:root {
    --primary-color: #222f6e;
    --secondary-color: #2563eb;
    --hover-bg: #f8f9fa;
    --text-color: #555;
    --border-color: #e0e0e0;
    --font-size-small: 0.7rem;
    --font-size-medium: 1rem;
    --font-size-large: 1.1rem;
}

.cursor-pointer {
    cursor: pointer;
}

.list-group-item:hover {
    background-color: var(--hover-bg);
}

.document-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.document-preview {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--hover-bg);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    overflow: hidden;
    margin-bottom: 0.5rem;
    width: 100px;
    height: 100px;
}

.document-preview img {
    max-width: 100%;
    max-height: 100%;
    object-fit: cover;
}

.document-preview .preview-text {
    font-size: var(--font-size-small);
    padding: 5px;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 5;
    -webkit-box-orient: vertical;
}

.document-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.document-item:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
}

.file-name {
    font-weight: 500;
    color: var(--text-color);
    text-align: center;
}

.pagination-container {
    display: flex;
    justify-content: center;
}

#noteContentContainer {
    max-width: 100%;
    overflow: hidden;
    position: relative;
}

#pdf-viewer {
    width: 100%;
    height: 80vh;
    min-height: 400px;
    overflow-y: auto;
    background-color: var(--hover-bg);
    border: 1px solid var(--border-color);
}

#pdf-viewer canvas {
    display: block;
    margin: 0 auto;
    border: 1px solid #ddd;
}

#pdf-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 10px;
}

#pdf-controls button {
    margin: 0 5px;
}

.unit-card {
    display: flex;
    align-items: center;
    background-color: #fff;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 1rem;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
}

.unit-icon {
    width: 50px;
    height: 50px;
    background-color: var(--hover-bg);
    border: 1px solid #d0d0d0;
    margin-right: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.unit-icon i {
    color: #999;
    font-size: 1.5rem;
}

.unit-info {
    flex-grow: 1;
}

.unit-name {
    margin: 0 0 0.25rem 0;
    font-size: var(--font-size-large);
    font-weight: bold;
    color: var(--primary-color);
}

.unit-details {
    font-size: 0.9rem;
    color: #666;
}

.download-button {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
    text-decoration: none;
    display: inline-block;
}

.download-button:hover {
    background-color: #1a2a60;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.4);
}

.modal-content {
    background-color: #fefefe;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 90%;
    max-width: 400px;
    border-radius: 5px;
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
}

.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
}

.watermark {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
    color: rgba(0, 0, 0, 0.1);
    pointer-events: none;
    user-select: none;
    transform: rotate(-45deg);
}

.icon-container {
    background-color: #f0f4f8;
    border-radius: 50%;
    padding: 10px;
}

.expand-icon {
    margin-left: auto;
    transition: transform 0.3s ease;
}

.expand-icon.collapsed {
    transform: rotate(180deg);
}

@media (max-width: 768px) {
    #pdf-viewer {
        height: 70vh;
    }
}

.pdf-container {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100vw;
    height: 100vh;
    background-color: #f5f5f5;
    overflow-y: auto;
}

canvas {
    max-width: 100%;
    height: auto;
    font-size: 30px;
}

/* Fullscreen Mode */
.fullscreen-pdf {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 1000;
    background-color: #fff;
}

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