* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    height: 100vh;
    background-color: bisque;
}

header, aside {
    background-color: #ffffff30;
    border: 1px solid #8080805e;
}

header {
    position: absolute;
    left: 200px;
    width: calc(100% - 220px);
}

aside {
    position: absolute;
    top: 200px;
    width: 200px;
    height: calc(100% - 400px);
}

h4 {
    padding-bottom: 30px;
}

li {
    position: relative;
    display: inline-block;
    width: 100%;
    list-style: none;
}

.landscape > menu > li {
    width: auto;
}

li > span {
    display: inline-block;
    width: 100%;
    height: 100%;
    padding: 3px;
    cursor: pointer;
}

menu menu {
    position: absolute;
    opacity: 0;
    visibility: hidden;
    transform: scale(0);
    transform-origin: left top;
    transition: all 250ms linear;
}


.landscape menu menu {
    left: 5px;
    width: 130px;
    background-color: whitesmoke;
    border: 1px solid gray;
}

.portrait menu menu {
    left: 90%;
    top: 5px;
    width: 200px;
    background-color: whitesmoke;
    border: 1px solid gray;
}

li:hover > span {
    background-color: goldenrod;
}

li:hover > menu {
    opacity: 1;
    visibility: visible;
    transform: scale(1);
}