add reset css and adjustment styles

src/assets/_reset.scss

@@ -0,0 +1,43 @@
+html, body, div, span, applet, object, iframe,
+h1, h2, h3, h4, h5, h6, p, blockquote, pre,
+a, abbr, acronym, address, big, cite, code,
+del, dfn, em, img, ins, kbd, q, s, samp,
+small, strike, strong, sub, sup, tt, var,
+b, u, i, center,
+dl, dt, dd, ol, ul, li,
+fieldset, form, label, legend,
+table, caption, tbody, tfoot, thead, tr, th, td,
+article, aside, canvas, details, embed,
+figure, figcaption, footer, header, hgroup,
+menu, nav, output, ruby, section, summary,
+time, mark, audio, video {
+	margin: 0;
+	padding: 0;
+	border: 0;
+	font-size: 100%;
+	font: inherit;
+	vertical-align: baseline;
+}
+/* HTML5 display-role reset for older browsers */
+article, aside, details, figcaption, figure,
+footer, header, hgroup, menu, nav, section {
+	display: block;
+}
+body {
+	line-height: 1;
+}
+ol, ul {
+	list-style: none;
+}
+blockquote, q {
+	quotes: none;
+}
+blockquote:before, blockquote:after,
+q:before, q:after {
+	content: '';
+	content: none;
+}
+table {
+	border-collapse: collapse;
+	border-spacing: 0;
+}

src/components/base/AppLanguage/style.scss

@@ -1,7 +1,8 @@
 .language {
+  margin-bottom: 2rem;
   button {
     flex: 1;
-    margin: 0.5rem;
+    margin: 10px;
     cursor: pointer;
     border: 0;
     background: #eee;

src/components/base/AppLogo/style.scss

@@ -6,6 +6,7 @@
   h1 {
     font-size: 2.5em;
     margin-bottom: 0;
+    font-weight: bold;
     @media (max-width: 640px) {
       font-size: 1.2em;
     }

src/index.js

@@ -2,6 +2,7 @@ import React from 'react';
 import { createRoot } from 'react-dom/client';
 import App from './app';
 import * as serviceWorker from './serviceWorker';
+import "./assets/_reset.scss";
 
 createRoot(document.getElementById('root')).render(<App />);