body {
    max-width: 800px;
    width: 90%;
    margin: 0 auto;
}

@media (min-width: 640px) {
    body {
        background-color: #eaf6ff;
    }
}

h1 {
    font-size: 1.5rem;
}
@media (min-width: 640px) {
    h1 {
        font-size: 2.5rem;
    }
}

#first-container {
    display: flex;
    flex-wrap: wrap;
    list-style: none;
    padding-left: 0;
}

#first-container aside {
    width: 170px;
    margin: 10px;
    font-size: 0.8rem;
}

#second-container {
    display: flex;
    flex-wrap: wrap;
    list-style: none;
    padding-left: 0;
    margin: -10px 1rem -10px 1rem;
}

#second-container li {
    width: 100%;
}

#second-container aside {
    margin: 10px;
}