<div class="menu-btn">
   <div></div>
</div>

.menu-btn {
  width: 60px;
  height: 60px;
  background: #8d99ae;
  
  display: flex;
  align-items: center;
  justify-content: center;
  
  cursor: pointer;
  transition: all 0.5s ease;

  div {
    width: 80%;
    height: 3px;
    border-radius: 2px;
    background: #fff;
    
    position: relative;
    transition: all 0.5s ease;

    &::before,
    &::after {
      content: "";
      position: absolute;
      
      width: 50%;
      height: 3px;
      border-radius: 2px;
      background: #fff;
      
      transition: all 0.5s ease;
      transform-origin: center;
    }

    &::before {
      top: -15px;
    }

    &::after {
      top: 15px;
      right: 0;
    }
  }
}

.close {
    background: #d1345b;
  div {
    transform: rotate(225deg);

    &::before {
      transform: rotate(90deg);
      width: 100%;
      top: 0px;
    }

    &::after {
      opacity: 0
    }
  }
}


body {
  padding: 0;
  margin: 0;
  background: #2b2d42;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

const menuBtn = document.querySelector(".menu-btn");

const addRemoveClass = (className) => {
  if(menuBtn.classList.contains(className)){
    menuBtn.classList.remove(className);
  } else {
    menuBtn.classList.add(className);
  }
};

menuBtn.addEventListener("click", () => addRemoveClass('close'));