Function toggleHistoryPanel

notes.js:605–615

(panel, btn)

        }
        
        function toggleHistoryPanel(panel, btn) {
            const isVisible = panel.classList.contains('show');
            
            // 先隐藏所有面板
            hideAllHistoryPanels();
            
            if (!isVisible) {
                panel.classList.add('show');
                btn.textContent = '▲';
            }
        }
        
        function hideAllHistoryPanels() {
            [fontHistoryPanel, bgHistoryPanel].forEach(panel => {