body {
    margin: 0;
    padding: 0;
    font-family: Roboto, 'Open Sans', Arial, Helvetica, sans-serif;
    --header-bg-color: #d0e0ff;
    --correct-bg-color: #e0ffd0;
    --incorrect-bg-color: #ffe0d0;
}

button, input {
    font-size: 1em;
}

button, input[type="submit"] {
    padding: 0.5em;
}

.row {
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-self: stretch;
    gap: 0.5em;
}

.text-row {
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: baseline;
    align-self: stretch;
    gap: 0.5em;
}

.column {
    display: flex;
    flex-direction: column;
    align-self: stretch;
    justify-content: center;
    align-items: center;
    gap: 0.5em;
}

.page {
    flex-grow: 1;
}

.header, .page {
    padding: 1em;
}

.header {
    background-color: var(--header-bg-color);
}

#logged_in_header { justify-content: space-between; }
#header_username { font-weight: bold; cursor: pointer; }

#login_page, #register_page { max-width: 40em; }
#login_form { max-width: 20em; margin: 0 auto; }
#register_form { max-width: 25em; margin: 0 auto; }

form label { flex-grow: 1; }
.error_message { color: red; }

#attempt_board { position: relative; }
#attempt_board canvas { z-index: 0; }
#result_container {
    position: absolute;
    left: 20%;
    right: 20%;
    top: 40%;
    bottom: 40%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1;
    border: 0.5em solid white;
}

#result_container.correct { background-color: var(--correct-bg-color); }
#result_container:not(.correct) { background-color: var(--incorrect-bg-color);}
#review_buttons { justify-content: center; }