:root {
    --primary-color: #FF006E;
    --secondary-color: #FB5607;
    --accent-color: #FFBE0B;
    --purple: #8338EC;
    --blue: #3A86FF;
    --dark: #1a1a1a;
    --light: #ffffff;
    --gray: #666666;
    --light-gray: #f5f5f5;
    --gradient-primary: linear-gradient(135deg, var(--primary-color), var(--purple));
    --gradient-secondary: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    --gradient-blue: linear-gradient(135deg, var(--blue), var(--purple));
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.15);
    --border-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--dark);
    line-height: 1.6;
    overflow-x: hidden;
    padding-bottom: 80px;
}

.app-header {
    background: var(--gradient-primary);
    color: var(--light);
    padding: 1rem;
    text-align: center;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.user-info {
    display: flex;
    justify-content: center;
    gap: 1rem;
    font-size: 0.9rem;
    opacity: 0.9;
}

.app-main {
    padding: 1rem;
    max-width: 1200px;
    margin: 0 auto;
    min-height: calc(100vh - 160px);
}

.screen {
    display: none;
    animation: fadeIn 0.3s ease-in-out;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Home Screen Styles */
.welcome-card {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    text-align: center;
}

.welcome-card h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.8rem;
}

.welcome-card p {
    color: var(--gray);
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.stats-overview {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--gray);
}

.stat-item i {
    color: var(--secondary-color);
    width: 20px;
}

.cta-button {
    background: var(--gradient-primary);
    color: var(--light);
    border: none;
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow);
    width: 100%;
}

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

.quick-actions {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

.action-button {
    background: var(--light);
    border: 2px solid var(--blue);
    color: var(--blue);
    padding: 1rem;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    justify-content: center;
}

.action-button:hover {
    background: var(--blue);
    color: var(--light);
    transform: translateY(-2px);
}

/* Quest Screen Styles */
.quest-header {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    text-align: center;
}

.quest-header h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.progress-bar {
    background: var(--light-gray);
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    background: var(--gradient-secondary);
    height: 100%;
    width: 0%;
    transition: width 0.3s ease;
}

#progress-text {
    color: var(--gray);
    font-size: 0.9rem;
}

.challenge-container {
    margin-bottom: 2rem;
}

.challenge-card {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow);
}

.challenge-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

.challenge-content {
    margin-bottom: 2rem;
}

.challenge-content p {
    color: var(--gray);
    font-size: 1.1rem;
    line-height: 1.7;
}

.options-container {
    margin-bottom: 2rem;
}

.option-item {
    background: var(--light-gray);
    border: 2px solid transparent;
    border-radius: var(--border-radius);
    padding: 1rem;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.option-item:hover {
    border-color: var(--blue);
    background: rgba(58, 134, 255, 0.1);
}

.option-item.selected {
    border-color: var(--primary-color);
    background: rgba(255, 0, 110, 0.1);
}

.option-item input[type="radio"] {
    margin: 0;
    width: 20px;
    height: 20px;
}

.option-item label {
    flex: 1;
    cursor: pointer;
    font-weight: 500;
}

.challenge-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.submit-button {
    background: var(--gradient-primary);
    color: var(--light);
    border: none;
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    flex: 1;
    min-width: 200px;
}

.submit-button:disabled {
    background: var(--gray);
    cursor: not-allowed;
    opacity: 0.6;
}

.submit-button:not(:disabled):hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.hint-button {
    background: var(--gradient-secondary);
    color: var(--light);
    border: none;
    padding: 1rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 2rem;
    max-width: 400px;
    width: 100%;
    text-align: center;
    box-shadow: var(--shadow-hover);
}

.modal-content h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.modal-content p {
    color: var(--gray);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.result-stats {
    display: flex;
    justify-content: space-around;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--light-gray);
    border-radius: var(--border-radius);
}

.result-stats span {
    font-weight: 600;
    color: var(--primary-color);
}

/* Stats Screen Styles */
.stats-header {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    text-align: center;
}

.stats-header h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.level-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--gradient-secondary);
    color: var(--light);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 600;
}

.stats-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.stat-card {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.stat-card i {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 1rem;
}

.stat-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.stat-card p {
    color: var(--gray);
    font-size: 1.1rem;
    font-weight: 600;
}

.style-description {
    color: var(--gray);
    font-size: 0.9rem;
    margin-top: 0.5rem;
    font-style: italic;
}

.performance-metrics, .activity-stats {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.metric {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--light-gray);
}

.metric:last-child {
    border-bottom: none;
}

.achievements-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.achievement-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem;
    background: var(--light-gray);
    border-radius: 8px;
}

.achievement-item.unlocked {
    background: rgba(255, 190, 11, 0.2);
    color: var(--accent-color);
}

/* FAQ Styles */
.faq-header {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    text-align: center;
}

.faq-header h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.faq-header p {
    color: var(--gray);
}

.faq-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-item {
    background: var(--light);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    padding: 1.5rem;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background: rgba(255, 0, 110, 0.05);
}

.faq-icon {
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: var(--gray);
    line-height: 1.7;
    animation: slideDown 0.3s ease;
}

.faq-answer[hidden] {
    display: none;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--light);
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding: 0.5rem;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.5rem;
    color: var(--gray);
    text-decoration: none;
    transition: var(--transition);
    border-radius: 12px;
    min-width: 60px;
}

.nav-item i {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.nav-item span {
    font-size: 0.7rem;
    font-weight: 600;
}

.nav-item.active {
    color: var(--primary-color);
    background: rgba(255, 0, 110, 0.1);
}

.nav-item:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Footer */
footer {
    background: var(--dark);
    color: var(--light);
    text-align: center;
    padding: 1rem;
    font-size: 0.8rem;
    opacity: 0.8;
    margin-top: 2rem;
}

/* Responsive Design */
@media (min-width: 768px) {
    .app-main {
        padding: 2rem;
    }
    
    .quick-actions {
        grid-template-columns: 1fr 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stats-overview {
        flex-direction: row;
        justify-content: space-around;
    }
    
    .challenge-actions {
        flex-wrap: nowrap;
    }
    
    .submit-button {
        min-width: auto;
    }
}

@media (min-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .bottom-nav {
        position: relative;
        box-shadow: none;
        background: transparent;
        justify-content: center;
        gap: 2rem;
        padding: 2rem;
    }
    
    .nav-item {
        background: var(--light);
        box-shadow: var(--shadow);
        padding: 1rem;
        border-radius: var(--border-radius);
        min-width: 120px;
    }
    
    body {
        padding-bottom: 0;
    }
}

/* Animations and Micro-interactions */
.pulse {
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.shake {
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-5px);
    }
    75% {
        transform: translateX(5px);
    }
}

.success {
    animation: success 0.6s ease-in-out;
}

@keyframes success {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
button:focus,
.nav-item:focus,
.faq-question:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
        --shadow-hover: 0 8px 16px rgba(0, 0, 0, 0.4);
    }
}