/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #2d3748;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Styles */
.header {
    text-align: center;
    margin-bottom: 40px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
}

.course-badge {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 12px 20px;
    border-radius: 25px;
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
    margin-right: 20px;
    height: fit-content;
    min-height: 60px;
    justify-content: center;
}

.course-title {
    font-size: 18px;
    font-weight: 600;
    display: block;
    margin-bottom: 2px;
    line-height: 1.1;
}

.course-subtitle {
    font-size: 12px;
    font-weight: 400;
    opacity: 0.9;
    display: block;
    line-height: 1.1;
}

.title {
    font-size: 2.5rem;
    font-weight: 700;
    color: #2d3748;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.title i {
    color: #667eea;
    font-size: 2.2rem;
}

.subtitle {
    font-size: 1.2rem;
    color: #718096;
    font-weight: 400;
}

/* Navigation Tabs */
.nav-tabs {
    display: flex;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 8px;
    margin-bottom: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    gap: 8px;
}

.nav-tab {
    flex: 1;
    padding: 16px 24px;
    border: none;
    background: transparent;
    border-radius: 12px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: #718096;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.nav-tab:hover {
    background: rgba(102, 126, 234, 0.1);
    color: #667eea;
}

.nav-tab.active {
    background: #667eea;
    color: white;
    box-shadow: 0 4px 16px rgba(102, 126, 234, 0.3);
}

/* Tab Content */
.tab-content {
    display: none;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.tab-content.active {
    display: block;
}

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.section-header p {
    font-size: 1.1rem;
    color: #718096;
}

/* Image Gallery */
.image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.image-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.image-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.15);
}

.image-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 16px;
    text-align: center;
}

.image-container {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 16px;
    background: #f7fafc;
}

.image-wrapper {
    position: relative;
    overflow: hidden;
    border-radius: 12px;
    background: #f7fafc;
    cursor: crosshair;
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.image-wrapper.dragging {
    cursor: grabbing !important;
}

.zoomable-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    transition: transform 0.3s ease;
    display: block;
    image-rendering: -moz-crisp-edges;
    image-rendering: -webkit-crisp-edges;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
}

.color-picker-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 10;
}

.color-picker-cursor {
    position: absolute;
    width: 20px;
    height: 20px;
    border: 2px solid #fff;
    border-radius: 50%;
    box-shadow: 0 0 0 1px #333, 0 0 8px rgba(0, 0, 0, 0.3);
    pointer-events: none;
    z-index: 11;
    transform: translate(-50%, -50%);
    transition: all 0.1s ease;
}

.color-picker-cursor::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 2px;
    height: 2px;
    background: #333;
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

.image-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 12px;
    background: rgba(255, 255, 255, 0.9);
    border-top: 1px solid #e2e8f0;
}

.control-btn {
    width: 36px;
    height: 36px;
    border: none;
    border-radius: 8px;
    background: #667eea;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.control-btn:hover {
    background: #5a67d8;
    transform: translateY(-2px);
}

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

.control-btn.max-zoom {
    background: #48bb78;
}

.control-btn.max-zoom:hover {
    background: #38a169;
}

.zoom-level {
    font-size: 0.9rem;
    font-weight: 500;
    color: #4a5568;
    min-width: 50px;
    text-align: center;
}

.zoom-canvas {
    image-rendering: -moz-crisp-edges;
    image-rendering: -webkit-crisp-edges;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
    border-radius: 12px;
    overflow: hidden;
    transition: opacity 0.2s ease;
}

.zoomable-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    transition: transform 0.3s ease, opacity 0.2s ease;
    display: block;
    image-rendering: -moz-crisp-edges;
    image-rendering: -webkit-crisp-edges;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
}

.image-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.image-container:hover .image-overlay {
    opacity: 1;
}

.analyze-btn {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.analyze-btn:hover {
    background: #5a67d8;
    transform: translateY(-2px);
}

.image-info {
    background: #f7fafc;
    padding: 16px;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.image-info p {
    margin: 0;
    color: #4a5568;
    font-size: 0.95rem;
}

/* Analysis Panel */
.analysis-panel {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 16px;
    padding: 30px;
    margin-top: 30px;
}

.analysis-panel h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.pixel-info {
    display: flex;
    align-items: center;
    gap: 30px;
    flex-wrap: wrap;
}

.color-preview {
    width: 80px;
    height: 80px;
    border-radius: 12px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    background: #f7fafc;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    color: #718096;
}

.color-values {
    display: flex;
    flex-direction: column;
    gap: 12px;
    flex: 1;
}

.color-value {
    display: flex;
    align-items: center;
    gap: 12px;
}

.color-label {
    font-weight: 600;
    width: 40px;
    text-align: center;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.9rem;
}

.color-label.red { background: rgba(239, 68, 68, 0.2); }
.color-label.green { background: rgba(34, 197, 94, 0.2); }
.color-label.blue { background: rgba(59, 130, 246, 0.2); }
.color-label.hex { background: rgba(255, 255, 255, 0.2); }

.color-number {
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 1.1rem;
    font-weight: 600;
    background: rgba(255, 255, 255, 0.1);
    padding: 6px 12px;
    border-radius: 6px;
    min-width: 60px;
    text-align: center;
}

.analysis-tip {
    margin-top: 20px;
    font-style: italic;
    opacity: 0.9;
    text-align: center;
}

/* Hex Generator */
.hex-generator {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.input-section, .output-section {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.input-section h3, .output-section h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

#hexInput {
    width: 100%;
    height: 200px;
    padding: 16px;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.9rem;
    resize: vertical;
    transition: border-color 0.3s ease;
}

#hexInput:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.input-controls {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5a67d8;
    transform: translateY(-2px);
}

.btn-secondary {
    background: #e2e8f0;
    color: #4a5568;
}

.btn-secondary:hover {
    background: #cbd5e0;
}

.btn-success {
    background: #48bb78;
    color: white;
}

.btn-success:hover {
    background: #38a169;
}

.image-output {
    text-align: center;
    margin-bottom: 20px;
}

#generatedCanvas {
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    max-width: 100%;
    height: auto;
    background: white;
}

.canvas-info {
    margin-top: 16px;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.canvas-info p {
    margin: 0;
    color: #718096;
    font-size: 0.9rem;
}

.download-section {
    text-align: center;
}

/* Tutorial Section */
.tutorial-section {
    background: #f7fafc;
    border-radius: 16px;
    padding: 30px;
    margin-top: 30px;
}

.tutorial-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.tutorial-content {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.tutorial-step {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.step-number {
    width: 40px;
    height: 40px;
    background: #667eea;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-content h4 {
    font-size: 1.2rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 8px;
}

.step-content p {
    color: #4a5568;
    margin-bottom: 12px;
}

.code-example {
    background: #2d3748;
    color: #e2e8f0;
    padding: 16px;
    border-radius: 8px;
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.9rem;
    margin: 12px 0;
}

.code-example code {
    display: block;
    margin-bottom: 4px;
}

.step-content ul {
    margin-left: 20px;
    color: #4a5568;
}

.step-content li {
    margin-bottom: 4px;
}

/* Footer */
.footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 16px;
    }
    
    .title {
        font-size: 2rem;
        flex-direction: column;
        gap: 8px;
    }
    
    .nav-tabs {
        flex-direction: column;
    }
    
    .nav-tab {
        justify-content: flex-start;
    }
    
    .hex-generator {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .pixel-info {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .tutorial-step {
        flex-direction: column;
        text-align: center;
    }
    
    .input-controls {
        flex-direction: column;
    }
    
    .btn {
        justify-content: center;
    }
    
    .image-controls {
        flex-wrap: wrap;
        gap: 8px;
    }
    
    .control-btn {
        width: 32px;
        height: 32px;
        font-size: 0.8rem;
    }
    
    .zoom-level {
        font-size: 0.8rem;
        min-width: 40px;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 24px;
    }
    
    .title {
        font-size: 1.8rem;
    }
    
    .tab-content {
        padding: 24px;
    }
    
    .image-gallery {
        grid-template-columns: 1fr;
    }
    
    .canvas-info {
        flex-direction: column;
        gap: 8px;
    }
}

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

.tab-content.active {
    animation: fadeIn 0.5s ease;
}

/* Loading State */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid #667eea;
    border-top: 2px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Floating RGB Display */
.floating-rgb-display {
    position: fixed;
    background: rgba(0, 0, 0, 0.9);
    color: white;
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 12px;
    font-family: 'Courier New', monospace;
    pointer-events: none;
    z-index: 1000;
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    display: none;
    white-space: nowrap;
}

.floating-rgb-display .rgb-line {
    display: flex;
    align-items: center;
    gap: 8px;
    margin: 2px 0;
}

.floating-rgb-display .color-label {
    font-weight: bold;
    min-width: 20px;
}

.floating-rgb-display .color-label.red { color: #ff6b6b; }
.floating-rgb-display .color-label.green { color: #51cf66; }
.floating-rgb-display .color-label.blue { color: #74c0fc; }
.floating-rgb-display .color-label.hex { color: #ffd43b; }

.floating-rgb-display .color-value {
    background: rgba(255, 255, 255, 0.1);
    padding: 2px 6px;
    border-radius: 3px;
    font-weight: bold;
}

.floating-rgb-display .color-preview {
    width: 16px;
    height: 16px;
    border-radius: 3px;
    border: 1px solid rgba(255, 255, 255, 0.3);
    display: inline-block;
    margin-left: 8px;
}