:root {
    --lightgray: #EEE;
    --darkgray: #AAA;
    --lightgreen: #EFED;
    --darkgreen: #060;
    --lightred: #FEE;
    --darkred: #A00;
    --lightblue: #EEF;
    --darkblue: #00A;
    --border: none;
    --radius: 1rem;
    --shadow: 0 0 4px var(--darkgray);
}

body {
    font-family: helvetica, arial, sans-serif;
    background-color: var(--lightgray);
    color: black;
    padding: 0;
    margin: 0;
    min-height: 100svh;
    display: flex;
    flex-direction: column;
    line-height: 1.5;
}

header, main, footer, #button-bar, #status {
    max-width: 40rem;
    margin: auto;
    width: calc(100% - 2rem);
    padding: 0 1rem;
}

header, footer {
    background-color: var(--lightblue);
    padding: 1rem;
    display: flex;
    flex-grow: 0;
}

header {
    justify-content: flex-end;
}

footer {
    justify-content: center;
}

main {
    background-color: white;
    padding: 1rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

dt {
    font-weight: bold;
    padding: 1rem 1rem 0.25rem;
}

#status {
    text-align:right;
    background-color: white;
    color: var(--darkgray);
    padding: 0 1rem;
}

/*** Cards ***/

fc-card {
    display: none;
    margin: 1rem;
    border: var(--border);
    padding: 1rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

@media (max-width: 30rem) {
    fc-card {
        margin: 1rem 0;
    }
}

fc-card.show {
    display: block;
}

fc-redact {
    background-color: var(--lightgray);
    color: var(--lightgray);
}

fc-card.reveal fc-redact {
    background-color: white;
    color: var(--darkgreen);
}

/*** Buttons ***/

button {
    padding: 1rem;
    width: 10rem;
    border: var(--border);
    border-radius: calc(var(--radius) / 2);
    background-color: var(--lightgray);
    box-shadow: var(--shadow);
    font-size: 1rem;
    color: black;
}

#button-bar {
    display: flex;
    justify-content: center;
    gap: 1rem;
    background-color: white;
    padding: 1rem;
}

#correct {
    background-color: var(--lightgreen);
}

#incorrect {
    background-color: var(--lightred);
}

button.hidden {
    display: none;
}

/*** Dialogs ***/

.dialog-button-bar {
    margin-top: 3rem;
    display:flex;
    justify-content: center;
}

dialog {
    padding: 2rem 1rem;
    text-align: center;
    border: var(--border);
    border-radius: var(--radius);
    max-width: calc(100% - 2rem);
    box-shadow: var(--shadow);
}

dialog::backdrop {
    background-color: var(--lightblue);
}

/*** Index ***/
main.index h1 {
    margin: 4rem;
    text-align: center;
}

main.index ol {
    width: 15rem;
    margin: auto;
    line-height: 2;
}

main.index {
    display: block;
}

/* counters */

#status__correct {
    color: var(--darkgreen);
}

#status__incorrect {
    color: var(--darkred);
}

/* version */

.version {
    color: var(--darkgray);
    text-align: right;
}

@media print {
    fc-card {
        break-after: page;
        box-shadow: none;
        border: 1px solid var(--darkgreen);
    }

    fc-redact {
        background-color: white;
        color: var(--darkgreen);

    }

    header {
        display: none;
    }
}