body {
    margin: 2em;
    font-family: sans-serif;
    line-height: 1.6;
    color: #222;
    background-color: #ffffff;
}
a {
    color: #0645ad;
    text-decoration: underline;
}
h2 {
    margin-top: 2em;
    border-bottom: 1px solid #ccc;
    padding-bottom: 0.3em;
}
h3 {
    margin-top: 1.5em;
    color: #333;
}
hr {
    margin: 2em 0;
}
.see-also a,
.references a {
  text-decoration: none;
  border-bottom: 1px dotted #888;
}
.see-also a:hover,
.references a:hover {
  border-bottom-style: solid;
}
.title-block {
    text-align: center;
    margin: 3em auto;
    font-family: "hiragino kaku gothic pron", meiryo, "yu gothic", arial, sans-serif;
    color: #222;
}
.title-block h1 {
    font-size: 1.8em;
    font-weight: 600;
    margin: 0.2em 0;
    letter-spacing: 0.5px;
}
.title-block .subtitle {
    font-size: 1.2em;
    font-weight: 400;
    color: #555;
    margin: 0.4em 0 1.2em;
    font-style: italic;
}
.title-block .meta {
    font-size: 0.95em;
    color: #666;
    line-height: 1.5;
    margin-top: 0;
}
.title-block .author {
    font-variant: small-caps;
    letter-spacing: 0.8px;
}
/* math / definition / important assumption block */
.math {
    margin: 1em 0;
    padding-left: 1em;
    border-left: 3px solid #ccc;
}
.quote {
    margin: 1em 0;
    padding-left: 1em;
    border-left: 3px solid #ccc;
}
.note {
    font-size: 0.9em;
    color: #555;
    padding: 0.1em 0.5em;
    border-left: 3px solid #f90;
    background-color: #fef;
}
/* standalone images */
.image {
    display: block;
    margin: 24px auto;
    border-radius: 12px;
    max-width: 100%;
    height: auto;
}
/* technical figures with caption */
.tech-figure {
    display: inline-block;
    max-width: 640px;
    margin: 0em 0 1em 2em;
}
.tech-figure img {
    width: 100%;
    height: auto;
    display: block;
}
.tech-figure figcaption {
    text-align: center;
    margin-top: 0.3em;
    font-size: 0.9em;
    color: #555;
    line-height: 1.4;
}

.safe-red { color: #ff4b00; }  /* JIS Z 9103:2018 safe color; red -- for P-type color vision */
.safe-orange { color: #f6aa00; }  /* JIS Z 9103:2018 safe color; yellow red -- adjust hue to red */
.safe-yellow { color: #f2e700; }  /* JIS Z 9103:2018 safe color; yello -- for P and D-type color vision */
.safe-green { color: #00b06b; }  /* JIS Z 9103:2018 safe color; green -- for P and D-type color vision */
.safe-blue { color: #1971ff; }  /* JIS Z 9103:2018 safe color; blue -- for low vision */
.safe-purple { color: #990099; }  /* JIS Z 9103:2018 safe color; red purple -- for D-type color vision */
.b-rose { color: #e36; } /* author emphasis / assertion */
.em-blue { color: #36f; font-style: italic; } /* conceptual emphasis */

.answer-head {
    font-size: 1.1em;
    font-weight: bold;
    margin-top: 0.5em;
}
@media (max-width: 768px) {
  .tech-figure {
    margin-left: 0;
  }
}
.switch2en {
    font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    text-align: right;
}
.switch2jp {
    font-family: "Hiragino Kaku Gothic ProN", Meiryo, "Yu Gothic", Arial, sans-serif;
    text-align: right;
}
.switch2jp img{
    border: none;
    vertical-align: middle;
}
.site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.2em 0.4em;
    margin-bottom: 0.8em;
    //border-bottom: 1px solid #ddd;
}

.site-logo img { /* logo side  */
    display: block;
    //height: 18px;
}

.lang-switch, /* language switch side */
.switch2jp,
.switch2en {
    white-space: nowrap;
}