style-formulaire.css

body {
    margin: 0 auto;
    padding: 0;
    font-family: Cambria, "Times New Roman", serif;
    background-color: #201d1d;
    font-size: 100%;
    color: white;
}

.menu {
    z-index: 3;
    position: fixed;
    top: 0;
    margin: 0;
    padding: 0;
    width: 100%;
    list-style-type: none;
    overflow: hidden;
    background-color: #1a1a1a;
}

.menu a {
    float: left;
    display: block;
    padding: 1.5625% 2%;
    color: white;
    overflow: hidden;
    text-align: center;
    text-decoration: none;
}

a.logo {
    float: right;
}

.menu a:hover {
    background: #111;
    color: red;
}

.main {
    z-index: 1;
    width: 100%;
    margin-top: 5%;
    overflow: hidden;
    text-align: left;
}

.right-bg {
    position: fixed;
    z-index: 2;
    top: 0;
    right: 0;
    height: 100%;
    width: 10%;
    margin-bottom: auto;
    background: #0d0c0c;
}

.left-bg {
    position: fixed;
    z-index: 2;
    top: 0;
    left: 0;
    height: 100%;
    width: 10%;
    margin-bottom: auto;
    background: #0d0c0c;
}

.image-intro {
    position: relative;
    min-width: 10%;
    width: 50%;
    max-width: 80%;
    max-height: 42.7%;
    margin-bottom: 25px;
    margin-left: 25%;
    opacity: 0.7;
}

img:hover {
    opacity: 0.45;
}

h1, h2, h3, h4 {
    position: relative;
    margin-bottom: 5%;
    margin-top: 5%;
    text-align: center;
    font-weight: bold;
    font-size: 140%;
    font-family: "Candara Light", Cambria, serif;
}

.description {
    position: relative;
    max-width: 70%;
    margin-left: 17%;
    text-align: left;
    font-size: 115%;
    font-weight: initial;
    letter-spacing: 1px;
    line-height: 150%;
}

.image-description-right {
    float: right;
    position: relative;
    width: 15%;
    margin: -2% 10% 5% 5%;
    overflow: hidden;
}

.form-titre {
    position: relative;
    font-style: italic;
}

form {
    position: relative;
    width: 60%;
    margin-left: 30%;
    text-align: inherit;
    font-weight: initial;
    letter-spacing: 1px;
}

form img {
    float: right;
    position: relative;
    width: 40%;
    height: 30%;
    margin: 0 5%;
    overflow: auto;

}

input[type=text] {
    display: inline-block;
    width: 20%;
    margin: 1% 1%;
    padding: 0.3%;
    text-align: left;
    border: 1px solid white;
    border-radius: 5px;
    color: white;
    background-color: #0d0c0c;
}

.erreur-champs {
    color: orangered;
}

input[name=age] {
    margin: 2% 0;
}

select {
    margin-top: 1%;
    margin-bottom: 2%;
}

textarea {
    position: inherit;
    margin: 1% 0;
    color: white;
    border: 1px solid white;
    background-color: #0d0c0c;
}


input[type=submit] {
    width: 10%;
    margin: 1%;
    padding: 1%;
    border: none;
    border-radius: 4px;
    background-color: #4CAF50;
    color: white;
    cursor: pointer;
    box-sizing: border-box;
}

input[type=submit] {
    position: relative;
    width: 20%;
}

span {
    position: relative;
    width: 100%;
    height: 15%;
    margin: 5% 5% 10% 20%;
    font-size: 115%;
}

.remerciements {
    width: 60%;
    margin: 5% 0 5% 20%;
    text-align: center;
    font-size: large;
    font-weight: bold;
}

footer {
    position: absolute;
    z-index: 3;
    width: 100%;
    margin-top: 2.5%;
    padding: 0;
    overflow: hidden;
    background-color: #1a1a1a;
}

footer li {
    display: block;
    float: left;
    padding: 1.5625% 3%;
    list-style-type: none;
    text-align: center;
    color: white;
    font-weight: bolder;
    font-size: small;
}

footer a {
    color: white;
}