/* --- NEW: PDF Attachment & Viewer Styles --- */
        .pdf-attachment-pill {
            display: inline-flex;
            align-items: stretch;
            vertical-align: middle;
            position: relative;
            border-radius: var(--border-radius);
            border: 1px solid var(--border-color);
            margin: 0.2em 0.25em;
            max-width: calc(100% - 0.5em);
            overflow: hidden;
            transition: all 0.2s ease-in-out;
            background-color: var(--bg-tertiary) !important;
            background-image: none !important;
        }

        .pdf-attachment-pill::before {
            content: 'PDF';
            display: flex;
            align-items: center;
            padding: 0 10px;
            font-size: 1rem;
            font-weight: 700;
            letter-spacing: 0.5px;
            background-color: var(--danger-color);
            color: var(--text-on-primary);
            border-right: 1px solid var(--border-color);
        }

        .pdf-attachment-name {
            display: block;
            padding: 6px 12px;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            outline: none;
            min-width: 100px;
            font-family: inherit;
            font-weight: 600;
            background-image: none !important;
        }

        body.read-mode .pdf-attachment-pill {
            cursor: pointer;
        }

        body.read-mode .pdf-attachment-pill:hover {
            border-color: var(--primary-color);
            box-shadow: var(--shadow);
            transform: translateY(-1px);
        }

        body.write-mode .pdf-attachment-name {
            cursor: text;
            transition: background-color 0.2s ease;
        }

        body.write-mode .pdf-attachment-pill:hover .pdf-attachment-name {
            background-color: color-mix(in srgb, var(--primary-color) 8%, var(--bg-tertiary));
        }

        body.write-mode .pdf-attachment-name:focus {
            background-color: var(--bg-secondary);
            box-shadow: inset 0 0 0 2px var(--primary-color);
            white-space: normal;
            overflow: visible;
        }

        /* --- PDF Viewer Styles (v2 Professional Redesign) --- */
        #pdf-viewer-container {
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            z-index: 25000;
            background-color: var(--bg-primary);
            display: none;
            flex-direction: column;
            animation: fadeIn 0.3s ease;
        }

        #pdf-viewer-container.visible {
            display: flex;
        }

        .pdf-viewer-header {
            flex-shrink: 0;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.5rem 1rem;
            border-bottom: 1px solid var(--border-color);
            background-color: rgba(var(--bg-secondary-rgb), 0.8);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            z-index: 30;
        }

        .pdf-viewer-controls {
            display: flex;
            align-items: center;
            gap: 0.25rem;
        }

        .pdf-viewer-title {
            font-weight: 600;
            font-size: 0.85rem;
            color: var(--text-primary);
            flex-grow: 1;
            flex-shrink: 1;
            min-width: 0;
            text-align: center;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            margin: 0 1rem;
        }

        .pdf-page-indicator {
            font-variant-numeric: tabular-nums;
            font-weight: 500;
            color: var(--text-secondary);
            display: flex;
            align-items: center;
        }

        #pdf-page-num {
            width: 45px;
            text-align: center;
            border: 1px solid var(--border-color);
            background-color: var(--bg-secondary);
            border-radius: var(--border-radius);
            color: var(--text-primary);
            padding: 4px;
            margin: 0 6px;
            font-size: 0.9rem;
            font-family: var(--font-body);
        }

        #pdf-page-num:focus {
            outline: 2px solid var(--primary-color);
        }

        #pdf-page-num::-webkit-outer-spin-button,
        #pdf-page-num::-webkit-inner-spin-button {
            -webkit-appearance: none;
            margin: 0;
        }

        #pdf-page-num[type=number] {
            -moz-appearance: textfield;
        }

        .pdf-viewer-main {
            flex-grow: 1;
            display: flex;
            position: relative;
            overflow: hidden;
        }

        #pdf-thumbnails-bar {
            width: 150px;
            background-color: var(--bg-tertiary);
            border-right: 1px solid var(--border-color);
            overflow-y: auto;
            padding: 12px;
            display: none;
            flex-direction: column;
            gap: 2px;
            z-index: 20;
        }

        .pdf-thumbnail {
            cursor: pointer;
            border: 3px solid transparent;
            border-radius: var(--border-radius);
            padding: 3px;
            transition: all 0.2s ease;
            text-align: center;
        }

        .pdf-thumbnail canvas {
            width: 100%;
            height: auto;
            border-radius: 4px;
            box-shadow: var(--shadow-sm);
        }

        .pdf-thumbnail:hover {
            border-color: var(--primary-color-hover);
            background-color: var(--bg-secondary);
        }

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

        .pdf-thumbnail span {
            font-size: 0.8rem;
            font-weight: 500;
            color: var(--text-secondary);
            margin-top: 4px;
            display: block;
        }

        .pdf-viewer-canvas-wrapper {
            flex-grow: 1;
            overflow: auto;
            display: grid;
            place-items: center;
            padding: 0.25rem;
            padding-top: 0px;
        }

        .pdf-viewer-main.thumbnails-active #pdf-thumbnails-bar {
            display: flex;
        }

        .pdf-viewer-main.thumbnails-active .pdf-viewer-canvas-wrapper {
            margin-left: 10px;
            transition: margin-left 0.3s ease-in-out;
        }

        /* --- THE CORE OF THE ALIGNMENT FIX --- */
        .pdf-page-container {
            position: relative;
            margin: 0 auto;
            box-shadow: var(--shadow-lg);
            border: 1px solid var(--border-color);
            line-height: 0;
        }

        #pdf-viewer-canvas {
            display: block;

        }

        #pdf-viewer-container.text-view-active #pdf-annotate-toggle,
        #pdf-viewer-container.text-view-active #pdf-annotation-toolbar {
            display: none !important;
        }

        /* --- DECOUPLED TEXT VIEW STYLES (v2) --- */
        #pdf-text-view-content {
            display: none;
            width: 100%;
            padding: 2rem 1rem;
            /* Restored correct padding */
            font-family: var(--article-font-family);
            background-color: var(--bg-primary);
            color: var(--text-primary);
        }

        #pdf-text-view-content p {
            margin-block-start: 0;
            margin-block-end: 0.5em;
        }

        #pdf-text-view-content pre {
            font-family: inherit;
            white-space: pre-wrap;
            word-wrap: break-word;
            font-size: inherit;
            text-align: left;
            margin: 0 auto;
            max-width: 80ch;
            line-height: 1.7;
        }

        /* --- END OF TEXT VIEW STYLES --- */

        #pdf-viewer-container .btn-icon.active {
            background-color: var(--bg-tertiary);
            color: var(--primary-color);
        }

        body.pdf-viewer-active>header {
            display: none;
        }

        .pdf-more-menu-container {
            position: relative;
            display: inline-block;
        }

        .pdf-more-menu {
            position: absolute;
            top: calc(100% + 8px);
            right: 0;
            z-index: 26000;
            background-color: var(--bg-secondary);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-lg);
            border: 1px solid var(--border-color);
            padding: 4px;
            display: none;
            flex-direction: column;
            gap: 4px;
            width: 180px;
        }

        .pdf-more-menu.visible {
            display: flex;
            animation: fadeIn 0.2s ease-out;
        }

        .pdf-more-menu .btn {
            width: 100%;
            justify-content: flex-start;
        }

        /* --- VIEW TOGGLING LOGIC --- */
        #pdf-viewer-container.text-view-active .pdf-page-container {
            display: none;
        }

        #pdf-viewer-container.text-view-active #pdf-text-view-content {
            display: block;
        }

        /* --- NEW: Control Visibility Logic --- */
        .text-view-only-btn {
            display: none;
        }

        /* Show them only when text view is active */
        #pdf-viewer-container.text-view-active .text-view-only-btn {
            display: inline-flex;
        }

        /* Hide standard zoom controls when in text view */
        #pdf-viewer-container.text-view-active #pdf-zoom-out,
        #pdf-viewer-container.text-view-active #pdf-zoom-percent,
        #pdf-viewer-container.text-view-active #pdf-zoom-in {
            display: none;
        }

        #pdf-viewer-container.pdf-fullscreen-active .pdf-viewer-header {
            display: none;
        }

        /* --- NEW: PDF Annotation Styles --- */
        .pdf-page-container {
            position: relative;
        }

        #annotation-layer {
            position: absolute;
            top: 0;
            left: 0;
            pointer-events: none;
            z-index: 10;
        }

        #pdf-viewer-container.annotation-active #annotation-layer {
            pointer-events: auto;
            cursor: crosshair;
        }

        #pdf-annotation-toolbar .btn-icon.active {
            background-color: var(--bg-tertiary);
            color: var(--primary-color);
        }

        /* PDF PAN MODE */
        #pdf-viewer-container.pan-active .pdf-viewer-canvas-wrapper,
        #pdf-viewer-container.grab-mode .pdf-viewer-canvas-wrapper {
            cursor: grab;
            user-select: none;
        }

        #pdf-viewer-container.pan-active.is-dragging .pdf-viewer-canvas-wrapper,
        #pdf-viewer-container.grab-mode.is-dragging .pdf-viewer-canvas-wrapper {
            cursor: grabbing;
        }

        .pdf-color-palette {
            display: flex;
            align-items: center;
            gap: 6px;
            padding: 0 4px;
        }

        .pdf-color-pick {
            width: 22px;
            height: 22px;
            border-radius: 50%;
            border: 2px solid var(--border-color);
            cursor: pointer;
            transition: transform 0.2s ease, box-shadow 0.2s ease;
        }

        .pdf-color-pick:hover {
            transform: scale(1.15);
        }

        .pdf-color-pick.active {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 2px color-mix(in srgb, var(--primary-color) 60%, transparent);
            transform: scale(1.1);
        }

        #pdf-thickness-cycler svg {
            transition: transform 0.2s ease-in-out;
        }

        /* This rule standardizes all icons in both toolbars for a consistent look */
        #annotation-toolbar .btn-icon svg,
        #pdf-annotation-toolbar .btn-icon svg {
            width: 20px;
            height: 20px;
        }

        /* NEW: A smaller inner circle for the color cycler button for visual balance */
        .color-cycler-inner {
            width: 22px;
            height: 22px;
            border-radius: 50%;
            transition: background-color 0.2s ease;
        }

        /* --- NEW: PDF Viewer Mobile Responsiveness --- */
        body.mobile-view #pdf-viewer-header {
            flex-wrap: wrap;
            padding: 0.4rem 0.25rem;
            gap: 0.25rem;
        }

        body.mobile-view .pdf-viewer-title {
            order: -1;
            width: 100%;
            text-align: center;
            padding-bottom: 0.5rem;
            font-size: 0.9rem;
            border-bottom: 1px solid var(--border-color);
            display: none;
        }

        body.mobile-view .pdf-viewer-main.thumbnails-active {
            flex-direction: column;
        }

        body.mobile-view #pdf-thumbnails-bar {
            width: 100%;
            height: 120px;
            flex-direction: row;
            overflow-x: auto;
            overflow-y: hidden;
            border-right: none;
            border-bottom: 1px solid var(--border-color);
        }

        body.mobile-view .pdf-thumbnail {
            min-width: 80px;
        }

        /* Hide less critical buttons on mobile main bar */
        body.mobile-view #pdf-thumbnails-toggle,
        body.mobile-view #pdf-fullscreen-toggle,
        body.mobile-view #pdf-viewer-header .control-divider {
            display: none;
        }

        .pdf-more-menu .mobile-only-btn {
            display: none;
        }

        body.mobile-view .pdf-more-menu .mobile-only-btn {
            display: flex;
        }

        .tutorial-btn {
            flex-shrink: 0;
            white-space: nowrap;
        }