:root {
    --padding: 20px;
    --gap: 0.5pt;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    height: 100vh;
    background-color: #f0f2f5;
    color: #333;
    overflow: hidden;
}

.container {
    display: flex;
    height: 100vh;
    align-items: center;
    justify-content: center;
}

.grid-area {
    flex: 3;
    display: grid;
    padding: var(--padding);
    gap: var(--gap);
    background-color: #ffffff;
    transition: all 0.3s ease;
    flex-grow: 0;
    flex-shrink: 0;
    width: calc(min(100vh, 75vw) - 2 * var(--padding));
    height: calc(min(100vh, 75vw) - 2 * var(--padding));
    aspect-ratio: 1 / 1;
}

.grid-cell {
    background-color: #e9ecef;
    border: 1px solid #dee2e6;
    border-radius: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: clamp(0.5rem, 3vw, 1.5rem);
    color: #6c757d;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    transition: background-color 0.2s, transform 0.2s;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.grid-cell:hover {
    background-color: #ced4da;
    transform: scale(1.05);
}

.grid-cell.has-photo {
    background-color: transparent;
    padding: 0;
}

.grid-cell.has-photo .quaternary-label {
    background: rgba(0, 0, 0, 0.85);
}

.grid-cell img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: opacity 0.3s ease-in-out;
}

.grid-area.labels-visible .grid-cell.has-photo img {
    opacity: 0.3;
}

.sidebar {
    flex: 1;
    padding: var(--padding);
    background-color: #f8f9fa;
    border-left: 1px solid #dee2e6;
    box-shadow: -2px 0 5px rgba(0,0,0,0.05);
    height: 100vh;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
}

.sidebar h2 {
    margin-top: 0;
    border-bottom: 1px solid #dee2e6;
    padding-bottom: 10px;
    font-weight: 600;
}

.control {
    margin-top: 20px;
}

.credits {
    font-size: 0.85em;
    color: #666;
    margin-top: auto; /* 推到底部 */
}

.credits a {
    color: inherit;
    text-decoration: none;
}

.credits a:hover {
    text-decoration: underline;
}

.size-control-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.size-control-group input[type="range"] {
    flex-grow: 1;
}

.size-control-group input[type="number"] {
    width: 60px;
    text-align: center;
}

.control label {
    user-select: none;
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    color: #495057;
}

/* Styles specifically for the toggle switch label */
.control .toggle-label {
    position: relative;
    padding-left: 60px;
    cursor: pointer;
}

.control .toggle-label::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    width: 48px;
    height: 24px;
    background-color: #ccc;
    border-radius: 24px;
    transition: background-color 0.3s;
}

.control .toggle-label::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 2px;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    background-color: white;
    border-radius: 50%;
    transition: transform 0.3s;
}

.control input[type="checkbox"]:checked + .toggle-label::before {
    background-color: #007bff;
}

.control input[type="checkbox"]:checked + .toggle-label::after {
    transform: translateY(-50%) translateX(24px);
}

.control input {
    width: 100%;
    padding: 10px;
    box-sizing: border-box;
    border: 1px solid #ced4da;
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.control input:focus {
    outline: none;
    border-color: #80bdff;
    box-shadow: 0 0 0 0.2rem rgba(0,123,255,.25);
}

.control input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    background: #dee2e6;
    border-radius: 5px;
    outline: none;
    opacity: 0.7;
    transition: opacity .2s;
    cursor: pointer;
    padding: 0;
}

.control input[type="range"]:hover {
    opacity: 1;
}

.control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: #007bff;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 2px rgba(0,0,0,0.2);
}

.control input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: #007bff;
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 0 2px rgba(0,0,0,0.2);
}

.control input[type="checkbox"] {
    width: 0;
    height: 0;
    visibility: hidden;
    position: absolute;
}

/* Modal Styles */
.modal-overlay {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #ffffff;
    padding: 30px;
    border-radius: 12px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    color: #666;
    transition: color 0.3s;
}

.close-modal:hover {
    color: #000;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 10px;
}

.modal-content h3 {
    margin-top: 0;
    margin-bottom: 0;
    color: #333;
    font-size: 1.5rem;
}

.modal-actions {
    display: none; /* No longer needed */
}

#clear-cell-button {
    padding: 10px 20px;
    background-color: #dc3545; /* Red for clear/delete */
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: background-color 0.2s, transform 0.1s;
    margin-right: 0; /* Remove auto margin-right */
    margin-left: auto; /* Push to right */
}

#clear-cell-button:hover {
    background-color: #c82333;
    transform: translateY(-1px);
}

.photo-grid {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.folder-section {
    margin-bottom: 20px;
}

.folder-section h4 {
    margin: 0 0 15px 0;
    color: #333;
    font-size: 1.2rem;
    font-weight: 600;
    padding-bottom: 5px;
    border-bottom: 2px solid #e9ecef;
}

.photo-grid-section {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 10px;
}

.photo-option {
    position: relative;
    border: 2px solid transparent;
    border-radius: 8px;
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.3s, border-color 0.3s, filter 0.3s, opacity 0.3s;
    aspect-ratio: 1;
}

.photo-option:hover {
    transform: scale(1.05);
    border-color: #007bff;
}

.photo-option:hover img {
    filter: brightness(0.6);
}

.photo-option:hover::after {
    content: attr(data-info);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 8px 12px;
    border-radius: 4px;
    font-size: 12px;
    white-space: nowrap;
    z-index: 10;
    pointer-events: none;
}

.photo-option img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.photo-option.selected {
    border-color: #007bff;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.3);
    filter: none;
    opacity: 1;
}

/* Styles for used photos */
.photo-option.used-photo {
    transform: none;
    border-color: transparent;
    box-shadow: none;
    position: relative;
}

.photo-option.used-photo img {
    filter: grayscale(100%);
}

.photo-option.used-photo::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1;
    pointer-events: none;
    border-radius: 8px;
    transition: background-color 0.2s ease;
}

/* Make overlay darker on hover for used photos */
.photo-option.used-photo:hover::before {
    background-color: rgba(0, 0, 0, 0.7);
}

/* Ensure selected state overrides used-photo visual effect */
.photo-option.selected.used-photo {
    border-color: #007bff;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.3);
    filter: none;
    opacity: 1;
}

.photo-option.selected.used-photo::before {
    content: none;
}

.photo-option.selected.used-photo img {
    filter: none;
}

/* Adjust general hover effects for used photos to prevent scaling and border */
.photo-option.used-photo:hover {
    cursor: default;
    transform: none;
    border-color: transparent;
    box-shadow: none;
    filter: none;
    opacity: 1;
}

/* Ensure hover info tooltip is above the overlay */
.photo-option:hover::after {
    content: attr(data-info);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 8px 12px;
    border-radius: 4px;
    font-size: 12px;
    white-space: nowrap;
    z-index: 10;
    pointer-events: none;
}

.quaternary-label {
    position: absolute;
    top: 2px;
    left: 2px;
    /* This will be overridden by specific color classes below */
    background: rgba(0, 0, 0, 0.75);
    color: white;
    padding: 4px 6px;
    border-radius: 3px;
    font-size: 14px; /* Increased font size */
    line-height: 1.1;
    pointer-events: none;
    z-index: 5;
    font-family: monospace;
    text-align: left;
}

/* This rule makes labels inside cells with photos have a specific background.
   It serves as a fallback. The series-specific rules below have higher specificity.
*/
.grid-cell.has-photo .quaternary-label {
    background: rgba(0, 0, 0, 0.85); 
}

/* Series-specific background colors for quaternary labels */
.grid-cell.has-photo .quaternary-label.A {
    background: darkred; /* Red for A series */
}

.grid-cell.has-photo .quaternary-label.B {
    background: darkgreen; /* Green for B series */
}

.grid-cell.has-photo .quaternary-label.C {
    background: black; /* Black for C series */
}

.grid-cell.has-photo .quaternary-label.D {
    background: darkblue; /* Blue for D series */
}

/* New styles for Export/Import buttons */
.button-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 30px;
}

.button-group button {
    padding: 12px 15px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: background-color 0.2s, transform 0.1s;
    width: 100%;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.button-group button:not(#clear-all-button) {
    background-color: #007bff;
    color: white;
}

.button-group button:not(#clear-all-button):hover {
    background-color: #0056b3;
    transform: translateY(-1px);
}

.button-group button:not(#clear-all-button):active {
    background-color: #004085;
    transform: translateY(0);
}

/* Specific color for Import button if needed, or keep generic */
#import-button {
    background-color: #28a745; /* Green for import */
}

#import-button:hover {
    background-color: #218838;
}

#import-button:active {
    background-color: #1e7e34;
}

/* Red color for clear-all button */
#clear-all-button {
    background-color: #dc3545;
    color: white;
}

#clear-all-button:hover {
    background-color: #c82333;
    transform: translateY(-1px);
}

#clear-all-button:active {
    background-color: #bd2130;
    transform: translateY(0);
}

.toggle-wrapper {
    display: flex;
    align-items: center;
    gap: 8px;
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
    border-radius: 24px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: #007bff;
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.toggle-label-inline {
    font-size: 0.9rem;
    color: #333;
    margin: 0;
    cursor: pointer;
}

.control.description {
    margin-top: 30px;
    padding: 15px;
    background: #e9ecef;
    border-radius: 8px;
    font-size: 0.95rem;
    line-height: 1.6;
    color: #495057;
}

.control.description h3 {
    margin: 0 0 10px 0;
    font-size: 1.1rem;
    color: #212529;
    border-bottom: 1px solid #dee2e6;
    padding-bottom: 5px;
}

.control.description p {
    margin: 5px 0;
}

.control.description kbd {
    display: inline-block;
    padding: 3px 6px;
    font-family: monospace;
    font-size: 0.85em;
    color: #fff;
    background: #333;
    border-radius: 4px;
    box-shadow: 0 1px 2px rgba(0,0,0,0.2);
}