:root {
    --primary-blue: #2196F3;
    --success-green: #4CAF50;
    --warning-yellow: #FFC107;
    --danger-red: #F44336;
    --accent-purple: #9C27B0;
    
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-gradient: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.05) 100%);
    --holographic: linear-gradient(45deg, #ff006e, #8338ec, #3a86ff, #06ffa5, #ffbe0b);
    
    --shadow-light: 0 4px 15px rgba(0,0,0,0.1);
    --shadow-medium: 0 8px 25px rgba(0,0,0,0.15);
    --shadow-heavy: 0 15px 35px rgba(0,0,0,0.2);
    
    --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: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-gradient);
    color: white;
    overflow-x: hidden;
    min-height: 100vh;
}

#app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    padding-bottom: 80px;
}

.app-header {
    text-align: center;
    padding: 20px;
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255,255,255,0.2);
    position: sticky;
    top: 0;
    z-index: 100;
}

.app-header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: var(--holographic);
    background-size: 400% 400%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: holographic 3s ease-in-out infinite;
}

@keyframes holographic {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.main-content {
    flex: 1;
    padding: 20px;
}

.section {
    display: none;
    animation: fadeIn 0.5s ease-out;
}

.section.active {
    display: block;
}

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

.welcome-card {
    background: var(--card-gradient);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--border-radius);
    padding: 30px;
    text-align: center;
    margin-bottom: 30px;
    box-shadow: var(--shadow-medium);
}

.welcome-card h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--warning-yellow);
}

.welcome-card p {
    opacity: 0.9;
    font-size: 1.1rem;
}

.game-setup {
    background: var(--card-gradient);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--border-radius);
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-medium);
}

.setup-group {
    margin-bottom: 20px;
}

.setup-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--warning-yellow);
}

.setup-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid rgba(255,255,255,0.2);
    border-radius: 12px;
    background: rgba(255,255,255,0.1);
    color: rgb(5, 0, 0);
    font-size: 1rem;
    transition: var(--transition);
}

.setup-group select:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.3);
}

.start-btn {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, var(--success-green), #66BB6A);
    border: none;
    border-radius: 12px;
    color: white;
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

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

.start-btn:active {
    transform: translateY(0);
}

.game-area {
    background: var(--card-gradient);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--border-radius);
    padding: 20px;
    box-shadow: var(--shadow-medium);
}

.game-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 10px;
}

.info-item {
    background: rgba(255,255,255,0.1);
    padding: 10px 15px;
    border-radius: 8px;
    text-align: center;
    flex: 1;
    min-width: 100px;
}

.info-item span:first-child {
    display: block;
    font-size: 0.9rem;
    opacity: 0.8;
    margin-bottom: 5px;
}

.info-item span:last-child {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--warning-yellow);
}

.game-board {
    display: grid;
    gap: 10px;
    margin: 20px 0;
    justify-content: center;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.game-board.size-2x2 {
    grid-template-columns: repeat(2, 1fr);
}

.game-board.size-4x4 {
    grid-template-columns: repeat(4, 1fr);
}

.game-board.size-6x6 {
    grid-template-columns: repeat(6, 1fr);
}

.card {
    aspect-ratio: 1;
    background: var(--card-gradient);
    border: 2px solid rgba(255,255,255,0.2);
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    min-height: 60px;
}

.card::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;
}

.card:hover::before {
    transform: translateX(100%);
}

.card.flipped {
    background: linear-gradient(135deg, var(--primary-blue), #42A5F5);
    border-color: var(--primary-blue);
    transform: rotateY(0deg);
}

.card.matched {
    background: linear-gradient(135deg, var(--success-green), #66BB6A);
    border-color: var(--success-green);
    cursor: default;
    animation: matchPulse 0.6s ease-out;
}

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

.card.wrong {
    background: linear-gradient(135deg, var(--danger-red), #EF5350);
    border-color: var(--danger-red);
    animation: wrongShake 0.5s ease-out;
}

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

.card-content {
    font-size: 1.8rem;
    opacity: 0;
    transition: opacity 0.3s;
}

.card.flipped .card-content,
.card.matched .card-content {
    opacity: 1;
}

.game-controls {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 20px;
}

.control-btn {
    padding: 12px 20px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 8px;
    color: white;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
}

.control-btn:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-1px);
}

.stats-header,
.settings-header,
.faq-header {
    text-align: center;
    margin-bottom: 30px;
}

.stats-header h2,
.settings-header h2,
.faq-header h2 {
    font-size: 1.8rem;
    color: var(--warning-yellow);
    margin-bottom: 10px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: var(--card-gradient);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--border-radius);
    padding: 25px;
    text-align: center;
    box-shadow: var(--shadow-medium);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-heavy);
}

.stat-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.stat-info h3 {
    font-size: 2rem;
    color: var(--primary-blue);
    margin-bottom: 5px;
}

.stat-info p {
    opacity: 0.8;
    font-size: 0.9rem;
}

.stats-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.action-btn {
    padding: 12px 24px;
    background: linear-gradient(135deg, var(--primary-blue), #42A5F5);
    border: none;
    border-radius: 8px;
    color: white;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 600;
}

.action-btn.danger {
    background: linear-gradient(135deg, var(--danger-red), #EF5350);
}

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

.settings-group {
    background: var(--card-gradient);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--border-radius);
    padding: 25px;
    margin-bottom: 30px;
    box-shadow: var(--shadow-medium);
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.setting-item:last-child {
    border-bottom: none;
}

.setting-item label {
    font-weight: 600;
    color: var(--warning-yellow);
}

.setting-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--success-green);
}

.settings-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--card-gradient);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--border-radius);
    margin-bottom: 15px;
    overflow: hidden;
    box-shadow: var(--shadow-light);
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    padding: 20px;
    text-align: left;
    color: white;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 600;
    transition: var(--transition);
}

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

.faq-icon {
    font-size: 1.5rem;
    color: var(--primary-blue);
    transition: var(--transition);
}

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

.faq-answer {
    padding: 0 20px 20px;
    color: rgba(255,255,255,0.9);
    line-height: 1.6;
    animation: fadeInDown 0.3s ease-out;
}

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

.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0,0,0,0.9);
    backdrop-filter: blur(20px);
    border-top: 1px solid rgba(255,255,255,0.2);
    display: flex;
    justify-content: space-around;
    padding: 10px 0;
    z-index: 1000;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: rgba(255,255,255,0.6);
    transition: var(--transition);
    padding: 8px;
    border-radius: 8px;
    min-width: 60px;
}

.nav-item.active {
    color: var(--primary-blue);
    background: rgba(33, 150, 243, 0.1);
}

.nav-item i {
    font-size: 1.2rem;
    margin-bottom: 4px;
}

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

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    backdrop-filter: blur(10px);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal.show {
    display: flex;
    animation: modalFadeIn 0.3s ease-out;
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: var(--card-gradient);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--border-radius);
    max-width: 400px;
    width: 100%;
    box-shadow: var(--shadow-heavy);
    animation: modalSlideUp 0.3s ease-out;
}

@keyframes modalSlideUp {
    from { transform: translateY(50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-header {
    padding: 25px 25px 15px;
    text-align: center;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.modal-header h2 {
    color: var(--warning-yellow);
    font-size: 1.5rem;
}

.modal-body {
    padding: 20px 25px;
}

.game-results {
    margin-top: 20px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.result-item:last-child {
    border-bottom: none;
}

.result-item span:last-child {
    color: var(--primary-blue);
    font-weight: 700;
}

.modal-actions {
    padding: 15px 25px 25px;
    display: flex;
    gap: 10px;
    justify-content: center;
}

.modal-btn {
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 600;
}

.modal-btn.primary {
    background: linear-gradient(135deg, var(--success-green), #66BB6A);
    color: white;
}

.modal-btn {
    background: rgba(255,255,255,0.1);
    color: white;
    border: 1px solid rgba(255,255,255,0.2);
}

.modal-btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-light);
}

footer {
    background: var(--gray-800);
    color: var(--white);
    text-align: center;
    padding: 1rem;
    font-size: 0.9rem;
    margin-top: 2rem;
    margin-bottom: 7rem;
}

.app-footer {
    background: var(--gray-800);
    color: var(--white);
    text-align: center;
    padding: 1rem;
    font-size: 0.9rem;
    margin-top: 2rem;
}

.app-footer p {
    margin: 0;
    color: var(--white);
    font-size: 0.9rem;
    line-height: 1.4;
}

.app-footer strong {
    color: var(--white);
    font-weight: 600;
}

.app-footer .footer-link {
    color: var(--white);
    text-decoration: none;
    cursor: pointer;
    transition: opacity 0.3s ease;
}

.app-footer .footer-link:hover {
    opacity: 0.8;
}

.app-footer .footer-link:visited {
    color: var(--white);
}

.app-footer .footer-link:active {
    color: var(--white);
}

@media (max-width: 768px) {
    .main-content {
        padding: 15px;
    }
    
    .game-info {
        flex-direction: column;
        gap: 8px;
    }
    
    .info-item {
        display: flex;
        justify-content: space-between;
        text-align: left;
    }
    
    .info-item span:first-child {
        display: inline;
        margin-bottom: 0;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }
    
    .stat-card {
        padding: 20px;
    }
    
    .stat-icon {
        font-size: 2rem;
    }
    
    .stat-info h3 {
        font-size: 1.5rem;
    }
    
    .game-controls {
        flex-direction: column;
    }
    
    .control-btn {
        width: 100%;
        justify-content: center;
    }
    
    .stats-actions,
    .settings-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .action-btn {
        width: 100%;
        justify-content: center;
        max-width: 300px;
    }
}

@media (max-width: 480px) {
    .app-header h1 {
        font-size: 1.5rem;
    }
    
    .welcome-card {
        padding: 20px;
    }
    
    .welcome-card h2 {
        font-size: 1.3rem;
    }
    
    .card {
        min-height: 50px;
        font-size: 1.2rem;
    }
    
    .card-content {
        font-size: 1.5rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        margin: 10px;
    }
}

.paused {
    filter: blur(5px);
    pointer-events: none;
}

.card.disabled {
    pointer-events: none;
    opacity: 0.7;
}

.loading {
    opacity: 0.7;
    cursor: wait;
}

.success-message {
    background: var(--success-green);
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
    margin: 10px 0;
    text-align: center;
    animation: slideInDown 0.5s ease-out;
}

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

.error-message {
    background: var(--danger-red);
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
    margin: 10px 0;
    text-align: center;
    animation: slideInDown 0.5s ease-out;
}