html { // Use border-box box sizing box-sizing: border-box; // Disable text size adjustment on device rotation text-size-adjust: 100%; // Always display vertical scrollbar overflow-y: scroll; } *, *::before, *::after { // Reset all spacing margin: 0; padding: 0; // Inherit box-sizing from html element box-sizing: inherit; // Disable default styling for certain elements list-style: none; border: none; box-shadow: none; } // Disable all vertical margins for first and last childs of a container :first-child { margin-top: 0; } :last-child { margin-bottom: 0; } // Make old browsers understand HTML5 elements article, aside, details, figcaption, figure, footer, header, main, menu, nav, section, summary { display: block; }