/* 14.3.1 Hidden elements */

[hidden], area, base, basefont, datalist, head, link, menu[type=popup i], meta,
noembed, noframes, param, rp, script, source, style, template, track, title {
  display: none;
}

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

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

/* 14.3.2 The page */

html, body { display: block; }

/* 14.3.3 Flow content */

address, blockquote, center, div, figure, figcaption, footer, form, header, hr,
legend, listing, main, p, plaintext, pre, summary, xmp {
  display: block;
}

blockquote, figure, listing, p, plaintext, pre, xmp {
  margin-top: 1em; margin-bottom: 1em;
}

blockquote, figure { margin-left: 40px; margin-right: 40px; }

address { font-style: italic; }
listing, plaintext, pre, xmp {
  font-family: monospace; white-space: pre;
}

dialog:not([open]) { display: none; }
dialog {
  position: absolute;
  left: 0; right: 0;
  width: fit-content;
  height: fit-content;
  margin: auto;
  border: solid;
  padding: 1em;
  background: white;
  color: black;
}
dialog::backdrop {
  position: fixed;
  top: 0; right: 0; bottom: 0; left: 0;
  background: rgba(0,0,0,0.1);
}

/* for small devices, modal dialogs go full-screen */
@media screen and (max-width: 540px) {
  dialog:modal {
    top: 0;
    width: auto;
    margin: 1em;
  }
}

/* 14.3.4 Phrasing content */

cite, dfn, em, i, var { font-style: italic; }
b, strong { font-weight: bolder; }
code, kbd, samp, tt { font-family: monospace; }
big { font-size: larger; }
small { font-size: smaller; }

sub { vertical-align: sub; }
sup { vertical-align: super; }
sub, sup { line-height: normal; font-size: smaller; }

ruby { display: ruby; }
rt { display: ruby-text; }

:link { color: #0000EE; }
:visited { color: #551A8B; }
:link:active, :visited:active { color: #FF0000; }
:link, :visited { text-decoration: underline; cursor: pointer; }
a:link[rel~=help], a:visited[rel~=help],
area:link[rel~=help], area:visited[rel~=help] { cursor: help; }

:focus { outline: auto; }

mark { background: yellow; color: black; } /* this colour is just a suggestion and can be changed based on implementation feedback */

abbr[title], acronym[title] { text-decoration: dotted underline; }
ins, u { text-decoration: underline; }
del, s, strike { text-decoration: line-through; }
blink { text-decoration: blink; }

q::before { content: open-quote; }
q::after { content: close-quote; }

br { display-outside: newline; } /* this also has bidi implications */
nobr { white-space: nowrap; }
wbr { display-outside: break-opportunity; } /* this also has bidi implications */
nobr wbr { white-space: normal; }

/* 14.3.5 Bidirectional text */

[dir]:dir(ltr), bdi:dir(ltr), input[type=tel]:dir(ltr) { direction: ltr; }
[dir]:dir(rtl), bdi:dir(rtl) { direction: rtl; }

address, blockquote, center, div, figure, figcaption, footer, form, header, hr,
legend, listing, main, p, plaintext, pre, summary, xmp, article, aside, h1, h2,
h3, h4, h5, h6, hgroup, nav, section, table, caption, colgroup, col, thead,
tbody, tfoot, tr, td, th, dir, dd, dl, dt, menu, ol, ul, li, bdi, output,
[dir=ltr i], [dir=rtl i], [dir=auto i] {
  unicode-bidi: isolate; 
}

bdo, bdo[dir] { unicode-bidi: isolate-override; } 

textarea[dir=auto i], pre[dir=auto i] { unicode-bidi: plaintext; }

/* the rules setting the 'content' property on br and wbr elements also has bidi implications */

/* 14.3.6 Quotes */

/* TODO: Revolting quotes handling CSS block. */

/* 14.3.7 Sections and headings */

article, aside, h1, h2, h3, h4, h5, h6, hgroup, nav, section {
  display: block;
}

h1 { margin-top: 0.67em; margin-bottom: 0.67em; font-size: 2.00em; font-weight: bold; }
h2 { margin-top: 0.83em; margin-bottom: 0.83em; font-size: 1.50em; font-weight: bold; }
h3 { margin-top: 1.00em; margin-bottom: 1.00em; font-size: 1.17em; font-weight: bold; }
h4 { margin-top: 1.33em; margin-bottom: 1.33em; font-size: 1.00em; font-weight: bold; }
h5 { margin-top: 1.67em; margin-bottom: 1.67em; font-size: 0.83em; font-weight: bold; }
h6 { margin-top: 2.33em; margin-bottom: 2.33em; font-size: 0.67em; font-weight: bold; }

/* TODO: Missing awful :matches(article, aside, nav, section) block */

/* 14.3.8 Lists */

dir, dd, dl, dt, menu, ol, ul { display: block; }
li { display: list-item; }

dir, dl, menu, ol, ul { margin-top: 1em; margin-bottom: 1em; }

:matches(dir, dl, menu, ol, ul) :matches(dir, dl, menu, ol, ul) {
  margin-top: 0; margin-bottom: 0;
}

dd { margin-left: 40px; } /* LTR-specific: use 'margin-right' for rtl elements */
dir, menu, ol, ul { padding-left: 40px; } /* LTR-specific: use 'padding-right' for rtl elements */

ol { list-style-type: decimal; }

dir, menu, ul {
  list-style-type: disc;
}
:matches(dir, menu, ol, ul) :matches(dir, menu, ul) {
  list-style-type: circle;
}
:matches(dir, menu, ol, ul) :matches(dir, menu, ol, ul) :matches(dir, menu, ul) {
  list-style-type: square;
}

/* 14.3.9 Tables */

table { display: table; }
caption { display: table-caption; }
colgroup, colgroup[hidden] { display: table-column-group; }
col, col[hidden] { display: table-column; }
thead, thead[hidden] { display: table-header-group; }
tbody, tbody[hidden] { display: table-row-group; }
tfoot, tfoot[hidden] { display: table-footer-group; }
tr, tr[hidden] { display: table-row; }
td, th, td[hidden], th[hidden] { display: table-cell; }

colgroup[hidden], col[hidden], thead[hidden], tbody[hidden],
tfoot[hidden], tr[hidden], td[hidden], th[hidden] {
  visibility: collapse;
}

table {
  box-sizing: border-box;
  border-spacing: 2px;
  border-collapse: separate;
  text-indent: initial;
}
td, th { padding: 1px; }
th { font-weight: bold; }

thead, tbody, tfoot, table > tr { vertical-align: middle; }
tr, td, th { vertical-align: inherit; }

table, td, th { border-color: gray; }
thead, tbody, tfoot, tr { border-color: inherit; }
table[rules=none i], table[rules=groups i], table[rules=rows i],
table[rules=cols i], table[rules=all i], table[frame=void i],
table[frame=above i], table[frame=below i], table[frame=hsides i],
table[frame=lhs i], table[frame=rhs i], table[frame=vsides i],
table[frame=box i], table[frame=border i],
table[rules=none i] > tr > td, table[rules=none i] > tr > th,
table[rules=groups i] > tr > td, table[rules=groups i] > tr > th,
table[rules=rows i] > tr > td, table[rules=rows i] > tr > th,
table[rules=cols i] > tr > td, table[rules=cols i] > tr > th,
table[rules=all i] > tr > td, table[rules=all i] > tr > th,
table[rules=none i] > thead > tr > td, table[rules=none i] > thead > tr > th,
table[rules=groups i] > thead > tr > td, table[rules=groups i] > thead > tr > th,
table[rules=rows i] > thead > tr > td, table[rules=rows i] > thead > tr > th,
table[rules=cols i] > thead > tr > td, table[rules=cols i] > thead > tr > th,
table[rules=all i] > thead > tr > td, table[rules=all i] > thead > tr > th,
table[rules=none i] > tbody > tr > td, table[rules=none i] > tbody > tr > th,
table[rules=groups i] > tbody > tr > td, table[rules=groups i] > tbody > tr > th,
table[rules=rows i] > tbody > tr > td, table[rules=rows i] > tbody > tr > th,
table[rules=cols i] > tbody > tr > td, table[rules=cols i] > tbody > tr > th,
table[rules=all i] > tbody > tr > td, table[rules=all i] > tbody > tr > th,
table[rules=none i] > tfoot > tr > td, table[rules=none i] > tfoot > tr > th,
table[rules=groups i] > tfoot > tr > td, table[rules=groups i] > tfoot > tr > th,
table[rules=rows i] > tfoot > tr > td, table[rules=rows i] > tfoot > tr > th,
table[rules=cols i] > tfoot > tr > td, table[rules=cols i] > tfoot > tr > th,
table[rules=all i] > tfoot > tr > td, table[rules=all i] > tfoot > tr > th {
  border-color: black;
}

/* 14.3.11 Form controls */

input, select, option, optgroup, button, textarea, keygen {
  text-indent: initial;
}

textarea { white-space: pre-wrap; }

input[type="radio"], input[type="checkbox"], input[type="reset"], input[type="button"],
input[type="submit"], select, button {
  box-sizing: border-box;
}

/* 14.3.12 The hr element */

hr { color: gray; border-style: inset; border-width: 1px; margin: 0.5em auto; }

/* 14.3.13 The fieldset and legend elements */

fieldset {
  display: block;
  margin-left: 2px; margin-right: 2px;
  border: groove 2px ThreeDFace;
  padding: 0.35em 0.625em 0.75em;
  min-width: min-content;
}

legend {
  padding-left: 2px; padding-right: 2px;
}

/* 14.4.1 Embedded content */

iframe:not([seamless]) { border: 2px inset; }
iframe[seamless] { display: block; }
video { object-fit: contain; }