app.css

:root {
    --primary-color: #4a6fa5;
    --primary-dark: #3a5a80;
    --secondary-color: #47b8d6;
    --dark-color: #333;
    --light-color: #f4f4f4;
    --danger-color: #dc3545;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --border-radius: 8px;
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --box-shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s ease;
}

[hidden] {
    display: none !important;
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background: var(--bg-color);
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.skip-link {
    position: fixed;
    top: 8px;
    left: 8px;
    z-index: 1000;
    padding: 10px 14px;
    border-radius: 6px;
    color: white;
    background: var(--primary-dark);
    transform: translateY(-150%);
    transition: transform 0.15s ease;
}

.skip-link:focus {
    transform: translateY(0);
}

h1, h2, h3 {
    margin-bottom: 10px;
    color: var(--primary-color);
    font-weight: 600;
}

h1 {
    font-size: 2.4rem;
    margin-bottom: 0.8rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
    letter-spacing: -0.5px;
}

h2 {
    font-size: 1.6rem;
    margin-top: 1rem;
}

h3 {
    font-size: 1.3rem;
    margin-top: 0.8rem;
}

p {
    margin-bottom: 1rem;
    color: #444;
}

ol {
	margin-left: 30px;
}
button {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: var(--border-radius);
    cursor: pointer;
    margin: 8px 4px;
    transition: var(--transition);
    font-weight: 500;
    font-size: 0.95rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

button:hover {
    opacity: 0.9;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

button:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

button:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.file-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 20px;
    margin: 8px 4px;
    border-radius: var(--border-radius);
    color: white;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    cursor: pointer;
    font-weight: 500;
}

input.visually-hidden:focus-visible + .file-button {
    outline: 3px solid var(--primary-color);
    outline-offset: 3px;
}

.template-preset-row select {
    flex: 1 1 280px;
    min-width: 0;
}

.template-preset-row button,
.template-actions > button,
.template-actions > .file-button {
    margin: 0;
}

.helper-text {
    margin-top: 8px;
    color: #666;
    font-size: 0.9rem;
}

select,
input[type="text"] {
    min-height: 42px;
    padding: 8px 10px;
    border: 1px solid #cfd5dc;
    border-radius: 5px;
    background: white;
    color: var(--dark-color);
    font: inherit;
}

.next-btn {
    background: linear-gradient(135deg, var(--success-color), #5cb85c);
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.next-btn:hover {
    background: linear-gradient(135deg, #239a3b, #4cae4c);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(40, 167, 69, 0.3);
}

.prev-btn {
    background: #6c757d;
    padding: 12px 24px;
    font-size: 1rem;
}

.prev-btn:hover {
    background: #5a6268;
}

input[type="file"] {
    margin: 15px 0;
    border: 2px dashed #d0d0d0;
    padding: 20px;
    border-radius: var(--border-radius);
    width: 100%;
    background: linear-gradient(145deg, #fafafa, #f5f5f5);
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

input[type="file"]:hover {
    border-color: var(--primary-color);
    background: linear-gradient(145deg, #fff, #fafafa);
    box-shadow: 0 2px 8px rgba(74, 111, 165, 0.1);
}

input[type="file"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.1);
}

input[type="number"] {
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

input[type="range"] {
    height: 5px;
    border-radius: 5px;
    background: #d7dcdf;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    transition: var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--secondary-color);
}

/* Checkbox styling */
input[type="checkbox"] {
    width: 20px;
    height: 20px;
    margin: 0 10px;
    cursor: pointer;
    position: relative;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    border: 2px solid #ddd;
    border-radius: 4px;
    background: white;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

input[type="checkbox"]:checked {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

input[type="checkbox"]:checked::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 14px;
    font-weight: bold;
}

input[type="checkbox"]:hover {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.1);
}

input[type="checkbox"]:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.2);
}

select {
    padding: 10px 14px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    background-color: white;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.06);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.95rem;
}

select:hover {
    border-color: var(--primary-color);
}

select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.1);
}

#lut-preview {
	max-width: 100%;
	height: auto;
}

canvas {
    border: 2px solid #e0e0e0;
    margin: 15px 0;
    max-width: 100%;
    border-radius: 6px;
    background-color: #fcfcfc;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: var(--transition);
}

canvas:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(74, 111, 165, 0.15);
}

.container {
    background: var(--card-bg);
    padding: 28px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 24px;
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.container:hover {
    box-shadow: var(--box-shadow-hover);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.step {
    margin-bottom: 28px;
    padding-bottom: 28px;
    border-bottom: 2px solid #f0f0f0;
    position: relative;
}

.step::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 50px;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), transparent);
}

.step:last-child {
    border-bottom: none;
}

.preview {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: linear-gradient(145deg, #fafafa, #f5f5f5);
    padding: 20px;
    border-radius: var(--border-radius);
    margin: 20px 0;
    border: 1px solid #e0e0e0;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.05);
}

.preview img {
    max-width: 100%;
    margin: 10px 0;
    border-radius: 4px;
}

.controls {
    margin: 24px 0;
    background: linear-gradient(145deg, #fbfbfb, #f7f7f7);
    padding: 20px;
    border-radius: var(--border-radius);
    border: 1px solid #e0e0e0;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
}

.slider-container {
    display: flex;
    align-items: center;
    margin: 16px 0;
    padding: 8px 0;
}

.slider-container label {
    min-width: 200px;
    font-weight: 500;
    color: #444;
    display: flex;
    align-items: center;
}

.slider-container small {
    margin-left: 10px;
    color: #666;
    font-size: 0.85rem;
    line-height: 1.4;
    flex: 1;
}

input[type="range"] {
    flex: 1;
    margin: 0 12px;
}

.slider-value {
    width: 50px;
    text-align: center;
    font-weight: 500;
    color: var(--primary-color);
}

.color-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    margin: 15px 0;
}

.color-cell {
    aspect-ratio: 1;
    border: 1px solid #ddd;
    cursor: pointer;
    border-radius: 4px;
    transition: transform 0.2s;
}

button.color-cell {
    width: 100%;
    min-width: 0;
    margin: 0;
    padding: 0;
    border: 1px solid #ddd;
    background: none;
    box-shadow: none;
    text-transform: none;
}

button.color-cell[aria-pressed="true"] {
    border: 3px solid #111;
    box-shadow: 0 0 0 2px white, 0 0 0 4px var(--primary-color);
}

.option-group {
    margin: 20px 0;
    padding: 18px;
    border: 1px solid #d9dee5;
    border-radius: var(--border-radius);
    background: #fbfcfd;
}

.option-group legend {
    padding: 0 8px;
    color: var(--primary-dark);
    font-weight: 650;
}

.control-row,
.checkbox-row,
.button-row {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    margin: 10px 0;
}

.checkbox-row input[type="checkbox"] {
    margin-left: 0;
}

#colorcard-preview.alignment-enabled {
    cursor: crosshair;
    touch-action: none;
}

.quality-report {
    margin: 20px 0;
    padding: 18px;
    border: 1px solid #d9dee5;
    border-radius: var(--border-radius);
    background: linear-gradient(145deg, #ffffff, #f6f9fc);
}

.quality-metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 12px;
    margin: 12px 0;
}

.quality-card {
    padding: 12px;
    border: 1px solid #e2e6ea;
    border-radius: 6px;
    background: white;
}

.quality-card strong,
.quality-card span {
    display: block;
}

.quality-card span {
    margin-top: 4px;
    font-size: 1.25rem;
    color: var(--primary-dark);
}

.quality-recommendation {
    padding: 10px 12px;
    border-left: 4px solid var(--info-color);
    background: #eef8fb;
}

.quality-swatches {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
    gap: 8px;
    margin-top: 12px;
}

.quality-swatch {
    display: grid;
    grid-template-columns: 22px 22px 1fr;
    align-items: center;
    gap: 7px;
    padding: 7px;
    border-radius: 5px;
    background: white;
    border: 1px solid #e4e7eb;
    font-size: 0.82rem;
}

.quality-swatch-color {
    width: 22px;
    height: 22px;
    border: 1px solid rgba(0, 0, 0, 0.2);
    border-radius: 3px;
}

.color-cell:hover {
    transform: scale(1.08);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    border-color: var(--primary-color);
    z-index: 10;
    position: relative;
}

.color-input {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin: 15px 0;
}

.rgb-input {
    display: flex;
    flex-direction: column;
    background-color: white;
    padding: 16px;
    border-radius: var(--border-radius);
    border: 1px solid #eee;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

.rgb-input label {
    margin-bottom: 8px;
    font-weight: 500;
}

.rgb-input input {
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 4px;
    width: 100%;
}

.chart-controls {
    margin: 10px 0;
    display: flex;
    gap: 10px;
}

.tab-container {
    margin: 24px 0;
}

.tab-buttons {
    display: flex;
    overflow-x: auto;
    border-bottom: 1px solid #ddd;
    scrollbar-width: thin;
    background-color: #f1f1f1;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    padding: 0 2px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 12px 20px;
    cursor: pointer;
    background-color: transparent;
    color: #666;
    transition: var(--transition);
    font-weight: 500;
    position: relative;
    box-shadow: none;
}

.tab-btn:hover {
    background-color: rgba(74, 111, 165, 0.1);
    color: var(--primary-color);
    box-shadow: none;
}

.tab-btn.active {
    color: var(--primary-color);
    font-weight: 600;
    background-color: white;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.05);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background-color: var(--primary-color);
}

.tab-content {
    padding: 24px;
    border: 1px solid #ddd;
    border-top: none;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    background-color: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
}

.tab-panel {
    display: none;
    animation: fadeIn 0.3s;
}

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

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

.visually-hidden,
input[type="file"].visually-hidden {
    position: absolute;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    clip-path: inset(50%) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

.log-container {
    background-color: #f8f8f8;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    padding: 12px;
    margin: 15px 0;
    max-height: 200px;
    overflow-y: auto;
    font-family: monospace;
    font-size: 0.9rem;
}

.log-entry {
    margin-bottom: 6px;
    padding-bottom: 6px;
    border-bottom: 1px dashed #eee;
}

.info {
    color: #0066cc;
}

.warning {
    color: #cc9900;
}

.error {
    color: #cc0000;
}

.success {
    color: #009900;
}

.progress-container {
    width: 100%;
    height: 12px;
    background-color: #f1f1f1;
    border-radius: 50px;
    margin: 15px 0;
    overflow: hidden;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
}

.progress-bar {
    height: 100%;
    width: 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    transition: width 0.3s ease;
    border-radius: 50px;
}

#selected-color-preview {
    margin: 10px auto;
    width: 120px;
    height: 120px;
    border: 1px solid #ddd;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

#lut-download-container {
    margin-top: 15px;
    display: flex;
    justify-content: center;
}

#lut-download-container button {
    min-width: 200px;
    padding: 14px 24px;
    font-size: 1rem;
    margin: 10px 5px;
}

#process-button {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    padding: 14px 28px;
    font-size: 1.05rem;
    font-weight: 600;
    margin-top: 20px;
    width: 100%;
    max-width: 300px;
}

#process-button:hover {
    background: linear-gradient(135deg, var(--primary-dark), #2a4a70);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(74, 111, 165, 0.3);
}

/* Loading animation */
@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.6; }
    100% { opacity: 1; }
}

.loading {
    animation: pulse 1.5s ease-in-out infinite;
}

/* Smooth scroll behavior */
html {
    scroll-behavior: smooth;
}

/* Better focus styles */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

@media (max-width: 768px) {
    .grid {
        grid-template-columns: 1fr;
    }

    .slider-container {
        flex-direction: column;
        align-items: flex-start;
    }

    .slider-container label {
        width: 100%;
        margin-bottom: 8px;
    }

    input[type="range"] {
        width: 100%;
        margin: 8px 0;
    }

    .tab-buttons {
        flex-wrap: nowrap;
        overflow-x: auto;
        white-space: nowrap;
    }

    .tab-btn {
        padding: 10px 15px;
        font-size: 0.9rem;
    }

    .button-row,
    .control-row {
        align-items: stretch;
        flex-direction: column;
    }

    .button-row button,
    .button-row .file-button,
    .control-row select,
    .control-row button {
        width: 100%;
    }
}