style: add basic css to header section

Author: dinushchathurya

src/App.vue

@@ -1,6 +1,13 @@
 <template>
   <div id="app">
-   
+    <header>
+      <h1>My Music Player</h1>
+    </header>
+    <main>
+      <section class="player">
+        <h2 class="song-title"></h2>
+      </section>
+    </main>
   </div>
 </template>
 
@@ -13,5 +20,20 @@ export default {
 </script>
 
 <style>
-
+*{
+  margin:0;
+  padding:0;
+  box-sizing:border-box;
+}
+body{
+  font-family: sans-serif;
+}
+header{
+  display:flex;
+  justify-content:center;
+  align-item:center;
+  padding: 15px;
+  background-color: #212121;
+  color:#fff;
+}
 </style>