rfc.css

:root {
  color-scheme: light dark;
  --background-color: #fff;
  --text-color: #222;
  --title-color: #191919;
  --link-color: #2a6496;
  --highlight-color: #f9f9f9;
  --line-color: #eee;
  --pilcrow-weak: #ddd;
  --pilcrow-strong: #bbb;
  --small-font-size: 14.5px;
  --font-mono: 'Oxygen Mono', monospace;
  scrollbar-color: #bbb #eee;
}
body {
  max-width: 600px;
  margin: 75px auto;
  padding: 0 5px;
  color: var(--text-color);
  background-color: var(--background-color);
  font: 16px/22px "Lora", serif;
  scroll-behavior: smooth;
}

.ears {
  display: none;
}

/* headings */
h1, h2, h3, h4, h5, h6 {
  font-family: "Cabin Condensed", sans-serif;
  font-weight: 600;
  margin: 0.8em 0 0.3em;
  font-size-adjust: 0.5;
  color: var(--title-color);
}
h1#title {
  font-size: 32px;
  line-height: 40px;
  clear: both;
}
h1#title, h1#rfcnum {
  margin: 1.5em 0 0.2em;
}
h1#rfcnum + h1#title {
  margin: 0.2em 0;
}

h1, h2, h3 {
  font-size: 22px;
  line-height: 27px;
}
h4, h5, h6 {
  font-size: 20px;
  line-height: 24px;
}

/* general structure */
.author {
  padding-bottom: 0.3em;
}
#abstract+p {
  font-size: 18px;
  line-height: 24px;
}
#abstract+p code, #abstract+p samp, #abstract+p tt {
  font-size: 16px;
  line-height: 0;
}

p {
  padding: 0;
  margin: 0.5em 0;
  text-align: left;
}
div {
  margin: 0;
}
.alignRight.art-text {
  background-color: var(--highlight-color);
  border: 1px solid var(--line-color);
  border-radius: 3px;
  padding: 0.5em 1em 0;
  margin-bottom: 0.5em;
}
.alignRight.art-text pre {
  padding: 0;
  width: auto;
}
.alignRight {
  margin: 1em 0;
}
.alignRight > *:first-child {
  border: none;
  margin: 0;
  float: right;
  clear: both;
}
.alignRight > *:nth-child(2) {
  clear: both;
  display: block;
  border: none;
}
svg {
  display: block;
}
/* font-family isn't space-separated, but =~ will have to do */
svg[font-family~="monospace" i], svg [font-family~="monospace" i] {
  font-family: var(--font-mono);
}
.alignCenter.art-text {
  background-color: var(--highlight-color);
  border: 1px solid var(--line-color);
  border-radius: 3px;
  padding: 0.5em 1em 0;
  margin-bottom: 0.5em;
}
.alignCenter.art-text pre {
  padding: 0;
  width: auto;
}
.alignCenter {
  margin: 1em 0;
}
.alignCenter > *:first-child {
  border: none;
  /* this isn't optimal, but it's an existence proof.  PrinceXML doesn't
     support flexbox yet.
  */
  display: table;
  margin: 0 auto;
}

/* lists */
ol, ul {
  padding: 0;
  margin: 0 0 0.5em 2em;
}
:is(ol, ul) :is(ol, ul) {
  margin-left: 1em;
}
li {
  margin: 0 0 0.25em 0;
}
.ulCompact li {
  margin: 0;
}
ul.empty, .ulEmpty {
  list-style-type: none;
}
ul.empty li, .ulEmpty li {
  margin-top: 0.5em;
}
:is(ul, ol).compact, .ulCompact, .olCompact {
  line-height: 1;
  margin: 0 0 0 2em;
}

/* definition lists */
dl {
  clear: left;
  --indent: 3ch;
  /* --indent: attr(indent ch); not supported in any browser, but we can dream */
}
dl.olPercent {
  --indent: 5ch;
}
dl > dt {
  float: left;
  margin-right: 2ch;
  min-width: 8ch;
}
dl.dlNewline > dt {
  float: none;
}
dl > dd {
  margin-bottom: .8em;
  margin-left: var(--indent) !important; /* stupid element overrides */
  min-height: 2ex;
}
dl.olPercent > dt {
  min-width: calc(var(--indent) - 2ch);
}
:is(dl.compact, .dlCompact) > dd {
  margin-bottom: 0;
}
:is(dl.compact, .dlCompact) > dd > :is(:first-child, .break:first-child + *) {
  margin-top: 0;
}
:is(dl.compact, .dlCompact) > dd > :is(:last-child) {
  margin-bottom: 0;
}
dl > dd > dl {
  margin-top: 0.5em;
  margin-bottom: 0;
}
:is(dd, span).break {
  display: none;
}

/* links */
a, a[href].selfRef:hover {
  text-decoration: none;
}
a[href] {
  color: var(--link-color);
}
a[href].selfRef, .iref + a[href].internal {
  color: var(--text-color);
}
a[href]:hover {
  text-decoration: underline;
}
a[href].selfRef:hover {
  background-color: var(--highlight-color);
}
a.xref:is(.cite, .auto), :is(#status-of-memo, #copyright) a {
  white-space: nowrap;
}

/* Figures */
tt, code, pre {
  background-color: var(--highlight-color);
  font: 14px/22px var(--font-mono);
}
tt, code {
  /* changing the font for inline elements leads to different ascender
     and descender heights; as we want to retain baseline alignment,
     remove leading to avoid altering the final height of lines
     note: this fails if these blocks take an entire line,
     a different solution would be great */
  line-height: 0;
}
:is(h1, h2, h3, h4, h5, h6) :is(tt, code) {
  font-size: 84%;
}
pre {
  border: 1px solid var(--line-color);
  font-size: 13.5px;
  line-height: 16px;
  letter-spacing: -0.2px;
  margin: 5px;
  padding: 5px;
}
img {
  max-width: 100%;
}
figure {
  margin: 0.5em 0;
  padding: 0;
}
figure blockquote {
  margin: 0.8em 0.4em 0.4em;
}
figcaption, caption {
  font-style: italic;
  margin: 0.5em 1.5em;
  text-align: left;
}
@media screen {
  /* Auto-collapse boilerplate. */
  :is(#status-of-memo, #copyright) p {
    margin: -2px 0;
    max-height: 0;
    transition: max-height 2s ease, margin 0.5s ease 0.5s;
    overflow: hidden;
  }
  :is(#status-of-memo, #copyright):hover p,
  :is(#status-of-memo, #copyright) h2:target ~ p {
    margin: 0.5em 0;
    max-height: 500px;
    overflow: auto;
  }
  pre, svg {
    display: inline-block;
    overflow-x: auto;
  }
  pre {
    max-width: 100%;
    width: calc(100% - 22px - 1em);
  }
  svg {
    max-width: calc(100% - 22px - 1em);
  }
  figure pre {
    display: block;
    width: calc(100% - 25px);
  }
  :is(pre, svg) + .pilcrow {
    display: inline-block;
    vertical-align: text-bottom;
    padding-bottom: 8px;
  }
}

/* aside, blockquote */
aside, blockquote {
  margin-left: 0;
  padding: 0 2em;
  font-style: italic;
}
blockquote {
  margin: 1em 0;
}
cite {
  display: block;
  text-align: right;
  font-style: italic;
}

/* tables */
table {
  max-width: 100%;
  margin: 0 0 1em;
  border-collapse: collapse;
}
table.right {
  margin-left: auto;
}
table.center {
  margin-left: auto;
  margin-right: auto;
}
table.left {
  margin-right: auto;
}
thead, tbody {
  border: 1px solid var(--line-color);
}
th, td {
  text-align: left;
  vertical-align: top;
  padding: 5px 10px;
}
th {
  background-color: var(--line-color);
}
:is(tr:nth-child(2n), thead+tbody > tr:nth-child(2n+1)) > td {
  background-color: var(--background-color);
}
:is(tr:nth-child(2n+1), thead+tbody > tr:nth-child(2n)) > td {
  background-color: var(--highlight-color);
}
table caption {
  margin: 0;
  padding: 3px 0 3px 1em;
}
table p {
  margin: 0;
}

/* pilcrow */
a.pilcrow {
  margin-left: 3px;
  opacity: 0.2;
  user-select: none;
}
a.pilcrow[href] { color: var(--pilcrow-weak); }
a.pilcrow[href]:hover { text-decoration: none; }
@media not print {
  :hover > a.pilcrow {
    opacity: 1;
  }
  a.pilcrow[href]:hover {
    color: var(--pilcrow-strong);
    background-color: transparent;
  }
}
@media print {
  a.pilcrow {
    display: none;
  }
}

/* misc */
hr {
  border: 0;
  border-top: 1px solid var(--line-color);
}
.bcp14 {
  font-variant: small-caps;
  font-weight: 600;
  font-size: var(--small-font-size);
}
.role {
  font-variant: all-small-caps;
}
sub, sup {
  line-height: 1;
  font-size: 80%;
}

/* info block */
#identifiers {
  margin: 0;
  font-size: var(--small-font-size);
  line-height: 18px;
  --identifier-width: 15ch;
}
#identifiers dt {
  width: var(--identifier-width);
  min-width: var(--identifier-width);
  clear: left;
  float: left;
  text-align: right;
}
#identifiers dd {
  margin: 0;
  margin-left: calc(1em + var(--identifier-width)) !important;
  min-width: 5em;
}
#identifiers .authors .author {
  display: inline-block;
  margin-right: 1.5em;
}
#identifiers .authors .org {
  font-style: italic;
}

/* The prepared/rendered info at the very bottom of the page */
.docInfo {
  color: #999;
  font-size: 0.9em;
  font-style: italic;
  margin-top: 2em;
}
.docInfo .prepared {
  float: left;
}
.docInfo .prepared {
  float: right;
}

/* table of contents */
#toc {
  padding: 0.75em 0 2em 0;
  margin-bottom: 1em;
}
#toc nav ul {
  margin: 0 0.5em 0 0;
  padding: 0;
  list-style: none;
}
#toc nav li {
  line-height: 1.3em;
  margin: 0.75em 0;
  padding-left: 1.2em;
  text-indent: -1.2em;
}
#toc a.xref {
  white-space: normal;
}
/* references */
.references dt {
  text-align: right;
  font-weight: bold;
  min-width: 7em;
}
.references dt:target::before {
  content: "⇒";
  width: 15px;
  margin: 0 10px 0 -25px;
}
.references dd {
  margin-left: 8em !important;
  overflow: auto;
}

.refInstance {
  margin-bottom: 1.25em;
}

.references .ascii {
  margin-bottom: 0.25em;
}

/* index */
#rfc\.index\.index + ul {
  margin-left: 0;
}

/* authors */
address.vcard {
  font-style: normal;
  margin: 1em 0;
}
address.vcard .nameRole {
  font-weight: 700;
  margin-left: 0;
}
address.vcard .label {
  margin: 0.5em 0;
}
address.vcard .type {
  display: none;
}
.alternative-contact {
  margin: 1.5em 0 1em;
}
hr.addr {
  border-top: 1px dashed;
  margin: 0;
  color: #ddd;
  max-width: calc(100% - 16px);
}
@media (min-width: 500px) {
  #authors-addresses > section {
    column-count: 2;
    column-gap: 20px;
  }
  #authors-addresses > section > h2 {
    column-span: all;
  }
  /* hack for break-inside: avoid-column */
  #authors-addresses address {
    display: inline-block;
    break-inside: avoid-column;
  }
}

.rfcEditorRemove p:first-of-type {
  font-style: italic;
}
.cref {
  background-color: rgba(249, 232, 105, 0.3);
  padding: 2px 4px;
}
.crefSource {
  font-style: italic;
}
/* alternative layout for smaller screens */
@media screen and (max-width: 929px) {
  #toc {
    position: fixed;
    z-index: 2;
    top: 0;
    right: 0;
    padding: 0;
    margin: 0;
    border-bottom: 1px solid #ccc;
    opacity: 0.6;
  }
  #toc.active {
      opacity: 1;
  }
  #toc h2 {
    margin: 0;
    padding: 2px 0 2px 6px;
    padding-right: 1em;
    font-size: 18px;
    line-height: 24px;
    min-width: 190px;
    text-align: right;
    background-color: #444;
    color: white;
    cursor: pointer;
  }
  #toc h2::before { /* css hamburger */
    float: right;
    position: relative;
    width: 1em;
    height: 1px;
    left: -164px;
    margin: 8px 0 0 0;
    background: white none repeat scroll 0 0;
    box-shadow: 0 4px 0 0 white, 0 8px 0 0 white;
    content: "";
  }
  #toc nav {
    display: none;
    background-color: var(--background-color);
    padding: 0.5em 1em 1em;
    overflow: auto;
    overscroll-behavior: contain;
    height: calc(100vh - 48px);
    border-left: 1px solid #ddd;
  }
  #toc.active nav {
    display: block;
  }
  /* Make the collapsed ToC header render white on gray also when it's a link */
  #toc h2 a,
  #toc h2 a:link,
  #toc h2 a:focus,
  #toc h2 a:hover,
  #toc a.toplink,
  #toc a.toplink:hover {
    color: white;
    background-color: #444;
    text-decoration: none;
  }
  #toc a.toplink {
    margin-top: 2px;
  }
}

/* alternative layout for wide screens */
@media screen and (min-width: 930px) {
  body {
    padding-right: 360px;
    padding-right: calc(min(180px + 20%, 500px));
  }
  #toc {
    position: fixed;
    bottom: 0;
    right: 0;
    right: calc(50vw - 480px);
    width: 312px;
    margin: 0;
    padding: 0;
    z-index: 1;
  }
  #toc h2 {
    margin: 0;
    padding: 0.25em 1em 1em 0;
  }
  #toc nav {
    display: block;
    height: calc(90vh - 84px);
    bottom: 0;
    padding: 0.5em 0 2em;
    overflow: auto;
    overscroll-behavior: contain;
    scrollbar-width: thin;
  }
  #toc nav > ul  {
    margin-bottom: 2em;
  }
  #toc ul {
    margin: 0 0 0 4px;
    font-size: var(--small-font-size);
  }
  #toc ul :is(p, li) {
    margin: 2px 0;
    line-height: 22px;
  }
  img { /* future proofing */
    max-width: 100%;
    height: auto;
  }
}

/* pagination */
@media print {
  body {
    width: 100%;
  }
  p {
    orphans: 3;
    widows: 3;
  }
  #n-copyright-notice {
    border-bottom: none;
  }
  #toc, #n-introduction {
    page-break-before: always;
  }
  #toc {
    border-top: none;
    padding-top: 0;
  }
  figure, pre {
    page-break-inside: avoid;
  }
  figure {
    overflow: scroll;
  }
  h1, h2, h3, h4, h5, h6 {
    page-break-after: avoid;
  }
  h2+*, h3+*, h4+*, h5+*, h6+* {
    page-break-before: avoid;
  }
  pre {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-size: 10pt;
  }
  table {
    border: 1px solid #ddd;
  }
  td {
    border-top: 1px solid #ddd;
  }
}

@page :first {
  padding-top: 0;
  @top-left {
    content: normal;
    border: none;
  }
  @top-center {
    content: normal;
    border: none;
  }
  @top-right {
    content: normal;
    border: none;
  }
}

@page {
  size: A4;
  margin-bottom: 45mm;
  padding-top: 20px;
}

/* Changes introduced to fix issues found during implementation */

/* Separate body from document info even without intervening H1 */
section {
  clear: both;
}

/* Top align author divs, to avoid names without organization dropping level with org names */
.author {
  vertical-align: top;
}

/* Style section numbers with more space between number and title */
.section-number {
  padding-right: 0.5em;
}

/* Add styling for a link in the ToC that points to the top of the document */
a.toplink {
  float: right;
  margin: 8px 0.5em 0;
}

/* Provide styling for table cell text alignment */
table .text-left {
  text-align: left;
}
table .text-center {
  text-align: center;
}
table .text-right {
  text-align: right;
}

/* Make the alternative author contact information look less like just another
   author, and group it closer with the primary author contact information */
.alternative-contact {
  margin: 0.5em 0 0.25em 0;
}
address .non-ascii {
  margin: 0 0 0 2em;
}

/* With it being possible to set tables with alignment
  left, center, and right, { width: 100%; } does not make sense */
table {
  width: auto;
}

/* Avoid reference text that sits in a block with very wide left margin,
   because of a long floating dt label.*/
.references dd {
  overflow: visible;
}

/* Control caption placement */
caption {
  caption-side: bottom;
}

/* Limit the width of the author address vcard, so names in right-to-left
   script don't end up on the other side of the page. */

address.vcard {
  max-width: 20em;
  margin-right: auto;
}

/* For address alignment dependent on LTR or RTL scripts */
address div.left {
  text-align: left;
}
address div.right {
  text-align: right;
}

/* Give the table caption label the same styling as the figcaption */

@media print {
  .toplink {
    display: none;
  }

  /* avoid overwriting the top border line with the ToC header */
  #toc {
    padding-top: 1px;
  }

  /* Avoid page breaks inside dl and author address entries */
  dd {
    page-break-before: avoid;
  }
  .vcard {
    page-break-inside: avoid;
  }

}

/* Dark mode. */
@media (prefers-color-scheme: dark) {
:root {
  --background-color: #121212;
  --text-color: #f0f0f0;
  --title-color: #fff;
  --link-color: #4da4f0;
  --highlight-color: #282828;
  --line-color: #444;
  --pilcrow-weak: #444;
  --pilcrow-strong: #666;
  scrollbar-color: #777 #333;
}
}

/* SVG Trick: a prefix match works because only black and white are allowed */
svg :is([stroke="black"], [stroke^="#000"]) {
  stroke: var(--text-color);
}
svg :is([stroke="white"], [stroke^="#fff"]) {
  stroke: var(--background-color);
}
svg :is([fill="black"], [fill^="#000"], :not([fill])) {
  fill: var(--text-color);
}
svg :is([fill="white"], [fill^="#fff"]) {
  fill: var(--background-color);
}