* {
    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;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.upload-section {
    background: white;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.upload-area {
    border: 3px dashed #ddd;
    border-radius: 10px;
    padding: 40px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: #667eea;
    background-color: #f8f9ff;
}

.upload-area i {
    font-size: 3rem;
    color: #667eea;
    margin-bottom: 20px;
}

.upload-area p {
    font-size: 1.2rem;
    margin-bottom: 20px;
    color: #666;
}

.upload-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 1rem;
    cursor: pointer;
    transition: transform 0.2s ease;
}

.upload-btn:hover {
    transform: translateY(-2px);
}

.text-share-section {
    background: white;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.text-actions {
    display: flex;
    gap: 10px;
}

.copy-btn {
    background: #007bff;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.copy-btn:hover {
    background: #0056b3;
}

.save-btn {
    background: #28a745;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.save-btn:hover {
    background: #218838;
}

.clear-btn {
    background: #dc3545;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.clear-btn:hover {
    background: #c82333;
}

.text-container {
    position: relative;
}

#sharedTextArea {
    width: 100%;
    min-height: 200px;
    padding: 15px;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    font-family: 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.5;
    resize: vertical;
    transition: border-color 0.3s ease;
}

#sharedTextArea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.text-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
    font-size: 0.9rem;
    color: #666;
}

.auto-save-indicator {
    font-size: 0.8rem;
    padding: 2px 8px;
    border-radius: 10px;
    background: #e9ecef;
    color: #666;
    transition: all 0.3s ease;
}

.auto-save-indicator.saving {
    background: #ffc107;
    color: #856404;
}

.auto-save-indicator.saved {
    background: #28a745;
    color: white;
}

.auto-save-indicator.error {
    background: #dc3545;
    color: white;
}

.file-list-section {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.section-header {
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid #f0f0f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.section-header h2 {
    color: #333;
    font-size: 1.5rem;
    margin: 0;
}

.batch-actions {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.btn-batch {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
    background: #667eea;
    color: white;
}

.btn-batch:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(102, 126, 234, 0.3);
}

.btn-batch.btn-danger {
    background: #dc3545;
}

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

.file-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.file-item {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 0;
    text-align: center;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    cursor: pointer;
    border: 2px solid transparent;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
}

.file-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    border-color: #667eea;
}

.file-item.selected {
    border-color: #667eea;
    background: #f0f4ff;
    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.3);
}

.file-checkbox {
    position: absolute;
    top: 10px;
    left: 10px;
    z-index: 10;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 4px;
    padding: 5px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.file-checkbox input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: #667eea;
}

.file-item-header {
    width: 100%;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f0f0f0;
}

.file-item-body {
    padding: 15px;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.file-icon {
    font-size: 3rem;
    color: #667eea;
}

.file-thumbnail {
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.file-thumbnail img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.file-thumbnail img:hover {
    transform: scale(1.05);
}

.file-thumbnail video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    background: #000;
}

.video-play-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 3rem;
    color: rgba(255, 255, 255, 0.9);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
    pointer-events: none;
    z-index: 1;
}

.file-name {
    font-weight: bold;
    margin-bottom: 8px;
    word-break: break-all;
    font-size: 0.85rem;
    color: #333;
}

.file-info {
    font-size: 0.75rem;
    color: #666;
    margin-bottom: 12px;
    line-height: 1.4;
    flex: 1;
}

.file-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.btn {
    padding: 6px 12px;
    border: none;
    border-radius: 15px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: all 0.2s ease;
}

.btn-download {
    background: #007bff;
    color: white;
}

.btn-download:hover {
    background: #0056b3;
}

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

.btn-delete:hover {
    background: #c82333;
}

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

.btn-preview:hover {
    background: #218838;
}

.btn-link {
    background: #6f42c1;
    color: white;
}

.btn-link:hover {
    background: #5a32a3;
}

.btn-edit {
    background: #ffc107;
    color: #000;
}

.btn-edit:hover {
    background: #e0a800;
}

.btn .btn-text {
    margin-left: 6px;
    display: inline-block;
}

@media (min-width: 768px) {
    /* 桌面端隐藏文字，仅显示图标；移动端保持原状 */
    .btn .btn-text {
        display: none;
    }
}

.loading {
    text-align: center;
    padding: 40px;
    color: #666;
    font-size: 1.1rem;
}

.loading i {
    margin-right: 10px;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.8);
}

.modal-content {
    position: relative;
    margin: 5% auto;
    padding: 20px;
    width: 90%;
    max-width: 800px;
    background: white;
    border-radius: 15px;
    text-align: center;
}

.close {
    position: absolute;
    right: 20px;
    top: 20px;
    color: #aaa;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

.close:hover {
    color: #000;
}

#modalImage {
    max-width: 100%;
    max-height: 500px;
    border-radius: 10px;
    margin-bottom: 20px;
}

.modal-info h3 {
    margin-bottom: 10px;
    color: #333;
}

.modal-info p {
    color: #666;
    margin-bottom: 20px;
}

.modal-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.modal-actions .btn {
    padding: 10px 20px;
    font-size: 1rem;
}

.toast {
    position: fixed;
    top: 20px;
    right: 20px;
    background: #333;
    color: white;
    padding: 15px 20px;
    border-radius: 5px;
    z-index: 1001;
    transform: translateX(400px);
    transition: transform 0.3s ease;
}

.toast.show {
    transform: translateX(0);
}

.toast.success {
    background: #28a745;
}

.toast.error {
    background: #dc3545;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .file-list {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 15px;
    }
    
    .file-item-header {
        aspect-ratio: 1;
    }
    
    .file-actions {
        flex-direction: column;
        gap: 5px;
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
    }
    
    .modal-actions {
        flex-direction: column;
        gap: 10px;
    }
}