import './index.less'; function isFlexSupported(style) { return 'flex' in style || 'webkitFlex' in style || 'MozFlex' in style; } if (typeof window !== 'undefined' && window.document && window.document.documentElement) { const { documentElement } = window.document; const NO_FLEX = 'no-flex'; if (!isFlexSupported(documentElement.style) && documentElement.className.indexOf(NO_FLEX) === -1) { documentElement.className += ` ${NO_FLEX}`; } }