.btn{
    background-color: #cea135;
    color: #11122b;
    font-size: 1.25em;
    padding: 10px 25px;
    border: 1px solid #cea135; 
    /* since many browser by default add ugly border so 
    we add border, with color equal to backgroud */
    border-radius: 2px;
    outline: none;
    transition: all 0.3s;
}

.center-button-wrapper{
    display: flex;
    justify-content: center;
}

.btn:active {
    box-shadow: 10px 10px 20px rgba(0,0,0,0.4);
}