:(

<div class="containerSearch">
        <input type="text" placeholder="Search Posts" class="filterPosts"/>

        <ul class="postsList">

        </ul>


        <div class="closeSearchContainer">
          <div class="closeSearch"></div>
        </div>

      </div>


 .containerSearch {
   position: relative;
 }

 .filterPosts {
   width: 0%;
   position: relative;
   float: right;
   transition: width 0.3s;
   transform: translateX(20%);
   border: none;
   box-sizing: border-box;
   padding-bottom: 100%;
   padding: 1% 1.5% 1% 2.5%;
   background: transparent;
   font-family: monospace;
 }

 .filterPosts:focus {
   outline: none;
 }

 .onInput {
   width: 100%;
   transition: width 0.3s;
   transform: translateX(0%);
 }

 .postsList {
   background: #F9F9FF;
   list-style: none;
   position: absolute;
   width: 100%;
   height: 0%;
   transition: height 0.2s;
   overflow: scroll;
   padding: 0%;
   box-sizing: border-box;
   border-bottom-left-radius: 15px;
   border-bottom-right-radius: 15px;
   top: 100%;
   box-shadow: 0px 2px 5px rgba(0,0,0,.2);
 }

 .postsList li {
   text-align: left;
   box-shadow: 0 0 1px rgba(0,0,0,.1) inset;
   padding: 3.5% 2% 3.5% 6%;
 }

 .postsList li:nth-child(odd) {
   background: #F1F1F7;
 }

 .postsList li:nth-child(even) {
   background: #F2F2FF;
 }

 .postsList li:last-child {
   border-bottom-left-radius: 15px;
   border-bottom-right-radius: 15px;
 }

 .postsList li a {
   text-decoration: none;
   color: #323232;
   font-family: monospace;
   font-weight: bold;
 }

 .onList {
   height: auto;
   transition: height 1s;
   top: 100%;
   padding: 2%;
 }

.closeSearchContainer {
  background: #F9F9FF;
  box-shadow: 0px 2px 5px rgba(0,0,0,.2);
  padding: 2% 7% 2% 7%;
  position: absolute;
  top: 100%;
  right: 0%;
  opacity: 0;
  z-index: 5;
  transition: opacity 0.2s;
  border-bottom-left-radius: 15px;
  border-bottom-right-radius: 15px;
}

.closeActive {
  opacity: 1;
  transition: opacity 1.4s;
}

.closeSearch {
  width: 2.5px;
  height: 20px;
  background: black;
  transform: rotateZ(40deg);
  border-radius: 50px;
}

.closeSearch::before {
  content: '';
  width: 2.5px;
  height: 20px;
  background: black;
  position: absolute;
  transform: rotateZ(-80deg);
  border-radius: 50px;
}