Add a css loader on every async API call

TODO: maybe be able to select not to show it by arg?

public/css/custom.css

@@ -94,6 +94,53 @@ main > div.content {
   text-align: center;
 }
 
+/* Loader
+–––––––––––––––––––––––––––––––––––––––––––––––––– */
+#loader {
+  display: flex;
+  position: fixed;
+  z-index: 100;
+  background: #ffffffa8;
+  width: 100vw;
+  height: 100vh;
+}
+.lds-ring {
+  display: inline-block;
+  position: relative;
+  width: 80px;
+  height: 80px;
+  margin: auto;
+}
+.lds-ring div {
+  box-sizing: border-box;
+  display: block;
+  position: absolute;
+  width: 64px;
+  height: 64px;
+  margin: 8px;
+  border: 4px solid #a2a2a2;
+  border-radius: 50%;
+  animation: lds-ring 1.2s cubic-bezier(0.5, 0, 0.5, 1) infinite;
+  border-color: #a2a2a2 transparent transparent transparent;
+}
+.lds-ring div:nth-child(1) {
+  animation-delay: -0.45s;
+}
+.lds-ring div:nth-child(2) {
+  animation-delay: -0.3s;
+}
+.lds-ring div:nth-child(3) {
+  animation-delay: -0.15s;
+}
+@keyframes lds-ring {
+  0% {
+    transform: rotate(0deg);
+  }
+  100% {
+    transform: rotate(360deg);
+  }
+}
+
 /* Shared
 –––––––––––––––––––––––––––––––––––––––––––––––––– */
 .button {

src/js/api.php

@@ -4,7 +4,12 @@ const http = {
 		payload = payload || null;
 		callbk = callbk || null;
 		const oReq = new XMLHttpRequest();
-		oReq.addEventListener("load", function() { if (callbk) callbk(this.responseText) });
+		document.getElementById('loader').style = '';
+		oReq.addEventListener("load", function() {
+			document.getElementById('loader').style = 'display: none';
+			if (callbk)
+				callbk(this.responseText);
+		});
 		oReq.open(method, path);
 		oReq.setRequestHeader('Content-Type', 'application/json');
 		oReq.send(payload);

src/views/public/head.php

@@ -1,3 +1,5 @@
+<div id="loader" style="display: none"><div class="lds-ring">
+  <div></div><div></div><div></div><div></div></div></div>
 <header>
 	<div class="icon">
 		<a href="/">