Install button

src/shared/prerendered-app/Intro/index.tsx

@@ -227,9 +227,6 @@ export default class Intro extends Component<Props, State> {
           type="file"
           onChange={this.onFileChange}
         />
-        {beforeInstallEvent && (
-          <button onClick={this.onInstallClick}>Install</button>
-        )}
         <div class={style.main}>
           {!__PRERENDER__ && (
             <canvas
@@ -328,6 +325,11 @@ export default class Intro extends Component<Props, State> {
             </footer>
           </div>
         </div>
+        {beforeInstallEvent && (
+          <button class={style.installBtn} onClick={this.onInstallClick}>
+            Install
+          </button>
+        )}
       </div>
     );
   }

src/shared/prerendered-app/Intro/style.css

@@ -148,3 +148,22 @@
     height: auto;
   }
 }
+
+@keyframes fade-in {
+  from {
+    opacity: 0;
+  }
+}
+
+.install-btn {
+  composes: unbutton from global;
+  position: absolute;
+  top: 1rem;
+  right: 1rem;
+  background: var(--deep-blue);
+  border-radius: 0.4em;
+  color: var(--white);
+  padding: 0.5em 1em;
+  font-size: 1.6rem;
+  animation: fade-in 600ms ease-in-out;
+}