/* ==========================================================================
   QUIZ RESPONSIVE SYSTEM
   Mobile-first, Premium Educational Assessment UI
   ========================================================================== */

:root {
    /* Color System */
    --qz-primary: #7c3aed;
    --qz-primary-hover: #6d28d9;
    --qz-primary-light: #ede9fe;
    
    --qz-correct: #059669;
    --qz-correct-bg: #d1fae5;
    
    --qz-incorrect: #dc2626;
    --qz-incorrect-bg: #fee2e2;
    
    --qz-surface: #ffffff;
    --qz-surface-alt: #f8fafc;
    --qz-border: #e2e8f0;
    --qz-border-hover: #cbd5e1;
    
    --qz-text-main: #1e293b;
    --qz-text-muted: #64748b;
    
    --qz-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    --qz-shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.08);

    /* Typography System using clamp() */
    --qz-font-title: clamp(1.5rem, 3vw, 2.5rem);
    --qz-font-question: clamp(1.1rem, 2vw, 1.4rem);
    --qz-font-option: clamp(1rem, 1.5vw, 1.1rem);
    --qz-font-body: clamp(0.95rem, 1vw, 1rem);
    
    /* Metrics */
    --qz-radius: 16px;
    --qz-touch-target: 48px; /* Minimum height for touch accessibility */
}

/* --------------------------------------------------------------------------
   DARK MODE
   -------------------------------------------------------------------------- */
@media (prefers-color-scheme: dark) {
    :root {
        --qz-primary: #8b5cf6;
        --qz-primary-hover: #a78bfa;
        --qz-primary-light: rgba(139, 92, 246, 0.15);
        
        --qz-correct: #34d399;
        --qz-correct-bg: rgba(5, 150, 105, 0.15);
        
        --qz-incorrect: #f87171;
        --qz-incorrect-bg: rgba(220, 38, 38, 0.15);
        
        --qz-surface: #1e293b;
        --qz-surface-alt: #0f172a;
        --qz-border: #334155;
        --qz-border-hover: #475569;
        
        --qz-text-main: #f8fafc;
        --qz-text-muted: #94a3b8;
        
        --qz-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
        --qz-shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.3);
    }
}

/* --------------------------------------------------------------------------
   GLOBAL RESET FOR QUIZ CONTEXT ONLY
   Ensures we don't bleed into existing site styles.
   -------------------------------------------------------------------------- */
.quiz-sys-container {
    box-sizing: border-box;
    font-family: inherit;
    color: var(--qz-text-main);
    line-height: 1.7;
    width: 100%;
    /* No horizontal scrolling */
    max-width: 100vw;
    overflow-x: hidden;
}

.quiz-sys-container * {
    box-sizing: inherit;
}

/* --------------------------------------------------------------------------
   LAYOUT ARCHITECTURE
   -------------------------------------------------------------------------- */
.quiz-sys-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
    width: 100%;
}

/* --------------------------------------------------------------------------
   HEADER
   -------------------------------------------------------------------------- */
.quiz-sys-header {
    background: var(--qz-surface);
    padding: 24px 20px;
    border-radius: var(--qz-radius);
    box-shadow: var(--qz-shadow);
    margin-bottom: 24px;
}

.quiz-sys-title {
    font-size: var(--qz-font-title);
    font-weight: 800;
    margin: 0 0 16px 0;
    color: var(--qz-text-main);
    line-height: 1.3;
}

.quiz-sys-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.quiz-sys-badge {
    background: var(--qz-surface-alt);
    color: var(--qz-text-muted);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid var(--qz-border);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

/* --------------------------------------------------------------------------
   PROGRESS BAR
   Sticky behavior: Top 0 on mobile, Top 20px on desktop
   -------------------------------------------------------------------------- */
.quiz-sys-progress-wrapper {
    position: sticky;
    top: 0;
    z-index: 50;
    background: var(--qz-surface);
    padding: 16px 20px;
    border-radius: var(--qz-radius);
    box-shadow: var(--qz-shadow);
    margin-bottom: 24px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.quiz-sys-progress-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--qz-text-muted);
}

.quiz-sys-progress-track {
    width: 100%;
    height: 8px;
    background: var(--qz-surface-alt);
    border-radius: 4px;
    overflow: hidden;
}

.quiz-sys-progress-fill {
    height: 100%;
    background: var(--qz-primary);
    border-radius: 4px;
    transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --------------------------------------------------------------------------
   QUESTION CARD
   -------------------------------------------------------------------------- */
.quiz-sys-card {
    background: var(--qz-surface);
    border-radius: var(--qz-radius);
    box-shadow: var(--qz-shadow);
    padding: 20px;
    margin-bottom: 24px;
    transition: box-shadow 0.3s ease;
    /* Prevent content overflow */
    overflow-wrap: break-word;
    word-break: break-word;
}

/* Premium hover effect on desktop */
@media (min-width: 1024px) {
    .quiz-sys-card:hover {
        box-shadow: var(--qz-shadow-hover);
    }
}

.quiz-sys-question-num {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--qz-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 12px;
    display: block;
}

.quiz-sys-question-text {
    font-size: var(--qz-font-question);
    font-weight: 600;
    color: var(--qz-text-main);
    margin-bottom: 24px;
    line-height: 1.6;
}

.quiz-sys-question-img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin-bottom: 20px;
}

/* Math Protection */
.quiz-sys-container .katex-display, 
.quiz-sys-container math {
    overflow-x: auto;
    overflow-y: hidden;
    padding: 10px 0;
    max-width: 100%;
    /* Ensure scrollbar looks okay on iOS */
    -webkit-overflow-scrolling: touch;
}

/* --------------------------------------------------------------------------
   OPTIONS AREA (Answer Cards)
   -------------------------------------------------------------------------- */
.quiz-sys-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.quiz-sys-option {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    background: var(--qz-surface);
    border: 2px solid var(--qz-border);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: var(--qz-touch-target); /* Touch friendly */
}

/* Focus and Keyboard Accessibility */
.quiz-sys-option:focus-visible,
.quiz-sys-option:focus-within {
    outline: 2px solid var(--qz-primary);
    outline-offset: 2px;
}

/* Hover state */
@media (hover: hover) {
    .quiz-sys-option:not(.selected):not(.correct):not(.incorrect):hover {
        border-color: var(--qz-border-hover);
        background: var(--qz-surface-alt);
    }
}

/* Selected state */
.quiz-sys-option.selected {
    border-color: var(--qz-primary);
    background: var(--qz-primary-light);
}

.quiz-sys-option.selected .quiz-sys-option-text {
    color: var(--qz-primary);
    font-weight: 600;
}

/* Correct state */
.quiz-sys-option.correct {
    border-color: var(--qz-correct);
    background: var(--qz-correct-bg);
}

.quiz-sys-option.correct .quiz-sys-option-text {
    color: var(--qz-correct);
    font-weight: 700;
}

/* Incorrect state */
.quiz-sys-option.incorrect {
    border-color: var(--qz-incorrect);
    background: var(--qz-incorrect-bg);
}

.quiz-sys-option.incorrect .quiz-sys-option-text {
    color: var(--qz-incorrect);
}

/* Hide native radio/checkbox visually but keep accessible */
.quiz-sys-option input[type="radio"],
.quiz-sys-option input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

/* Custom indicator */
.quiz-sys-indicator {
    width: 24px;
    height: 24px;
    border: 2px solid var(--qz-border-hover);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: all 0.2s;
    color: transparent;
    font-size: 12px;
}

/* Checkbox specific */
.quiz-sys-option input[type="checkbox"] ~ .quiz-sys-indicator {
    border-radius: 6px;
}

.quiz-sys-option.selected .quiz-sys-indicator {
    border-color: var(--qz-primary);
    background: var(--qz-primary);
    color: white;
}

.quiz-sys-option.correct .quiz-sys-indicator {
    border-color: var(--qz-correct);
    background: var(--qz-correct);
    color: white;
}

.quiz-sys-option.incorrect .quiz-sys-indicator {
    border-color: var(--qz-incorrect);
    background: var(--qz-incorrect);
    color: white;
}

.quiz-sys-option-text {
    font-size: var(--qz-font-option);
    line-height: 1.5;
    flex: 1;
}

/* --------------------------------------------------------------------------
   NAVIGATION AREA
   -------------------------------------------------------------------------- */
.quiz-sys-nav {
    display: flex;
    gap: 16px;
    margin-top: 32px;
}

.quiz-sys-btn {
    flex: 1;
    min-height: var(--qz-touch-target);
    padding: 0 24px;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.2s;
    border: none;
    font-family: inherit;
}

.quiz-sys-btn-secondary {
    background: var(--qz-surface);
    color: var(--qz-text-main);
    border: 2px solid var(--qz-border);
}

.quiz-sys-btn-secondary:hover {
    background: var(--qz-surface-alt);
    border-color: var(--qz-border-hover);
}

.quiz-sys-btn-primary {
    background: var(--qz-primary);
    color: white;
}

.quiz-sys-btn-primary:hover {
    background: var(--qz-primary-hover);
}

/* --------------------------------------------------------------------------
   RESULTS SCORE DASHBOARD
   -------------------------------------------------------------------------- */
.quiz-sys-results {
    background: var(--qz-surface);
    border-radius: var(--qz-radius);
    box-shadow: var(--qz-shadow);
    padding: 32px 20px;
    text-align: center;
}

.quiz-sys-score-circle {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    border: 8px solid var(--qz-primary-light);
    border-top-color: var(--qz-primary);
    margin: 0 auto 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.quiz-sys-score-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--qz-primary);
    line-height: 1;
}

.quiz-sys-score-label {
    font-size: 0.85rem;
    color: var(--qz-text-muted);
    font-weight: 600;
    text-transform: uppercase;
    margin-top: 4px;
}

.quiz-sys-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 16px;
    margin: 32px 0;
}

.quiz-sys-stat-card {
    background: var(--qz-surface-alt);
    padding: 16px;
    border-radius: 12px;
    border: 1px solid var(--qz-border);
}

.quiz-sys-stat-val {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--qz-text-main);
}

.quiz-sys-stat-title {
    font-size: 0.8rem;
    color: var(--qz-text-muted);
    font-weight: 600;
}

/* --------------------------------------------------------------------------
   RESPONSIVE BREAKPOINTS
   -------------------------------------------------------------------------- */

/* Mobile Enhancements (< 768px) */
@media (max-width: 767px) {
    .quiz-sys-container {
        padding-bottom: 80px; /* Space for fixed bottom nav */
    }
    
    .quiz-sys-nav {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        background: var(--qz-surface);
        padding: 16px 20px;
        margin: 0;
        box-shadow: 0 -4px 12px rgba(0,0,0,0.05);
        z-index: 100;
        /* Safe area support for notched phones */
        padding-bottom: calc(16px + env(safe-area-inset-bottom));
    }
    
    .quiz-sys-sidebar {
        grid-column: 1 / -1;
        /* Force sidebar to stack below results/quiz */
        order: 99;
    }
}

/* Tablet (768px - 1023px) */
@media (min-width: 768px) and (max-width: 1023px) {
    .quiz-sys-grid {
        width: 90%;
        margin: 0 auto;
    }
    
    .quiz-sys-options {
        /* Two columns if the options are short, but generally 1 col is safer. 
           Using auto-fit for basic grid layout if desired. */
        display: grid;
        grid-template-columns: 1fr;
    }
    
    .quiz-sys-sidebar {
        /* Move below quiz content */
        grid-column: 1 / -1;
    }
}

/* Desktop (1024px+) */
@media (min-width: 1024px) {
    .quiz-sys-grid {
        grid-template-columns: 1fr 300px;
        max-width: 1100px;
        margin: 0 auto;
        gap: 40px;
    }
    
    .quiz-sys-progress-wrapper {
        top: 20px;
    }
    
    .quiz-sys-main {
        /* Limit reading width for cognitive ease */
        max-width: 900px;
    }
    
    .quiz-sys-sidebar {
        position: sticky;
        top: 20px;
        align-self: start;
    }
}

/* --------------------------------------------------------------------------
   PRINT & REDUCED MOTION
   -------------------------------------------------------------------------- */
@media print {
    .quiz-sys-nav,
    .quiz-sys-sidebar,
    .quiz-sys-progress-wrapper {
        display: none !important;
    }
    
    .quiz-sys-card {
        box-shadow: none !important;
        border: 1px solid #ccc;
        page-break-inside: avoid;
    }
    
    .quiz-sys-option {
        border-color: #ccc !important;
        background: transparent !important;
        color: #000 !important;
    }
}

@media (prefers-reduced-motion: reduce) {
    .quiz-sys-option,
    .quiz-sys-progress-fill,
    .quiz-sys-indicator,
    .quiz-sys-btn {
        transition: none !important;
    }
}


@media (max-width: 480px) {
    .quiz-sys-card {
        padding: 14px !important;
    }
    .quiz-sys-option {
        padding: 12px 14px !important;
    }
    .quiz-sys-header {
        padding: 16px 14px !important;
    }
    .quiz-sys-results {
        padding: 20px 14px !important;
    }
}