:root {
    --primary-green: #4CAF50;
    --dark-green: #388E3C;
    --light-green: #81C784;
    --accent-blue: #2196F3;
    --dark-blue: #1976D2;
    --neutral-50: #FAFAFA;
    --neutral-100: #F5F5F5;
    --neutral-200: #EEEEEE;
    --neutral-300: #E0E0E0;
    --neutral-400: #BDBDBD;
    --neutral-500: #9E9E9E;
    --neutral-600: #757575;
    --neutral-700: #616161;
    --neutral-800: #424242;
    --neutral-900: #212121;
    --gradient-primary: linear-gradient(135deg, #4CAF50 0%, #81C784 100%);
    --gradient-glass: linear-gradient(135deg, rgba(255,255,255,0.1), rgba(255,255,255,0.05));
    --gradient-background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 25px rgba(0,0,0,0.15);
    --shadow-xl: 0 12px 40px rgba(0,0,0,0.2);
    --blur-backdrop: blur(20px);
    --border-radius: 20px;
    --border-radius-lg: 28px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Space+Grotesk:wght@300;400;500;600;700&display=swap');

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--neutral-800);
    background: var(--gradient-background);
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.15) 0%, transparent 50%),
        var(--gradient-background);
    pointer-events: none;
    z-index: -1;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
    position: relative;
    z-index: 1;
}

/* Glass Morphism Components */
.glass-card {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
}

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

/* Header Styles */
.header {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    border: 1px solid rgba(255, 255, 255, 0.2);
    margin-bottom: 3rem;
    border-radius: var(--border-radius);
    overflow: hidden;
}

.header-content {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem 2rem;
    justify-content: flex-start;
}

.logo-image {
    height: 50px;
    width: auto;
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.1));
}

.header-text {
    flex: 1;
}

.logo {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    color: white;
    margin: 0;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.tagline {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.85);
    margin-top: 0.25rem;
    font-weight: 400;
    letter-spacing: 0.01em;
    line-height: 1.4;
}

/* Screen Components */
.screen {
    display: none;
    animation: fadeIn 0.5s ease-out;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Welcome Screen */
.welcome-screen {
    text-align: center;
    padding: 3rem;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
}

.welcome-screen h2 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 3rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.welcome-screen p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.8;
}

/* Modern Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    border: none;
    border-radius: 16px;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    position: relative;
    overflow: hidden;
    min-width: 140px;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
}

/* Quiz Screen */
.quiz-screen {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-lg);
    min-height: auto;
    overflow: hidden;
}

.question-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.question-counter {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.9rem;
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
}

.system-tag {
    background: rgba(76, 175, 80, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(76, 175, 80, 0.3);
}

.question-text {
    font-size: 1.1rem;
    color: white;
    margin-bottom: 1.25rem;
    line-height: 1.6;
    font-weight: 500;
    letter-spacing: 0.01em;
}

.options-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
}

.option {
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 1rem;
    cursor: pointer;
    transition: var(--transition);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    position: relative;
    overflow: hidden;
}

.option::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
    transition: left 0.3s;
}

.option:hover::before {
    left: 100%;
}

.option:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateX(4px);
}

.option.selected {
    background: rgba(76, 175, 80, 0.3);
    border-color: var(--primary-green);
    box-shadow: 0 0 20px rgba(76, 175, 80, 0.3);
}

.option-text {
    color: white;
    font-size: 1rem;
    font-weight: 500;
    position: relative;
    z-index: 1;
}

/* Navigation */
.quiz-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.25rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
}

/* Progress Bar */
.progress-container {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    height: 8px;
    margin: 1.25rem 0 1rem 0;
    overflow: hidden;
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
}

.progress-bar {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 10px;
    transition: width 0.3s ease;
    box-shadow: 0 0 10px rgba(76, 175, 80, 0.5);
}

/* Results Screen */
.results-screen {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-lg);
    padding: 3rem;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.results-screen h2 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 2rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.overall-score {
    background: var(--gradient-primary);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: var(--shadow-md);
}

.score-value {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 4rem;
    font-weight: 800;
    color: white;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.score-label {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.9);
    margin-top: 0.5rem;
}

.pass-probability {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin: 2rem 0;
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
}

.probability-text {
    font-size: 1.1rem;
    color: white;
    margin-bottom: 1rem;
}

.probability-bar {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    height: 12px;
    overflow: hidden;
}

.probability-fill {
    height: 100%;
    border-radius: 10px;
    transition: width 1s ease-out;
}

.probability-high {
    background: linear-gradient(90deg, #4CAF50, #81C784);
    box-shadow: 0 0 15px rgba(76, 175, 80, 0.5);
}

.probability-medium {
    background: linear-gradient(90deg, #FF9800, #FFB74D);
    box-shadow: 0 0 15px rgba(255, 152, 0, 0.5);
}

.probability-low {
    background: linear-gradient(90deg, #F44336, #EF5350);
    box-shadow: 0 0 15px rgba(244, 67, 54, 0.5);
}

/* System Breakdown */
.system-breakdown {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.system-score {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: var(--transition);
}

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

.system-name {
    font-weight: 600;
    color: white;
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.system-percentage {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--light-green);
}

/* Feedback Section */
.feedback-section {
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin: 2rem 0;
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.feedback-section h3 {
    font-family: 'Space Grotesk', sans-serif;
    color: white;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.feedback-section p {
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.7;
    margin-bottom: 1rem;
}

/* CTA Section */
.cta-section {
    background: var(--gradient-primary);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    margin: 3rem 0;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.cta-section h3 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.8rem;
    color: white;
    margin-bottom: 1rem;
}

.cta-section p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    .header-content {
        flex-direction: row;
        text-align: left;
        gap: 1rem;
        padding: 1rem 1.5rem;
    }
    
    .logo {
        font-size: 1.5rem;
    }
    
    .tagline {
        font-size: 0.9rem;
    }
    
    .welcome-screen h2 {
        font-size: 2.2rem;
    }
    
    .welcome-screen p {
        font-size: 1.1rem;
    }
    
    .quiz-screen {
        padding: 1.5rem;
    }
    
    .question-header {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }
    
    .question-text {
        font-size: 1rem;
    }
    
    .option {
        padding: 0.875rem;
    }
    
    .quiz-navigation {
        flex-direction: column;
        gap: 1rem;
    }
    
    .results-screen {
        padding: 2rem;
    }
    
    .score-value {
        font-size: 3rem;
    }
    
    .system-breakdown {
        grid-template-columns: 1fr;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0.5rem;
    }
    
    .welcome-screen {
        padding: 2rem;
    }
    
    .quiz-screen {
        padding: 1rem;
    }
    
    .results-screen {
        padding: 1.5rem;
    }
    
    .logo {
        font-size: 1.5rem;
    }
    
    .welcome-screen h2 {
        font-size: 1.8rem;
    }
    
    .results-screen h2 {
        font-size: 2rem;
    }
    
    .score-value {
        font-size: 2.5rem;
    }
}

/* Animations */
@keyframes pulse {
    0% {
        box-shadow: 0 0 0 0 rgba(76, 175, 80, 0.7);
    }
    70% {
        box-shadow: 0 0 0 10px rgba(76, 175, 80, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(76, 175, 80, 0);
    }
}

.btn-primary:focus {
    animation: pulse 2s infinite;
}

/* Loading States */
.loading {
    opacity: 0.7;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    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); }
}

/* Loading Indicator */
.loading-container {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.loading-content {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius);
    padding: 3rem;
    text-align: center;
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
    box-shadow: var(--shadow-xl);
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top: 4px solid var(--primary-green);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1.5rem auto;
}

.loading-content h3 {
    color: white;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.loading-content p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1rem;
}

/* Feature Highlights */
.feature-highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
}

.feature-item {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 1rem;
    text-align: center;
    backdrop-filter: var(--blur-backdrop);
    -webkit-backdrop-filter: var(--blur-backdrop);
}

.feature-item strong {
    display: block;
    color: white;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.feature-item span {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.85rem;
}