body{ } button{ padding: 10px; border-radius: 10px; color: black; background-color:yellowgreen ; transition: duration 4s; border: #000 outset; } button:hover{ background-color: deeppink; color: white; } .container { display: flex; align-items: center; justify-content: center; height: 100vh; width: 100vw; } .container{ height: 33%; width: 50%; }