html {
  background: #efefef;
  font-size: 16px;
  font-family: "ヒラギノ角ゴシック", "Hiragino Sans", "ヒラギノ角ゴ Pro W3",
    "Hiragino Kaku Gothic Pro", sans-serif;
  color: #333;
}
body {
  margin: 0;
}
a {
  color: #007bff;
}

.canvas {
  position: relative;
  height: 500px;
}
.canvas canvas {
  position: relative;
  z-index: 2;
}

[target="_blank"] {
  display: inline-block;
  position: relative;
  padding-right: 1em;
  margin-right: 0.3em;
}

[target="_blank"]::before,
[target="_blank"]::after {
  background: #fff;
  content: "";
  display: block;
  position: absolute;
  right: 0;
  top: 0;
  width: 0.3em;
  height: 0.3em;
  border: 1px solid #007bff;
  transform: translateY(0.5em);
}
[target="_blank"]::before {
  right: 3px;
  top: 3px;
}
.container {
  max-width: 760px;
  box-shadow: 0 0 4px rgba(0, 0, 0, 0.01);
}
.content {
  background: #fff;
  padding: 4em;
}

.rel {
  background: #f9f9f9;
  margin-top: 3em;
  padding: 2em;
}

.rel h2 {
  margin-top: 0;
  font-size: 1.2rem;
}

nav,
aside {
  background: #fff;
  margin-top: 1.5em;
  padding: 2em;
}

blockquote {
  margin-left: 1em;
  padding-left: 1em;
  border-left: 5px solid #ccc;
}

p {
  line-height: 1.8;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.4;
}
h1 {
  margin: 0em;
  padding: 1em;
  font-size: 2rem;
  background: #2980b9;
  color: #fff;
}
h2 {
  margin-top: 2em;
  font-size: 1.8rem;
}
h3 {
  margin-top: 1.6em;
  font-size: 1.5rem;
}
h4 {
  margin-top: 1.3em;
  font-size: 1.3rem;
}
.content > *:first-child,
nav *:first-child,
aside *:first-child {
  margin-top: 0;
}
table {
  border-collapse: collapse;
  border-spacing: 1px;
}
table th,
table td {
  padding: 0.6em;
  border: 1px solid #333;
  line-height: 1.4;
}
li {
  margin-bottom: 0.5em;
}
figure {
  margin: 1em 0;
}
figcaption {
  margin: 0.3em 0;
  line-height: 1.4;
  font-size: 80%;
}
code {
  overflow: auto;
  display: block;
  white-space: pre;
  line-height: 1.6;
  background: #efefef;
  margin: 1.8em 0;
  padding: 1.6em 2em;
  color: #333;
  border-radius: 2px;
}
output {
  display: block;
  padding: 0.4em 1em;
  border: 1px solid #ccc;
  border-radius: 4px;
}
button,
input[type="submit"] {
  cursor: pointer;
  padding: 0.6em 2em;
  font-size: 1.2rem;
  border-radius: 100px;
  box-shadow: none;
  border: 0;
  border-right: 1px solid #ccc;
  border-bottom: 1px solid #ccc;
  background: #007bff;
  color: #fff;
  line-height: 1.1;
}
input[type="text"],
input[type="number"],
input[type="email"],
input[type="password"],
select {
  padding: 0.3em;
  font-size: 1.2rem;
  border: 1px solid #ccc;
  border-radius: 4px;
}
.lil-gui input[type="text"],
.lil-gui input[type="number"],
.lil-gui input[type="email"],
.lil-gui input[type="password"],
select {
  font-size: 100%;
  border: 0;
}
mark {
  background: #fffcc2;
}
small {
  font-size: 98%;
}

.current {
  font-weight: bold;
  color: #333;
  text-decoration: none;
}

.next:before {
  content: "次は -> ";
}

.answer {
  background: url("../img/robot.svg") 0 0 / 80px auto no-repeat;
  margin: 2em 0;
  padding-left: 90px;
  min-height: 120px;
}

@media screen and (min-width: 501px) {
  .container {
    margin: 0 auto;
  }
}
@media screen and (max-width: 500px) {
  html {
    font-size: 5vw;
  }
  h1 {
    padding: 0.8em;
    font-size: 1.6rem;
  }
  .content {
    padding: 2em;
  }
  .rel {
    padding: 1.6em;
  }
}

.references h2 {
  margin-top: 0;
}

@keyframes s7 {to{transform: translate(-50%,-50%) rotate(.5turn)}}
.custom-loader {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  width:50px;
  height:50px;
  --c:radial-gradient(farthest-side,#007bff 92%,#0000);
  background: 
    var(--c) 50% 0,
    var(--c) 50% 100%,
    var(--c) 100% 50%,
    var(--c) 0    50%;
  background-size:12px 12px;
  background-repeat:no-repeat;
  animation:s7 1s infinite;
}