cost/mass blink when modified

src/components/CostMass.svelte

@@ -16,4 +16,6 @@
   .cost:after { content: '\00A4'; margin-left: 0.5em; }
   .mass:after { content: url("mass.svg"); width: 0.75em; display:
   inline-block; margin-left: 0.5em; }
+
+
 </style>

src/components/ShipItem/index.svelte

@@ -1,13 +1,29 @@
 <div class="ship-item">
     <slot />
 
-    <div class="mass">{ mass }</div>
-    <div class="cost">{ cost }</div>
+    <div class="mass" bind:this={mass_el}>{ mass }</div>
+    <div class="cost" bind:this={cost_el}>{ cost }</div>
 </div>
 
 <script>
+  import { tick } from 'svelte';
+
   export let mass;
   export let cost;
+
+  let mass_el;
+  let cost_el;
+
+  const update_el = async (el) => {
+    if(!el) return;
+    el.classList.remove('updated');
+    void el.offsetWidth;
+    el.classList.add('updated');
+  }
+
+  $: update_el( mass_el, mass );
+  $: update_el( cost_el, cost );
+
 </script>
 
 <style>
@@ -26,4 +42,18 @@
   .cost:after { content: '\00A4'; margin-left: 0.5em; }
   .mass:after { content: url(mass.svg); width: 0.75em; display:
   inline-block; margin-left: 0.5em; }
+
+  :global(.updated) {
+    animation-name: update;
+    animation-duration: 1.5s;
+    animation-fill-mode: forwards;
+  }
+
+@keyframes update {
+  0%   {color:inherit; font-weight: inherit;}
+  20% {color:red; font-weight: bold;}
+  80% {color:red; font-weight: bold;}
+  100% {color:inherit; font-weight: inherit; }
+}
+
 </style>