#timer {
    text-align: center;
    font: bold 2em Arial;
    color: crimson;
}
table {
    margin: 0 auto;
    border-collapse: collapse;
    filter: drop-shadow(0 0 1rem crimson);
}
tr,td {
    text-align: center;
    width: 100px; 
    height: 100px;
    border: 1px solid #aaa;
}
td { transition: 1s }
.one, .two, .three, .four {
    color: red;
    font: bold 1.5em Arial;
}
div { text-align: center }
#reset {
    margin: 0 auto;
    background: black;
    border: none;
    width: 150px;
    height: 50px;
    font: bold 1em Arial;
    border-radius: 20px;
    color: orange;
}