{"rowid": 238, "title": "Everything You Wanted To Know About Gradients (And a Few Things You Didn\u2019t)", "contents": "Hello. I am here to discuss CSS3 gradients. Because, let\u2019s face it, what the web really needed was more gradients.\n\nStill, despite their widespread use (or is it overuse?), the smartly applied gradient can be a valuable contributor to a designer\u2019s vocabulary. There\u2019s always been a tension between the inherently two-dimensional nature of our medium, and our desire for more intensity, more depth in our designs. And a gradient can evoke so much: the splay of light across your desk, the slow decrease in volume toward the end of your favorite song, the sunset after a long day. When properly applied, graded colors bring a much needed softness to our work.\n\nOf course, that whole \u2018proper application\u2019 thing is the tricky bit.\n\nBut given their place in our toolkit and their prominence online, it really is heartening to see we can create gradients directly with CSS. They\u2019re part of the draft images module, and implemented in two of the major rendering engines.\n\nStill, I\u2019ve always found CSS gradients to be one of the more confusing aspects of CSS3. So if you\u2019ll indulge me, let\u2019s take a quick look at how to create CSS gradients\u2014hopefully we can make them seem a bit more accessible, and bring a bit more art into the browser.\n\nGradient theory 101 (I hope that\u2019s not really a thing)\n\nRight. So before we dive into the code, let\u2019s cover a few basics. Every gradient, no matter how complex, shares a few common characteristics. Here\u2019s a straightforward one:\n\n I spent seconds hours designing this gradient. I hope you like it.\n\nAt either end of our image, we have a final color value, or color stop: on the left, our stop is white; on the right, black. And more color-rich gradients are no different:\n\n (Don\u2019t ever really do this. Please. I beg you.)\n\nIt\u2019s visually more intricate, sure. But at the heart of it, we have just seven color stops (red, orange, yellow, and so on), making for a fantastic gradient all the way.\n\nNow, color stops alone do not a gradient make. Between each is a transition point, the fail-over point between the two stops. Now, the transition point doesn\u2019t need to fall exactly between stops: it can be brought closer to one stop or the other, influencing the overall shape of the gradient.\n\nA tale of two syntaxes\n\nArmed with our new vocabulary, let\u2019s look at a CSS gradient in the wild. Behold, the simple input button:\n\n\n\nThere\u2019s a simple linear gradient applied vertically across the button, moving from a bright sunflowerish hue (#FAA51A, for you hex nuts in the audience) to a much richer orange (#F47A20). And here\u2019s the CSS that makes it happen:\n\ninput[type=submit] {\n\tbackground-color: #F47A20;\n\tbackground-image: -moz-linear-gradient(\n\t\t#FAA51A,\n\t\t#F47A20\n\t\t);\n\tbackground-image: -webkit-gradient(linear, 0 0, 0 100%,\n\t\tcolor-stop(0, #FAA51A),\n\t\tcolor-stop(1, #F47A20)\n\t\t);\n}\n\nI\u2019ve borrowed David DeSandro\u2019s most excellent formatting suggestions for gradients to make this snippet a bit more legible but, still, the code above might have turned your stomach a bit. And that\u2019s perfectly understandable\u2014heck, it sort of turned mine. But let\u2019s step through the CSS slowly, and see if we can\u2019t make it a little less terrifying.\n\nVerbose WebKit is verbose\n\nHere\u2019s the syntax for our little gradient on WebKit:\n\nbackground-image: -webkit-gradient(linear, 0 0, 0 100%,\n\tcolor-stop(0, #FAA51A),\n\tcolor-stop(1, #F47A20)\n\t);\n\nWoof. Quite a mouthful, no? Well, here\u2019s what we\u2019re looking at:\n\n\n\tWebKit has a single -webkit-gradient property, which can be used to create either linear or radial gradients.\n\tThe next two values are the starting and ending positions for our gradient (0 0 and 0 100%, respectively). Linear gradients are simply drawn along the path between those two points, which allows us to change the direction of our gradient simply by altering its start and end points.\n\tAfterward, we specify our color stops with the oh-so-aptly named color-stop parameter, which takes the stop\u2019s position on the gradient (0 being the beginning, and 100% or 1 being the end) and the color itself.\n\n\nFor a simple two-color gradient like this, -webkit-gradient has a bit of shorthand notation to offer us:\n\nbackground-image: -webkit-gradient(linear, 0 0, 0 100%,\n\tfrom(#FAA51A),\n\tto(#FAA51A)\n\t);\n\nfrom(#FAA51A) is equivalent to writing color-stop(0, #FAA51A), and to(#FAA51A) is the same as color-stop(1, #FAA51A) or color-stop(100%, #FAA51A)\u2014in both cases, we\u2019re simply declaring the first and last color stops in our gradient.\n\nTerse Gecko is terse\n\nWebKit proposed its syntax back in 2008, heavily inspired by the way gradients are drawn in the canvas specification. However, a different, leaner syntax came to the fore, eventually appearing in a draft module specification in CSS3.\n\nNaturally, because nothing on the web was meant to be easy, this is the one that Mozilla has implemented.\n\nHere\u2019s how we get gradient-y in Gecko:\n\nbackground-image: -moz-linear-gradient(\n\t#FAA51A,\n\t#F47A20\n\t);\n\nWait, what? Done already? That\u2019s right. By default, -moz-linear-gradient assumes you\u2019re trying to create a vertical gradient, starting from the top of your element and moving to the bottom. And, if that\u2019s the case, then you simply need to specify your color stops, delimited with a few commas.\n\nI know: that was almost\u2026 painless. But the W3C/Mozilla syntax also affords us a fair amount of flexibility and control, by introducing features as we need them.\n\nWe can specify an origin point for our gradient:\n\nbackground-image: -moz-linear-gradient(50% 100%,\n\t#FAA51A,\n\t#F47A20\n\t);\n\nAs well as an angle, to give it a direction:\n\nbackground-image: -moz-linear-gradient(50% 100%, 45deg,\n\t#FAA51A,\n\t#F47A20\n\t);\n\nAnd we can specify multiple stops, simply by adding to our comma-delimited list:\n\nbackground-image: -moz-linear-gradient(50% 100%, 45deg,\n\t#FAA51A,\n\t#FCC,\n\t#F47A20\n\t);\n\nBy adding a percentage after a given color value, we can determine its position along the gradient path:\n\nbackground-image: -moz-linear-gradient(50% 100%, 45deg,\n\t#FAA51A,\n\t#FCC 20%,\n\t#F47A20\n\t);\n\nSo that\u2019s some of the flexibility implicit in the W3C/Mozilla-style syntax.\n\nNow, I should note that both syntaxes have their respective fans. I will say that the W3C/Mozilla-style syntax makes much more sense to me, and lines up with how I think about creating gradients. But I can totally understand why some might prefer WebKit\u2019s more verbose approach to the, well, looseness behind the -moz syntax. \u00c0 chacun son gradient syntax.\n\nStill, as the language gets refined by the W3C, I really hope some consensus is reached by the browser vendors. And with Opera signaling that it will support the W3C syntax, I suppose it falls on WebKit to do the same.\n\nReusing color stops for fun and profit\n\nBut CSS gradients aren\u2019t all simple colors and shapes and whatnot: by getting inventive with individual color stops, you can create some really complex, compelling effects.\n\nTim Van Damme, whose brain, I believe, should be posthumously donated to science, has a particularly clever application of gradients on The Box, a site dedicated to his occasional podcast series. Now, there are a fair number of gradients applied throughout the UI, but it\u2019s the feature image that really catches the eye.\n\nYou see, there\u2019s nothing that says you can\u2019t reuse color stops. And Tim\u2019s exploited that perfectly.\n\nHe\u2019s created a linear gradient, angled at forty-five degrees from the top left corner of the photo, starting with a fully transparent white (rgba(255, 255, 255, 0)). At the halfway mark, he\u2019s established another color stop at an only slightly more opaque white (rgba(255, 255, 255, 0.1)), making for that incredibly gradual brightening toward the middle of the photo.\n\n\n\nBut then he has set another color stop immediately on top of it, bringing it back down to rgba(255, 255, 255, 0) again. This creates that fantastically hard edge that diagonally bisects the photo, giving the image that subtle gloss.\n\n\n\nAnd his final color stop ends at the same fully transparent white, completing the effect. Hot? I do believe so.\n\nRocking the radials\n\nWe\u2019ve been looking at linear gradients pretty exclusively. But I\u2019d be remiss if I didn\u2019t at least mention radial gradients as a viable option, including a modest one as a link accent on a navigation bar:\n\n\n\nAnd here\u2019s the relevant CSS:\n\nbackground: -moz-radial-gradient(50% 100%, farthest-side,\n\trgb(204, 255, 255) 1%,\n\trgb(85, 85, 85) 15%,\n\trgba(85, 85, 85, 0)\n\t);\nbackground: -webkit-gradient(radial, 50% 100%, 0, 50% 100%, 15,\n\tfrom(rgb(204, 255, 255)),\n\tto(rgba(85, 85, 85, 0))\n\t);\n\nNow, the syntax builds on what we\u2019ve already learned about linear gradients, so much of it might be familiar to you, picking out color stops and transition points, as well as the two syntaxes\u2019 reliance on either a separate property (-moz-radial-gradient) or parameter (-webkit-gradient(radial, \u2026)) to shift into circular mode.\n\nMozilla introduces another stand-alone property (-moz-radial-gradient), and accepts a starting point (50% 100%) from which the circle radiates. There\u2019s also a size constant defined (farthest-side), which determines the reach and shape of our gradient.\n\nWebKit is again the more verbose of the two syntaxes, requiring both starting and ending points (50% 100% in both cases). Each also accepts a radius in pixels, allowing you to control the skew and breadth of the circle.\n\nAgain, this is a fairly modest little radial gradient. Time and article length (and, let\u2019s be honest, your author\u2019s completely inadequate grasp of geometry) prevent me from covering radial gradients in much more detail, because they are incredibly powerful. For those interested in learning more, I can\u2019t recommend the references at Mozilla and Apple strongly enough.\n\nLeave no browser behind\n\nBut no matter the kind of gradients you\u2019re working with, there is a large swathe of browsers that simply don\u2019t support gradients. Thankfully, it\u2019s fairly easy to declare a sensible fallback\u2014it just depends on the kind of fallback you\u2019d like. Essentially, gradient-blind browsers will disregard any properties containing references to either -moz-linear-gradient, -moz-radial-gradient, or -webkit-gradient, so you simply need to keep your fallback isolated from those properties.\n\nFor example: if you\u2019d like to fall back to a flat color, simply declare a separate background-color:\n\n.nav {\n\tbackground-color: #000;\n\tbackground-image: -moz-linear-gradient(rgba(0, 0, 0, 0), rgba(255, 255, 255, 0.45));\n\tbackground-image: -webkit-gradient(linear, 0 0, 0 100%, from(rgba(0, 0, 0, 0)), to(rgba(255, 255, 255, 0.45)));\n}\n\nOr perhaps just create three separate background properties.\n\n.nav {\n\tbackground: #000;\n\tbackground: #000 -moz-linear-gradient(rgba(0, 0, 0, 0), rgba(255, 255, 255, 0.45));\n\tbackground: #000 -webkit-gradient(linear, 0 0, 0 100%, from(rgba(0, 0, 0, 0)), to(rgba(255, 255, 255, 0.45)));\n}\n\nWe can even build on this to fall back to a non-gradient image:\n\n.nav {\n\tbackground: #000 <strong>url(\"faux-gradient-lol.png\") repeat-x</strong>;\n\tbackground: #000 -moz-linear-gradient(rgba(0, 0, 0, 0), rgba(255, 255, 255, 0.45));\n\tbackground: #000 -webkit-gradient(linear, 0 0, 0 100%, from(rgba(0, 0, 0, 0)), to(rgba(255, 255, 255, 0.45)));\n}\n\nNo matter the approach you feel most appropriate to your design, it\u2019s really just a matter of keeping your fallback design quarantined from its CSS3-ified siblings.\n\n(If you\u2019re feeling especially masochistic, there\u2019s even a way to get simple linear gradients working in IE via Microsoft\u2019s proprietary filters. Of course, those come with considerable performance penalties that even Microsoft is quick to point out, so I\u2019d recommend avoiding those.\n\nAnd don\u2019t tell Andy Clarke I told you, or he\u2019ll probably unload his Derringer at me. Or something.)\n\nGo forth and, um, gradientify!\n\nIt\u2019s entirely possible your head\u2019s spinning. Heck, mine is, but that might be the effects of the \u2019nog. But maybe you\u2019re wondering why you should care about CSS gradients. After all, images are here right now, and work just fine. \n\nWell, there are some quick benefits that spring to mind: fewer HTTP requests are needed; CSS3 gradients are easily made scalable, making them ideal for variable widths and heights; and finally, they\u2019re easily modifiable by tweaking a few CSS properties. Because, let\u2019s face it, less time spent yelling at Photoshop is a very, very good thing.\n\nOf course, CSS-generated gradients are not without their drawbacks. The syntax can be confusing, and it\u2019s still under development at the W3C. As we\u2019ve seen, browser support is still very much in flux. And it\u2019s possible that gradients themselves have some real performance drawbacks\u2014so test thoroughly, and gradient carefully.\n\nBut still, as syntaxes converge, and support improves, I think generated gradients can make a compelling tool in our collective belts. The tasteful design is, of course, entirely up to you.\n\nSo have fun, and get gradientin\u2019.", "year": "2010", "author": "Ethan Marcotte", "author_slug": "ethanmarcotte", "published": "2010-12-22T00:00:00+00:00", "url": "https://24ways.org/2010/everything-you-wanted-to-know-about-gradients/", "topic": "code"}