Improved styling

Let’s update the style.css as follows

body {
  text-align: center;
  color: aliceblue;
  background-color: darkblue;
}

.output {
   border: 3px solid white;
   margin: 1em 5em 1em 5em;
+  padding: 2em;
   display: none;
+}
+
+#hours {
+  font-size: x-large;
 }

Notice the leading # in #hours. When we aim to declare style attributes for an element with a particular ID attribute, we use the # selector together with the ID.

Stage and commit changes:

git add style.css 
git commit -m "increase padding and font size of wake up hours."

Additionally, update the script.js file as follows:

+const colors = [
+  "rgb(168, 39, 254)",
+  "rgb(154, 3, 254)",
+  "rgb(150, 105, 254)",
+  "rgb(140, 140, 255)",
+  "rgb(187, 187, 255)",
+  "rgb(143, 254, 221)",
+]
+
+function createWakeUpTimeElement(time, cycle) {
+  let elm = document.createElement("div");
+  elm.innerText = time;
+  elm.style.color = colors[cycle];
+  return elm;
+}
+
 function handleOnClick() {
   let output = document.querySelector(".output");
   output.style.display = "block";

   let hours = document.getElementById("hours");
   hours.innerHTML = "";

   let now = new Date();
   // allow 14 minutes to fall sleep!
   now.setMinutes(now.getMinutes() + 14);

   // calculate sleep cycles!
   for (let i = 1; i <= 6; i++) {
     now.setMinutes(now.getMinutes() + 90);
-    hours.innerHTML += now.toLocaleTimeString("en-US", { timeStyle: "short" }) + "<br />";
+    const elm = createWakeUpTimeElement(
+      now.toLocaleTimeString("en-US", { timeStyle: "short" }),
+      i
+    )
+    hours.appendChild(elm);
   } 
 }

Notice we are using JavaScript to create content!

I'm personally not a fan of using JavaScript in this capacity. However, many JavaScript frameworks for building front-end applications work this way.

Stage and commit changes:

git add script.js
git commit -m "Use a different color for each wakeup time."

Now push the changes to the GitHub repository:

git push

Give it a minute or two and then visit your GitHub Page. The deployed app should reflect the latest changes.