*{
    box-sizing: border-box;
}

.a {
    background-color: aquamarine;
    border: solid 2px black;
    height: 30vh;
}

.B{
    background: aquamarine;
    border: solid 2px black;
    min-height: 200px;
    font-size: 80px;

    display: flex;
    flex-direction: column;
    justify-content: center;

}

.a img{
    max-width: 100%;
    height: auto;
}