feat: demo style tweaks

demo/src/sass/lib/mixins.scss

@@ -4,25 +4,6 @@
 
 @use 'sass:math';
 
-// Convert a <button> into an <a>
-// ---------------------------------------
-@mixin cancel-button-styles() {
-  background: transparent;
-  border: 0;
-  border-radius: 0;
-  cursor: pointer;
-  font: inherit;
-  line-height: $line-height-base;
-  margin: 0;
-  padding: 0;
-  position: relative;
-  text-align: inherit;
-  text-shadow: inherit;
-  user-select: text;
-  vertical-align: baseline;
-  width: auto;
-}
-
 // Nicer focus styles
 // ---------------------------------------
 @mixin focus-visible($color: $focus-default-color) {

demo/src/sass/lib/reset.scss

@@ -9,3 +9,7 @@
 *::before {
   box-sizing: border-box;
 }
+
+button {
+  all: unset;
+}