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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #06b6d4;
    --secondary-hover: #0891b2;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --accent-color: #f59e0b;
    
    /* Dark theme colors */
    --bg-primary: #0f1419;
    --bg-secondary: #1a1f2e;
    --bg-tertiary: #242b3d;
    --bg-elevated: #2d3548;
    --bg-hover: #353d52;
    
    --border-color: #2d3548;
    --border-hover: #3d4558;
    
    --text-primary: #e5e7eb;
    --text-secondary: #9ca3af;
    --text-tertiary: #6b7280;
    
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
}

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

.container {
    max-width: 1800px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 24px 30px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.header-content h1 {
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
}

.header-content h1 i {
    color: var(--primary-color);
}

.header-content p {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* Processing Section */
.processing-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

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

/* Editor Panel with Tabs */
.editor-panel {
    background: var(--bg-secondary);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.editor-header {
    background: var(--bg-tertiary);
    padding: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.tabs {
    display: flex;
    gap: 0;
}

.tab {
    padding: 16px 28px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: all 0.2s ease;
    border-bottom: 2px solid transparent;
    position: relative;
}

.tab:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

.tab.active {
    color: var(--primary-color);
    background: var(--bg-secondary);
    border-bottom-color: var(--primary-color);
}

.tab i {
    font-size: 1.1rem;
}

.editor-actions {
    display: flex;
    gap: 8px;
    padding: 10px 16px;
}

.tab-content {
    display: none;
    height: 600px;
}

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

/* Upload Area as Tab */
.upload-area-tab {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: var(--bg-primary);
    border: 2px dashed var(--border-color);
    border-radius: 0;
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-area-tab:hover {
    border-color: var(--primary-color);
    background: var(--bg-tertiary);
}

.upload-area-tab i {
    font-size: 4rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.upload-area-tab h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-primary);
    font-weight: 600;
}

.upload-area-tab p {
    color: var(--text-secondary);
    margin-bottom: 24px;
    font-size: 1rem;
}

/* Panel (legacy support) */
.panel {
    background: var(--bg-secondary);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.panel-header {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    border-bottom: 1px solid var(--border-color);
}

.panel-header h2 {
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
}

.panel-controls {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.canvas-container {
    position: relative;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

#sourceCanvas,
#selectionCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    cursor: crosshair;
}

#sourceCanvas {
    z-index: 1;
}

#selectionCanvas {
    z-index: 2;
    pointer-events: auto;
}

#resultCanvas {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    display: block;
}

.instructions {
    position: absolute;
    top: 12px;
    left: 12px;
    transform: none;
    background: rgba(99, 102, 241, 0.95);
    color: white;
    padding: 8px 14px;
    border-radius: 8px;
    font-size: 0.85rem;
    z-index: 3;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: var(--shadow-lg);
    max-width: 320px;
    text-align: left;
    pointer-events: none;
    transition: opacity 0.2s ease;
    backdrop-filter: blur(8px);
}

.result-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: var(--text-tertiary);
    z-index: 1;
}

.result-placeholder i {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.3;
    color: var(--text-secondary);
}

.result-placeholder p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.result-placeholder small {
    font-size: 0.9rem;
    color: var(--text-tertiary);
}

/* Controls Panel */
.controls-panel {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 28px;
}

.control-section {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.control-section h3 {
    font-size: 1.1rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 10px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    margin: 0;
}

.control-section h3 i {
    color: var(--primary-color);
}

.control-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.slider-control {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.slider-control label {
    display: flex;
    justify-content: space-between;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.slider-control label span {
    color: var(--primary-color);
    font-weight: 600;
}

.slider-control input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 5px;
    background: var(--bg-tertiary);
    outline: none;
    -webkit-appearance: none;
    appearance: none;
    border: 1px solid var(--border-color);
}

.slider-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.slider-control input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--primary-hover);
    transform: scale(1.15);
}

.slider-control input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.slider-control input[type="range"]::-moz-range-thumb:hover {
    background: var(--primary-hover);
    transform: scale(1.15);
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

/* API Key Input */
.api-key-input {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.api-key-input label {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.api-key-input label i {
    color: var(--accent-color);
}

.input-group {
    display: flex;
    gap: 8px;
    align-items: stretch;
}

.input-group input[type="text"],
.input-group input[type="password"] {
    flex: 1;
    padding: 10px 14px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: 'Courier New', monospace;
    transition: all 0.2s ease;
}

.input-group input[type="text"]:focus,
.input-group input[type="password"]:focus {
    outline: none;
    border-color: var(--primary-color);
    background: var(--bg-elevated);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-group input::placeholder {
    color: var(--text-tertiary);
}

.input-hint {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    line-height: 1.4;
}

.input-hint a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

.input-hint a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Buttons */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    box-shadow: var(--shadow);
    font-family: inherit;
}

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

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

.btn-large {
    padding: 12px 24px;
    font-size: 1rem;
}

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

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

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

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

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

.btn-success:hover {
    background: #059669;
}

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

.btn-accent:hover {
    background: #d97706;
}

.btn-icon {
    padding: 10px;
    width: 40px;
    height: 40px;
    background: var(--bg-elevated);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-icon:hover {
    background: var(--bg-hover);
    border-color: var(--border-hover);
}

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

.btn-icon.btn-primary:hover {
    background: var(--primary-hover);
}

.btn-small {
    padding: 6px 14px;
    font-size: 0.85rem;
    background: var(--bg-elevated);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-small:hover {
    background: var(--bg-hover);
}

/* Loading Overlay */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 20, 25, 0.9);
    backdrop-filter: blur(8px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.loading-content {
    background: var(--bg-secondary);
    padding: 36px 56px;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
}

.loading-content i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 16px;
}

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

/* Footer */
footer {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    text-align: center;
    padding: 20px;
    margin-top: 20px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

/* Responsive Design */
@media (max-width: 1400px) {
    .controls-panel {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 1024px) {
    .controls-panel {
        grid-template-columns: 1fr;
    }
    
    .tab-content {
        height: 450px;
    }
}

@media (max-width: 768px) {
    .header-content h1 {
        font-size: 1.6rem;
    }
    
    .header-content p {
        font-size: 0.95rem;
    }
    
    .upload-area-tab i {
        font-size: 3rem;
    }
    
    .upload-area-tab h3 {
        font-size: 1.2rem;
    }
    
    .editor-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .tabs {
        width: 100%;
        border-bottom: 1px solid var(--border-color);
    }
    
    .tab {
        flex: 1;
        justify-content: center;
    }
    
    .editor-actions {
        justify-content: center;
        padding: 12px;
        border-top: 1px solid var(--border-color);
    }
    
    .tab-content {
        height: 350px;
    }
    
    .instructions {
        font-size: 0.8rem;
        padding: 6px 12px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }
    
    header {
        padding: 18px 20px;
    }
    
    .header-content h1 {
        font-size: 1.4rem;
        gap: 8px;
    }
    
    .upload-area-tab h3 {
        font-size: 1rem;
    }
    
    .upload-area-tab p {
        font-size: 0.9rem;
    }
    
    .controls-panel {
        padding: 16px;
        gap: 20px;
    }
    
    .btn-large {
        padding: 10px 18px;
        font-size: 0.9rem;
    }
    
    .tab {
        padding: 12px 16px;
        font-size: 0.85rem;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
    }
    
    header,
    .upload-section,
    .controls-panel,
    footer {
        display: none;
    }
    
    .workspace {
        display: block;
    }
    
    .panel {
        page-break-inside: avoid;
    }
}