Modify several CSS properties at once Identifiers GreenIT V2 V3 V4 34 32 45 Categories Life cycle Tiers Responsible 3. Implementation User/Device Software Architect/Developer Indications Priority Implementation difficulty Ecological impact 3 4 2 Saved resources Processor Description Avoid modifying CSS properties one by one to limit the number of repaints/reflows. Rather add/remove CSS classes, which allow several properties to be modified at once while only generating a single repaint/reflow (see rule no. 45). Example Write: <styling> .in-error { color: red; font-weight: bold; } </style> <script> $el.bind('error', function () { $el.addClass('in-error'); }); $el.bind('running', function () { $el.removeClass('in-error'); }; </script> Validation rule The number of ... is equal to or less than CSS declarations that can be grouped into a single one (margin, padding, ...) 0