*{
    box-sizing: border-box;
}

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

#contenedor{
    width: 50%;
    height: 400px;
    margin: 20px auto;
    background-color: grey;
    border: 5px solid black;
    padding: 10px;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

#titulo {
    width: 100%;
    height: 100px;
    font-size: 50px;
    border-bottom: 10px double black;
    text-align: center;
    background-color: cadetblue;
}

#bloque1{
    width: 32%;
    height: 150px;
    background-color: yellow;

}

#bloque2{
    width: 32%;
    height: 150px;
    background-color: green;
    text-align: center;
}

#bloque3{
    width: 32%;
    height: 150px;
    background-color: red;
    text-align: right;
}