.titre {
text-align: center;
}

body {
background-color: white;
}

#input_bases {
font-size: 27px;
display: flex;
background-color: white;
flex-wrap: wrap;
}

input[type=checkbox] {
 /* Double-sized Checkboxes */
  -ms-transform: scale(1.1); /* IE */
  -moz-transform: scale(1.2); /* FF */
  -webkit-transform: scale(1.1); /* Safari and Chrome */
  -o-transform: scale(1.1); /* Opera */
  transform: scale(1.1);
  margin: 0px;
}

input {
appearance: none;
position: relative;
width: 1rem;
height: 1rem;
border: 1px solid;
line-height: 1;
background: #aaa;
}

input[type="checkbox"]::before {
        position: absolute;
        width: 100%;
        height: 100%;
        text-align: center;
        white-space: pre;
        content: " ";
      }

input[type="checkbox"]:checked::before {
        content: "\2713";
      }