Minor UI improvement.

src/App.js

@@ -109,7 +109,7 @@ function App() {
       <div className="head">
         <input className="search" type="search" placeholder="&#xf002; Search" onChange={search}/>
         <button className="add-btn btn" onClick={() => setNewBox(true)}>&#xf067;</button>
-        <button className="dark-light-btn btn" onClick={() => setLightMode(!lightMode)}>&#xf042;</button>
+        <button className="dark-light-btn btn" onClick={() => setLightMode(!lightMode)}></button>
       </div>
 
       <p className="results">{numberOfResults > 0 ? numberOfResults + ' Bookmarks found' : null}</p>

src/styles/App.css

@@ -81,5 +81,5 @@ textarea:focus, input:focus{
 
 .dark-light-btn {
   margin-left: 10px;
-  font-size: 1.3em;
+  font-size: 1.2em;
 }

src/styles/index.css

@@ -19,6 +19,10 @@ body {
 
 /* Dark Mode settings (Default) */
 
+.dark-light-btn::before {
+  content: '';
+}
+
 .delete {
   background-color: #1f2c38;
   color: #ffffffb6;
@@ -84,6 +88,10 @@ body {
 
 /* Light Mode settings */
 
+.light .dark-light-btn::before {
+  content: '';
+}
+
 .light {
   text-shadow: 0px 1px 2px #ffffff;
   background-color:rgb(233, 220, 179);