/* ================= FLASHCARDS ================= */
.deck-selector {
    display: flex;
    gap: 0;
    flex-wrap: wrap;
    margin-bottom: 32px;
    border-bottom: 1px solid var(--border);
}

.deck-chip {
    padding: 12px 18px;
    border: none;
    border-bottom: 2px solid transparent;
    background: none;
    cursor: pointer;
    font-weight: 700;
    font-size: .85rem;
    color: var(--text-muted);
    font-family: 'Public Sans', sans-serif;
    margin-bottom: -1px;
}

.deck-chip.active {
    color: var(--text);
    border-bottom-color: var(--accent);
}

/* a deck with no authored cards — generated from key point records */
.deck-chip.derived {
    display: inline-flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 1px;
    text-align: left;
}

.deck-chip .chip-note {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .58rem;
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: .06em;
    color: var(--text-muted);
}

.flash-stage {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.flash-fullscreen-toggle {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    align-self: flex-end;
    margin-bottom: 10px;
    padding: 7px 12px;
    border: 1.5px solid var(--border);
    border-radius: 2px;
    background: var(--bg-raised);
    color: var(--text-muted);
    font-family: 'IBM Plex Mono', monospace;
    font-size: .68rem;
    text-transform: uppercase;
    letter-spacing: .06em;
    cursor: pointer;
}

.flash-fullscreen-toggle:hover {
    border-color: var(--border-strong);
    color: var(--text);
}

.flash-fullscreen-toggle .ic-collapse {
    display: none;
}

/* ---- full-screen study mode ---- */
.flash-stage.fullscreen {
    position: fixed;
    inset: 0;
    z-index: 200;
    justify-content: center;
    background: var(--bg);
    padding: 32px 24px;
    overflow-y: auto;
}

.flash-stage.fullscreen .flash-fullscreen-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    margin-bottom: 0;
}

.flash-stage.fullscreen .flash-fullscreen-toggle .ic-expand {
    display: none;
}

.flash-stage.fullscreen .flash-fullscreen-toggle .ic-collapse {
    display: block;
}

.flash-stage.fullscreen .flashcard {
    max-width: 640px;
    height: min(60vh, 420px);
}

.flash-stage.fullscreen .flashcard-face h3 {
    font-size: 2.1rem;
}

.flash-stage.fullscreen .flashcard-face.back p {
    font-size: 1.15rem !important;
}

body.flash-fullscreen-lock {
    overflow: hidden;
}

.flashcard {
    width: 100%;
    max-width: 460px;
    height: 280px;
    perspective: 1300px;
    cursor: pointer;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform .5s;
    transform-style: preserve-3d;
}

.flashcard.flipped .flashcard-inner {
    transform: rotateY(180deg);
}

.flashcard-face {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    border-radius: 4px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 32px 28px;
    border: 1.5px solid var(--text);
    box-shadow: var(--shadow);
    background: var(--bg-raised);
}

.flashcard-face::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: var(--accent);
}

.flashcard-face .punch {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 34px;
}

.flashcard-face .punch span {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--bg);
    border: 1px solid var(--border-strong);
}

.flashcard-face.back {
    transform: rotateY(180deg);
}

.flashcard-face .flip-hint {
    position: absolute;
    bottom: 14px;
    font-size: .68rem;
    color: var(--text-muted);
    font-family: 'IBM Plex Mono', monospace;
    text-transform: uppercase;
    letter-spacing: .04em;
}

.flashcard-face .f-kicker {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .66rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: .08em;
    margin-bottom: 10px;
}

.flashcard-face h3 {
    font-size: 1.55rem;
    margin-bottom: 0;
}

.flash-progress {
    margin: 20px 0 8px;
    font-family: 'IBM Plex Mono', monospace;
    color: var(--text-muted);
    font-size: .84rem;
}

.flash-controls {
    display: flex;
    gap: 10px;
    margin-top: 16px;
    flex-wrap: wrap;
    justify-content: center;
}

.flash-tally {
    display: flex;
    gap: 20px;
    margin-top: 18px;
    font-size: .84rem;
}

.flash-tally b {
    font-family: 'IBM Plex Mono', monospace;
}

.flash-tally .known b {
    color: var(--success);
}

.flash-tally .unknown b {
    color: var(--danger);
}


@media (max-width: 720px) {

    /* decks become a swipeable tab strip rather than a ragged wrap */
    .deck-selector {
        flex-wrap: nowrap;
        overflow-x: auto;
        scrollbar-width: none;
        margin: 0 -16px 24px;
        padding: 0 16px;
        scroll-padding: 0 16px;
    }

    .deck-selector::-webkit-scrollbar {
        display: none;
    }

    .deck-chip {
        flex: none;
        padding: 12px 14px;
        white-space: nowrap;
    }

    /* the card is the point of the page: it comes before the stats and explainer */
    #page-flashcards>.wrap {
        display: flex;
        flex-direction: column;
    }

    #page-flashcards .stat-row {
        order: 3;
    }

    #page-flashcards .todo-card {
        order: 4;
    }

    .flash-stage {
        margin-bottom: 36px;
    }

    .flashcard {
        height: 300px;
    }

    .flashcard-face {
        padding: 28px 22px 28px 34px;
    }

    /* Known / Unknown are the thumb targets; shuffle and skip sit beneath */
    .flash-controls {
        display: grid;
        grid-template-columns: 1fr 1fr;
        width: 100%;
        max-width: 460px;
        gap: 10px;
    }

    .flash-controls .btn {
        min-height: 48px;
    }

    .flash-controls .btn:nth-child(1) {
        order: 1;
    }

    .flash-controls .btn:nth-child(3) {
        order: 2;
    }

    .flash-controls .btn:nth-child(2) {
        order: 3;
    }

    .flash-controls .btn:nth-child(4) {
        order: 4;
    }

    .flash-controls .btn-ghost {
        justify-content: center;
    }

    .flash-stage.fullscreen {
        padding: 72px 16px calc(24px + var(--safe-b));
        justify-content: flex-start;
    }

    .flash-stage.fullscreen .flashcard {
        height: min(58vh, 420px);
    }

    .flash-stage.fullscreen .flashcard-face h3 {
        font-size: 1.6rem;
    }
}