Thanks, it’s working :-)

1. It’s working but only for 3 columns, if I put less or more columns it’s not working anymore :-(

2. For the image overlay do I have to put .image-overlay {display: none !important;} only ?

3. How add an effect on the image as the masonry example ?

Thanks a lot !

PS : here is my custom css for masonry & post slider
/* ————————MANSONRY———————— */
/* Modifier la taille et le style du texte dans masonry */
#top #main .av-masonry-entry .av-masonry-entry-title.entry-title {font-size:20px; color:#009da5; font-weight:400;}

/* Modifier le texte du filtre masonry */
#top div.container .av-masonry .av-masonry-sort {font-size:20px; text-align:left; text-transform:uppercase; font-family:’Oswald’;}

/* Cacher la date dans masonry */
#top span.av-masonry-date { display: none; }

/* Ajoute une ombre aux vignettes dans masonry */
#top .av-inner-masonry {box-shadow: 0 0 10px rgba(0,0,0,0.1);}

/* ————————Post Slider———————— */

/* personnalise les fleches de deplacement du slider */
.avia-slideshow-arrows a::before {border-radius: 0px;}

/* Cacher la date */
.avia-content-slider .slide-meta .slide-meta-time {display: none;}

/* Cacher les separator */
.avia-content-slider .slide-meta .slide-meta-del {display: none;border:none;}
.html_elegant-blog .avia-content-slider .slide-meta {display: none;border:none;}

/* Cacher les Meta area */
.html_elegant-blog #top .post-entry .blog-categories {display: none;}

/* marge du texte des vignettes */
#top .avia-content-slider {padding:0 10px;}
#top .avia-content-slider article.slide-entry {margin-bottom:40px;}

#top .avia-content-slider .slide-content {padding: 30px 20px;}

/* personalisation du titre h3 */
.html_elegant-blog .avia-content-slider .slide-entry-title {text-align:left;letter-spacing: 0px;font-size:20px; color:#009da5; font-weight:400;}

/* Ajoute un fond et une ombre aux vignettes */
#top .avia-content-slider article.slide-entry {box-shadow: 0 0 10px rgba(0,0,0,0.1);background: #F8F8F8;}
.avia-content-slider .slide-image img {border-radius: 0px;}
.avia-content-slider .slide-image {border-radius: 0px;}

/* Text area */
#top .avia-content-slider .slide-content {padding:30px 20px;margin-top:-10px;}