*,
*::before,
*::after {
  box-sizing: inline-block;
}

body {
  font-family: system-ui, sans-serif;
}

section {
  padding: 2rem 4rem;
}

details {
  padding-bottom: 1rem;
  border-bottom: 1px solid lightgrey;
}

details * {
  max-width: 65ch;
}

summary {
  font-weight: bold;
  font-size: 1.1rem;
  cursor: pointer;
  list-style-position: outside;

}
summary::marker {
  content: "+   ";
  font-size: 2rem;
  font-weight: normal;
  text-align: center;
  color: red;
}

details[open] summary::marker {
  content: "–   ";
}

/* Fix: By default, block elements (e.g. a heading) nested inside the <summary> render below the marker, rather than keeping it inline: */
 summary * {
  display: inline-block;
}