.bloc_index_title {
    font-size: 36px;
    color: #FFF;
    text-transform: uppercase;
    font-weight: bold;
    letter-spacing: 2px;
    line-height: 36px;
    position: relative;
    padding-bottom: 10px;
}
.bloc_index_title.red {
    color: #cd2129;
    display: table;
    margin: 0 auto;
}
.bloc_index_title:after {
    position: absolute;
    content: "";
    background: #FFF;
    width: 80px;
    height: 5px;
    bottom: 0;
    left: 0;
}
.bloc_index_title.red:after {
    background: #cd2129;
}

.principal_banner_wrapper {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
}
.page_index_wrapper {
    position: relative;
    z-index: 99;
    margin-top: 100vh;
    background: #FFF;
}

@media (max-width: 767px) {
.principal_banner_wrapper {
    height: 400px;
}
.page_index_wrapper {
    margin-top: 400px;
}
.bloc_index_title {
    font-size: 28px;
    padding: 10px;
}
}

@media (max-width: 425px) {
.principal_banner_wrapper {
    height: 300px;
}
.page_index_wrapper {
    margin-top: 300px;
}
.bloc_index_title {
    font-size: 20px;
    padding: 10px;
}
}