:root {
  --colour-fg: #262626;
  --colour-bg: #fdfdfd;
  --colour-primary-bright: #0085cc;
  --colour-primary-muted: #006094;
  --colour-neutral-1: #888888;
  --colour-neutral-2: #aaaaaa;
  --colour-neutral-3: #cccccc;
  --colour-pre: #f6f8fa;
  --bg-dots: url(../images/dots-light.svg);
  --bg-nav: url(../images/pcre2-hero-light.svg);

  --content-width: 850px;
  --content-gutter: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --colour-fg: #f0f6fc;
    --colour-bg: #0d1417;
    --colour-primary-bright: #33b8ff;
    --colour-primary-muted: #0075b4;
    --colour-neutral-1: #888888;
    --colour-neutral-2: #666666;
    --colour-neutral-3: #444444;
    --colour-pre: #151b23;
    --bg-dots: url(../images/dots-dark.svg);
    --bg-nav: url(../images/pcre2-hero-dark.svg);
  }
}

:root, body, p, h1, h2, h3, h4, h5, h6, pre, blockquote, ul, ol, dl, li, dd, dt {
  margin: 0;
  padding: 0;
}

html {
  background-color: var(--colour-primary-bright);
}

body {
  color: var(--colour-fg);
  background-color: var(--colour-bg);
  overflow-wrap: break-word;
}

body, input {
  font-family: 'Fira Sans', Optima, Candara, 'Noto Sans', source-sans-pro, sans-serif;
}

pre {
  text-align: start;
}

pre, code, kbd {
  font-family: 'Fira Mono', ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, Consolas, 'DejaVu Sans Mono', monospace;
  overflow-wrap: initial;
  hyphens: initial;
}

input[type="text"] {
  background: var(--colour-bg);
  color: var(--colour-fg);
  border: none;
  border-radius: 16px;
  height: 32px;
  padding: 8px 12px;
  box-sizing: border-box;

  &:focus {
    outline: 2px solid var(--colour-fg);
  }
}

hr {
  border: none;
  border-top: 1px solid var(--colour-neutral-3);
  margin: 16px 0 15px 0;
}

details {
  padding-left: 24px;
}
summary {
  cursor: pointer;
  list-style-position: outside;
}

a {
  color: var(--colour-primary-muted);
}
a:hover, a:focus {
  color: var(--colour-primary-bright);
}

@media (prefers-color-scheme: dark) {
  a {
    color: var(--colour-primary-bright);
  }
  a:hover, a:focus {
    color: var(--colour-primary-muted);
  }
}

body {
  min-height: 100vh;
  width: 100%;
  display: flex;
  flex-direction: column;
  font-size: 16px;
  line-height: 24px;

  & > * {
    padding: 0 var(--content-gutter);
    & > * {
      width: 100%;
      max-width: var(--content-width);
      margin: auto;
    }
  }
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
}

h1 {
  font-size: 32px;
  line-height: 48px;
}
h2 {
  font-size: 24px;
  line-height: 36px;
  margin: 32px 0 16px;
}
h3 {
  font-size: 20px;
  line-height: 30px;
  margin: 24px 0 12px;
}
h4 {
  font-size: 18px;
  line-height: 24px;
  margin: 16px 0 8px;
}
:is(h2, h3, h4):first-child {
  margin-top: 0;
}

h1, .man-h1, .guide-h1 {
  padding-bottom: 4px;
  border-bottom: 1px solid var(--colour-neutral-3);
  margin: 0 0 32px;
}

:is(p, pre, blockquote, ul, ol, table):not(:first-child) {
  margin: 16px 0;
}

:is(li, dt):not(:first-child) {
  margin: 16px 0 0;
}

dt {
  font-weight: 600;
}
ol, ul, dd {
  padding-left: 32px;
}

pre {
  padding: 8px;
  background: var(--colour-pre);
  border: 1px solid var(--colour-neutral-3);
  border-radius: 2px;
  overflow-x: auto;
}
.pre {
  border: 1px solid var(--colour-neutral-3);
  border-radius: 2px;
}

strong, b {
  font-weight: 600;
}
:is(pre, code) :is(strong, b) {
  font-weight: 500;
}

img {
  max-width: 100%;
  box-sizing: border-box;
}

table, caption, tbody, tfoot, thead, tr, th, td {
  margin: 0;
  padding: 0;
  border: 0;
  font: inherit;
  vertical-align: baseline;
}
table {
  border-collapse: collapse;
  border-spacing: 0;
  border-top: 1px solid var(--colour-neutral-3);
}
td, th {
  padding: 8px 16px 8px 8px;
}
tr {
  border-bottom: 1px solid var(--colour-neutral-3);
}
thead tr {
  background-color: var(--colour-pre);
}
thead + tbody tr:first-child {
  border-top: 2px solid var(--colour-neutral-2);
}
tbody tr:nth-child(odd) {
  background-color: var(--colour-pre);
}
thead + tbody tr {
  &:nth-child(odd) {
    background-color: transparent;
  }
  &:nth-child(even) {
    background-color: var(--colour-pre);
  }
}
th {
  font-weight: 600;

  pre, code {
    font-weight: 500;
  }
}

header {
  background-color: var(--colour-primary-bright);
  box-shadow: 0px 0px 2px 1px var(--colour-neutral-2);
  position: relative;
  z-index: 1;
}

nav {
  padding-top: 12px;
  margin-bottom: 12px;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 16px 0;
}

.nav-home {
  height: 32px;
  width: 64px;
  background: var(--bg-nav);
  background-size: auto 60px;
  background-position: -7px -14px;
}

.nav-row {
  display: flex;
  flex-direction: row;
  align-items: center;
}

.nav-row-rhs {
  gap: 16px;
}

.nav-menu {
  position: relative;
  height: 32px;
  line-height: 32px;
  color: var(--colour-bg);
  padding: 0 16px;
  border-radius: 4px 4px 0 0;

  &:focus-within, &:hover {
    background: var(--colour-primary-muted);

    & > ul {
      display: block;
    }
  }

  & > div {
    display: inline;
    user-select: none;
    position: relative;
    z-index: 1;
    &::before {
      content: "▾";
    }
  }

  & > ul {
    display: none;
    position: absolute;
    top: 30px;
    left: 0;
    background: var(--colour-primary-muted);
    border-radius: 0 4px 4px 4px;
    margin: 0;
    padding: 2px 0px 0px 0px;
    list-style: none;
    line-height: 24px;
    min-width: calc(100% + 12px);
    width: max-content;
    box-sizing: border-box;
  }
  li {
    margin: 0;
    padding: 0;
    & > a {
      padding: 4px 16px;
      display: block;
      color: var(--colour-bg);
      text-decoration: none;
    }
    & > a:hover {
      text-decoration: underline;
    }
  }
}

@media (prefers-color-scheme: dark) {
  .nav-menu {
    &:focus-within, &:hover {
      color: var(--colour-fg);
    }
    li {
      & > a {
        color: var(--colour-fg);
      }
    }
  }
}

.nav-item {
  display: block;
  height: 32px;
  line-height: 32px;
  padding: 0 16px;
  user-select: none;
  color: var(--colour-bg);
  text-decoration: none;

  &:focus-within, &:hover {
    background: var(--colour-primary-muted);
    border-radius: 4px;
  }
  &:hover, &:focus {
    color: var(--colour-bg);
    text-decoration: underline;
  }
}

@media (prefers-color-scheme: dark) {
  .nav-item {
    &:hover, &:focus {
      color: var(--colour-fg);
    }
  }
}

.nav-glue {
  flex-grow: 1;
  min-width: 16px;
}

.nav-search {
  position: absolute;
  z-index: 1;
}
.nav-search > input {
  width: 150px;
}

.nav-github {
  height: 32px;
  width: 32px;
  padding: 4px;
  margin: -4px;
  border-radius: 20px;

  &:hover, &:focus {
    outline: none;
    background: var(--colour-primary-muted);
  }

  & > svg {
    height: 32px;
    width: 32px;
    color: var(--colour-bg);
    fill: currentColor;
  }
}

@media (prefers-color-scheme: dark) {
  .nav-github {
    &:hover, &:focus {
      & > svg {
        color: var(--colour-fg);
      }
    }
  }
}

@media (max-width: 410px) {
  .nav-glue {
    min-width: initial;
  }
  .nav-menu, .nav-item {
    font-size: 14px;
  }
}

#search-results {
  margin-top: 12px;
  margin-bottom: 24px;
  flex-direction: row;
  justify-content: space-between;
  gap: 8px;
  border: 2px solid var(--colour-bg);
  border-radius: 16px;
  padding: 16px;
  position: relative;
  box-sizing: border-box;
  color: var(--colour-bg);

  &::before {
    background: var(--colour-bg);
    height: 18px;
    width: 8px;
    content: " ";
    position: absolute;
    right: 182px;
    top: -19px;
  }

  ul {
    padding: 0;
    margin: 0;
    list-style: none;
    margin-top: 8px;
    ul {
      border-left: 1px solid var(--colour-bg);
      margin-left: 16px;
      padding-left: 15px;

      a::before {
        content: "# ";
      }
    }
  }
  li {
    padding: 0;
    margin: 0;
  }
  li:not(:first-child) {
    padding-top: 12px;
  }
  a {
    color: var(--colour-bg);
    font-weight: 600;
    text-decoration: none;

    & > span {
      text-decoration: underline;
    }
  }
  a:hover {
    color: var(--colour-fg);
  }
}

#search-clear {
  width: 16px;
  height: 16px;
  background: radial-gradient(white, white 6px, transparent 6px);
  display: block;
  cursor: pointer;

  & > svg {
    height: 16px;
    width: 16px;
    fill: rgb(181, 0, 0);
  }
}

.search-excerpt {
  font-size: 12px;
  padding-top: 4px;
}

.search-count {
  font-size: 12px;
  font-style: italic;
}

.index-intro {
  background-image: linear-gradient(180deg, var(--colour-bg) 0%, transparent 500%), var(--bg-dots);
  background-position: bottom;
  box-shadow: 0px 0px 2px 1px var(--colour-neutral-3);

  h2 {
    display: none;
  }
}

.index-intro-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;

  padding: 32px 0;

  & > div {
    padding: 0 0 0 16px;
    position: relative;

    & > svg {
      height: 32px;
      width: 32px;
      padding: 8px 0;
      fill: var(--colour-primary-bright);
      position: absolute;
      top: 10px;
      left: 0;
      background: linear-gradient(0deg, transparent 0, var(--colour-bg) 4px, var(--colour-bg) 44px, transparent 48px);
    }

    & > div {
      background: var(--colour-bg);
      box-shadow: 0px 0px 2px 1px var(--colour-neutral-3);
      border-radius: 16px;
      padding: 16px 16px 16px 32px;
      font-size: 16px;
      min-height: 36px;
    }
  }
  & > div:first-child {
    grid-column: 1 / 3;
    padding: 0;
    justify-self: center;
    text-align: center;

    & > div {
      padding-left: 16px;
      font-size: 18px;
    }
  }
}

@media (max-width: 650px) {
  .index-intro-content {
    grid-template-columns: 1fr;

    & > div:first-child {
      grid-column: 1 / 2;
      padding-left: 16px;
      justify-self: stretch;
      text-align: inherit;
    }
  }
}

.man-h1, .guide-h1 {
  display: flex;
  flex-direction: row;
  justify-content: flex-end;
  align-items: baseline;
  flex-wrap: wrap;

  & > h1 {
    padding-bottom: 0;
    border-bottom: none;
    margin-bottom: 0;
    min-width: 0;
    flex-grow: 1;
  }

  & > :not(:first-child) {
    text-transform: uppercase;
    font-size: 12px;
    line-height: 20px;
    padding-left: 24px;
    text-align: end;
  }
}

.guide-content {
  font-size: calc(min(1.7vw, 16px));
  line-height: 1.5em;
}

main {
  hyphens: auto;
  text-align: justify;
}

main > div {
  padding: 32px 0;
}

.footer-glue {
  flex-grow: 1;
}

footer {
  height: 32px;
  background-color: var(--colour-primary-bright);
  box-shadow: 0px 0px 2px 1px var(--colour-neutral-2);
}

/* fira-sans-regular - latin_latin-ext */
@font-face {
  font-display: swap;
  font-family: 'Fira Sans';
  font-style: normal;
  font-weight: 400;
  src: url('../fonts/fira-sans-v17-latin_latin-ext-regular.woff2') format('woff2');
}
/* fira-sans-italic - latin_latin-ext */
@font-face {
  font-display: swap;
  font-family: 'Fira Sans';
  font-style: italic;
  font-weight: 400;
  src: url('../fonts/fira-sans-v17-latin_latin-ext-italic.woff2') format('woff2');
}
/* fira-sans-600 - latin_latin-ext */
@font-face {
  font-display: swap;
  font-family: 'Fira Sans';
  font-style: normal;
  font-weight: 600;
  src: url('../fonts/fira-sans-v17-latin_latin-ext-600.woff2') format('woff2');
}
/* fira-sans-600italic - latin_latin-ext */
@font-face {
  font-display: swap;
  font-family: 'Fira Sans';
  font-style: italic;
  font-weight: 600;
  src: url('../fonts/fira-sans-v17-latin_latin-ext-600italic.woff2') format('woff2');
}
/* fira-mono-regular - latin_latin-ext */
@font-face {
  font-display: swap; /* Check https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-display for other options. */
  font-family: 'Fira Mono';
  font-style: normal;
  font-weight: 400;
  src: url('../fonts/fira-mono-v14-latin_latin-ext-regular.woff2') format('woff2'); /* Chrome 36+, Opera 23+, Firefox 39+, Safari 12+, iOS 10+ */
}
/* fira-mono-500 - latin_latin-ext */
@font-face {
  font-display: swap; /* Check https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-display for other options. */
  font-family: 'Fira Mono';
  font-style: normal;
  font-weight: 500;
  src: url('../fonts/fira-mono-v14-latin_latin-ext-500.woff2') format('woff2'); /* Chrome 36+, Opera 23+, Firefox 39+, Safari 12+, iOS 10+ */
}