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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-color: #f9fafb;
    --surface-color: #ffffff;
    --text-color: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s ease;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: 12px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.3s ease;
}

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

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

.modal-content h1 {
    margin-bottom: 0.75rem;
    color: var(--primary-color);
    font-size: 2rem;
}

.modal-content p {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
}

.code-display {
    margin: 1rem 0;
    padding: 0.75rem;
    background: var(--bg-color);
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 1.5rem;
    font-weight: bold;
    text-align: center;
    color: var(--primary-color);
    letter-spacing: 0.2em;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-submit {
    background: var(--success-color);
    color: white;
    font-size: 1.1rem;
    padding: 1rem 2rem;
}

.btn-submit:hover:not(:disabled) {
    background: #059669;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Challenge Area */
.challenge-area {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.challenge-area.hidden {
    display: none;
}

.header {
    background: var(--surface-color);
    padding: 1rem 1.5rem;
    box-shadow: var(--shadow);
    border-bottom: 1px solid var(--border-color);
}

.header h1 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.progress-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.progress-bar {
    flex: 1;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

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

.progress-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    white-space: nowrap;
}

.main-content {
    flex: 1;
    padding: 1rem 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

/* Challenges Container */
.challenges-container {
    display: grid;
    gap: 1rem;
    margin-bottom: 1rem;
}

.challenge {
    background: var(--surface-color);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem 1.25rem;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.challenge.active {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.challenge.completed {
    border-color: var(--success-color);
    opacity: 0.7;
}

.challenge-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

.challenge-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
}

.challenge-timer {
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--warning-color);
    font-family: 'Courier New', monospace;
}

.challenge-instructions {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.challenge-explanation {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    font-style: italic;
    line-height: 1.6;
    font-size: 0.95rem;
}

.challenge-content {
    margin-bottom: 0.75rem;
}

/* Challenge-specific styles */
.pattern-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(35px, 1fr));
    gap: 0.25rem;
    margin: 0.5rem 0;
    max-width: 400px;
    overflow: visible;
}

.pattern-item {
    aspect-ratio: 1;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

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

.pattern-item.selected {
    border-color: var(--primary-color);
    background: rgba(37, 99, 235, 0.1);
}

.math-puzzle {
    font-size: 1.5rem;
    text-align: center;
    padding: 1rem;
    background: var(--bg-color);
    border-radius: 8px;
    margin: 0.5rem 0;
}

.sequence-container {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    justify-content: center;
    margin: 0.75rem 0;
}

.sequence-item {
    width: 80px;
    height: 80px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
    background: var(--surface-color);
}

.sequence-item.missing {
    border-color: var(--primary-color);
    border-style: dashed;
    background: var(--bg-color);
}

.spatial-container {
    display: flex;
    gap: 1rem;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    margin: 0.75rem 0;
}

.shape {
    width: 120px;
    height: 120px;
    border: 3px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: var(--surface-color);
}

.shape:hover {
    transform: scale(1.1);
    border-color: var(--primary-color);
}

.shape.selected {
    border-color: var(--primary-color);
    background: rgba(37, 99, 235, 0.1);
}

.input-group {
    margin: 0.5rem 0;
}

.input-group label {
    display: block;
    margin-bottom: 0.25rem;
    color: var(--text-color);
    font-weight: 500;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s ease;
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Controls */
.controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    margin-top: 1rem;
}

.button-group {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.hidden {
    display: none !important;
}

.result-display {
    text-align: center;
    padding: 1.5rem;
    background: var(--surface-color);
    border-radius: 12px;
    box-shadow: var(--shadow);
    max-width: 600px;
    width: 100%;
}

.result-display h2 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    font-size: 2rem;
}

.result-display p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.btn-giveup {
    background: var(--error-color);
    color: white;
    font-size: 1.1rem;
    padding: 1rem 2rem;
}

.btn-giveup:hover:not(:disabled) {
    background: #dc2626;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.feedback {
    min-height: 2rem;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
    transition: all 0.3s ease;
}

.feedback.success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

.feedback.error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error-color);
    border: 1px solid var(--error-color);
}

.feedback.info {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

/* Responsive */
@media (max-width: 768px) {
    .modal-content {
        padding: 1.5rem;
    }

    .main-content {
        padding: 1rem;
    }

    .challenge {
        padding: 1.5rem;
    }

    .challenges-container {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.pulsing {
    animation: pulse 1s infinite;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

.shake {
    animation: shake 0.5s;
}