body {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: flex-start;
    background-color: lightgrey;
}
.header-main {
    width: 100%;
    text-align: center;
    margin: 20px 0;
}
.image-container {
    width: 50%;
    text-align: center;
    padding: 10px;
    box-sizing: border-box;
}
.image-container img {
    width: auto;
    height: 800px;
}