Haga lo que hicimos

Adjunto lo realizado en CSS

body{
    background: #4B79A1;  /* fallback for old browsers */
    background: -webkit-linear-gradient(to right, #283E51, #4B79A1);  /* Chrome 10-25, Safari 5.1-6 */
    background: linear-gradient(to right, #283E51, #4B79A1); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
    color: #ffff;
    margin: 0; 
    padding: 0; 
    box-sizing: border-box; 
}

p{
    margin: 20px; 
    padding: 10px; 
    border: 2px solid black; 
}

strong{
    color: #22D4FD;
}

.texto-destacado{
    font-weight: 700;
    text-align: center;
    font-size: 24px;
    color: #47b17c;
}

.titulo-blog{
    color: #45ca3f;
    text-transform: uppercase;
}

.urgente{
    color: #dc0000;
    font-weight: bold;
}

.cuadro{
    margin: auto;
    border: 2px solid black;
    padding: 20px;
    background-color: lightblue;
}