Как заполнить пустое место на сайте другим блоком css html

 @import "font-awesome/css/all.css"; 
@import "font-awesome/css/fontawesome.min.css"; 
 
* { 
    margin: 0; 
    box-sizing: border-box; 
 } 
 body { 
    background: #39383F; 
    font-family: 'Montserrat Alternates', sans-serif; 
 } 
 .post-wrap { 
    max-width: 1120px; 
    margin: 0 0; 
    display: flex; 
    justify-content: space-between; 
    align-items: stretch; 
    flex-wrap: wrap; 
 } 
 .post-item { 
    padding: 15px; 
    cursor: pointer; 
 } 
 .post-item * { 
    transition: .3s linear; 
 } 
 .item-content { 
    background: #413D4C; 
    padding: 40px; 
 } 
 .item-icon { 
    margin-bottom: 20px; 
    font-family: FontAwesome; 
 } 
 .item-icon:before { 
    content: ""; 
    font-family: FontAwesome; 
    color: #F09EA3; 
    font-size: 50px; 
    line-height: 1; 
 } 
 .item-icon.photo:before { 
    content: "\f030"; 
 } 
 .item-icon.car:before { 
   content: "\f1b9"; 
} 
 .item-icon.video:before { 
    content: "\f03d"; 
 } 
 .item-icon.gift:before { 
    content: "\f06b"; 
 } 
 .item-icon.group:before { 
    content: "\f0c0"; 
 } 
 .item-icon.tree:before { 
    content: "\f1bb"; 
 } 
 .item-icon.anchor:before { 
    content: "\f13d"; 
 } 
 .post-item:hover .item-icon, .post-item:hover .item-body h3, .post-item:hover .item-body p { 
    transform: translateY(-8px); 
 } 
 .item-body { 
    color: #F5E2CD; 
    font-size: 14px; 
 } 
 .item-body h3 { 
    font-weight: 500; 
    margin-bottom: 15px; 
    transition-delay: .05s; 
 } 
 .item-body p { 
    transition-delay: .1s; 
 } 
 .item-footer { 
    padding-top: 15px; 
 } 
 .link { 
    text-decoration: none; 
    display: inline-block; 
    overflow: hidden; 
    position: relative; 
    padding-right: 30px; 
    font-size: 12px; 
    text-transform: uppercase; 
    font-weight: 600; 
    color: #F5E2CD; 
 } 
 .link:before { 
    content: ""; 
    position: absolute; 
    top: 0; 
    left: 0; 
    width: 100%; 
    bottom: 0; 
    height: .125rem; 
    margin: auto; 
    background: #F09EA3; 
    transform: scaleX(.2); 
    transform-origin: left center; 
    z-index: 0; 
    transition: .6s cubic-bezier(.6, .01, 0, 1); 
 } 
 .link span { 
    display: inline-block; 
    position: relative; 
    transform: translateX(-200%); 
    transition: .6s cubic-bezier(.6, .01, 0, 1); 
 } 
 .post-item:hover .link span { 
    transform: translateX(0%); 
 } 
 .post-item:hover .link:before { 
    transform-origin: right center; 
 } 
 @media (min-width: 768px) { 
    .post-item { 
       flex-basis: 1000%; 
       flex-shrink: 0; 
    } 
 } 
 @media (min-width: 960px) { 
    .post-item { 
       flex-basis: 33%; 
    } 
 }