/* ===============================================
   MAIN.CSS - BUSINESS ANALYST QUIZ FORM
   Core Layout, Typography & Base Styles
   
   TABLE OF CONTENTS:
   1. CSS Reset & Base Styles
   2. Typography System
   3. Layout System
   4. Utility Classes
   5. Responsive Design System
   6. Navigation & Interactive Elements
   7. Accessibility & Focus Management
   8. Loading States & Animations
   9. Print Styles
   =============================================== */

/* ===============================================
   1. CSS RESET & BASE STYLES
   Modern CSS reset with sensible defaults
   =============================================== */

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

html {
    font-size: 16px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, 
                 "Helvetica Neue", Arial, sans-serif;
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-normal);
    line-height: var(--line-height-normal);
    color: var(--text-primary);
    background-color: transparent; /* Let parent handle background */
    min-height: 100vh;
    overflow-x: hidden;
}

/* ===============================================
   2. TYPOGRAPHY SYSTEM
   Consistent text hierarchy and styling
   =============================================== */

/* 2.1 Heading Hierarchy */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-bold);
    line-height: var(--line-height-tight);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: var(--font-size-4xl);
    letter-spacing: -0.025em;
}

h2 {
    font-size: var(--font-size-3xl);
    letter-spacing: -0.025em;
}

h3 {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-semibold);
}

h4 {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-semibold);
}

h5 {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-medium);
}

h6 {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* 2.2 Body Text */
p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
    line-height: var(--line-height-relaxed);
}

p:last-child {
    margin-bottom: 0;
}

/* 2.3 Typography Utility Classes */
.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-base { font-size: var(--font-size-base); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-2xl { font-size: var(--font-size-2xl); }
.text-3xl { font-size: var(--font-size-3xl); }
.text-4xl { font-size: var(--font-size-4xl); }

.font-normal { font-weight: var(--font-weight-normal); }
.font-medium { font-weight: var(--font-weight-medium); }
.font-semibold { font-weight: var(--font-weight-semibold); }
.font-bold { font-weight: var(--font-weight-bold); }

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-tertiary { color: var(--text-tertiary); }
.text-accent { color: var(--accent-primary); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-error { color: var(--error); }

.text-left { text-align: left; }
.text-center { text-align: center; }
.text-right { text-align: right; }

/* ===============================================
   3. LAYOUT SYSTEM
   Container, grid, and flexbox utilities
   =============================================== */

/* 3.1 Main Containers */
.quiz-container {
    width: 100%;
    max-width: 42rem; /* 672px - optimal reading width */
    margin: 0 auto;
    padding: var(--spacing-lg);
    position: relative;
}

.quiz-section {
    background-color: var(--bg-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-primary);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    transition: all var(--transition-normal);
}

.quiz-section:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-2px);
}

.content-section {
    margin-bottom: var(--spacing-2xl);
}

.content-section:last-child {
    margin-bottom: 0;
}

/* 3.2 Flexbox System */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }

.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.items-end { align-items: flex-end; }
.items-stretch { align-items: stretch; }

.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }

.flex-1 { flex: 1 1 0%; }
.flex-auto { flex: 1 1 auto; }
.flex-none { flex: none; }

/* 3.3 Grid System */
.grid { display: grid; }
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.gap-xs { gap: var(--spacing-xs); }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* ===============================================
   4. UTILITY CLASSES
   Spacing, visual, and interaction utilities
   =============================================== */

/* 4.1 Spacing Utilities */
/* Margin */
.m-0 { margin: 0; }
.m-xs { margin: var(--spacing-xs); }
.m-sm { margin: var(--spacing-sm); }
.m-md { margin: var(--spacing-md); }
.m-lg { margin: var(--spacing-lg); }
.m-xl { margin: var(--spacing-xl); }
.m-2xl { margin: var(--spacing-2xl); }

.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }
.mt-2xl { margin-top: var(--spacing-2xl); }

.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }
.mb-2xl { margin-bottom: var(--spacing-2xl); }

.ml-0 { margin-left: 0; }
.ml-xs { margin-left: var(--spacing-xs); }
.ml-sm { margin-left: var(--spacing-sm); }
.ml-md { margin-left: var(--spacing-md); }
.ml-auto { margin-left: auto; }

.mr-0 { margin-right: 0; }
.mr-xs { margin-right: var(--spacing-xs); }
.mr-sm { margin-right: var(--spacing-sm); }
.mr-md { margin-right: var(--spacing-md); }
.mr-auto { margin-right: auto; }

/* Padding */
.p-0 { padding: 0; }
.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }
.p-2xl { padding: var(--spacing-2xl); }

.pt-0 { padding-top: 0; }
.pt-xs { padding-top: var(--spacing-xs); }
.pt-sm { padding-top: var(--spacing-sm); }
.pt-md { padding-top: var(--spacing-md); }
.pt-lg { padding-top: var(--spacing-lg); }
.pt-xl { padding-top: var(--spacing-xl); }

.pb-0 { padding-bottom: 0; }
.pb-xs { padding-bottom: var(--spacing-xs); }
.pb-sm { padding-bottom: var(--spacing-sm); }
.pb-md { padding-bottom: var(--spacing-md); }
.pb-lg { padding-bottom: var(--spacing-lg); }
.pb-xl { padding-bottom: var(--spacing-xl); }

.px-0 { padding-left: 0; padding-right: 0; }
.px-xs { padding-left: var(--spacing-xs); padding-right: var(--spacing-xs); }
.px-sm { padding-left: var(--spacing-sm); padding-right: var(--spacing-sm); }
.px-md { padding-left: var(--spacing-md); padding-right: var(--spacing-md); }
.px-lg { padding-left: var(--spacing-lg); padding-right: var(--spacing-lg); }
.px-xl { padding-left: var(--spacing-xl); padding-right: var(--spacing-xl); }

.py-0 { padding-top: 0; padding-bottom: 0; }
.py-xs { padding-top: var(--spacing-xs); padding-bottom: var(--spacing-xs); }
.py-sm { padding-top: var(--spacing-sm); padding-bottom: var(--spacing-sm); }
.py-md { padding-top: var(--spacing-md); padding-bottom: var(--spacing-md); }
.py-lg { padding-top: var(--spacing-lg); padding-bottom: var(--spacing-lg); }
.py-xl { padding-top: var(--spacing-xl); padding-bottom: var(--spacing-xl); }

/* 4.2 Visual Utilities */
/* Display */
.hidden { display: none; }
.block { display: block; }
.inline { display: inline; }
.inline-block { display: inline-block; }

/* Position */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

/* Visibility & Overflow */
.invisible { visibility: hidden; }
.visible { visibility: visible; }
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-scroll { overflow: scroll; }

/* Border Radius */
.rounded-none { border-radius: 0; }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

/* Borders */
.border { border: 1px solid var(--border-primary); }
.border-0 { border: 0; }
.border-t { border-top: 1px solid var(--border-primary); }
.border-b { border-bottom: 1px solid var(--border-primary); }
.border-l { border-left: 1px solid var(--border-primary); }
.border-r { border-right: 1px solid var(--border-primary); }

/* Shadows */
.shadow-none { box-shadow: none; }
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

/* 4.3 Animation & Transition Utilities */
.transition-none { transition: none; }
.transition-all { transition: all var(--transition-normal); }
.transition-colors { 
    transition: color var(--transition-fast), 
                background-color var(--transition-fast), 
                border-color var(--transition-fast); 
}
.transition-opacity { transition: opacity var(--transition-normal); }
.transition-transform { transition: transform var(--transition-normal); }

/* Transform */
.transform { transform: translateZ(0); } /* Enable 3D acceleration */
.scale-95 { transform: scale(0.95); }
.scale-100 { transform: scale(1); }
.scale-105 { transform: scale(1.05); }
.translate-y-1 { transform: translateY(0.25rem); }
.translate-y-2 { transform: translateY(0.5rem); }
.-translate-y-1 { transform: translateY(-0.25rem); }
.-translate-y-2 { transform: translateY(-0.5rem); }

/* Opacity */
.opacity-0 { opacity: 0; }
.opacity-25 { opacity: 0.25; }
.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }
.opacity-100 { opacity: 1; }

/* ===============================================
   5. RESPONSIVE DESIGN SYSTEM
   Mobile-first breakpoints with optimized spacing
   =============================================== */

/* 5.1 Ultra-Small Mobile (≤320px) - Maximum Efficiency */
@media (max-width: 20rem) {
    :root {
        --container-padding: 8px;
        --card-padding: 12px;
        --section-padding: 16px;
        --element-gap: 4px;
    }
    
    .quiz-container {
        padding: var(--container-padding);
        max-width: 100%;
    }
    
    .quiz-section,
    .question-card {
        padding: var(--section-padding);
        margin-bottom: 8px;
        border-radius: var(--radius-md);
    }
    
    .answer-options {
        gap: var(--element-gap);
    }
    
    .quiz-navigation {
        gap: var(--element-gap);
        padding: 12px 0;
    }
}

/* 5.2 Compact Mobile (321px - 375px) - Balanced Efficiency */
@media (min-width: 20.0625rem) and (max-width: 23.4375rem) {
    :root {
        --container-padding: 12px;
        --card-padding: 16px;
        --section-padding: 20px;
        --element-gap: 6px;
    }
    
    .quiz-container {
        padding: var(--container-padding);
    }
    
    .quiz-section,
    .question-card {
        padding: var(--section-padding);
        margin-bottom: 12px;
        border-radius: var(--radius-lg);
    }
    
    .answer-options {
        gap: var(--element-gap);
    }
    
    .quiz-navigation {
        gap: var(--element-gap);
        padding: 16px 0;
    }
}

/* 5.3 Standard Mobile (376px - 414px) - Comfortable Spacing */
@media (min-width: 23.5rem) and (max-width: 25.875rem) {
    :root {
        --container-padding: var(--spacing-md);
        --card-padding: var(--spacing-lg);
        --section-padding: var(--spacing-xl);
    }
    
    .quiz-container {
        padding: var(--container-padding);
    }
    
    .quiz-section,
    .question-card {
        padding: var(--section-padding);
        margin-bottom: var(--spacing-lg);
    }
}

/* 5.4 Large Mobile (415px - 480px) - Enhanced Experience */
@media (min-width: 25.9375rem) and (max-width: 30rem) {
    :root {
        --container-padding: 24px;
        --card-padding: 32px;
        --section-padding: 40px;
        --element-gap: 16px;
    }
    
    .quiz-container {
        padding: var(--container-padding);
        max-width: 28rem;
    }
    
    .quiz-section,
    .question-card {
        padding: var(--section-padding);
        margin-bottom: 24px;
        border-radius: var(--radius-xl);
    }
    
    .answer-options {
        gap: 8px;
        margin-bottom: 40px;
    }
    
    .quiz-navigation {
        gap: var(--element-gap);
        padding: 32px 0;
    }
    
    /* Enhanced Typography for Large Mobile */
    .question-text {
        font-size: 22px;
        line-height: 1.4;
        font-weight: var(--font-weight-semibold);
        margin-bottom: 8px;
    }
    
    .answer-text {
        font-size: 16px;
        line-height: 1.4;
    }
    
    .welcome-title {
        font-size: 40px;
        line-height: 1.25;
        margin-bottom: 8px;
    }
    
    .welcome-subtitle {
        font-size: 18px;
        line-height: 1.6;
        margin-bottom: 40px;
    }
    
    .results-title {
        font-size: 32px;
        line-height: 1.25;
        margin-bottom: 8px;
    }
    
    .results-score {
        font-size: 22px;
        margin-bottom: 16px;
    }
}

/* 5.5 Large Mobile & Small Tablets (415px - 767px) */
@media (min-width: 25.9375rem) and (max-width: 47.9375rem) {
    .quiz-container {
        max-width: 36rem;
        padding: var(--spacing-lg);
    }
    
    .quiz-section,
    .question-card {
        padding: var(--spacing-2xl);
        margin-bottom: var(--spacing-xl);
    }
}

/* 5.6 Tablets & Desktop (768px+) */
@media (min-width: 48rem) {
    :root {
        --container-padding: var(--spacing-xl);
        --card-padding: var(--spacing-2xl);
        --section-padding: 64px;
    }
    
    .quiz-container {
        padding: var(--container-padding);
        max-width: 42rem;
    }
    
    .quiz-section,
    .question-card {
        padding: var(--section-padding);
        margin-bottom: var(--spacing-2xl);
    }

    .results-cta {
        flex-direction: row;
        justify-content: center;
        gap: 24px;
    }
    
    .cta-button {
        min-width: 180px;
        max-width: 260px;
    }
}

/* 5.7 Large Desktop (992px+) */
@media (min-width: 62rem) {
    .quiz-container {
        max-width: 48rem;
        padding: var(--spacing-2xl);
    }
}

/* 5.8 Mobile-First Typography Optimizations */
@media (max-width: 48rem) {
    .question-text {
        font-size: var(--font-size-xl);
        line-height: 1.4;
        margin-bottom: var(--spacing-lg);
    }
    
    .answer-text {
        font-size: var(--font-size-base);
        line-height: 1.5;
    }
    
    .welcome-title {
        font-size: var(--font-size-3xl);
        line-height: 1.2;
        margin-bottom: var(--spacing-lg);
    }
    
    .welcome-subtitle {
        font-size: var(--font-size-lg);
        line-height: 1.6;
    }
    
    .results-title {
        font-size: var(--font-size-2xl);
        line-height: 1.3;
    }
    
    .results-description {
        font-size: var(--font-size-base);
        line-height: 1.6;
    }
}

/* ===============================================
   6. NAVIGATION & INTERACTIVE ELEMENTS
   Simplified navigation system to match app.js changes
   =============================================== */

/* 6.1 Navigation Buttons */
.nav-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    
    min-height: 48px; /* Touch-friendly minimum */
    padding: var(--spacing-md) var(--spacing-xl);
    
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    text-decoration: none;
    
    border: 2px solid transparent;
    border-radius: var(--radius-lg);
    background-color: var(--accent-primary);
    color: var(--text-inverse);
    
    cursor: pointer;
    transition: all var(--transition-fast);
    
    /* Ensure consistent button sizing */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.nav-btn:hover:not(:disabled) {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.nav-btn:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.nav-btn:focus-visible {
    outline: none;
    box-shadow: 0 0 0 3px var(--focus-ring);
}

/* Navigation button variants */
.nav-btn-primary {
    background-color: var(--accent-primary);
    color: var(--text-inverse);
}

.nav-btn-secondary {
    background-color: transparent;
    color: var(--accent-primary);
    border-color: var(--accent-primary);
}

.nav-btn-secondary:hover:not(:disabled) {
    background-color: var(--accent-primary);
    color: var(--text-inverse);
}

/* 6.2 Navigation Layout */
.quiz-navigation {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-primary);
}

.quiz-navigation-single {
    justify-content: center;
}

.nav-btn-centered {
    min-width: 140px; /* Consistent button width */
    max-width: 200px;
}

/* 6.3 CTA Buttons (Results page) */
.cta-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    
    min-height: 56px;
    padding: 16px 32px;
    
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    letter-spacing: 0.025em;
    
    border: none;
    border-radius: 12px;
    
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Prevent text overflow and ensure proper sizing */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    
    /* Key constraint for button width */
    min-width: 160px;
    max-width: 240px;
    
    /* Modern shadow */
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    
    /* Position for hover effects */
    position: relative;
    overflow: hidden;
}

.cta-button .btn-icon,
.nav-btn .nav-btn-icon {
    display: none !important;
}

.btn-primary.cta-button {
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    color: white;
}

.btn-secondary.cta-button {
    background: white;
    color: #3b82f6;
    border: 2px solid #3b82f6;
}

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

.btn-primary.cta-button:hover {
    background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.4);
}

.btn-primary.cta-button:active {
    transform: translateY(0);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-secondary.cta-button:hover {
    background: #3b82f6;
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.25);
}

.btn-secondary.cta-button:active {
    transform: translateY(0);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

.results-cta {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-top: 32px;
    align-items: center;
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.1) 50%, transparent 70%);
    transform: translateX(-100%);
    transition: transform 0.6s;
}

.cta-button:hover::before {
    transform: translateX(100%);
}

/* 6.4 Button Icons */
.nav-btn-icon,
.btn-icon {
    font-size: 1.1em;
    opacity: 0.9;
}

/* 6.5 Button States */
.btn-clicked {
    transform: scale(0.98);
    opacity: 0.8;
}

/* ===============================================
   7. ACCESSIBILITY & FOCUS MANAGEMENT
   =============================================== */

/* 7.1 Focus Styles */
.focus-ring:focus,
.focus-ring:focus-visible {
    outline: none;
    box-shadow: 0 0 0 3px var(--focus-ring);
}

/* 7.2 Skip Links */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--bg-primary);
    color: var(--text-primary);
    padding: 8px;
    text-decoration: none;
    border-radius: var(--radius-md);
    z-index: var(--z-tooltip);
}

.skip-link:focus {
    top: 6px;
}

/* 7.3 Screen Reader Only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* 7.4 Enhanced Button Accessibility */
.nav-btn:focus-visible,
.cta-button:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* ===============================================
   8. LOADING STATES & ANIMATIONS
   =============================================== */

/* 8.1 Loading States */
.loading {
    opacity: 0.6;
    pointer-events: none;
    cursor: wait;
}

/* 8.2 Skeleton Loading */
.skeleton {
    background: linear-gradient(90deg, 
        var(--bg-secondary) 25%, 
        var(--bg-tertiary) 50%, 
        var(--bg-secondary) 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* 8.3 Button Loading Animation */
.nav-btn.loading::after {
    content: '';
    width: 16px;
    height: 16px;
    margin-left: var(--spacing-sm);
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 8.4 Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    .skeleton {
        animation: none;
        background: var(--bg-secondary);
    }
    
    .nav-btn.loading::after {
        animation: none;
        border: 2px solid currentColor;
    }
    
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ===============================================
   9. PRINT STYLES
   =============================================== */

@media print {
    .quiz-container {
        max-width: none;
        padding: 0;
        box-shadow: none;
    }
    
    .quiz-section {
        box-shadow: none;
        border: 1px solid #ccc;
        break-inside: avoid;
        margin-bottom: var(--spacing-lg);
    }
    
    /* Hide interactive elements */
    button,
    .btn,
    .nav-btn,
    .cta-button,
    input[type="button"],
    input[type="submit"],
    .quiz-navigation {
        display: none;
    }
    
    /* Ensure good contrast for print */
    .question-card,
    .results-container {
        border: 1px solid #333;
        background: white;
        color: black;
    }
}

/* ===============================================
   RESPONSIVE NAVIGATION ADJUSTMENTS
   Mobile-specific navigation optimizations
   =============================================== */

/* Ultra-small mobile navigation */
@media (max-width: 20rem) {
    .nav-btn {
        min-height: 44px;
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: var(--font-size-sm);
    }
    
    .cta-button {
        min-height: 48px;
        padding: 12px 20px;
        font-size: 14px;
        min-width: 140px;
        max-width: 200px;
    }

    .results-cta {
        gap: 12px;
    }
    
    .nav-btn-centered {
        min-width: 120px;
    }
}

/* Compact mobile navigation */
@media (min-width: 20.0625rem) and (max-width: 23.4375rem) {
    .nav-btn {
        min-height: 46px;
        padding: var(--spacing-sm) var(--spacing-lg);
        font-size: var(--font-size-sm);
    }
    
    .cta-button {
        min-height: 52px;
        padding: 14px 24px;
        font-size: 15px;
        min-width: 150px;
        max-width: 220px;
    }
    
    .nav-btn-centered {
        min-width: 130px;
    }

    .results-cta {
        gap: 14px;
    }
}

/* Standard mobile navigation - use defaults */

/* Large mobile navigation enhancements */
@media (min-width: 25.9375rem) and (max-width: 30rem) {
    .nav-btn {
        min-height: 52px;
        padding: var(--spacing-md) var(--spacing-xl);
        font-size: var(--font-size-lg);
        max-width: 200px; /* Prevent excessive width expansion */
    }
    
    .cta-button {
        min-height: 56px;
        padding: 16px 32px;
        font-size: 16px;
        min-width: 180px;
        max-width: 240px; /* Constrain width at 425px */
    }
    
    .nav-btn-centered {
        min-width: 160px;
        max-width: 200px; /* Match nav-btn max-width */
    }

    .results-cta {
        gap: 16px;
    }
}

/* Additional constraint for all buttons at larger mobile sizes */
@media (min-width: 25.9375rem) and (max-width: 47.9375rem) {
    .quiz-navigation-single {
        display: flex;
        justify-content: center;
        align-items: center;
    }
    
    .quiz-navigation-single .nav-btn {
        flex: 0 0 auto; /* Prevent flex growth */
        width: auto; /* Use content width */
        max-width: min(200px, 60vw); /* Responsive max-width */
    }
}