add upload file boilerplate + changes to results page

frontend/src/styles/App.css

@@ -1,3 +1,6 @@
+html {
+  width: 100%;
+}
 nav {
   display: flex;
   justify-content: space-between;
@@ -26,10 +29,12 @@ nav div {
     justify-content: center; /* If you're centering the content */
     height: 100vh; /* Full height */
     margin-top: -100px; /* Move up */
+    width: 100%;
   }
 
   body {
     background-color: #0C2D48;
     font-family: 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', Meiryo, sans-serif;
+    width: 100%;
   }