.container {
    width: 100%;
    position: relative;
    /*top: 90px;*/
}

.header {
    height: 100vh;
    background-image: url("../images/gta.jpg");
    background-position: top center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: cover;
    color: white;

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
.header > h1, h4 {
    text-shadow: 0 0 20px black;
}

.header > h1 {
    font-size: 5vw;
    margin: 0;
}
.header > h4 {
    font-size: 2vw;
}
.header > img {
    filter: drop-shadow(2px 7px 15px black);
}
/**************************************************************/
/*  */
.lettre {
    color: #484848;
    font-size: 80px;
    /*letter-spacing: 15px;*/
    margin-bottom: 150px;
    animation: flash 1.2s linear infinite;
}
@keyframes flash {
    0% {
        color: #ffffff;
        text-shadow: 0 0 7px #f1f1f1;
    }
    90% {
        color: #484848;
        text-shadow: none;
    }
    100% {
        color: #ffffff;
        text-shadow: 0 0 7px #ffffff;
    }
}

.lettre:nth-child(1){
    animation-delay: 0.1s;
}
.lettre:nth-child(2){
    animation-delay: 0.2s;
}
.lettre:nth-child(3){
    animation-delay: 0.3s;
}
.lettre:nth-child(4){
    animation-delay: 0.4s;
}
.lettre:nth-child(5){
    animation-delay: 0.5s;
}
.lettre:nth-child(6){
    animation-delay: 0.6s;
}
.lettre:nth-child(7){
    animation-delay: 0.7s;
}
.lettre:nth-child(8){
    animation-delay: 0.8s;
}
.lettre:nth-child(9){
    animation-delay: 0.9s;
}
.lettre:nth-child(10){
    animation-delay: 1s;
}
@media screen and (max-width: 830px) {
    .lettre{
        font-size: 13vw;
    }

}