[css] png 파일 이미지만 보이게 처리하기

    <!--Buttons-->
    <button class="btn">
      <img src="img/blue_t.png" alt="tshirt" class="imgBtn" />
    </button>
    <button class="btn">
      <img src="img/blue_p.png" alt="pants" class="imgBtn" />
    </button>
    <button class="btn">
      <img src="img/blue_s.png" alt="skirt" class="imgBtn" />
    </button>
    <button class="btn colorBtn blue">Blue</button>
    <button class="btn colorBtn yellow">Yellow</button>
    <button class="btn colorBtn pink">Pink</button>

 

.btn {
  background-color: transparent !important;
  border: none !important;
  outline: none !important;
  cursor: pointer !important;
}