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

:root {
    --color-bg-dark: #1e1e1e;
    --color-bg-medium: #2a2a2a;
    --color-bg-light: #353535;
    --color-border: #3a3a3a;
    --color-text-primary: #e0e0e0;
    --color-text-secondary: #999;
    --color-text-muted: #666;
    --color-text-dim: #888;
    --color-primary: #4a9eff;
    --color-primary-hover: #3a8eef;
    --color-secondary: #5a5a5a;
    --color-secondary-hover: #6a6a6a;
    --color-danger: #ff4a4a;
    --color-danger-hover: #ef3a3a;
    --transition-standard: all 0.2s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--color-bg-medium);
    color: var(--color-text-primary);
    overflow: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Toolbar */
.toolbar {
    background: var(--color-bg-dark);
    padding: 12px 20px;
    display: flex;
    gap: 12px;
    align-items: center;
    border-bottom: 2px solid var(--color-border);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.hidden {
    opacity: 0 !important;
    pointer-events: none;
    transform: scale(0.95);
    visibility: hidden;
}

.btn-group,
.btn {
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0s 0.3s;
}

.btn-group:not(.hidden),
.btn:not(.hidden) {
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0s 0s;
}

.btn {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-standard);
    outline: none;
    color: white;
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn:hover:not(:disabled) {
    transform: translateY(-1px);
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--color-primary-hover);
}

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

.btn-secondary:hover:not(:disabled) {
    background: var(--color-secondary-hover);
}

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

.btn-danger:hover:not(:disabled) {
    background: var(--color-danger-hover);
}

.btn-group {
    display: flex;
    gap: 0;
}

.btn-group .btn {
    border-radius: 6px 0 0 6px;
}

.btn-sub {
    padding: 8px 10px;
    font-size: 12px;
    min-width: unset;
    border-radius: 0 6px 6px 0 !important;
    border-left: 1px solid rgba(0, 0, 0, 0.2);
}

.zoom-info {
    margin-left: auto;
    font-size: 13px;
    color: var(--color-text-secondary);
    font-family: 'Courier New', monospace;
}

/* Main Container */
.container {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Image Pane (80%) */
.image-pane {
    width: 80%;
    background: var(--color-bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

#canvas {
    cursor: crosshair;
    display: block;
}

.upload-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(53, 53, 53, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 10;
    transition: var(--transition-standard);
}

.upload-overlay:hover {
    background: rgba(53, 53, 53, 1);
}

.instructions {
    text-align: center;
    color: var(--color-text-dim);
    pointer-events: none;
}

.instructions .hint {
    margin-top: 12px;
    color: var(--color-primary);
    font-size: 13px;
}

.instructions p {
    margin: 8px 0;
    font-size: 18px;
}

.instructions .small {
    font-size: 14px;
    color: var(--color-text-muted);
}

/* Sidebar (20%) */
.sidebar {
    width: 20%;
    background: #252525;
    border-left: 2px solid var(--color-border);
    padding: 20px;
    display: flex;
    flex-direction: column;
    overflow-y: hidden;
}

.sidebar h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--color-text-primary);
}

.color-count {
    font-size: 13px;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
    font-family: 'Courier New', monospace;
}

/* Palette Grid - Fixed 21 slots (3x7) */
.palette-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    flex: 1;
    align-content: start;
    overflow-y: auto;
}

.color-block {
    aspect-ratio: 1;
    border-radius: 8px;
    position: relative;
    cursor: pointer;
    transition: var(--transition-standard), opacity 0.4s ease, transform 0.4s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    animation: colorBlockFadeIn 0.4s ease;
}

.color-block.no-animation {
    animation: none;
}

.color-block:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

@keyframes colorBlockFadeIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

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

.color-swatch {
    width: 100%;
    height: 60%;
    border-radius: 8px 8px 0 0;
}

.color-hex {
    font-size: 10px;
    font-family: 'Courier New', monospace;
    font-weight: bold;
    padding: 4px;
    background: rgba(0, 0, 0, 0.6);
    width: 100%;
    text-align: center;
    color: white;
}

.delete-btn {
    position: absolute;
    top: 4px;
    right: 4px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: rgba(255, 0, 0, 0.8);
    color: white;
    border: none;
    font-size: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition-standard);
}

.color-block:hover .delete-btn {
    opacity: 1;
}

.delete-btn:hover {
    background: rgba(255, 0, 0, 1);
}

/* Responsive */
@media (max-width: 800px) {
    .container {
        flex-direction: column;
    }
    
    .image-pane,
    .sidebar {
        width: 100%;
    }
    
    .sidebar {
        border-left: none;
        border-top: 2px solid var(--color-border);
        max-height: 300px;
    }
}

/* Empty state for palette */
.palette-empty {
    grid-column: 1 / -1;
    text-align: center;
    color: var(--color-text-muted);
    font-size: 13px;
    padding: 20px;
}

/* Notification and Tooltip */
.notification {
    position: fixed;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-primary);
    color: white;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    animation: slideInFromRight 0.3s ease;
    transition: top 0.3s ease;
    margin-bottom: 8px;
}

.notification-exit {
    animation: fadeOutUp 0.5s ease forwards;
}

.tooltip {
    position: absolute;
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 11px;
    top: -25px;
    left: 50%;
    transform: translateX(-50%);
    pointer-events: none;
    z-index: 1000;
}

/* Animations */
@keyframes slideInFromRight {
    from {
        transform: translateX(calc(-50% + 30px));
        opacity: 0;
    }
    to {
        transform: translateX(-50%);
        opacity: 1;
    }
}

@keyframes fadeOutUp {
    from {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
    to {
        transform: translateX(-50%) translateY(-30px);
        opacity: 0;
    }
}