/* ==========================================================================
   PRODUCTION-GRADE GLOBAL STYLES & CSS VARIABLES
   ========================================================================== */
:root {
    --primary: #1e3a8a;          /* Rich Navy (WCAG AAA Contrast) */
    --primary-hover: #1e40af;
    --primary-light: #eff6ff;
    --accent: #2563eb;           /* Modern Blue Accent */
    --accent-gold: #d97706;      /* Safety/Caution Yellow-Gold */
    --accent-gold-light: #fef3c7;
    --success: #15803d;          /* Accessibility Green */
    --success-light: #f0fdf4;
    --danger: #b91c1c;           /* Accessibility Red */
    --danger-light: #fef2f2;
    --bg-main: #f8fafc;          /* Off-White Canvas */
    --bg-card: #ffffff;
    --text-primary: #0f172a;     /* Deep Charcoal */
    --text-secondary: #475569;   /* Mid Slate */
    --border-color: #e2e8f0;
    --border-hover: #cbd5e1;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
    --shadow-lg: 0 10px 15px -3px rgba(30, 41, 59, 0.08), 0 4px 6px -2px rgba(30, 41, 59, 0.03);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 18px;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-main);
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ==========================================================================
   NAVIGATION BRANDING
   ========================================================================== */
.mainNav {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    padding: 12px 0;
    position: sticky;
    top: 0;
    z-index: 200;
    box-shadow: var(--shadow-sm);
}

.mainNav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 0;
    flex-wrap: wrap;
}

.mainNav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 14px;
    transition: all var(--transition-fast);
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    display: inline-block;
}

.mainNav a:hover {
    color: var(--accent);
    background: var(--primary-light);
}

.mainNav a.active {
    color: var(--primary);
    background: var(--primary-light);
    box-shadow: inset 0 0 0 1px rgba(37, 99, 235, 0.15);
}

/* ==========================================================================
   HERO / BILLBOARD SECTIONS
   ========================================================================== */
.hero {
    background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
    color: #ffffff;
    padding: 64px 0;
    text-align: center;
}

.hero h1 {
    font-size: 38px;
    font-weight: 800;
    margin-bottom: 14px;
    line-height: 1.25;
    letter-spacing: -0.02em;
}

.hero p {
    font-size: 18px;
    color: #93c5fd;
    max-width: 720px;
    margin: 0 auto 20px;
}

.trustLine {
    font-size: 13px;
    color: #cbd5e1;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ==========================================================================
   LAYOUT STRUCTURE & CONTENT CARDS
   ========================================================================== */
main {
    margin-top: 32px;
}

.contentBlock {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 40px;
    margin-bottom: 32px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.contentBlock h2 {
    font-size: 26px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 20px;
    letter-spacing: -0.01em;
}

.contentBlock p {
    color: var(--text-secondary);
    margin-bottom: 18px;
    font-size: 16px;
}

/* Inline lists styling */
ul, ol {
    margin-bottom: 20px;
    padding-left: 24px;
    color: var(--text-secondary);
}

li {
    margin-bottom: 8px;
}

/* ==========================================================================
   ACCESS COMPLIANT BUTTONS
   ========================================================================== */
a.primary, button.primary, .btn-action {
    background: var(--success);
    color: #ffffff;
    border: none;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-weight: 700;
    cursor: pointer;
    font-size: 16px;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    box-shadow: 0 4px 10px rgba(21, 128, 61, 0.25);
}

a.primary:hover, button.primary:hover {
    background: #166534;
    transform: translateY(-1px);
    box-shadow: 0 6px 12px rgba(21, 128, 61, 0.3);
}

a.secondary, button.secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    font-size: 15px;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

a.secondary:hover, button.secondary:hover {
    background: var(--bg-main);
    border-color: var(--border-hover);
}

/* ==========================================================================
   DYNAMIC INTERACTIVE QUIZ ENGINE
   ========================================================================== */
#startScreen, #quizScreen, #resultsScreen {
    max-width: 760px;
    margin: 32px auto;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    padding: 36px;
    transition: opacity var(--transition-normal);
}

/* Layout stabilization wrappers */
.quiz-header {
    margin-bottom: 24px;
}

#chapterTitle {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    font-weight: 800;
    margin-bottom: 4px;
}

#questionCounter {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
}

#questionText {
    font-size: 22px;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.4;
    margin-bottom: 24px;
}

/* Progress indicator styles */
.progressWrap {
    height: 6px;
    background: var(--border-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-bottom: 24px;
}

#progressBar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent) 0%, #3b82f6 100%);
    transition: width var(--transition-normal);
}

/* Multiple choice selection buttons */
#answers {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 24px;
}

.quizOption {
    width: 100%;
    text-align: left;
    padding: 16px 20px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    cursor: pointer;
    font-size: 16px;
    color: var(--text-primary);
    font-weight: 500;
    transition: all var(--transition-fast);
    outline: none;
    position: relative;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.quizOption:hover:not(:disabled) {
    border-color: var(--accent);
    background: var(--primary-light);
}

/* Focus indicator for keyboard accessible navigations */
.quizOption:focus-visible {
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.4);
    border-color: var(--accent);
}

/* Option letter label styling */
.quizOption .opt-badge {
    background: var(--bg-main);
    color: var(--text-secondary);
    font-weight: 700;
    width: 24px;
    height: 24px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 13px;
    transition: all var(--transition-fast);
}

.quizOption:hover:not(:disabled) .opt-badge {
    background: var(--accent);
    color: #ffffff;
}

/* Visual states for answered options */
.quizOption.correctResponse {
    background-color: var(--success-light) !important;
    border-color: var(--success) !important;
    color: var(--success) !important;
    font-weight: 600;
}

.quizOption.correctResponse .opt-badge {
    background: var(--success) !important;
    color: #ffffff !important;
}

.quizOption.wrongResponse {
    background-color: var(--danger-light) !important;
    border-color: var(--danger) !important;
    color: var(--danger) !important;
}

.quizOption.wrongResponse .opt-badge {
    background: var(--danger) !important;
    color: #ffffff !important;
}

/* Mode Selection Grids */
.modeGrid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 14px;
    margin-top: 24px;
}

.modeBtn {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 18px 12px;
    cursor: pointer;
    text-align: center;
    transition: all var(--transition-normal);
    font-weight: 700;
    color: var(--text-primary);
}

.modeBtn:hover {
    border-color: var(--accent);
    background: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.modeBtn span {
    display: block;
    font-size: 13px;
    color: var(--accent);
    margin-top: 4px;
    font-weight: 500;
}

/* ==========================================================================
   FEEDBACK & EXPLANATION PANELS (AUTOMATIC EXPANSION UX)
   ========================================================================== */
#feedback {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

#infoSection {
    background-color: var(--success-light);
    border-left: 5px solid var(--success);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    padding: 20px;
    margin-bottom: 24px;
    overflow: hidden;
    transition: max-height 0.3s ease-out, opacity 0.2s ease-out;
}

#infoSection h3 {
    font-size: 15px;
    font-weight: 700;
    color: var(--success);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

#summary ul {
    margin: 0;
    padding-left: 20px;
    color: var(--text-secondary);
}

#summary li {
    margin-bottom: 6px;
    font-size: 15px;
}

/* ==========================================================================
   ADVERTISING LAYOUT STABILIZERS (CLS REMEDIATION)
   ========================================================================== */
.adBox {
    display: block;           /* Allows standard, unrestricted script/iframe rendering */
    margin: 32px auto;
    width: 100%;
    text-align: center;
    clear: both;
}

/* ==========================================================================
   AUXILIARY CONTENT SYSTEM
   ========================================================================== */
.infoGrid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 32px;
}

.infoCard {
    background: var(--bg-card);
    padding: 30px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.infoCard:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.infoCard h3 {
    margin-top: 0;
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.textLink {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
}

.textLink:hover {
    text-decoration: underline;
}

/* Roadmap Grid */
.roadmapGrid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
    margin: 32px 0;
}

.roadmapStep {
    background: var(--bg-card);
    padding: 24px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    text-align: center;
    transition: transform var(--transition-fast);
}

.roadmapStep:hover {
    transform: translateY(-2px);
}

.stepNum {
    background: var(--primary);
    color: #ffffff;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-weight: 800;
    font-size: 15px;
}

.roadmapStep h3 {
    font-size: 16px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.roadmapStep p {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ==========================================================================
   SUPPORT & CONTACT SYSTEMS
   ========================================================================== */
.supportBox, .resultSupport {
    background: #fffbeb;
    border: 1px solid #fde68a;
    padding: 36px 24px;
    border-radius: var(--radius-lg);
    text-align: center;
    margin: 48px auto;
    max-width: 760px;
}

.supportBtn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-gold);
    color: #ffffff;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 700;
    margin-top: 16px;
    box-shadow: 0 4px 6px rgba(217, 119, 6, 0.2);
    transition: all var(--transition-fast);
}

.supportBtn:hover {
    background: #b45309;
    transform: translateY(-1px);
}

/* FAQ Dropdown Layout */
.faqBlock {
    margin-top: 48px;
}

.faqBlock h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 24px;
}

.faqItem {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 12px;
}

.faqItem h3 {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.faqItem p {
    font-size: 15px;
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ==========================================================================
   STANDARDIZED FOOTER SYSTEM
   ========================================================================== */
.footer {
    background: var(--bg-card);
    padding: 48px 0 32px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    margin-top: 64px;
}

.footerNav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    margin-bottom: 20px;
}

.footerNav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 13px;
    padding: 4px 12px;
    border-right: 1px solid var(--border-color);
    line-height: 1.4;
}

.footerNav a:last-child {
    border-right: none;
}

.footerNav a:hover {
    color: var(--accent);
}

.footerSource {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.footerSource a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}

.footerCopy {
    font-size: 12px;
    color: #94a3b8;
}

/* ==========================================================================
   RESPONSIVE DESIGN ADAPTATIONS
   ========================================================================== */
@media (max-width: 768px) {
    .hero {
        padding: 48px 0;
    }
    
    .hero h1 {
        font-size: 28px;
    }
    
    .contentBlock {
        padding: 24px 18px;
    }
    
    #startScreen, #quizScreen, #resultsScreen {
        padding: 24px 16px;
    }
    
    .footerNav {
        flex-direction: column;
        align-items: center;
        gap: 12px;
    }
    
    .footerNav a {
        border-right: none;
        padding: 0;
    }
}

.hidden {
    display: none !important;
}