body {
    font-family: Arial;
    margin: 0;
    padding: 0;
}

.header {
    background-color: grey;
    color: white;
    text-align: center;
    padding: 10px;
    height: 10vh;
}

.menu {
    float: left;
    min-width: 200px;
    background-color: lightgrey;
    padding: 20px;
    height: 80vh;
    overflow: auto;
}

.menu ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.menu li {
    margin: 10px 0;
}

.menu a {
    text-decoration: none;
    color: #333;
    display: block;
    padding: 5px;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.menu a:hover {
    background-color: #ddd;
}

.main {
    float: left;
    width: calc(70% - 270px); /* 270 = 200 + 30 + 40*/
    background-color: black;
    padding: 15px;
    height: 80vh;
    overflow: auto;
}

aside {
    float: right;
    width: calc(30% - 30px);/* 30 = 15 + 15*/
    background-color: lightsteelblue;
    padding: 15px;
    height: 80vh;
    overflow: auto;
}
.image{
    width: 200px ;
    height: auto;
    display: block;
    margin: 0 auto;
}
.item {
    margin: 10px 0;
    padding: 10px;
    background-color: #e8e8e8;
}

.image {
    max-width: 100%;
    width: 200px;
    height: auto;
    display: block;
    margin: 0 auto;
}

footer {
    background-color: lightslategrey;
    color: white;
    text-align: center;
    padding: 20px;
    width: 100%;
    float: right;
}

@media (max-width: 1000px) {
    .menu, .main, aside {
        float: none;
        width: auto;
        height: auto;
        padding: 15px;
    }
    .image {
        width: 100%;
    }
}