serenity/Userland/Libraries/LibWeb/CSS/Default.css

html {
    font-family: sans-serif;
    color: -libweb-palette-base-text;
}

a {
    cursor: pointer;
}

body {
    margin: 8px;
}

h1 {
    font-size: 2em;
    margin: 0.67em 0;
}

h2 {
    font-size: 1.5em;
    margin: 0.83em 0;
}

h3 {
    font-size: 1.17em;
    margin: 1em 0;
}

h4 {
    margin: 1.33em 0;
}

h5 {
    font-size: 0.83em;
    margin: 1.67em 0;
}

h6 {
    font-size: 0.67em;
    margin: 2.33em 0;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: bold;
}

pre {
    font-family: monospace;
    margin-bottom: 8px;
    margin-top: 8px;
    white-space: pre;
}

code,
kbd,
samp,
tt {
    font-family: monospace;
}

u,
ins {
    text-decoration: underline;
}

s,
strike,
del {
    text-decoration: line-through;
}

strong,
b {
    font-weight: bold;
}

i,
em,
address,
cite,
dfn,
var {
    font-style: italic;
}

html,
address,
blockquote,
body,
dd,
div,
dl,
dt,
fieldset,
form,
frame,
frameset,
hgroup,
h1,
h2,
h3,
h4,
h5,
h6,
noframes,
ol,
p,
ul,
center,
dir,
hr,
menu,
pre,
header,
footer,
nav,
main,
article,
aside,
section {
    display: block;
}

center {
    text-align: -libweb-center;
}

h1,
h2,
h3 {
    margin: 8px 0 8px 0;
}

h4,
p,
blockquote,
ul,
fieldset,
form,
ol,
dl,
dir,
menu {
    margin: 4px 0 4px 0;
}

h5,
h6 {
    margin: 2px 0 2px 0;
}

li {
    display: list-item;
    margin-left: 8px;
    margin-top: 2px;
    margin-bottom: 2px;
}

a:link {
    color: -libweb-link;
    text-decoration: underline;
}

a:hover {
    color: red;
}

hr {
    margin-top: 0.5em;
    margin-bottom: 0.5em;
    border: 1px inset #888888;
}

blink {
    display: inline;
}

table {
    display: table;
}

thead {
    display: table-header-group;
    vertical-align: middle;
    border-color: inherit;
}

tbody {
    display: table-row-group;
    vertical-align: middle;
    border-color: inherit;
}

tfoot {
    display: table-footer-group;
    vertical-align: middle;
    border-color: inherit;
}

tr {
    display: table-row;
}

td,
th {
    display: table-cell;
}

th {
    font-weight: bold;
}

col {
    display: table-column;
}

colgroup {
    display: table-column-group;
}

blockquote {
    margin-left: 25px;
    margin-right: 25px;
}

ul,
ol {
    padding-left: 20px;
}

ul {
    list-style-type: disc;
}

ol {
    list-style-type: decimal;
}

:is(ul, ol) ul {
    list-style-type: circle;
}

:is(ul, ol) :is(ul, ol) ul {
    list-style-type: square;
}

/* FIXME: This is a temporary hack until we can render a native-looking frame for these. */
input, textarea {
    border: 1px solid -libweb-palette-threed-shadow1;
    min-width: 80px;
    min-height: 16px;
    width: 120px;
    cursor: text;
    overflow: hidden;
}

textarea {
    padding: 2px;
    display: inline-block;
    overflow: scroll;
}

input[type=submit], input[type=button], input[type=reset], input[type=checkbox], input[type=radio] {
    border: none;
    min-width: unset;
    min-height: unset;
    width: unset;
    cursor: unset;
}

button, input[type=submit], input[type=button], input[type=reset] {
    padding: 1px 4px;
    background-color: -libweb-palette-button;
    border: 1px solid -libweb-palette-threed-shadow1;
    color: -libweb-palette-button-text;
}

button:hover, input[type=submit]:hover, input[type=button]:hover, input[type=reset]:hover {
    background-color: -libweb-palette-hover-highlight;
}

option {
    display: none;
}

details {
    display: block;
    padding-left: 1em;
}

summary {
    display: block;
    font-weight: bold;
}

/* 15.3.1 Hidden elements
 * https://html.spec.whatwg.org/multipage/rendering.html#hidden-elements
 */
/* FIXME: Add `noframes` once frames are implemented. */
/* FIXME: Add `noembed` once <embed> is implemented. */
/* FIXME: Add `rp` once <ruby> is implemented. */
[hidden], area, base, basefont, datalist, head, link, meta, /*noembed,*/
/*noframes,*/ param, /*rp,*/ script, style, template, title {
  display: none;
}

embed[hidden] { display: inline; height: 0; width: 0; }

input[type=hidden i] { display: none !important; }

@media (scripting) {
  noscript { display: none !important; }
}

/* 15.3.4 Phrasing content
 * https://html.spec.whatwg.org/multipage/rendering.html#phrasing-content-3
 */
abbr[title],
acronym[title] {
    text-decoration: dotted underline;
}

mark {
    background: yellow;
    color: black;
}

/* 15.4.1 Embedded content
 * https://html.spec.whatwg.org/multipage/rendering.html#embedded-content-rendering-rules
 */
iframe { border: 2px inset; }

/* https://www.w3.org/TR/mediaqueries-5/#descdef-media-inverted-colors
 */
@media (inverted-colors) {
    img:not(picture>img),
    picture,
    video {
        filter: invert(100%);
    }
}

/* This is the same as default intrinsic size of a <progress> element */
progress {
    width: 300px;
    height: 12px;
}

/* The default progress-value/bar CSS below is the same as Blink/WebKit.
 * Note: Setting any more than the backgrond-color may have unintended consequences, as sites don't expect to unset more than that.
 */

progress::-webkit-progress-bar {
    width: inherit;
    height: inherit;
    background-color: grey;
}

progress::-webkit-progress-value {
    height: inherit;
    background-color: green;
}