Add solution to exercise no.3

Author: piotr-sarna

03 - CSS Variables/index-START.html

@@ -9,7 +9,7 @@ <h2>Update CSS Variables with <span class='hl'>JS</span></h2>
 
   <div class="controls">
     <label for="spacing">Spacing:</label>
-    <input type="range" name="spacing" min="10" max="200" value="10" data-sizing="px">
+    <input type="range" name="spacing" min="0" max="200" value="10" data-sizing="px">
 
     <label for="blur">Blur:</label>
     <input type="range" name="blur" min="0" max="25" value="10" data-sizing="px">
@@ -21,6 +21,21 @@ <h2>Update CSS Variables with <span class='hl'>JS</span></h2>
   <img src="https://source.unsplash.com/7bwQXzbF6KE/800x500">
 
   <style>
+    :root {
+      --spacing: 10px;
+      --blur: 10px;
+      --base: #ffc600;
+    }
+
+    img {
+      padding: var(--spacing);
+      filter: blur(var(--blur));
+      background: var(--base);
+    }
+
+    .hl {
+      color: var(--base);
+    }
 
     /*
       misc styles, nothing to do with CSS variables
@@ -48,6 +63,18 @@ <h2>Update CSS Variables with <span class='hl'>JS</span></h2>
   </style>
 
   <script>
+    const inputs = document.querySelectorAll('.controls input');
+
+    function handleUpdate(e) {
+      const suffix = this.dataset.sizing || '';
+
+      document.documentElement.style.setProperty(`--${this.name}`, `${this.value + suffix}`);
+    }
+
+    inputs.forEach(input => {
+      input.addEventListener('change', handleUpdate);
+      input.addEventListener('mousemove', handleUpdate);
+    });
   </script>
 
 </body>