/* All CSS styles remain the same as in your original code */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, sans-serif;
}

body {
    background-color: #f8f9fa;
    color: #333;
    line-height: 1.6;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
}

nav {
    width: 100%;
    background: linear-gradient(130deg, #4361ee, #3a0ca3);
    display: flex;
    align-items: center;
    color: white;
    gap: 13px;
}

nav img {
    width: 80px;
    height: 70px;
    margin-left: 20px;
}

.app-container {
    width: 80%;
    display: flex;
    flex-direction: column;
    gap: 25px;
    background-color: white;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    padding: 25px;
}

.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 15px;
    border-bottom: 1px solid #eaeaea;
}

.app-header h1 {
    font-size: 28px;
    font-weight: 700;
    color: #2c3e50;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 15px;
}

.search-box {
    display: flex;
    align-items: center;
    background-color: #f1f3f4;
    border-radius: 8px;
    padding: 10px 15px;
    width: 300px;
}

.search-box i {
    color: #7f8c8d;
    margin-right: 10px;
}

.search-box input {
    border: none;
    background: transparent;
    width: 100%;
    font-size: 15px;
    outline: none;
    color: #333;
}

.btn-add-note {
    background-color: #1a73e8;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 10px 20px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background-color 0.2s;
}

.btn-add-note:hover {
    background-color: #0d62d9;
}

.main-content {
    display: flex;
    gap: 30px;
}

.sidebar {
    flex: 0 0 240px;
    border-right: 1px solid #eaeaea;
    padding-right: 25px;
}

.notes-list {
    flex: 1;
}

.section-title {
    font-size: 14px;
    font-weight: 600;
    color: #7f8c8d;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 15px;
}

.nav-list,
.category-list {
    list-style: none;
    margin-bottom: 30px;
}

.nav-item,
.category-item {
    padding: 10px 15px;
    margin-bottom: 5px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
}

.nav-item:hover,
.category-item:hover {
    background-color: #f1f3f4;
}

.nav-item.active,
.category-item.active {
    background-color: #e3f2fd;
    color: #1a73e8;
    font-weight: 600;
}

.nav-item i,
.category-item i {
    margin-right: 12px;
    width: 20px;
    text-align: center;
}

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

.notes-header h2 {
    font-size: 22px;
    font-weight: 600;
    color: #2c3e50;
}

.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    min-height: 300px;
}

.note-card {
    background-color: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    border: 1px solid #eaeaea;
    position: relative;
}

.note-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.note-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 12px;
}

.note-title {
    font-size: 18px;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 5px;
}

.note-date {
    font-size: 13px;
    color: #7f8c8d;
    margin-bottom: 10px;
}

.note-category {
    display: inline-block;
    background-color: #e3f2fd;
    color: #1a73e8;
    font-size: 12px;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 20px;
    margin-bottom: 15px;
}

.note-content {
    font-size: 14px;
    color: #555;
    line-height: 1.5;
    margin-bottom: 15px;
    max-height: 100px;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
}

.note-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.favorite-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 18px;
    color: #ddd;
    transition: color 0.2s ease;
}

.favorite-btn.favorited {
    color: #ffc107;
}

.note-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.note-tag {
    background-color: #f1f3f4;
    color: #5f6368;
    font-size: 12px;
    padding: 4px 10px;
    border-radius: 12px;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #7f8c8d;
    grid-column: 1 / -1;
}

.empty-state i {
    font-size: 64px;
    margin-bottom: 15px;
    color: #e0e0e0;
}

.empty-state h3 {
    font-size: 22px;
    margin-bottom: 10px;
    color: #5f6368;
}

.empty-state p {
    font-size: 16px;
    margin-bottom: 25px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.btn-empty-state {
    background-color: #1a73e8;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 12px;
    font-weight: 500;
    font-size: 16px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: background-color 0.2s;
}

.btn-empty-state i {
    font-size: 60px;
}

.btn-empty-state:hover {
    background-color: #0d62d9;
}

.highlight {
    background-color: #fff9c4;
    padding: 0 2px;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: white;
    border-radius: 16px;
    width: 90%;
    max-width: 800px;
    max-height: 90vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.modal-header {
    padding: 20px 25px;
    border-bottom: 1px solid #eaeaea;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    font-size: 22px;
    color: #2c3e50;
}

.modal-body {
    padding: 25px;
    flex: 1;
    overflow-y: auto;
}

.close-btn {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #7f8c8d;
}

.note-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 600;
    color: #2c3e50;
}

.form-group input,
.form-group select {
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #1a73e8;
}

.formatting-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    padding: 12px;
    background-color: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #eaeaea;
}

.format-btn {
    background-color: white;
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 8px 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 14px;
    transition: all 0.2s;
}

.format-btn:hover {
    background-color: #f1f3f4;
}

.format-btn.active {
    background-color: #e3f2fd;
    border-color: #1a73e8;
    color: #1a73e8;
}

.khmer-font-options {
    display: flex;
    gap: 5px;
    margin-left: 10px;
}

.khmer-font-btn {
    background-color: white;
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 8px 12px;
    cursor: pointer;
    font-family: 'Khmer OS', 'MoolBoran', sans-serif;
    font-size: 16px;
}

.note-content-editor {
    min-height: 300px;
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    line-height: 1.6;
    outline: none;
    overflow-y: auto;
}

.note-content-editor:focus {
    border-color: #1a73e8;
}

.khmer-font-dok {
    font-family: 'Khmer OS', 'MoolBoran', sans-serif;
    font-size: 1.2em;
    font-weight: bold;
}

.khmer-font-trey {
    font-family: 'Khmer OS', 'MoolBoran', sans-serif;
    font-style: italic;
}

.tags-input {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 8px;
    min-height: 50px;
}

.tag-item {
    background-color: #e3f2fd;
    color: #1a73e8;
    padding: 5px 10px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 14px;
}

.tag-remove {
    cursor: pointer;
    font-size: 12px;
}

.tag-input {
    border: none;
    outline: none;
    flex: 1;
    min-width: 100px;
}

.modal-footer {
    padding: 20px 25px;
    border-top: 1px solid #eaeaea;
    display: flex;
    justify-content: flex-end;
    gap: 15px;
}

.btn {
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
}

.btn-primary {
    background-color: #1a73e8;
    color: white;
}

.btn-primary:hover {
    background-color: #0d62d9;
}

.btn-secondary {
    background-color: #f1f3f4;
    color: #333;
}

.btn-secondary:hover {
    background-color: #e0e0e0;
}

.btn-success {
    background-color: #28a745;
    color: white;
}

.btn-success:hover {
    background-color: #218838;
}

.btn-danger {
    background-color: #dc3545;
    color: white;
}

.btn-danger:hover {
    background-color: #c82333;
}

/* Note card action buttons */
.note-card-actions {
    display: flex;
    gap: 8px;
}

.action-btn {
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    border: 1px solid #ddd;
    background-color: white;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 5px;
}

.action-btn-edit {
    color: #1a73e8;
    border-color: #1a73e8;
}

.action-btn-edit:hover {
    background-color: #e3f2fd;
}

.action-btn-pdf {
    color: #d32f2f;
    border-color: #d32f2f;
}

.action-btn-pdf:hover {
    background-color: #ffebee;
}

.action-btn-delete {
    color: #dc3545;
    border-color: #dc3545;
}

.action-btn-delete:hover {
    background-color: #f8d7da;
}

/* Download History Section */
.download-history {
    margin-top: 30px;
    border-top: 1px solid #eaeaea;
    padding-top: 25px;
}

.download-history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.download-history-header h3 {
    font-size: 18px;
    color: #2c3e50;
}

.download-history-list {
    background-color: #f8f9fa;
    border-radius: 12px;
    padding: 20px;
}

.download-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 15px;
    border-bottom: 1px solid #eaeaea;
}

.download-item:last-child {
    border-bottom: none;
}

.download-item-info {
    display: flex;
    align-items: center;
    gap: 15px;
}

.download-icon {
    color: #1a73e8;
    font-size: 20px;
}

.download-details h4 {
    font-size: 15px;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 4px;
}

.download-details p {
    font-size: 13px;
    color: #7f8c8d;
}

.download-time {
    font-size: 13px;
    color: #7f8c8d;
}

.clear-downloads-btn {
    background: none;
    border: 1px solid #ddd;
    color: #7f8c8d;
    padding: 8px 15px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}

.clear-downloads-btn:hover {
    background-color: #f1f3f4;
}

@media (max-width: 900px) {
    .main-content {
        flex-direction: column;
    }

    .sidebar {
        border-right: none;
        border-bottom: 1px solid #eaeaea;
        padding-right: 0;
        padding-bottom: 25px;
        flex: 0;
    }

    .notes-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }

    .app-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }

    .header-controls {
        flex-direction: column;
        width: 100%;
    }

    .search-box {
        width: 100%;
    }
}

@media (max-width: 600px) {
    .notes-grid {
        grid-template-columns: 1fr;
    }

    .formatting-toolbar {
        align-items: flex-start;
    }

    .note-card-actions {
        flex-wrap: wrap;
    }

    .download-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .download-time {
        align-self: flex-end;
    }
}