:root {
    --paper: #f6f1e8;
    --ink: #171717;
    --muted: #6b6257;
    --line: #d8cdbd;
    --accent: #0b6bcb;
    --wrong: #b3261e;
    --right: #137333;
}

* {
    box-sizing: border-box;
}

html,
body {
    min-height: 100%;
    margin: 0;
}

body {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--paper);
    color: var(--ink);
    font-family:
        ui-sans-serif,
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;
}

.flashcards {
    width: min(960px, 100vw);
    min-height: 100vh;
    display: grid;
    grid-template-rows: auto 1fr auto;
    gap: 20px;
    padding: 24px;
}

.scoreboard {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.scoreboard > div {
    min-width: 128px;
    border: 1px solid var(--line);
    background: #fffaf2;
    padding: 12px 16px;
}

.score-label {
    display: block;
    color: var(--muted);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0;
    text-transform: uppercase;
}

.scoreboard strong {
    display: block;
    margin-top: 2px;
    font-size: clamp(1.9rem, 6vw, 3.1rem);
    line-height: 1;
}

.staff-panel {
    display: grid;
    align-items: center;
}

#staff-canvas {
    width: 100%;
    aspect-ratio: 5 / 3.4;
    display: block;
    border: 1px solid var(--line);
    background: #fffdf8;
}

.answer-panel {
    display: grid;
    gap: 12px;
}

.answer-buttons {
    display: grid;
    grid-template-columns: repeat(7, minmax(0, 1fr));
    gap: 8px;
}

.answer-buttons button {
    min-height: 64px;
    border: 2px solid var(--ink);
    background: #ffffff;
    color: var(--ink);
    font: inherit;
    font-size: clamp(1.4rem, 5vw, 2.2rem);
    font-weight: 800;
    cursor: pointer;
}

.answer-buttons button:hover,
.answer-buttons button:focus-visible {
    border-color: var(--accent);
    color: var(--accent);
    outline: none;
}

.answer-buttons button.correct {
    border-color: var(--right);
    background: #e7f4e8;
    color: var(--right);
}

.answer-buttons button.incorrect {
    border-color: var(--wrong);
    background: #fbe9e7;
    color: var(--wrong);
}

.feedback {
    min-height: 1.5em;
    margin: 0;
    color: var(--muted);
    text-align: center;
    font-size: 1rem;
    font-weight: 650;
}

.feedback.right {
    color: var(--right);
}

.feedback.wrong {
    color: var(--wrong);
}

@media (max-width: 560px) {
    body {
        align-items: stretch;
    }

    .flashcards {
        gap: 14px;
        padding: 14px;
    }

    .scoreboard > div {
        min-width: 0;
        flex: 1;
    }

    #staff-canvas {
        aspect-ratio: 3 / 4;
    }

    .answer-buttons {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
}