:root {
    --primary-color: #2196F3;
    --secondary-color: #4CAF50;
    --accent-color: #FFC107;
    --danger-color: #F44336;
    --purple-color: #9C27B0;
    --bg-color: #f5f5f0;
    --text-color: #333;
    --text-light: #666;
    --border-color: #ddd;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
    --border-radius: 12px;
    --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, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--bg-color);
    background-image: 
        radial-gradient(circle at 25px 25px, rgba(255,255,255,0.3) 2px, transparent 0),
        radial-gradient(circle at 75px 75px, rgba(255,255,255,0.2) 1px, transparent 0);
    background-size: 100px 100px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--purple-color));
    color: white;
    padding: 2rem 1rem;
    text-align: center;
    box-shadow: var(--shadow);
}

.header-content h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.header-content p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Navigation */
.nav {
    background: white;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.nav-container {
    display: flex;
    justify-content: center;
    padding: 0 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-btn {
    background: none;
    border: none;
    padding: 1rem 1.5rem;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-light);
    transition: var(--transition);
    border-bottom: 3px solid transparent;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-btn:hover {
    color: var(--primary-color);
    background: rgba(33, 150, 243, 0.05);
}

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

/* Main Content */
.main {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

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

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

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

/* Controls */
.controls {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
    display: grid;
    gap: 1.5rem;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    align-items: end;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

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

.control-group input,
.control-group select {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

.control-group input:focus,
.control-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1);
}

input[type="color"] {
    width: 100%;
    height: 50px;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
}

/* Buttons */
.primary-btn, .secondary-btn, .danger-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    justify-content: center;
}

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

.primary-btn:hover {
    background: #1976D2;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

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

.secondary-btn:hover {
    background: #388E3C;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

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

.danger-btn:hover {
    background: #D32F2F;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

/* Upload Area */
.upload-area {
    border: 3px dashed var(--border-color);
    border-radius: var(--border-radius);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: white;
    margin-bottom: 2rem;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--primary-color);
    background: rgba(33, 150, 243, 0.05);
}

.upload-content i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.upload-content p {
    font-size: 1.1rem;
    color: var(--text-light);
}

/* Palette Display */
.palette-display {
    display: grid;
    gap: 1rem;
}

.palette-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
}

.palette-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.palette-colors {
    display: flex;
    height: 120px;
}

.color-swatch {
    flex: 1;
    position: relative;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.color-swatch:hover {
    transform: scale(1.05);
    z-index: 10;
    box-shadow: var(--shadow);
}

.color-code {
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
    opacity: 0;
    transition: var(--transition);
    font-family: 'Courier New', monospace;
}

.color-swatch:hover .color-code {
    opacity: 1;
}

.palette-actions {
    padding: 1rem;
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

.action-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background: white;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

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

.action-btn.favorited {
    background: var(--danger-color);
    color: white;
    border-color: var(--danger-color);
}

/* Trending Grid */
.trending-header,
.favorites-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.trending-grid,
.favorites-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    justify-content: center;
    align-items: center;
    padding: 1rem;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: var(--border-radius);
    max-width: 90vw;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-hover);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-light);
    transition: var(--transition);
}

.close-btn:hover {
    color: var(--danger-color);
}

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

.export-options {
    display: flex;
    gap: 1rem;
    padding: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

.export-btn {
    padding: 1rem 2rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    min-width: 120px;
}

.export-btn:hover {
    border-color: var(--primary-color);
    background: rgba(33, 150, 243, 0.05);
}

.export-preview {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    background: #f8f9fa;
}

/* FAQ Section */
.faq-section {
    margin-top: 3rem;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.faq-section h2 {
    padding: 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--purple-color));
    color: white;
    margin: 0;
    text-align: center;
}

.faq-container {
    padding: 1rem;
}

.faq-item {
    border-bottom: 1px solid var(--border-color);
}

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

.faq-question {
    width: 100%;
    padding: 1.5rem;
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background: rgba(33, 150, 243, 0.05);
}

.faq-icon {
    font-size: 1.2rem;
    color: var(--primary-color);
    transition: var(--transition);
}

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

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: var(--text-light);
    line-height: 1.6;
    animation: slideDown 0.3s ease-out;
}

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

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

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--text-color);
    color: white;
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-hover);
    z-index: 1001;
    opacity: 0;
    transition: var(--transition);
    pointer-events: none;
}

.toast.show {
    opacity: 1;
    pointer-events: auto;
}

.toast.success {
    background: var(--secondary-color);
}

.toast.error {
    background: var(--danger-color);
}

/* Footer */
footer {
    background: var(--text-color);
    color: white;
    text-align: center;
    padding: 2rem 1rem;
    margin-top: 3rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-content h1 {
        font-size: 1.5rem;
    }
    
    .nav-container {
        overflow-x: auto;
        justify-content: flex-start;
        padding: 0;
    }
    
    .nav-btn {
        flex-shrink: 0;
        padding: 1rem;
        font-size: 0.8rem;
    }
    
    .controls {
        grid-template-columns: 1fr;
        padding: 1.5rem;
    }
    
    .trending-grid,
    .favorites-grid {
        grid-template-columns: 1fr;
    }
    
    .trending-header,
    .favorites-header {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
    
    .modal-content {
        max-width: 95vw;
        margin: 1rem;
    }
    
    .export-options {
        flex-direction: column;
        align-items: stretch;
    }
    
    .comparison-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .main {
        padding: 1rem 0.5rem;
    }
    
    .palette-actions {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .action-btn {
        justify-content: center;
    }
    
    .faq-question {
        padding: 1rem;
        font-size: 0.9rem;
    }
    
    .faq-answer {
        padding: 0 1rem 1rem;
    }
}

/* Print Styles */
@media print {
    .nav, .controls, .modal, .toast {
        display: none !important;
    }
    
    .palette-card {
        break-inside: avoid;
        margin-bottom: 1rem;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000;
        --text-light: #000;
    }
    
    .nav-btn {
        border: 1px solid var(--border-color);
    }
}

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