/* Shared theme for all tool pages. */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
    gap: 18px;
}

/* Navigation between tool pages */
.tool-nav {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.tool-nav .nav-brand {
    color: #fff;
    font-weight: 800;
    font-size: 1.05em;
    letter-spacing: 0.02em;
    padding: 8px 10px 8px 0;
    align-self: center;
}

.tool-nav a.nav-signout {
    margin-left: auto;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.4);
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.login-form input[type="password"] {
    padding: 12px 14px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1em;
}

.login-form input[type="password"]:focus {
    outline: none;
    border-color: #667eea;
}

.login-error {
    color: #c0392b;
    background: #fdecea;
    border-radius: 8px;
    padding: 10px 14px;
    margin-bottom: 16px;
    font-weight: 600;
}

.tool-nav a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.92em;
    padding: 8px 16px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.12);
    transition: background 0.15s ease, color 0.15s ease;
}

.tool-nav a:hover {
    background: rgba(255, 255, 255, 0.25);
    color: #fff;
}

.tool-nav a.active {
    background: #fff;
    color: #667eea;
}

.container {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 40px;
    max-width: 600px;
    width: 100%;
}

h1 {
    color: #333;
    margin-bottom: 10px;
    font-size: 2em;
}

.subtitle {
    color: #666;
    margin-bottom: 30px;
    font-size: 0.95em;
}

.upload-area {
    border: 3px dashed #667eea;
    border-radius: 15px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #f8f9ff;
}

.upload-area:hover {
    border-color: #764ba2;
    background: #f0f2ff;
}

.upload-area.dragover {
    background: #e8ebff;
    border-color: #764ba2;
}

.upload-icon {
    font-size: 48px;
    margin-bottom: 15px;
    color: #667eea;
}

.upload-text {
    color: #333;
    font-size: 1.1em;
    margin-bottom: 5px;
}

.upload-hint {
    color: #999;
    font-size: 0.9em;
}

input[type="file"] {
    display: none;
}

.file-list {
    margin-top: 20px;
    max-height: 420px;
    overflow-y: auto;
}

/* An empty list must not leave a phantom gap under the upload area. */
.file-list:empty {
    display: none;
}

.file-item {
    background: #f8f9ff;
    padding: 10px 12px;
    margin: 8px 0;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9em;
    border-top: 3px solid transparent;
    transition: opacity 0.15s ease, box-shadow 0.15s ease;
}

.file-item.dragging {
    opacity: 0.45;
}

.file-item.drag-over-top {
    border-top: 3px solid #764ba2;
}

.file-item.drag-over-bottom {
    border-bottom: 3px solid #764ba2;
}

.drag-handle {
    cursor: grab;
    color: #b7b7d8;
    font-size: 1.1em;
    user-select: none;
    line-height: 1;
}

.drag-handle:active {
    cursor: grabbing;
}

.file-info {
    color: #333;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.file-item .file-number {
    color: #667eea;
    font-weight: bold;
    margin-right: 8px;
}

.file-size {
    color: #999;
    white-space: nowrap;
}

.file-actions {
    display: flex;
    align-items: center;
    gap: 2px;
}

.icon-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    color: #667eea;
    font-size: 0.95em;
    width: 26px;
    height: 26px;
    border-radius: 6px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: background 0.15s ease, color 0.15s ease;
    line-height: 1;
}

.icon-btn:hover:not(:disabled) {
    background: #e8ebff;
}

.icon-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.icon-btn.remove-btn {
    color: #c0392b;
}

.icon-btn.remove-btn:hover:not(:disabled) {
    background: #fde8e6;
}

.btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 10px;
    font-size: 1em;
    cursor: pointer;
    width: 100%;
    margin-top: 20px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    font-weight: 600;
}

.btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 10px;
    text-align: center;
    display: none;
}

.message.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.download-btn {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    margin-top: 10px;
}

.loading {
    display: none;
    margin-top: 20px;
    text-align: center;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.features {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #e0e0e0;
}

.feature-item {
    display: flex;
    align-items: center;
    margin: 10px 0;
    color: #666;
    font-size: 0.9em;
}

.feature-item::before {
    content: "✓";
    color: #667eea;
    font-weight: bold;
    margin-right: 10px;
    font-size: 1.2em;
}

/* Form controls for tool option panels */
.options-panel {
    margin-top: 20px;
    padding: 16px;
    background: #f8f9ff;
    border-radius: 10px;
}

.options-panel label {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #444;
    font-size: 0.92em;
    margin: 8px 0;
}

/* ---- Page thumbnails (merge rows + Page Tools grid) ---- */

/* First-page thumbnail at the left of a merge file row. */
.file-thumb {
    flex: 0 0 auto;
    width: 30px;
    height: 39px;
    border-radius: 4px;
    overflow: hidden;
    background: #fff;
    border: 1px solid #d5d9f2;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.file-thumb .thumb-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top center;
    display: block;
}

/* Placeholder shown while a preview is still being fetched. */
.thumb-loading {
    background: linear-gradient(100deg, #eef0fb 30%, #dfe3f8 50%, #eef0fb 70%);
    background-size: 300% 100%;
    animation: thumb-shimmer 1.2s ease-in-out infinite;
    border: 1px solid #e3e6f7;
}

@keyframes thumb-shimmer {
    0% { background-position: 150% 0; }
    100% { background-position: -50% 0; }
}

/* Page Tools: clickable grid of page previews. */
.thumb-hint {
    margin-top: 18px;
    color: #666;
    font-size: 0.88em;
}

.thumb-grid {
    margin-top: 10px;
    padding: 12px;
    background: #f8f9ff;
    border-radius: 10px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
    gap: 10px;
    max-height: 340px;
    overflow-y: auto;
}

.page-thumb {
    background: #fff;
    border: 1px solid #d5d9f2;
    border-radius: 8px;
    padding: 5px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    transition: border-color 0.15s ease, box-shadow 0.15s ease,
                transform 0.15s ease;
}

.page-thumb:hover {
    border-color: #667eea;
    box-shadow: 0 3px 10px rgba(102, 126, 234, 0.25);
    transform: translateY(-1px);
}

.page-thumb:focus-visible {
    outline: 2px solid #667eea;
    outline-offset: 2px;
}

.page-thumb img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 4px;
}

.page-thumb-caption {
    color: #667eea;
    font-size: 0.78em;
    font-weight: 700;
    line-height: 1;
}

/* Loading tiles inside the grid have no image to size them, and must win the
   plain white .page-thumb background they also carry. */
.thumb-grid .thumb-loading {
    min-height: 86px;
    border-radius: 8px;
    cursor: default;
    background: linear-gradient(100deg, #eef0fb 30%, #dfe3f8 50%, #eef0fb 70%);
    background-size: 300% 100%;
}

.thumb-grid .thumb-loading:hover {
    border-color: #d5d9f2;
    box-shadow: none;
    transform: none;
}

.thumb-note {
    margin-top: 8px;
    color: #999;
    font-size: 0.85em;
    text-align: right;
}

.options-panel select,
.options-panel input[type="text"],
.options-panel input[type="number"],
.options-panel input[type="password"] {
    border: 1px solid #d5d9f2;
    border-radius: 6px;
    padding: 6px 8px;
    font-size: 0.92em;
    color: #333;
    background: #fff;
}