body {
    margin: 0;
    padding: 0;
    background-image: url(fond.jpg);
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;
    background-attachment: fixed;
    display: flex;
    font-family: sans-serif;
    height: 100vh;
    color: black;
}
#gauche h2, #droite h2 {
    font-size: 45px;
    margin-top: 40px;
}
#gauche {
    width: 40%;
    backdrop-filter: blur(10px);
}
#gauche h2 {
    text-align: right;
    margin-right: 15px;
    color: white;
    text-shadow: 0 0 3px black;
}
#gauche div {
    width: 70%;
    margin: 70px auto;
}
#gauche input {
    display: block;
    padding: 15px;
    width: 80%;
    margin: 20px auto;
    border: none;
    outline: none;
    border-radius: 10px;
    background-color: #f3f3f3;
}
#gauche input[type="submit"] {
    background-color: orange;
    cursor: pointer;
    color: white;
    font-size: 18px;
    letter-spacing: 1px;
    transition: 0.5s;
}
#gauche input[type="submit"]:hover {
    background-color: orangered;
    transition: 0.5s;
}
#droite {
    width: 60%;
}
#droite h2 {
    margin-left: 15px;
    text-shadow: 0 0 3px white;
}
#droite div {
    width: 75%;
    background-color: antiquewhite;
    padding: 15px;
    margin: auto;
    margin-top: 70px;
    border-radius: 15px;
}
#droite h3 {
    text-align: center;
    color: #333;
}

@media screen and (max-width: 800px) {
    body {
        flex-direction: column;
    }
    #gauche, #droite {
        width: 100%;
    }
    #gauche h2, #droite h2 {
        text-align: center;
        margin-top: 15px;
    }
    #droite div {
        margin-top: 0;
    }
}