.chat-panel.drag-over {
    background: rgba(102, 126, 234, 0.08);
    outline: 2px dashed #667eea;
    outline-offset: -2px;
}

.upload-confirm-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    animation: fadeIn 0.2s ease;
}

.upload-confirm-dialog {
    background: white;
    border-radius: 12px;
    padding: 24px;
    width: 90%;
    max-width: 400px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    animation: slideUp 0.3s ease;
}

.upload-confirm-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #4a5568;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.upload-confirm-file {
    display: flex;
    align-items: center;
    gap: 12px;
    background: #f7fafc;
    border-radius: 8px;
    padding: 16px;
    margin-bottom: 20px;
}

.upload-confirm-file > i {
    font-size: 2rem;
    color: #667eea;
}

.upload-confirm-info {
    flex: 1;
    min-width: 0;
}

.upload-confirm-name {
    font-weight: 500;
    color: #2d3748;
    word-break: break-all;
    margin-bottom: 4px;
}

.upload-confirm-size {
    font-size: 0.85rem;
    color: #718096;
}

.upload-confirm-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.upload-confirm-actions .btn {
    width: auto;
    padding: 10px 20px;
}

.upload-confirm-size .upload-size-warning {
    color: #e53e3e;          /* 红色 */
    font-size: 0.85rem;
}

.upload-confirm-actions .btn:disabled {
    background: #a0aec0;     /* 灰色背景 */
    cursor: not-allowed;
    opacity: 0.7;            /* 降低不透明度 */
}