#box {
  width: 200px;
  height: 200px;
  background-color: red;
  position: absolute;
  text-align: center;
  font-size: 2.3rem;
  font-weight: bold;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 2px 2px 2px black;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background: linear-gradient(45deg, #f3ec78, #af4261);
  overflow: hidden;
}

/* Responsive Design */
@media (max-width: 600px) {
  #box {
    width: 150px;
    height: 150px;
    font-size: 1.8rem;
  }
}

@media (max-width: 400px) {
  #box {
    width: 100px;
    height: 100px;
    font-size: 1.5rem;
  }
}