus-within .track {
+  outline: white solid 2px;
+}
+
 .thumb {
   position: relative;
   width: var(--thumb-size);

src/client/lazy-app/Compress/Options/style.css

@@ -53,6 +53,16 @@
   composes: option-toggle;
   grid-template-columns: auto 1fr;
   gap: 1em;
+
+  border-top: 1px solid #fff4;
+
+  transition-property: background-color;
+  transition-duration: 250ms;
+}
+
+.option-reveal:focus-within,
+.option-reveal:hover {
+  background-color: #fff2;
 }
 
 .option-one-cell {
@@ -118,6 +128,11 @@
   svg {
     fill: var(--header-text-color);
   }
+
+  &:focus {
+    outline: var(--header-text-color) solid 2px;
+    outline-offset: 0.25em;
+  }
 }
 
 .save-button,