.gallerie_blog img{
    margin: 1vw;
    height:8vw;
    flex:1 ;
    object-fit: contain;
}

.gallerie_blog{
    display: flex;
    position: relative;
    height: 10vw;
}

.grayed{
    filter: grayscale(0.9);
    transition: filter 1s, height 1s;
}

.grayed:hover{
    filter: grayscale(0);
    height:10vw;
}

.hidden_text{
    display: none;
    visibility: hidden;
    opacity: 0;
    transition: opacity 1s;
    display: block;
    position: absolute;
    top : 10vw;
    left:0;
    right:0;
}

.grayed:hover + .hidden_text{
    visibility: visible;
    opacity: 1;
}

#hidden_text_placeholder{
    position: absolute;
    top : 10vw;
    left:0;
    right:0;
    opacity: 1;
    transition: opacity 1s;

}

.gallerie_blog:hover #hidden_text_placeholder{
    opacity: 0;
}