html {
  font-family: "メイリオ", Meiryo, Hiragino Sans, Hiragino Kaku Gothic ProN,
    'ヒラギノ角ゴ ProN W3', 'ヒラギノ角ゴ Pro W3', Helvetica Neue, Helvetica, sans-serif;
  font-size: 16px;
  word-spacing: 1px;
  -ms-text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background-color: #e4f0d6;
}

a {
  color: #36a736;
  text-decoration: none;
}

a:hover {
  color: #304999;
  text-decoration: underline;
}

header {
  display: flex;
  flex-direction: column;
  gap: .25em;
  padding: 1em;
  background: linear-gradient(to top, #309935 0%, #309935 100%);
  color: #fff;
  text-align: center;
}

header > * {
  margin: 0;
}

header h1 {
  font-size: 1.75em;
  letter-spacing: .1em;
}

header a {
  color: inherit;
  text-decoration: none;
}

header a:hover {
  color: #b7e2b6;
}

header ruby {
  ruby-position: under;
}

header p {
  margin: 0;
  font-size: .8em;
}

@media screen and (min-width: 920px) {
  nav {
    width: 912px;
    margin-left: auto;
    margin-right: auto;
  }
}

nav ul {
  display: flex;
  gap: 1em;
  margin: 0;
  padding: 0;
  list-style: none;
}

nav li {
  display: inline;
  line-height: 1.6;
  border-bottom: 2px solid #fff;
}

nav li.selected {
  border-bottom: 2px solid #cc0051;
}

main {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin: 1em;
}

main > section {
  width: 100%;
  border-radius: .5em;
  background-color: white;
  padding: 1em;

  display: flex;
  flex-direction: column;
  gap: .75em;
}

main.top > section {
  width: 448px;
}

main > section > h1 {
  margin: 0;
}

main > section > article > * {
  margin: 0;
}

@media screen and (min-width: 920px) {
  main {
    width: 912px;
    margin-left: auto;
    margin-right: auto;
  }
}

section > h1 > a {
  color: black;
}

table {
  border-collapse: collapse;
}

table, td, th, tr {
  border: 1px solid black;
}

td, th {
  padding: .25em;
}

footer {
  margin: 1em;
}

footer ul {
  margin: 0;
  padding: 0 0 0;
  list-style: none;
  text-align: center;
}

footer li {
  display: inline;
  line-height: 1.6;
}

footer small {
  display: block;
  margin: 1em;
  text-align: center;
  color: #666;
}

.d-flex {
  display: flex;
}

.flex-direction-column {
  flex-direction: column;
}

.gap-_5em {
  gap: .5em;
}