:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 40px -10px rgba(0, 0, 0, 0.15);
    --border-radius: 16px;
    --border-radius-sm: 8px;
    --font-family: 'Montserrat', sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-family);
    background: var(--primary-gradient);
    min-height: 100vh;
    color: var(--text-primary);
    overflow-x: hidden;
}

#app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 2rem;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.app-title {
    font-size: 1.8rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-controls {
    display: flex;
    gap: 0.5rem;
}

.icon-btn {
    background: none;
    border: none;
    font-size: 1.2rem;
    padding: 0.5rem;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background: rgba(102, 126, 234, 0.1);
    transform: translateY(-2px);
}

.streak-display {
    text-align: center;
    margin-top: 0.5rem;
}

.streak-text {
    font-weight: 600;
    color: var(--warning-color);
}

.screen {
    flex: 1;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    animation: fadeIn 0.5s ease-out;
}

.screen.hidden {
    display: none;
}

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

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

@keyframes bounce {
    0%, 20%, 53%, 80%, 100% { transform: translate3d(0,0,0); }
    40%, 43% { transform: translate3d(0, -15px, 0); }
    70% { transform: translate3d(0, -7px, 0); }
    90% { transform: translate3d(0, -2px, 0); }
}

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

.welcome-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    margin-bottom: 2rem;
}

.welcome-card h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.puzzle-packs h3 {
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--bg-white);
    font-size: 1.5rem;
}

.pack-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.pack-card {
    background: var(--bg-white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

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

.pack-card.locked {
    opacity: 0.6;
    cursor: not-allowed;
}

.pack-card.locked::after {
    content: '🔒';
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 1.2rem;
}

.pack-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.pack-card h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.pack-progress {
    margin-top: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.primary-btn {
    background: var(--secondary-gradient);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
    display: block;
}

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

.secondary-btn {
    background: var(--bg-white);
    color: var(--text-primary);
    border: 2px solid rgba(102, 126, 234, 0.2);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.secondary-btn:hover {
    border-color: rgba(102, 126, 234, 0.5);
    background: rgba(102, 126, 234, 0.05);
}

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

.puzzle-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    background: var(--bg-white);
    padding: 1rem 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.puzzle-info {
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.puzzle-content {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
    min-height: 300px;
}

#puzzleArea {
    text-align: center;
}

.puzzle-question {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.pattern-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
    max-width: 300px;
    margin: 2rem auto;
}

.pattern-cell {
    width: 60px;
    height: 60px;
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
}

.pattern-cell:hover {
    border-color: var(--success-color);
    transform: scale(1.05);
}

.pattern-cell.selected {
    background: var(--success-color);
    color: white;
}

.memory-sequence {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin: 2rem 0;
}

.memory-item {
    width: 50px;
    height: 50px;
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    animation: flash 0.5s ease-in-out;
}

@keyframes flash {
    0%, 100% { background: var(--bg-white); }
    50% { background: var(--warning-color); color: white; }
}

.puzzle-controls {
    background: var(--bg-white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

#answerArea {
    margin-bottom: 1rem;
}

.answer-input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    margin-bottom: 1rem;
    transition: var(--transition);
}

.answer-input:focus {
    outline: none;
    border-color: var(--success-color);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.answer-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}

.answer-option {
    padding: 0.75rem;
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

.answer-option:hover {
    border-color: var(--success-color);
    background: rgba(16, 185, 129, 0.05);
}

.answer-option.selected {
    border-color: var(--success-color);
    background: var(--success-color);
    color: white;
}

.stats-container, .achievements-container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 2rem;
}

.stats-header, .achievements-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition);
}

.close-btn:hover {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error-color);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    text-align: center;
    padding: 1.5rem 1rem;
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.stat-card:hover {
    border-color: var(--success-color);
    transform: translateY(-2px);
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--success-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.achievements-list {
    display: grid;
    gap: 1rem;
}

.achievement-item {
    display: flex;
    align-items: center;
    padding: 1rem;
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
}

.achievement-item.unlocked {
    border-color: var(--success-color);
    background: rgba(16, 185, 129, 0.05);
}

.achievement-icon {
    font-size: 2rem;
    margin-right: 1rem;
}

.achievement-info h4 {
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.achievement-info p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn 0.3s ease-out;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    max-width: 400px;
    width: 90%;
    text-align: center;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.success-content .success-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

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

.success-stats {
    background: var(--bg-light);
    padding: 1rem;
    border-radius: var(--border-radius-sm);
    margin: 1rem 0;
    font-weight: 600;
}

.success-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1.5rem;
}

.success-buttons button {
    flex: 1;
    max-width: none;
}

.bounce {
    animation: bounce 1s ease-out;
}

@media (max-width: 768px) {
    .header { padding: 1rem; }
    .app-title { font-size: 1.4rem; }
    .screen { padding: 1rem; }
    .pack-grid { grid-template-columns: 1fr; }
    .puzzle-header { flex-wrap: wrap; gap: 1rem; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .success-buttons { flex-direction: column; }
    .modal-content { padding: 1.5rem; }
}

@media (max-width: 480px) {
    .header-content { flex-wrap: wrap; gap: 1rem; }
    .stats-grid { grid-template-columns: 1fr; }
    .pattern-grid { max-width: 250px; }
    .pattern-cell { width: 50px; height: 50px; }
}