/* Variables */
:root {
    --color-00: #ffffff; /* white pure */
    --color-01: #f9f9f9; /* white ghost */
    --color-10: #222222; /* black */
    --color-20: #dbe7fb; /* blue light */
    --color-21: #91bdff; /* blue soft */
    --opacity-1: 0.5;
    --opacity-2: 0.8;
}

/* Elements */
html {
  box-sizing: border-box;
}

* {
  box-sizing: inherit;
}

.h-centered {
  margin-left: auto;
  margin-right: auto;
}

.h-boxes {
  /* V */
  display: flex;
  /* H */
  gap: 1.5rem;
}

.boxed {
  background: var(--color-01);
  border: 1px solid var(--color-10);
  border-radius: 2px;
  padding: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.boxed h3 {
  /* V */
  margin-top: 0;
}

.boxed p {
  /* V */
  margin-bottom: 0;
  line-height: 1.6;
  /* Other */
  opacity: var(--opacity-2);
}

.button {
  cursor: pointer;
  background: none;
}

.button:hover {
  color: var(--color-00); /* text: white */
  background: var(--color-10); /* background: black */
  opacity: 1;
}

.svg-button {
  appearance: none;
  border: none;
  background: none;
  padding: 0;
}
 
details summary {
    color: var(--color-20);
}

details summary h4 {
    display: inline;
    margin: 0;
    color: var(--color-21);
}