CSS TextBox Design

.txt{
    background: rgb(239 228 228 / 50%);
    border: 4px solid rgba(255,255,255,1);
    border-radius: 10px;
    position: relative;
    display: block;
    outline: none;
    width: 500px;
    height: 40p;
    top: 10px;
    margin: 0 auto;
    padding: 10px;
    color: #716565;
    -webkit-box-shadow: 0 2px 10px 1px rgba(0,0,0,0.4);
    box-shadow: 0 0px 10px 1px rgba(0,0,0,0.3);
    font-size: 20px;
}