p {
    display: inline-block;
    line-height: 1em;
}

.fecha {
    font-family: Arial;
    text-align: center;
    font-size: 1.5em;
    margin-bottom: 0.3125rem;
    /*margin-bottom: 5px;*/
    background: rgba(255, 53, 53, 0.5);
    padding: 20px;
    width: 100%;

}

.reloj {
    font-family: Arial;
    width: 100%;
    padding: 20px;
    font-size: 4em;
    text-align: center;
    background: rgba(255, 53, 53, 0.5);

}

.caja_segundos {
    display: inline-block;
}