* {
  box-sizing: border-box;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  width: 100%;
}

.header {
  padding: 20px;
  text-align: center;
  background: #1abc9c;
  color: white;
  font-size: 30px;
  font-weight:bold;
  margin : 10px 10px 10px 10px;
}

.grid-container {
  display : grid;
  grid-template-columns : repeat(auto-fit, 300px);
  justify-content : center;
}

/* Float four columns side by side */
.column {
  float: left;
  width: 100%;
  padding: 0 10px;
  height: 100%;
}

.img {
  height:50%;
}

/* Remove extra left and right margins, due to padding in columns */
.row {margin: 0 -5px;}

/* Clear floats after the columns */
.row:after {
  content: "";
  display: table;
  clear: both;
}

/* Style the counter cards */
.card {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2); /* this adds the "card" effect */
  padding: 16px;
  text-align: center;
  border-radius : 15px;
  background-color: #C3DFC2; /* #f1f1f1; gris */
  height:100%;
}

.button {
  border: none;
  outline: 0;
  display: inline-block;
  padding: 8px;
  color: white;
  font-weight:bold;
  font-size:24px;
  background-color: #000;
  text-align: center;
  cursor: pointer;
  width: 100%;
}

.button:hover {
  background-color: #555;
} 
/* Responsive columns - one column layout (vertical) on small screens */
@media screen and (max-width: 600px) {
  .column {
    width: 100%;
    display: block;
    margin-bottom: 20px;
  }
}