Constant MODAL_PANEL_BASE 

const MODAL_PANEL_BASE: &str = "flex flex-col max-h-[80vh] rounded-[2rem] border border-[var(--color-paper-border)] bg-[var(--color-paper-entry)] shadow-xl overflow-hidden modal-panel animate-modal-panel-enter";

弹窗面板基础类（不含宽度——不同弹窗尺寸不同，经 panel_class 传入追加）。