/* ============================================
   FLIPBOOK VIEWER CSS
   ============================================ */

.flipbook-viewer {
    background: #f5f5f5;
}

.viewer-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing);
}

.viewer-header {
    background: white;
    padding: var(--spacing);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    margin-bottom: var(--spacing);
    text-align: center;
}

.viewer-header h1 {
    color: var(--primary);
    margin-bottom: 5px;
    font-size: 1.8em;
}

.viewer-header .author {
    color: var(--text-light);
    font-style: italic;
    font-size: 1em;
}

/* ============================================
   VIEWER CONTROLS
   ============================================ */

.viewer-controls {
    background: white;
    padding: 15px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    margin-bottom: var(--spacing);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing);
}

.control-left,
.control-right {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.btn-control {
    background: var(--primary);
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.95em;
    font-weight: 500;
    min-height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-control:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-control:active {
    transform: translateY(0);
}

.btn-control:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
    opacity: 0.6;
}

.page-counter {
    color: var(--text);
    font-weight: 500;
    min-width: 150px;
    text-align: center;
    font-size: 0.95em;
}

.zoom-level {
    color: var(--text);
    font-weight: 500;
    min-width: 60px;
    text-align: center;
    display: inline-block;
    background: var(--secondary);
    padding: 5px 10px;
    border-radius: var(--radius);
    font-size: 0.9em;
}

/* ============================================
   PDF VIEWER
   ============================================ */

.pdf-viewer {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: auto;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 600px;
    padding: var(--spacing);
    margin-bottom: var(--spacing);
    position: relative;
}

.pdf-canvas {
    max-width: 100%;
    height: auto;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border-radius: 4px;
    display: block;
    margin: 0 auto;
}

/* ============================================
   LOADING STATE
   ============================================ */

.pdf-loading {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    padding: 40px;
    color: var(--primary);
    font-size: 1.1em;
    font-weight: 500;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: var(--radius-lg);
    z-index: 10;
    min-width: 300px;
}

.progress-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    width: 100%;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.progress-bar {
    width: 250px;
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--primary-dark));
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 3px;
}

.progress-percent {
    font-size: 0.9em;
    color: var(--text-light);
    margin: 0;
}

/* ============================================
   SKELETON LOADING
   ============================================ */

.skeleton-loader {
    display: flex;
    flex-direction: column;
    gap: 20px;
    width: 100%;
    opacity: 0;
    animation: fadeIn 0.3s ease 0.1s forwards;
}

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

.skeleton-page {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.skeleton-line {
    height: 16px;
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    border-radius: 4px;
    animation: shimmer 2s infinite;
}

.skeleton-line.short {
    width: 60%;
}

@keyframes shimmer {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

.skeleton-canvas {
    width: 100%;
    height: 500px;
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    border-radius: var(--radius);
    animation: shimmer 2s infinite;
}

/* ============================================
   FLIPBOOK FOOTER
   ============================================ */

.flipbook-footer {
    background: white;
    padding: var(--spacing);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.flipbook-footer p {
    margin-bottom: 10px;
    line-height: 1.6;
    color: var(--text);
}

.meta-info {
    color: var(--text-light);
    font-size: 0.9em;
    border-top: 1px solid var(--border);
    padding-top: var(--spacing);
    margin-top: var(--spacing);
}

/* ============================================
   TABLET RESPONSIVENESS
   ============================================ */

@media (max-width: 768px) {
    .viewer-container {
        padding: 10px;
    }

    .viewer-header {
        padding: 15px;
        margin-bottom: 15px;
    }

    .viewer-header h1 {
        font-size: 1.4em;
    }

    .viewer-controls {
        padding: 12px;
        gap: 10px;
        flex-direction: column;
        justify-content: center;
    }

    .control-left,
    .control-right {
        width: 100%;
        justify-content: center;
    }

    .btn-control {
        padding: 10px 12px;
        font-size: 0.85em;
        flex: 1;
        min-width: 100px;
    }

    .page-counter {
        min-width: 120px;
        font-size: 0.9em;
    }

    .pdf-viewer {
        min-height: 400px;
        padding: 10px;
    }

    .pdf-loading {
        min-width: 280px;
    }

    .progress-bar {
        width: 200px;
    }

    .skeleton-canvas {
        height: 300px;
    }

    .flipbook-footer {
        padding: 15px;
    }

    .flipbook-footer p {
        font-size: 0.95em;
    }
}

/* ============================================
   MOBILE RESPONSIVENESS
   ============================================ */

@media (max-width: 480px) {
    .viewer-container {
        padding: 5px;
    }

    .viewer-header {
        padding: 10px;
        margin-bottom: 10px;
    }

    .viewer-header h1 {
        font-size: 1.2em;
        margin-bottom: 3px;
    }

    .viewer-header .author {
        font-size: 0.85em;
    }

    .viewer-controls {
        padding: 10px;
        gap: 8px;
    }

    .control-left,
    .control-right {
        width: 100%;
    }

    .btn-control {
        padding: 10px 12px;
        font-size: 0.8em;
        flex: 1;
        min-height: 44px;
        min-width: auto;
    }

    .page-counter {
        width: 100%;
        min-width: auto;
        font-size: 0.85em;
        margin: 8px 0;
    }

    .zoom-level {
        font-size: 0.8em;
        padding: 5px 8px;
        min-width: 50px;
    }

    .pdf-viewer {
        min-height: 300px;
        padding: 5px;
        margin-bottom: 15px;
    }

    .pdf-canvas {
        max-width: 100%;
        border-radius: 2px;
    }

    .pdf-loading {
        min-width: 90vw;
        max-width: 100%;
        padding: 20px;
    }

    .spinner {
        width: 40px;
        height: 40px;
    }

    .progress-bar {
        width: 150px;
    }

    .progress-percent {
        font-size: 0.85em;
    }

    .skeleton-canvas {
        height: 200px;
    }

    .flipbook-footer {
        padding: 10px;
    }

    .flipbook-footer p {
        font-size: 0.9em;
        margin-bottom: 8px;
    }

    .meta-info {
        font-size: 0.85em;
    }
}

/* ============================================
   ZOOM LEVELS
   ============================================ */

.zoom-level-100 {
    /* Scale 100% */
}

.zoom-level-125 {
    /* Scale 125% */
}

.zoom-level-150 {
    /* Scale 150% */
}

/* ============================================
   FULLSCREEN
   ============================================ */

.flipbook-viewer.fullscreen {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100vw;
    height: 100vh;
    background: #000;
    z-index: 2000;
    overflow: hidden;
}

.flipbook-viewer.fullscreen .viewer-container {
    max-width: 100%;
    padding: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.flipbook-viewer.fullscreen .viewer-header {
    display: none;
}

.flipbook-viewer.fullscreen .viewer-controls {
    border-radius: 0;
    margin-bottom: 0;
}

.flipbook-viewer.fullscreen .flipbook-wrapper {
    flex: 1;
    border-radius: 0;
    margin-bottom: 0;
    box-shadow: none;
}

.flipbook-viewer.fullscreen .flipbook-footer {
    display: none;
}

/* ============================================
   LOADING STATE
   ============================================ */

.pdf-loading {
    position: relative;
    text-align: center;
    padding: 40px;
}

.pdf-loading::after {
    content: '';
    position: absolute;
    width: 40px;
    height: 40px;
    border: 4px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 1024px) {
    .flipbook-wrapper {
        min-height: 500px;
        padding: var(--spacing-sm);
    }

    .viewer-controls {
        padding: 10px;
        gap: var(--spacing-sm);
    }

    .control-left,
    .control-right {
        gap: 5px;
        flex: 1;
    }

    .btn-control {
        padding: 8px 10px;
        font-size: 0.85em;
        min-height: 40px;
    }
}

@media (max-width: 768px) {
    .viewer-container {
        padding: var(--spacing-sm);
    }

    .flipbook-wrapper {
        min-height: 350px;
        padding: var(--spacing-sm);
    }

    .viewer-controls {
        flex-direction: column;
        align-items: stretch;
        padding: 10px;
        gap: var(--spacing-sm);
    }

    .control-left,
    .control-right {
        width: 100%;
        justify-content: space-between;
        gap: 5px;
    }

    .page-counter {
        min-width: auto;
        flex: 1;
        text-align: center;
    }

    .btn-control {
        flex: 1;
        padding: 8px 6px;
        font-size: 0.8em;
        min-height: 40px;
    }

    .goto-input {
        width: 40px;
        padding: 6px 4px;
    }

    .viewer-header {
        padding: var(--spacing);
    }

    .viewer-header h1 {
        font-size: 1.3em;
    }

    .viewer-header .author {
        font-size: 0.9em;
    }

    .flipbook-footer {
        padding: var(--spacing);
    }

    .flipbook-footer p {
        font-size: 0.9em;
    }

    #flipbook {
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    .viewer-container {
        padding: var(--spacing-sm);
    }

    .flipbook-wrapper {
        min-height: 300px;
        padding: 8px;
    }

    .viewer-controls {
        flex-direction: column;
        padding: 8px;
        gap: 8px;
    }

    .control-left,
    .control-right {
        width: 100%;
    }

    .btn-control {
        padding: 6px 8px;
        font-size: 0.7em;
        min-height: 36px;
    }

    .goto-label {
        display: none;
    }

    .goto-input {
        display: none;
    }

    #fullscreenBtn {
        display: block;
    }

    .page-counter {
        font-size: 0.85em;
    }

    .viewer-header {
        padding: var(--spacing-sm);
        margin-bottom: var(--spacing-sm);
    }

    .viewer-header h1 {
        font-size: 1.1em;
    }

    .flipbook-footer {
        padding: var(--spacing-sm);
    }

    .flipbook-footer p {
        font-size: 0.85em;
    }

    .btn-control {
        font-weight: normal;
    }

    #prevBtn::before,
    #nextBtn::after {
        display: none;
    }
}

/* Print Styles */
@media print {
    .viewer-controls,
    .navbar,
    .footer {
        display: none;
    }

    .flipbook-wrapper {
        box-shadow: none;
    }
}