:root {
  --sans-font: -apple-system, BlinkMacSystemFont, "Avenir Next", Avenir,
    "Nimbus Sans L", Roboto, "Noto Sans", "Segoe UI", Arial, Helvetica,
    "Helvetica Neue", sans-serif;
  --mono-font: Consolas, Menlo, Monaco, "Andale Mono", "Ubuntu Mono", monospace;
  --bg: #fff;
  --accent-bg: #f5f7ff;
  --text: #212121;
  --text-light: #585858;
  --border: #d8dae1;
  --accent: #0d47a1;
  --code: #d81b60;
  --preformatted: #444;
  --marked: #ffdd33;
  --disabled: #efefef;
}
@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #212121;
    --accent-bg: #2b2b2b;
    --text: #dcdcdc;
    --text-light: #ababab;
    --border: #666;
    --accent: #ffb300;
    --code: #f06292;
    --preformatted: #ccc;
    --disabled: #111;
  }
  img,
  video {
    opacity: 0.8;
  }
}
*,
::after,
::before {
  box-sizing: border-box;
}
input,
progress,
select,
textarea {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
}
html {
  font-family: var(--sans-font);
  scroll-behavior: smooth;
}
body {
  color: var(--text);
  background: var(--bg);
  font-size: 1.15rem;
  line-height: 1.5;
  display: grid;
  grid-template-columns: 1fr min(45rem, 90%) 1fr;
  margin: 0;
}
body > * {
  grid-column: 2;
}
body > header {
  background: var(--accent-bg);
  border-bottom: 1px solid var(--border);
  text-align: center;
  padding: 0 0.5rem 2rem 0.5rem;
  grid-column: 1/-1;
}
body > header h1 {
  max-width: 1200px;
  margin: 1rem auto;
}
body > header p {
  max-width: 40rem;
  margin: 1rem auto;
}
main {
  padding-top: 1.5rem;
}
body > footer {
  margin-top: 4rem;
  padding: 2rem 1rem 1.5rem 1rem;
  color: var(--text-light);
  font-size: 0.9rem;
  text-align: center;
  border-top: 1px solid var(--border);
}
h1 {
  font-size: 3rem;
}
h2 {
  font-size: 2.6rem;
  margin-top: 3rem;
}
h3 {
  font-size: 2rem;
  margin-top: 3rem;
}
h4 {
  font-size: 1.44rem;
}
h5 {
  font-size: 1.15rem;
}
h6 {
  font-size: 0.96rem;
}
h1,
h2,
h3,
h4,
h5,
h6,
p {
  overflow-wrap: break-word;
}
h1,
h2,
h3 {
  line-height: 1.1;
}
@media only screen and (max-width: 720px) {
  h1 {
    font-size: 2.5rem;
  }
  h2 {
    font-size: 2.1rem;
  }
  h3 {
    font-size: 1.75rem;
  }
  h4 {
    font-size: 1.25rem;
  }
}
a,
a:visited {
  color: var(--accent);
}
a:hover {
  text-decoration: none;
}
[role="button"],
button,
input[type="button"],
input[type="reset"],
input[type="submit"],
label[type="button"] {
  border: none;
  border-radius: 5px;
  background: var(--accent);
  font-size: 1rem;
  color: var(--bg);
  padding: 0.7rem 0.9rem;
  margin: 0.5rem 0;
}
[role="button"][aria-disabled="true"],
button[disabled],
input[type="button"][disabled],
input[type="checkbox"][disabled],
input[type="radio"][disabled],
input[type="reset"][disabled],
input[type="submit"][disabled],
select[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
}
input:disabled,
select:disabled,
textarea:disabled {
  cursor: not-allowed;
  background-color: var(--disabled);
}
input[type="range"] {
  padding: 0;
}
abbr {
  cursor: help;
}
[role="button"]:focus,
[role="button"]:not([aria-disabled="true"]):hover,
button:enabled:hover,
button:focus,
input[type="button"]:enabled:hover,
input[type="button"]:focus,
input[type="reset"]:enabled:hover,
input[type="reset"]:focus,
input[type="submit"]:enabled:hover,
input[type="submit"]:focus,
label[type="button"]:focus,
label[type="button"]:hover {
  filter: brightness(1.4);
  cursor: pointer;
}
header > nav {
  font-size: 1rem;
  line-height: 2;
  padding: 1rem 0 0 0;
}
header > nav ol,
header > nav ul {
  align-content: space-around;
  align-items: center;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: center;
  list-style-type: none;
  margin: 0;
  padding: 0;
}
header > nav ol li,
header > nav ul li {
  display: inline-block;
}
header > nav a,
header > nav a:visited {
  margin: 0 0.5rem 1rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  display: inline-block;
  padding: 0.1rem 1rem;
  text-decoration: none;
}
header > nav a:hover {
  filter: brightness(1.4);
  cursor: pointer;
}
@media only screen and (max-width: 720px) {
  header > nav a {
    border: none;
    padding: 0;
    text-decoration: underline;
    line-height: 1;
  }
}
aside,
details,
pre,
progress {
  background: var(--accent-bg);
  border: 1px solid var(--border);
  border-radius: 5px;
  margin-bottom: 1rem;
}
aside {
  font-size: 1rem;
  width: 30%;
  padding: 0 15px;
  margin-left: 15px;
  float: right;
}
@media only screen and (max-width: 720px) {
  aside {
    width: 100%;
    float: none;
    margin-left: 0;
  }
}
article,
fieldset {
  border: 1px solid var(--border);
  padding: 1rem;
  border-radius: 5px;
  margin-bottom: 1rem;
}
article h2:first-child,
section h2:first-child {
  margin-top: 1rem;
}
section {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 2rem 1rem;
  margin: 3rem 0;
}
summary {
  cursor: pointer;
  font-weight: 700;
  padding: 0.6rem 1rem;
}
details[open] {
  padding: 0.6rem 1rem 0.75rem 1rem;
}
details[open] summary + * {
  margin-top: 0;
}
details[open] summary {
  margin-bottom: 0.5rem;
  padding: 0;
}
details[open] > :last-child {
  margin-bottom: 0;
}
table {
  border-collapse: collapse;
  display: block;
  margin: 1.5rem 0;
  overflow: auto;
  width: 100%;
}
td,
th {
  border: 1px solid var(--border);
  text-align: left;
  padding: 0.5rem;
}
th {
  background: var(--accent-bg);
  font-weight: 700;
}
tr:nth-child(even) {
  background: var(--accent-bg);
}
table caption {
  font-weight: 700;
  margin-bottom: 0.5rem;
}
input,
select,
textarea {
  font-size: inherit;
  font-family: inherit;
  padding: 0.5rem;
  margin-bottom: 0.5rem;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 5px;
  box-shadow: none;
  max-width: 100%;
  display: inline-block;
}
label {
  display: block;
}
textarea:not([cols]) {
  width: 100%;
}
select:not([multiple]) {
  background-image: linear-gradient(45deg, transparent 49%, var(--text) 51%),
    linear-gradient(135deg, var(--text) 51%, transparent 49%);
  background-position: calc(100% - 15px), calc(100% - 10px);
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: 25px;
}
input[type="checkbox"],
input[type="radio"] {
  vertical-align: middle;
  position: relative;
}
input[type="radio"] {
  border-radius: 100%;
}
input[type="checkbox"]:checked,
input[type="radio"]:checked {
  background: var(--accent);
}
input[type="checkbox"]:checked::after {
  content: " ";
  width: 0.18em;
  height: 0.32em;
  border-radius: 0;
  position: absolute;
  top: 0.05em;
  left: 0.17em;
  background: 0 0;
  border-right: solid var(--bg) 0.08em;
  border-bottom: solid var(--bg) 0.08em;
  font-size: 1.8em;
  transform: rotate(45deg);
}
input[type="radio"]:checked::after {
  content: " ";
  width: 0.25em;
  height: 0.25em;
  border-radius: 100%;
  position: absolute;
  top: 0.125em;
  background: var(--bg);
  left: 0.125em;
  font-size: 32px;
}
@media only screen and (max-width: 720px) {
  input,
  select,
  textarea {
    width: 100%;
  }
}
input[type="checkbox"],
input[type="radio"] {
  width: auto;
}
input[type="color"] {
  height: 2.5rem;
  padding: 0.2rem;
}
input[type="file"] {
  border: 0;
}
hr {
  color: var(--border);
  border-top: 1px;
  margin: 1rem auto;
}
mark {
  padding: 2px 5px;
  border-radius: 4px;
  background: var(--marked);
}
img,
video {
  max-width: 100%;
  height: auto;
  border-radius: 5px;
}
figure {
  margin: 0;
  text-align: center;
}
figcaption {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 1rem;
}
blockquote {
  margin: 2rem 0 2rem 2rem;
  padding: 0.4rem 0.8rem;
  border-left: 0.35rem solid var(--accent);
  color: var(--text-light);
  font-style: italic;
}
cite {
  font-size: 0.9rem;
  color: var(--text-light);
  font-style: normal;
}
dl {
  display: grid;
  grid-template-columns: auto 1fr;
}
dl dt {
  grid-column-start: 1;
  color: var(--text-light);
}
dl dd {
  grid-column-start: 2;
}
code,
kbd,
pre,
pre span,
samp {
  font-family: var(--mono-font);
  color: var(--code);
}
kbd {
  color: var(--preformatted);
  border: 1px solid var(--preformatted);
  border-bottom: 3px solid var(--preformatted);
  border-radius: 5px;
  padding: 0.1rem 0.4rem;
}
pre {
  padding: 1rem 1.4rem;
  max-width: 100%;
  overflow: auto;
  color: var(--preformatted);
}
pre code {
  color: var(--preformatted);
  background: 0 0;
  margin: 0;
  padding: 0;
}
progress {
  width: 100%;
}
progress:indeterminate {
  background-color: var(--accent-bg);
}
progress::-webkit-progress-bar {
  border-radius: 5px;
  background-color: var(--accent-bg);
}
progress::-webkit-progress-value {
  border-radius: 5px;
  background-color: var(--accent);
}
progress::-moz-progress-bar {
  border-radius: 5px;
  background-color: var(--accent);
  transition-property: width;
  transition-duration: 0.3s;
}
progress:indeterminate::-moz-progress-bar {
  background-color: var(--accent-bg);
}
