div#content
{
    scroll-behavior: smooth;
}

* {font-family: Avenir,
   Helvetica,
   Arial,
   Verdana,
   Roboto,
   "游ゴシック",
   "Yu Gothic",
   "游ゴシック体",
   "YuGothic",
   "ヒラギノ角ゴ Pro W3",
   "Hiragino Kaku Gothic Pro",
   "Meiryo UI",
   "メイリオ",
   Meiryo,
   "ＭＳ Ｐゴシック",
   "MS PGothic",
   sans-serif;}

body {
    color: white;
    background-color: #333;
    background-image: url("icon_512x512@2x.png");
    background-repeat: no-repeat;
    background-position: right -380px;
    margin: 0;
    padding: 0;
    width: 100%;
}

h2 {
    font-size: x-large;
    color: #cc9;
}

h2 a:hover {
    color: inherit;
}

h2+* {margin-left: 1em}

h3 {
    margin-left: 1em;
    font-size: large;
    color: #ff9;
}

h3+* {margin-left: 2em}

a:link {
    color: #00ffcc;
}
a:visited {
    color: #6cf;
}
a:hover {
    color: #cfc;
    /* background-color: #333; */
}
a:active {
    color: #0ff;
}
a:focus {
    color: #0ff;
}
a {
    transition: color .5s;
    transition: background-color .5s;
    border-radius: .2em;
}

h1 {
    background-color: rgba(51, 51, 51, 0.7);
    color: #6c6;
    font-size: xx-large;
    position: fixed;
    top: 0;
    left: 0;
    margin: 0;
    width: 100%;
    height: 5em;
    padding-top: .5em;
    padding-left: 1em;
}

div#body {
    background-color: #333;
    position: fixed;
    top: 5em;
    bottom: 0;
    border-top: solid;
    border-width: 1px;
}

div#navi {
    background-color: #666;
    padding-left: 2%;
    color: white;
    width: 18%;
    height: 100%;
    float: left;
}

div#content {
    padding-left: 2%;
    padding-right: 18%;
    width: 60%;
    height: 100%;
    float: left;
    overflow: auto;
}

dt {
    color: #cf0;
    font-size: large;
}

ul#navi {
    padding-left: 1%;
}

div#navi a {
    text-decoration: none;
    padding-left: .6em;
    padding-right: .6em;
}

p#os {
    font-size: x-large;
}

pre {
    margin-top: 0;
    color: #ccc;
}

div#dl {
    border-radius: .5em;
    border: solid;
    margin-right: 2em;
    margin-top: 2em;
    padding-left: 1em;
}

div#dl p {
    margin-top: .1em;
}

div#screen_shot {
    position: relative;
    padding-top: 0px;
    height: 280px;
}

div#screen_shot p {
    transition: opacity 1s;
    position: absolute;
    top: 0;
}

button {
    width: 8em;
    background-color: #666;
    border-radius: .4em;
    padding: 2px 2px 2px 2px;
    margin: 0em .1em 0em .1em;
    transition: color .5s;
    transition: background-color .3s;
}

button:hover {
    background-color: #999;
    cursor: pointer;
}