style.css

* {
    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: #1867c0;
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding-bottom: 10px;
    -webkit-box-shadow: 5px 5px 15px 5px rgba(0,0,0,0.69); 
    box-shadow: 5px 5px 15px 5px rgba(0,0,0,0.69);
}

.cabecalho > h1 {
    margin: 0px;
    font-weight: 300;
    font-size: 2.8rem;
}

.cabecalho > h2 {
    margin: 0px;
    font-weight: 200;
    font-size: 1.6rem;
}
.principal {
    grid-area: principal;
    height: calc(100vh - 180px);
    background-color: #f0f0f0;
    padding: 20px;
}

.conteudo {
    position: relative;
    height: 100%;
    overflow-y: scroll;
    background-color: #fff;
    padding: 20px;
    box-shadow: 0px 0px 25px 0px rgba(0,0,0,0.2);
}

.rodape {
    grid-area: rodape;
    background-color: #fff;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    font-size: 1.2rem;
    padding-right: 20px;
    color: #444;
    position: sticky;

}