add java script to the project

Author: MDJAmin

css/style.css

@@ -4,8 +4,8 @@
     box-sizing: border-box;
 }
 :root{
-    --primaryClr:#33ff00;
-    --secondaryClr:#00b545;
+    --primaryClr:#ffffff;
+    --secondaryClr:#dddddd;
     --thirdClr:#393E46;
     --txtClr:#222831;
 }

js/script.js

@@ -0,0 +1,33 @@
+"use strict";
+const numEls = document.querySelectorAll(".num");
+const screenEl = document.querySelector("#screen-txt");
+const dotEl = document.querySelector("#point");
+const plusEl = document.querySelector("#plus");
+const minusEl = document.querySelector("#minus");
+const multiplyEl = document.querySelector("#Multiply");
+const divideEl = document.querySelector("#divide");
+const clearEl = document.querySelector("#clear");
+const equalEl = document.querySelector("#equal");
+const btnEls = document.querySelectorAll("button");
+
+for (let i = 0; i < btnEls.length; i++) {
+  btnEls[i].addEventListener("mousedown", () => {
+    btnEls[i].style.opacity = ".5";
+  });
+  btnEls[i].addEventListener("mouseup", () => {
+    btnEls[i].style.opacity = "1";
+  });
+  btnEls[i].addEventListener("click", () => {
+    if (btnEls[i] != equalEl) {
+      screenEl.innerHTML += btnEls[i].innerHTML;
+    }
+  });
+}
+
+clearEl.addEventListener("click", () => {
+  screenEl.innerHTML = "";
+});
+
+equalEl.addEventListener("click", () => {
+  screenEl.innerHTML = eval(screenEl.innerHTML);
+});