main.css

@import url('https://fonts.googleapis.com/css2?family=Poppins&display=swap');

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
body{
    font-family: 'Poppins';
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
}

.content {
    background: rgb(22 22 22 / 30%);
    padding: 2rem;
    box-shadow: 5px 5px 10px 0px rgb(22 22 22 / 70%);
    border-radius: 5px;
    height: 80vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 2px;
}
  
#change_bg {
    cursor: pointer;
    outline: none;
    border: 1px solid #161616;
    padding: 10px 20px;
    color: #161616;
    background: transparent;
    font-family: 'Poppins';
}
button#change_bg:hover {
    background: #161616;
    color: #fff;
    transition: .7s;
}