* {
  border-collapse: collapse;
  margin: 0;
  padding: 0;
}

ul {
  margin-left: 1em;
}

footer,
div,
article,
header {
  display: grid;
  justify-content: center;
  row-gap: 2em;
}

body {
  font-family: monospace;
  font-size: 1rem;
}

blockquote {
  border-left: 1em solid rgba(192, 192, 192, 0.256);
  padding: 0.5em 1em;
}

.alert-note {
  border-left: 1em solid rgba(140, 175, 191, 0.75);
}

.alert-tip {
  border-left: 1em solid rgba(255,220,0,0.5);
}

article {
  row-gap: 1.5em;
}

.main {
  padding: 1em;
  max-width: 80ch;
  margin: 0 auto;
}

header h1{
  font-size: 1.75rem;
}

article h1{
  font-size: 1.5rem;
}

h1,
footer {
  text-align: center;
  margin: 0;
}

th,
td {
  border: 1px solid #dddddd;
  text-align: left;
  padding: 0.5em;
}

th,
td:first-child {
  background-color: #f2f2f2;
  font-weight: bold;
}

p {
  line-height: 1.5;
}

a[target="_blank"]::after {
  content: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAQElEQVR42qXKwQkAIAxDUUdxtO6/RBQkQZvSi8I/pL4BoGw/XPkh4XigPmsUgh0626AjRsgxHTkUThsG2T/sIlzdTsp52kSS1wAAAABJRU5ErkJggg==);
  margin: 0 0.3em;
}

figure {
  border: 1px solid #ccc;
  padding: 0.5em;
  border-radius: 3%;
  margin: 0 auto;
}

figcaption {
  font-style: italic;
  text-align: center;
  margin-top: 0.5em;
}

.table {
  overflow-x: auto;
}

details {
  border: 1px solid #e0e0e0;
  border-radius: 0.5em;
}

details>summary {
  cursor: pointer;
  padding: 1rem;
  background-color: #f8f8f8;
  font-weight: 600;
}