{"rowid": 307, "title": "Get the Balance Right: Responsive Display Text", "contents": "Last year in 24 ways I urged you to Get Expressive with Your Typography. I made the case for grabbing your readers\u2019 attention by setting text at display sizes, that is to say big. You should consider very large text in the same way you might a hero image: a picture that creates an atmosphere and anchors your layout.\nWhen setting text to be read, it is best practice to choose body and subheading sizes from a pre-defined scale appropriate to the viewport dimensions. We set those sizes using rems, locking the text sizes together so they all scale according to the page default and your reader\u2019s preferences.  You can take the same approach with display text by choosing larger sizes from the same scale.\nHowever, display text, as defined by its purpose and relative size, is text to be seen first, and read second. In other words a picture of text. When it comes to pictures, you are likely to scale all scene-setting imagery - cover photos, hero images, and so on - relative to the viewport. Take the same approach with display text: lock the size and shape of the text to the screen or browser window.\nIntroducing viewport units\nWith CSS3 came a new set of units which are locked to the viewport. You can use these viewport units wherever you might otherwise use any other unit of length such as pixels, ems or percentage. There are four viewport units, and in each case a value of 1 is equal to 1% of either the viewport width or height as reported in reference1 pixels:\n\nvw - viewport width,\nvh - viewport height,\nvmin - viewport height or width, whichever is smaller\nvmax - viewport height or width, whichever is larger\n\nIn one fell swoop you can set the size of a display heading to be proportional to the screen or browser width, rather than choosing from a scale in a series of media queries. The following makes the heading font size 13% of the viewport width:\nh1 {\n    font-size: 13 vw;\n}\nSo for a selection of widths, the rendered font size would be:\nRendered font size (px)\nViewport width\n13\u202fvw\n320\n42\n768\n100\n1024\n133\n1280\n166\n1920\n250\n\nA problem with using vw in this manner is the difference in text block proportions between portrait and landscape devices. Because the font size is based on the viewport width, the text on a landscape display is far bigger than when rendered on the same device held in a portrait orientation. \nLandscape text is much bigger than portrait text when using vw units.\nThe proportions of the display text relative to the screen are so dissimilar that each orientation has its own different character, losing the inconsistency and considered design you would want when designing to make an impression.\nHowever if the text was the same size in both orientations, the visual effect would be much more consistent. This where vmin comes into its own. Set the font size using vmin and the size is now set as a proportion of the smallest side of the viewport, giving you a far more consistent rendering.\nh1 {\n    font-size: 13vmin;\n}\nLandscape text is consistent with portrait text when using vmin units.\nComparing vw and vmin renderings for various common screen dimensions, you can see how using vmin keeps the text size down to a usable magnitude:\nRendered font size (px)\nViewport\n13\u202fvw\n13\u202fvmin\n320 \u00d7 480\n42\n42\n414 \u00d7 736\n54\n54\n768 \u00d7 1024\n100\n100\n1024 \u00d7 768\n133\n100\n1280 \u00d7 720\n166\n94\n1366 \u00d7 768\n178\n100\n1440 \u00d7 900\n187\n117\n1680 \u00d7 1050\n218\n137\n1920 \u00d7 1080\n250\n140\n2560 \u00d7 1440\n333\n187\n\nHybrid font sizing\nUsing vertical media queries to set text in direct proportion to screen dimensions works well when sizing display text. In can be less desirable when sizing supporting text such as sub-headings, which you may not want to scale upwards at the same rate as the display text. For example, we can size a subheading using vmin so that it starts at 16 px on smaller screens and scales up in the same way as the main heading:\nh1 {\n    font-size: 13vmin;\n}\nh2 {\n    font-size: 5vmin;\n}\nUsing vmin alone for supporting text can scale it too quickly\nThe balance of display text to supporting text on the phone works well, but the subheading text on the tablet, even though it has been increased in line with the main heading, is starting to feel disproportionately large and a little clumsy. This problem becomes magnified on even bigger screens.\nA solution to this is use a hybrid method of sizing text2. We can use the CSS calc() function to calculate a font size simultaneously based on both rems and viewport units. For example:\nh2 {\n    font-size: calc(0.5rem + 2.5vmin);\n}\nFor a 320 px wide screen, the font size will be 16 px, calculated as follows:\n(0.5 \u00d7 16) + (320 \u00d7 0.025) = 8 + 8 = 16px\nFor a 768 px wide screen, the font size will be 27 px:\n(0.5 \u00d7 16) + (768 \u00d7 0.025) = 8 + 19 = 27px\nThis results in a more balanced subheading that doesn\u2019t take emphasis away from the main heading:\n\nTo give you an idea of the effect of using a hybrid approach, here\u2019s a side-by-side comparison of hybrid and viewport text sizing:\ntable.ex--scale{width:100%;overflow: hidden;} table.ex--scale td{vertical-align:baseline;text-align:center;padding:0} tr.ex--scale-key{color:#666} tr.ex--scale-key td{font-size:.875rem;padding:0 0.125em} .ex--scale-2 tr.ex--scale-size{color:#ccc} tr.ex--scale-size td{font-size:1em;line-height:.34em;padding-bottom:.5rem} td.ex--scale-step{color:#000} td.ex--scale-hilite{color:red} .ex--scale-3 tr.ex--scale-size td{line-height:.9em}\n\ntop: calc() hybrid method; bottom: vmin only\n16\n20\n27\n32\n35\n40\n44\n16\n24\n38\n48\n54\n64\n72\n320\n480\n768\n960\n1080\n1280\n1440\n\nOver this festive period, try experiment with the proportion of rem and vmin in your hybrid calculation to see what feels best for your particular setting.\n\n\n\n\nA reference pixel is based on the logical resolution of a device which takes into account double density screens such as Retina displays.\u00a0\u21a9\ufe0e\n\n\nFor even more sophisticated uses of hybrid text sizing see the work of Mike Riethmuller.\u00a0\u21a9\ufe0e", "year": "2016", "author": "Richard Rutter", "author_slug": "richardrutter", "published": "2016-12-09T00:00:00+00:00", "url": "https://24ways.org/2016/responsive-display-text/", "topic": "code"}