:root {
  --material-color-main: #1f6fa8;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: #f5f5f5;
  color: #333;
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.8;
}

.book-header {
  position: sticky;
  top: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 1em;
  padding: .5em 1em;
  background: var(--material-color-main);
  color: #fff;
}
.book-header a { color: #fff; font-size: .9em; white-space: nowrap; }
.book-header h1 {
  margin: 0;
  overflow: hidden;
  font-size: 1em;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.page-wrapper { padding: 1.5em 1em 4em; outline: none; }

.markdown-section {
  max-width: 800px;
  margin: 0 auto;
  padding: 1.5em 2em 2em;
  background: #fff;
  border-radius: 4px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, .12);
}
.markdown-section h1 { font-size: 1.8em; line-height: 1.4; }
.markdown-section h2 {
  margin-top: 2em;
  padding-bottom: .3em;
  border-bottom: 2px solid var(--material-color-main);
  font-size: 1.4em;
}
.markdown-section h3 { margin-top: 1.5em; font-size: 1.15em; }
.markdown-section pre {
  overflow-x: auto;
  padding: 1em;
  background: #263238;
  border-radius: 4px;
  color: #eceff1;
  line-height: 1.5;
}
.markdown-section code { font-family: Menlo, Consolas, monospace; font-size: .9em; }
.markdown-section p code, .markdown-section li code {
  padding: .1em .3em;
  background: #eef2f5;
  border-radius: 3px;
}
.markdown-section img { max-width: 100%; height: auto; }
.markdown-section .note {
  padding: .75em 1em;
  background: #fff8e1;
  border-left: 4px solid #f9a825;
}

#toc { padding: .75em 1em .75em 2em; background: #f7f9fb; border-radius: 4px; }

.share-button-wrapper {
  margin-top: 3em;
  padding: 1.5em;
  background: #f0f6fb;
  border-radius: 4px;
  text-align: center;
}
.share-button-wrapper .ending-h2 { margin: 0 0 .5em; border: 0; }

@media (max-width: 600px) {
  .page-wrapper { padding: .75em .5em 3em; }
  .markdown-section { padding: 1em; }
}