body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    background: transparent;
    overflow: hidden;
}

.export-container {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 900px;
    max-height: 80vh;
    margin: 0 auto;
}

.export-header {
    padding: 24px 32px;
    border-bottom: 1px solid #e5e7eb;
}

.export-header h2 {
    margin: 0;
    font-size: 20px;
    font-weight: 600;
    color: #1f2937;
}

.export-content {
    flex: 1;
    padding: 24px 32px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.export-section h3 {
    margin: 0 0 12px 0;
    font-size: 15px;
    font-weight: 600;
    color: #374151;
}

/* Spritesheet 预览 */
.preview-box {
    width: 100%;
    min-height: 300px;
    background: repeating-conic-gradient(#f3f4f6 0% 25%, white 0% 50%) 50% / 20px 20px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: auto;
}

#spritesheetCanvas {
    max-width: 100%;
    max-height: 100%;
    display: none;
}

#spritesheetCanvas.show {
    display: block;
}

.preview-placeholder {
    position: absolute;
    color: #9ca3af;
    font-size: 15px;
}

.preview-placeholder.hide {
    display: none;
}

/* 参考图上传 */
.reference-upload {
    width: 100%;
}

.reference-preview {
    width: 100%;
    height: 200px;
    border: 2px dashed #d1d5db;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    background: #f9fafb;
}

.reference-preview:hover {
    border-color: #9ca3af;
    background: #f3f4f6;
}

.reference-preview.has-image {
    border-style: solid;
    border-color: #667eea;
    background: white;
}

.upload-hint {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: #9ca3af;
}

.upload-hint svg {
    color: #d1d5db;
}

.upload-hint p {
    margin: 0;
    font-size: 14px;
}

.reference-preview img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

/* 操作按钮 */
.export-actions {
    padding: 20px 32px;
    border-top: 1px solid #e5e7eb;
    display: flex;
    gap: 12px;
    justify-content: flex-end;
}

.export-btn {
    padding: 12px 28px;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    font-weight: 500;
    letter-spacing: 0.3px;
    min-width: 100px;
}

.export-cancel {
    background: #f3f4f6;
    color: #6b7280;
    border: 1px solid #e5e7eb;
}

.export-cancel:hover {
    background: #e5e7eb;
    color: #4b5563;
    border-color: #d1d5db;
}

.export-cancel:active {
    transform: scale(0.98);
}

.export-confirm {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.export-confirm:hover {
    box-shadow: 0 6px 16px rgba(102, 126, 234, 0.5);
    transform: translateY(-1px);
}

.export-confirm:active {
    transform: translateY(0) scale(0.98);
}

.export-confirm:disabled {
    background: #d1d5db;
    color: #9ca3af;
    box-shadow: none;
    cursor: not-allowed;
    transform: none;
}