index.css

body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    font-family:
        -apple-system,
        BlinkMacSystemFont,
        'Segoe UI',
        'Roboto',
        'Oxygen',
        'Ubuntu',
        'Cantarell',
        'Fira Sans',
        'Droid Sans',
        'Helvetica Neue',
        sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    line-height: 1;
}

code {
    font-family:
        source-code-pro,
        Menlo,
        Monaco,
        Consolas,
        'Courier New',
        monospace;
}

/* http://meyerweb.com/eric/tools/css/reset/
   v4.0 | 20180602
   License: none (public domain)
*/

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,
main,
menu,
nav,
output,
ruby,
section,
summary,
time,
mark,
audio,
video {
    margin: 0;
    padding: 0;
    border: 0;
    font: inherit;
    font-size: 100%;
}

/* HTML5 display-role reset for older browsers */
article,
aside,
details,
figcaption,
figure,
footer,
header,
hgroup,
main,
menu,
nav,
section {
    display: block;
}

/* HTML5 hidden-attribute fix for newer browsers */
*[hidden] {
    display: none;
}

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;
}