html, body {
    margin: 0;
    padding: 0;
}
@keyframes buttonhover {
    0%  {
        border-radius: 0;
        font-size: small;
    }
    100% {
        border-radius: 50%;
        font-size: large;
    }
}
@keyframes buttonunhover {
    0%  {
        border-radius: 50%;
        font-size: large;
    }
    100% {
        border-radius: 0;
        font-size: small;
    }
}
header {
    display: flex;
    flex-direction: row;
    background-color: rgb(166, 166, 166);
}
header h1 {
    margin-left: 20px;
}

header button {
    font-size: small;
    width: 50px;
    height: 50px;
    margin-top: 15px;
    margin-left: 10px;
    border: none;
    background-color: rgb(255, 255, 255);
}
header button:hover {
    border-radius: 0;
    animation-name: buttonhover;
    animation-duration: 250ms;
    font-size: large;
    border-radius: 50%;
}
header button:not(:hover) {
    animation-name: buttonunhover;
    animation-duration: 250ms;
    font-size: small;
}
header button:active {
    background-color: rgb(235, 235, 235);
}
main {
    width: 90%;
    height: 90vh;
    padding: 10px;
}
aside {
    width: 20%;
    height: 90vh;
    background-color: rgb(210, 210, 210);
}
aside h3 {
    margin: 0;
}
header nav {
    margin-left: 10px;
    height: 100%;
    width: auto;
    padding: 25px;
}

header nav a {
    margin-left: 5px;
    margin-right: 5px;
    text-decoration: none;
    font-size: large;
    color: black;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

#am {
    width: 100%;
    height: 90vh;
    display: flex;
    flex-direction: row;
}