* {box-sizing: border-box}


/* Style tab links */
.parent {
  background-color: #555;
  color: white;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  font-size: 17px;
  width: 25%;
}

/* Style the tab content (and add height:100% for full page content) */
.categories {
  color: white;
  display: none;
  padding: 100px 20px;
  width: 100%;
}
.posts , .postz {
  color: white;
  display: none;
  padding: 100px 20px;
  width: 30%; 
  float :left;
}