Fix: style install button

content/install-user-css.css

@@ -75,6 +75,22 @@ button.install {
   padding: 0.4em 0.8em;
 }
 
+button.install {
+  background: #3586FF;
+  color: white;
+  border-radius: 0.2em;
+  border: 1px solid #0026ff;
+}
+
+button.install:not([disabled]):active {
+  box-shadow: inset 0px 0px 0.4em 0px #6A3B82;
+}
+
+button.install.installed {
+  background: #00F587;
+  border-color: #00ae08;
+}
+
 .code {
   padding: 2em;
   font-family: monospace;

content/install-user-css.js

@@ -16,6 +16,7 @@ function install(style) {
         .forEach(el => el.remove());
       $('button.install').textContent = 'Installed';
       $('button.install').disabled = true;
+      $('button.install').classList.add('installed');
       window.dispatchEvent(new CustomEvent('installed', {detail: result}));
     })
     .catch(err => {