aula

* {
    font-family: 'oswald', sans-serif;
    box-sizing: border-box;
}

body {
    height: 100vh;
    margin: 0px;
    display: grid;
    grid-template-rows: 120px 1fr 60px;
    grid-template-columns: 1fr;
    grid-template-areas:
    "cabecalho"
    "principal"
    "rodape";
}

.cabecalho{
    grid-area: cabecalho;
    background-color: blue;
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding-bottom: 10px;
    z-index: 1;
    box-shadow: 0px 4px 9px -2px rgba(0,0,0,0.75);
}

.cabecalho > h2 {
    margin: 0px;
    font-weight: 200;
    font-size: 1.6rem;
}

.principal{
    grid-area: rodape;
    height: calc(100vh - 180px);
    background-color: #f0f0f0;
    padding: 20px ;
}

.conteudo{
    position: relative;
    height: 100%;
    overflow-y: scroll;
    background-color: whitesmoke;
    padding: 20px;
    box-shadow: 0px 0px 25px 0px rgba(0,0,0,0.75)
}

.rodape{
    grid-area: rodape;
    background-color: #ffffff;
    display: flex ;
    justify-content: center; /*alinha no meio*/
    align-items: center;
    font-size: 1.2rem;
    padding-right: 20px;
    color: #444444;
    position: sticky;
    bottom: 0px,
}