Add notifications

* Fix entry edit

popup.css

@@ -5,6 +5,7 @@
 		--highlight-bg-color: hsl(213, 10%, 28%);
 		--fg-color: #ccc;
 		--border-color: #888;
+		--error-bg-color: hsl(0, 38%, 30%);
 		--img-filter: ;
 	}
 }
@@ -16,16 +17,23 @@
 		--highlight-bg-color: #ccc;
 		--fg-color: #666;
 		--border-color: #888;
+		--error-bg-color: hsl(0, 38%, 70%);
 		--img-filter: invert(1);
 	}
 }
 
+*
+{
+	box-sizing: border-box;
+}
+
 body {
 	background-color: var(--bg-color);
 	color: var(--fg-color);
 	max-height: 600px;
 	margin: 0;
 	font-size: 12px;
+	position: relative;
 }
 
 input {
@@ -171,6 +179,30 @@ h2 {
 	cursor: pointer;
 }
 
+#notification {
+	position: absolute;
+	top: 0;
+	left: 0;
+	right: 0;
+	z-index: 10;
+	display: flex;
+	flex-direction: row;
+	justify-content: space-between;
+	background-color: var(--error-bg-color);
+	font-size: 1.2em;
+	padding: 4px;
+	transform: translateY(-100%);
+	transition: transform 0.3s;
+}
+
+#notification.show {
+	transform: translateY(0);
+}
+
+#notification img {
+	height: 1em;
+}
+
 #password-container {
 	padding: 1em;
 }