header {
    min-height: 20vh;
    border: 2px solid red;
    background: #5dc5b7;
    text-align:center;
}

nav, footer{
    display:flex;
    justify-content: space-around;
}
nav a{
    width: 20vw;
    padding-top: 1vh;
    height: 5vh;
    border: 1px solid black; 
    background: #acd1cc;
}
nav a:hover{
    background: #5378df;
}
.container{
    display:flex;
}
aside, main, footer {
    padding: 8px; 
    box-sizing:border-box;
    border: 1px solid black;
}
aside{
    width: 15vw;
    background: #43d87c;
}
.aside-link{margin: 5px}
.aside-link a{text-decoration: none}

main{
    width: 85vw;
    height: 75vh;
    overflow-y: auto;
    
}
.content, .content a{
    margin: 3px;
    padding: 3px;
    background: #e9ecff;
}
.content {
    color: black;
}
.content a{
    color: #3c15e9;
    text-decoration: none;
}
footer {
    min-height: 5vh;
    background: #0f0e33;
    color: #fff;
}
.error {
    color: red;
    font-weight: bold;
    font-size: 32px;
}
.author {
    color:blue;
    font-weight: bold;
    font-size: 32px;
}
.sheet .select{
    background-color: #bbeeaa;
}