.btn {

    width: 150px;
    height: 150px;

    display: inline-flex;
    background: grey;
    
    margin: 50px 50px;

    transition: width 0.5s ease-in-out,
    width 0.5s ease-in-out 0.5s;

    font-family: monospace;
    font-weight: 700;
    padding: 0;
    display: inline-block;
    line-height: 150px;
    text-align: center;

}

#btn1:hover {

    cursor: pointer;
    background: indianred;

}

#btn2:hover {

    background: hwb(30 25% 20%);
    cursor: pointer;
    width: 200px;
    transform: rotate(180deg);
}

#btn3:hover {
    
    width:100x;
    height:100px;
    
    background :rgb(255, 176, 222);
    border-radius:50%;
    transition:all 01s ease-in-out;
}


#btn4:hover {

    background: rgb(137, 212, 255);
    -webkit-transform: scale(1.3);
    -ms-transform: scale(1.3);
    transform: scale(1.3);
    transition:all 01s ease-in-out;
}


#btn5:hover {

    background: rgb(174, 255, 137);
    border: 3px dotted rgb(255, 137, 137);
    transition:0.5s ease-in;
}