body {
    background-color:powderblue;
    margin:0;
    padding:0;
    >form {
        background-color:white;
    }
}
form {
    > label > input {
        width:100%;
        height:100%;
        margin:0;

        font-size:1.2em;
    }

    >hr {
        margin-bottom:25px;
    }

    width: min(95%, 900px);
    margin:auto;

}

form.principal {
    border: 1px solid black;

    display:block;
    > * {
        display:block;

        margin:10px 5px;
        width: calc(100% - 18px);
        box-sizing: border-box;

        font-size:1.2em;
    }
    box-shadow: 0 0 10px gray;

    > button, >a.faux-bouton {
        width: calc(100% - 10px);
    }
}

button, a.faux-bouton {
    text-align:center;
    color:black;
    border-radius: 3px;
    border: 1px solid gray;
    text-decoration: none;
    background-color:#FCFCFC;
    font-family: "Segoe UI", sans-serif;
    padding:3px;
    box-sizing: border-box;
}
button:hover,a.faux-bouton:hover {
    background-color:powderblue;
}

h1 {
    text-align:center;
}

.cache {
    display:none;
}

.erreur {
    color:red;
    font-size: 1em;
    font-family: "Segoe UI", sans-serif;
}