This article from DiviBooster has helped me resizing the image size. Following is the modified copy of the CSS with the values which I have used in my website.
.et_pb_fullwidth_header { padding: 0 !important; } #copyright{ visibility: hidden; }
/* Set the image widths */ .et_pb_gallery_grid .et_pb_gallery_item, .et_pb_gallery_grid .column_width, .et_pb_gallery_grid .et_pb_gallery_image, .et_pb_gallery_grid .et_pb_gallery_image.portrait img { width: 330px !important; } .et_pb_gallery_grid .et_pb_gallery_image img { min-width: 330px; }
/* Set the spacing between images */ .et_pb_gallery_grid .gutter_width { width: 25px; } .et_pb_gallery_grid .et_pb_gallery_item { margin-bottom:25px !important; } /*——————————————-*/ .et_pb_gallery_grid .et_pb_gallery_item { clear:none !important; } .et_pb_gallery_grid .et_pb_gallery_item:nth-child(3n) { margin-right:0 !important; } .et_pb_gallery_grid .et_pb_gallery_item:nth-child(3n+1) { clear:both !important; } .et_pb_gallery_grid .et_pb_gallery_item { margin-right:24px !important; } .et_pb_gallery_grid .et_pb_gallery_image img { min-height: 0 !important; } .et_pb_gallery_grid .et_pb_gallery_image, .et_pb_gallery_grid .et_pb_gallery_image.landscape img { height: auto !important; }