*{
    box-sizing: border-box;
}

body{
    background-image: url("../img/pattern.gif");
}

.padre{
    width: 80%;
    height: 400px;
    margin: 20px auto;
    border: 5px solid black;
    background-color: darkgray;
    padding: 1%;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}
h1{
    width: 100%;
    background-color: lightgray;
    text-align: center;
    padding: 1%;
    border-bottom: 4px double black;
}

.uno{
    width: 32%;
    height: 220px;
    padding: 16px;
    background-color: aquamarine;
}
.dos{
    width: 32%;
    height: 220px;
    padding: 16px;
    background-color: rgb(99, 181, 236);
    text-align: center;
}
.tres{
    width: 32%;
    height: 220px;
    padding: 16px;
    background-color: rgb(189, 30, 91);
    text-align: right;
}