*{
  font-family: Avenir, sans-serif;
  font-size: 1em;
  text-align: center;
  margin: 0px;
  padding: 0px;
  box-sizing: border-box;
}
.conteneur-grid{
  display: grid;
  grid-template-columns: 1fr 2fr 1fr;
  border: 2px solid red;
}
.conteneur-grid > div{
  padding: 20px 0px;
  background-color: gold;
  border: 2px solid RGB(120,40,160);
}