/* ==========================================================================
   MCQ Examination Management System - Common CSS Architecture
   All application styles reside here. Zero inline CSS permitted.
   ========================================================================== */

:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #06b6d4;
    --light-bg: #f8fafc;
    --dark-bg: #0f172a;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

body {
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: #f1f5f9;
    color: #1e293b;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.main-wrapper {
    flex: 1 0 auto;
}

.footer {
    flex-shrink: 0;
    background-color: #ffffff;
    border-top: 1px solid #e2e8f0;
    padding: 1rem 0;
    margin-top: 2rem;
}

/* --------------------------------------------------------------------------
   Auth Layout
   -------------------------------------------------------------------------- */
.auth-container {
    max-width: 440px;
    margin: 4rem auto;
}

.auth-card {
    border: none;
    border-radius: 12px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
}

.auth-header {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: #ffffff;
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
    padding: 1.75rem 1.5rem;
    text-align: center;
}

/* --------------------------------------------------------------------------
   Dashboard Stat Cards
   -------------------------------------------------------------------------- */
.stat-card {
    border: none;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
}

.stat-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.stat-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 10px;
    background-color: #f8fafc;
}

/* --------------------------------------------------------------------------
/* --------------------------------------------------------------------------
   Exam Header & Timer Architecture
   -------------------------------------------------------------------------- */
.exam-header-card {
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    z-index: 1020;
    width: 100%;
    overflow: hidden;
    transition: all 0.2s ease;
}

.exam-timer-normal {
    font-size: 1.35rem;
    font-weight: 800;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    color: #2563eb;
    letter-spacing: 1px;
}

.exam-timer-mobile {
    font-size: 1.05rem;
    letter-spacing: 0.5px;
}

.exam-timer-warning {
    font-size: 1.35rem;
    font-weight: 800;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    color: #ef4444;
    letter-spacing: 1px;
    animation: blinker 1s linear infinite;
}

@keyframes blinker {
    50% { opacity: 0.5; }
}

/* --------------------------------------------------------------------------
   Question Content Card & Modern Typography
   -------------------------------------------------------------------------- */
.question-main-card {
    border: 1px solid #e2e8f0;
    background: #ffffff;
    transition: box-shadow 0.2s ease;
}

.question-text {
    font-size: 1.15rem;
    line-height: 1.65;
    color: #0f172a;
}

/* --------------------------------------------------------------------------
   Question Option Radio Cards (Touch-Friendly & Modern)
   -------------------------------------------------------------------------- */
.options-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.option-card {
    border: 1.5px solid #e2e8f0;
    border-radius: 12px;
    padding: 0.85rem 1.1rem;
    margin-bottom: 0;
    cursor: pointer;
    transition: all 0.18s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: flex-start;
    gap: 0.85rem;
    background-color: #ffffff;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.option-card:hover {
    background-color: #f8fafc;
    border-color: #93c5fd;
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.04);
}

.option-card.selected {
    background-color: #eff6ff;
    border-color: #2563eb;
    box-shadow: 0 0 0 1px #2563eb, 0 2px 6px rgba(37, 99, 235, 0.12);
}

.option-radio-wrap {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    flex-shrink: 0;
    margin-top: 2px;
}

.option-card input[type="radio"] {
    width: 1.25rem;
    height: 1.25rem;
    cursor: pointer;
    accent-color: #2563eb;
    margin: 0;
}

.option-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background-color: #f1f5f9;
    color: #475569;
    font-weight: 700;
    font-size: 0.85rem;
    transition: all 0.18s ease;
}

.option-card:hover .option-badge {
    background-color: #e2e8f0;
    color: #1e293b;
}

.option-card.selected .option-badge {
    background-color: #2563eb;
    color: #ffffff;
    box-shadow: 0 2px 4px rgba(37, 99, 235, 0.3);
}

.option-label {
    flex: 1 1 auto;
    font-size: 0.98rem;
    line-height: 1.55;
    color: #334155;
    word-break: break-word;
    cursor: pointer;
}

.option-card.selected .option-label {
    color: #0f172a;
    font-weight: 600;
}

/* --------------------------------------------------------------------------
   Question Action Bar (Mobile Responsive Grid / Desktop Flex)
   -------------------------------------------------------------------------- */
.question-action-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.75rem;
}

.action-nav-buttons {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* --------------------------------------------------------------------------
   Exam Header Semantic Typography & Layout (Zero Inline Style Requirement)
   -------------------------------------------------------------------------- */
.exam-header-desktop-wrap {
    width: 100%;
}

.exam-header-info {
    flex: 1 1 auto;
    min-width: 0;
    overflow: hidden;
}

.exam-header-title-desktop {
    font-size: 1.12rem;
    line-height: 1.3;
}

.exam-header-stats {
    flex-shrink: 0;
}

.exam-stat-badge {
    padding: 0.4rem 0.65rem;
    font-size: 0.8rem;
    font-weight: 600;
    white-space: nowrap;
    border-radius: 6px;
}

@media (min-width: 1200px) {
    .exam-stat-badge {
        padding: 0.5rem 0.85rem;
        font-size: 0.85rem;
    }
}

.exam-header-actions {
    flex-shrink: 0;
    white-space: nowrap;
}

.exam-timer-wrapper {
    white-space: nowrap;
}

.exam-header-final-submit-btn {
    padding: 0.4rem 0.85rem;
    font-size: 0.88rem;
    white-space: nowrap;
    flex-shrink: 0;
}

@media (min-width: 1200px) {
    .exam-header-final-submit-btn {
        padding: 0.5rem 1.15rem;
        font-size: 0.92rem;
    }
}

@media (min-width: 768px) and (max-width: 991.98px) {
    .exam-header-desktop-wrap {
        flex-wrap: wrap;
        gap: 0.5rem !important;
    }

    .exam-header-info {
        flex: 1 1 55%;
    }

    .exam-header-actions {
        flex: 0 0 auto;
    }

    .exam-header-stats {
        width: 100%;
        order: 3;
        padding-top: 0.35rem;
        border-top: 1px solid #f1f5f9;
    }
}

.exam-header-mobile-wrap {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    width: 100%;
}

.exam-header-mobile-row1 {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    border-bottom: 1px solid #f1f5f9;
    padding-bottom: 0.45rem;
    width: 100%;
}

.exam-header-mobile-title-wrap {
    flex: 1 1 0%;
    min-width: 0; /* Critical for CSS flexbox text truncation */
    overflow: hidden;
}

.exam-header-mobile-title {
    font-size: 0.88rem;
    font-weight: 700;
    color: #2563eb;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.25;
}

.exam-header-mobile-roll {
    font-size: 0.72rem;
    color: #64748b;
    line-height: 1.2;
    margin-top: 2px;
}

.exam-header-mobile-submit-btn {
    flex-shrink: 0;
    padding: 0.35rem 0.75rem;
    font-size: 0.82rem;
    font-weight: 700;
    border-radius: 6px;
    white-space: nowrap;
}

.exam-header-mobile-row2 {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.35rem;
    width: 100%;
}

.exam-header-mobile-timer {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    background-color: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 6px;
    height: 32px;
    padding: 0 0.45rem;
    flex-shrink: 0;
}

.exam-mobile-timer-icon {
    font-size: 0.8rem;
    line-height: 1;
}

.exam-header-mobile-stats {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.exam-mobile-stat-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    height: 32px;
    padding: 0 0.45rem;
    font-size: 0.72rem;
    font-weight: 600;
    border-radius: 6px;
    background-color: #f8fafc;
    border: 1px solid #e2e8f0;
    color: #475569;
    white-space: nowrap;
}

.stat-divider {
    width: 1px;
    height: 14px;
    background-color: #cbd5e1;
    margin: 0 0.2rem;
}

.stat-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    display: inline-block;
    flex-shrink: 0;
}

.exam-header-mobile-actions {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.exam-header-mobile-palette-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    height: 32px;
    padding: 0 0.45rem;
    font-size: 0.76rem;
    font-weight: 600;
    border-radius: 6px;
    white-space: nowrap;
}

/* Specific styling for screens <= 420px (iPhone SE 375px, Samsung Galaxy 360px) */
@media (max-width: 420px) {
    .exam-header-mobile-row2 {
        gap: 0.25rem;
    }

    .exam-header-mobile-timer {
        padding: 0 0.35rem;
        gap: 0.15rem;
    }

    .exam-timer-mobile {
        font-size: 0.95rem;
        letter-spacing: 0;
    }

    .exam-mobile-stat-pill {
        padding: 0 0.35rem;
        font-size: 0.7rem;
        gap: 0.18rem;
    }

    .stat-divider {
        margin: 0 0.12rem;
    }

    .exam-header-mobile-palette-btn {
        padding: 0 0.4rem;
        font-size: 0.74rem;
        gap: 0.2rem;
    }
}

@media (max-width: 340px) {
    .exam-palette-label {
        display: none;
    }
}

.exam-title-mobile {
    font-size: 0.88rem;
}

.exam-roll-mobile {
    font-size: 0.72rem;
}

.exam-stat-badge-mobile {
    font-size: 0.72rem;
}

.exam-saving-indicator-mobile {
    font-size: 0.75rem;
}

.exam-question-badge {
    font-size: 0.85rem;
}

/* --------------------------------------------------------------------------
   Redesigned Question Navigation Palette (Public / Exam Engine)
   -------------------------------------------------------------------------- */
.question-palette-card {
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    box-shadow: var(--card-shadow);
    background: #ffffff;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.question-palette-body {
    display: flex !important;
    flex-direction: column !important;
    width: 100% !important;
    padding: 1rem 1.25rem 1.25rem 1.25rem !important;
    flex-grow: 1;
}

.question-palette-legend {
    display: flex !important;
    flex-direction: row !important;
    justify-content: space-around !important;
    align-items: center !important;
    width: 100% !important;
    margin-bottom: 0.85rem !important;
    padding: 0.55rem 0.4rem !important;
    background-color: #f8fafc !important;
    border: 1px solid #e2e8f0 !important;
    border-radius: 8px !important;
    color: #475569 !important;
    font-size: 0.78rem !important;
    font-weight: 600 !important;
    flex-shrink: 0 !important;
}

.palette-legend-dot {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.question-nav-grid {
    display: grid !important;
    grid-template-columns: repeat(5, 1fr) !important;
    gap: 8px !important;
    width: 100% !important;
    max-height: 440px;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 4px 4px 14px 4px !important;
}

/* Modern smooth thin scrollbar for Question Palette */
.question-nav-grid::-webkit-scrollbar {
    width: 6px;
}
.question-nav-grid::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 4px;
}
.question-nav-grid::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 4px;
}
.question-nav-grid::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}

.question-box {
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    width: 100% !important;
    aspect-ratio: 1 / 1 !important;
    font-weight: 700 !important;
    font-size: 0.85rem !important;
    border-radius: 8px !important;
    border: 1px solid #e2e8f0 !important;
    cursor: pointer !important;
    user-select: none !important;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1) !important;
    background-color: #ffffff !important;
    color: #334155 !important;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05) !important;
    text-decoration: none !important;
}

.question-box:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.question-answered {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%) !important;
    color: #ffffff !important;
    border-color: #059669 !important;
}

.question-unanswered {
    background: linear-gradient(135deg, #64748b 0%, #475569 100%) !important;
    color: #ffffff !important;
    border-color: #475569 !important;
}

.question-current {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%) !important;
    color: #ffffff !important;
    border-color: #1d4ed8 !important;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.4) !important;
    transform: scale(1.08);
    z-index: 2;
}

/* Desktop layout enforcement (>= 992px) */
@media (min-width: 992px) {
    .question-palette-card.offcanvas-lg {
        position: static !important;
        visibility: visible !important;
        transform: none !important;
        width: 100% !important;
        max-width: 100% !important;
        height: auto !important;
        display: flex !important;
        flex-direction: column !important;
        background-color: #ffffff !important;
    }

    .question-palette-card .question-palette-body {
        display: flex !important;
        flex-direction: column !important;
        width: 100% !important;
        padding: 1rem 1.25rem 1.25rem 1.25rem !important;
    }
}

/* --------------------------------------------------------------------------
   Mobile View Specific Optimizations (< 768px and < 576px)
   -------------------------------------------------------------------------- */
@media (max-width: 767.98px) {
    .main-wrapper main.container {
        padding-left: 10px;
        padding-right: 10px;
        padding-top: 8px !important;
        padding-bottom: 24px !important;
    }

    .exam-header-card {
        top: 0;
        margin-left: 0;
        margin-right: 0;
        width: 100%;
        border-radius: 10px;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08) !important;
    }

    .question-palette-card.offcanvas-lg {
        max-width: 320px;
        width: 85%;
        border-radius: 0;
    }

    .question-palette-card.offcanvas-lg .question-nav-grid {
        max-height: calc(100vh - 160px);
        padding: 10px 4px;
        gap: 10px;
    }
}

@media (max-width: 575.98px) {
    .question-text {
        font-size: 1.02rem;
        line-height: 1.55;
    }

    .option-card {
        padding: 0.75rem 0.85rem;
        gap: 0.7rem;
    }

    .option-badge {
        width: 26px;
        height: 26px;
        font-size: 0.8rem;
    }

    .option-label {
        font-size: 0.92rem;
    }

    /* Fixed single-row 3-button layout on mobile to prevent any breaking/wrapping */
    .question-action-bar {
        display: grid;
        grid-template-columns: 1fr 1fr 1fr;
        gap: 8px;
    }

    .action-nav-buttons {
        display: contents;
    }

    .question-action-bar .btn {
        width: 100%;
        padding: 0.65rem 0.25rem;
        font-size: 0.85rem;
        font-weight: 600;
        display: flex;
        align-items: center;
        justify-content: center;
        white-space: nowrap;
        border-radius: 8px;
    }
}

/* --------------------------------------------------------------------------
   Tablet & Mobile Palette Toggle Triggers (< 992px)
   -------------------------------------------------------------------------- */
.exam-palette-toggle-tablet {
    padding: 0.35rem 0.65rem;
    font-size: 0.82rem;
    white-space: nowrap;
}

.exam-palette-fab {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 52px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1050;
    box-shadow: 0 4px 16px rgba(37, 99, 235, 0.45) !important;
    border: 2px solid #ffffff;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.exam-palette-fab:hover {
    transform: scale(1.08);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.55) !important;
}

.exam-palette-fab-icon {
    font-size: 1.35rem;
    line-height: 1;
}

/* --------------------------------------------------------------------------
   Utility Classes
   -------------------------------------------------------------------------- */
.is-hidden {
    display: none !important;
}

.status-saving {
    font-size: 0.85rem;
    font-weight: 600;
    color: #2563eb;
}

.status-saved {
    font-size: 0.85rem;
    font-weight: 600;
    color: #10b981;
}

.status-error {
    font-size: 0.85rem;
    font-weight: 600;
    color: #ef4444;
}

.table-responsive {
    border-radius: 8px;
}