:root {
  --color: #333;
  --border: #333;
  --bg-color: whitesmoke;
  --a-link-color: mediumblue;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body,
h1,
h2,
h3,
h4,
h5,
h6,
p,
figure,
blockquote,
pre,
code,
dl,
dd {
  margin: 0;
}

h2,
h3,
h4,
h5,
h6 {
  margin-top: 2rem;
}

h2:first-child {
  margin-top: 0;
}

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

html {
  scroll-behavior: smooth;
}

body {
  max-width: 900px;
  min-height: 100vh;
  line-height: 1.5;
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", "BIZ UDPGothic", Meiryo,
    sans-serif;
  color: var(--color);
  margin: auto;

  display: flex;
  flex-direction: column;
}

.page-header {
  padding: 1rem;
  font-weight: 600;
  flex-shrink: 0;
}

.page-footer {
  border-top: solid 1px var(--color);
  padding: 1rem;
  font-size: 0.8em;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  flex-shrink: 0;
}

.page-header a,
.page-footer a,
.summary-header a,
.summary a {
  text-decoration: none;
  color: var(--color);
}

.copyright {
  margin-right: 2em;
}

main {
  padding: 2rem 1rem;
  flex-grow: 0.8;
}

article > * {
  margin-top: 1em;
}

article > header {
  margin-top: 0;
}

header.summary-header {
  margin-bottom: 1em;
}

h2 {
  border-bottom: solid 1px var(--bg-color);
}

h2 small {
  margin-left: 0.5em;
  font-size: 0.5em;
  font-weight: normal;
}

a {
  -ms-touch-action: manipulation;
  touch-action: manipulation;
}

main > a:link {
  color: --a-link-color;
}
main > nav {
  margin-top: 2em;
}

main > section {
  margin-bottom: 2em;
}

section > header {
  margin-top: 1.5em;
}

section > footer {
  margin-top: 1.5em;
}

img,
picture {
  max-width: 100%;
  max-height: 500px;
  display: block;
  margin: 1em auto;
}

figure > img {
  margin: 0 auto;
  max-height: none;
}

figcaption {
  text-align: center;
}

div.gallery {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2px;
  margin: 1em auto;
  align-items: flex-start;
}

div.gallery > a, div.gallery > div{
  display: block;
  max-width: 210px;
  margin: 0;
  width: clamp(60px, 24%, 210px);
  padding: 0;
}

div.gallery > * > img {
  margin: 0;
  aspect-ratio: 3/2;
}

div.slide {
  text-overflow: ellipsis;
  overflow-x: hidden;
  white-space: nowrap;
}

div.slide img {
  display: inline;
  max-width: 100px;
  vertical-align: middle;
  margin: 3px 0.5em;
  border-radius: 3px;
}

pre > code {
  padding: 1em;
  display: block;
  overflow-x: auto;
  font-family: Monaco, Consolas, Courier New, Courier, monospace, sans-serif;
}

blockquote {
  padding: 1em;
  border-left: 0.05em solid var(--border);
}

hr {
  border: none;
  border-top: 1px solid var(--border);
}

code {
  margin: 0 0.1em;
  padding: 0.05em 0.4em;
  border-radius: 3px;
  background-color: var(--bg-color);
}

ul {
  list-style-type: "-";
  padding-inline-start: 1em;
}

ul.flex {
  list-style: none;
  display: flex;
  padding-inline-start: 0;
  flex-wrap: wrap;
}

li {
  line-height: 1.8;
  padding-left: 1em;
}

.pagination {
  margin-top: 2rem;
  text-align: center;
}

.pagination a {
  display: inline-block;
  width: 1.5rem;
  text-align: center;
  color: var(--color);
}

.pagination a[aria-current="page"] {
  background-color: var(--color);
  color: var(--bg-color);
}

@media screen and (max-width: 600px) {
  figure {
    margin: 0 -1rem;
  }
}