:root {
    --brand: #3b3fa8;
    --brand-dark: #1f2260;
    --accent: #0ea5a4;
    --surface: #f4f6fb;
}

body {
    background: var(--surface);
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: #1f2433;
}

.app-nav {
    background: linear-gradient(90deg, var(--brand-dark), var(--brand));
}

.app-nav .navbar-brand {
    font-weight: 700;
    letter-spacing: .2px;
}

.app-nav .navbar-brand span {
    color: #7ee7e6;
    font-weight: 500;
}

.app-nav .nav-link.active {
    font-weight: 600;
    border-bottom: 2px solid #7ee7e6;
}

.card {
    border: 0;
    border-radius: .75rem;
    box-shadow: 0 1px 3px rgba(20, 24, 60, .08), 0 4px 14px rgba(20, 24, 60, .04);
}

.card-header {
    background: transparent;
    font-weight: 600;
}

.stat-card .stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--brand);
    line-height: 1.1;
}

.page-title {
    font-weight: 700;
    color: var(--brand-dark);
}

.table > :not(caption) > * > * {
    vertical-align: middle;
}

.table thead th {
    font-size: .78rem;
    text-transform: uppercase;
    letter-spacing: .04em;
    color: #5b6280;
    border-bottom-width: 1px;
}

.btn-primary {
    --bs-btn-bg: var(--brand);
    --bs-btn-border-color: var(--brand);
    --bs-btn-hover-bg: var(--brand-dark);
    --bs-btn-hover-border-color: var(--brand-dark);
    --bs-btn-active-bg: var(--brand-dark);
}

.btn-outline-primary {
    --bs-btn-color: var(--brand);
    --bs-btn-border-color: var(--brand);
    --bs-btn-hover-bg: var(--brand);
    --bs-btn-hover-border-color: var(--brand);
}

a {
    color: var(--brand);
}

.login-wrap {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: radial-gradient(1200px 600px at 10% -10%, #dfe3ff 0, transparent 60%),
    radial-gradient(900px 500px at 110% 110%, #c9f3f2 0, transparent 55%), var(--surface);
}

.login-card {
    width: 100%;
    max-width: 420px;
}

.q-text {
    white-space: pre-wrap;
    word-break: break-word;
}

.q-image {
    max-width: 100%;
    max-height: 360px;
    border-radius: .5rem;
    border: 1px solid #e3e6f0;
}

.app-footer {
    border-top: 1px solid #e3e6f0;
    margin-top: 2rem;
}

.option-row {
    border: 1px solid #e3e6f0;
    border-radius: .5rem;
    padding: .5rem .75rem;
    margin-bottom: .5rem;
    background: #fff;
}

.option-row:hover {
    border-color: var(--brand);
}

/* ---------- Exam player ---------- */
body.bare {
    background: #eef1f8;
}

.player-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: #fff;
    border-bottom: 1px solid #dfe3f0;
}

.player-timer {
    font-variant-numeric: tabular-nums;
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--brand-dark);
}

.player-timer.warn {
    color: #d97706;
}

.player-timer.danger {
    color: #dc2626;
    animation: pulse 1s infinite;
}

@keyframes pulse {
    50% {
        opacity: .55;
    }
}

.palette-btn {
    width: 2.4rem;
    height: 2.4rem;
    padding: 0;
    font-weight: 600;
}

.palette-btn.answered {
    background: #16a34a;
    border-color: #16a34a;
    color: #fff;
}

.palette-btn.flagged {
    background: #f59e0b;
    border-color: #f59e0b;
    color: #fff;
}

.palette-btn.current {
    outline: 3px solid var(--brand);
    outline-offset: 1px;
}

.no-select {
    -webkit-user-select: none;
    user-select: none;
}

.player-overlay {
    position: fixed;
    inset: 0;
    z-index: 1000;
    background: rgba(20, 24, 60, .85);
    display: none;
    align-items: center;
    justify-content: center;
    color: #fff;
    text-align: center;
    padding: 2rem;
}

.player-overlay.show {
    display: flex;
}

.save-state {
    font-size: .8rem;
}

.matching-row select {
    min-width: 12rem;
}

@media print {
    .app-nav, .app-footer, .no-print {
        display: none !important;
    }
}

.q-thumb { max-height: 90px; max-width: 160px; border: 1px solid #dee2e6; border-radius: .375rem; }

.palette-legend { width: 1rem; height: 1rem; padding: 0; vertical-align: middle; }
.option-row:has(input:checked) { border-color: var(--brand); background: #f3f5ff; }

/* picture inside an answer option */
.opt-image { max-height: 140px; max-width: 100%; display: block; margin-top: .35rem; border-radius: .35rem; }

img.q-image { cursor: zoom-in; }
.img-zoom { position: fixed; inset: 0; z-index: 2000; background: rgba(10, 12, 40, .85); display: flex; align-items: center; justify-content: center; padding: 24px; cursor: zoom-out; }
.img-zoom img { max-width: 100%; max-height: 100%; background: #fff; border-radius: 8px; box-shadow: 0 10px 40px rgba(0,0,0,.5); }
.fs-overlay { position: fixed; inset: 0; z-index: 3000; background: rgba(20, 23, 58, .97); display: flex; align-items: center; justify-content: center; padding: 24px; }
.fs-box { max-width: 560px; background: #fff; border-radius: 16px; padding: 32px; text-align: center; }
.q-text { white-space: pre-wrap; }