<div class="icon">👍🏽</div>

.icon {
  background: linear-gradient( #d6ff7f, #003bcc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: 
    drop-shadow(0px -1px 0 black) 
    drop-shadow(1px -1px 0 black) 
    drop-shadow(-1px 0 0 black) 
    drop-shadow(1px 0 0 black) 
    drop-shadow(-1px 1px 0 black) 
    drop-shadow(0 1px 0 black) 
    drop-shadow(1px 1px 0 black) 
 }

body {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  margin: 0;
}