Neumorphism and CSS

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Neumorphism (aka neomorphism) is a relatively new design trend and a term that’s gotten a good amount of buzz lately. It’s aesthetic is marked by minimal and real-looking UI that’s sort of a new take on skeuomorphism — hence the name. It got its name in a UX Collective post from December 2019, and since then, various design and development communities have been actively discussing the trend, usually with differing opinions. Chris poked fun at it on Twitter. Adam Giebl created an online generator for it. Developers, designers, and UX specialists are weighing in on the topic of aesthetics, usability, accessibility, and practicality of this design trend.

Clearly, it’s stricken some sort of chord in the community.

Let’s dip our toes into the neumorphism pool, showcasing the various neumorphic effects that can be created using our language of choice, CSS. We’ll take a look at both the arguments for and against the style and weigh how it can be used in a web interface.

Neumorphism as a user interface

We’ve already established that the defining quality of neumorphism is a blend of minimalism and skeuomorphism. And that’s a good way to look at it. Think about the minimal aesthetic of Material Design and the hyper-realistic look of skeuomorphism. Or, think back to Apple’s design standards circa 2007-12 and compare it to the interfaces it produces today.

Nine years of Apple Calendar! The image on the left is taken from 2011 and exhibits the look and feel of a real, leather-bound journal, said to be inspired by one on Steve Jobs’ personal yacht. The right is the same app as shown today in 2020, bearing a lot less physical inspiration with a look and feel we might describe as “flat” or minimal.

If we think about Apple’s skeuomorphic designs from earlier in the century as one extreme and today’s minimal UI as another, then we might consider neumorphism as something in the middle.

Alexander Plyuto has championed and evolved neomorphic designs on his Dribbble account. (Source)

Neumorphic UI elements look like they’re connected to the background, as if the elements are extruded from the background or inset into the background. They’ve been described by some as “soft UI” because of the way soft shadows are used to create the effect.

Another way to understand neumorphic UI is to compare it to Material Design. Let’s use a regular card component to draw a distinction between the two.

Notice how the Material Design card (left) looks like it floats above the background, while the neumorphic variation(right) appears to be pushed up through the background, like a physical protrusion.

Let’s break down the differences purely from a design standpoint.

QualityMaterial DesignNeomorphism
ShadowsElements have a single or multiple dark shadows around them. Elements have two shadows: one light and one dark.
Background colorsAn element’s background color can be different than the background color of the parent element.Background colors must be the same (or very similar) as the background color of the parent element.
EdgesElements can be rounded or squared.Rounded edges are a defining quality.
BordersThere are no hard rules on borders. Using them can help prevent elements that look like they are floating off the screen.Elements can have an optional subtle border to improve contrast and make the edges a bit sharper

That should draw a pretty picture of what we’re talking about when we refer to neumorphism. Let’s move on to how it’s implemented in CSS.

Neumorphism and CSS

Creating a neumorphic interface with CSS is seemingly as easy as applying a regular box-shadow property on any element, but it’s more nuanced than that. The distinctiveness of a neumorphic UI comes from using multiple box-shadow and background-color values to achieve different types of effects and variations.

Neumorphic box shadows

Let’s do a quick refresher on the box-shadow property first so we can get a better understanding. Here’s the syntax:

box-shadow: [horizontal offset] [vertical offset] [blur radius] [optional spread radius] [color];

Following options can be adjusted:

  • Horizontal offset: A positive value offsets shadow to the right, while a negative value offsets it to the left.
  • Vertical offset: A positive value offsets shadow upwards, while a negative value offsets it downwards.
  • Blur Radius: The length of the shadow. The longer the length, the bigger and lighter the shadow becomes. There are no negative values.
  • Spread Radius: This is another length value, where larger values result in bigger, longer shadows.
  • Color: This defines the shadow’s color, just as we’d do for the CSS color property.
  • Inset: The default value (initial) results in a drop shadow. Using the inset value moves the shadow inside the frame of the element, resulting in an inner shadow.

We can apply multiple shadows using comma-separated box-shadow values. Up to four values can be concatenated, one for each side of the box.

box-shadow: 20px 20px 50px #00d2c6, 
            -30px -30px 60px #00ffff;

The following shows the box-shadow property values for a neumorphic UI element. Individual offset, blur and opacity values can be adjusted to be higher or lower, depending on the size of an element and the intensity of the effect that you’re trying to achieve. For neumorphism, it’s required to keep the shadows soft and low contrast.

As we’ve mentioned before, a core part of neumorphic elements is the use of two shadows: a light shadow and a dark shadow. That’s how we get that sort of “raised” effect and we can create variations by changing the “light source” of the shadows.

Two positive and two negative offset values need to be set. Taking this into account, we get the following four combinations, simply by changing the placement of each shadow.

Let’s use CSS variables to keep the values abstract and better understand the variations.

box-shadow: var(--h1) var(--v1) var(--blur1) var(--color-dark), 
            var(--h2) var(--v2) var(--blur2) var(--color-light);
Light SourcePositive ValuesNegative Values
Top Left--h1, --v1--h2, --v2
Top Right--h2, --v1--h1, --v2
Bottom Left--h1, --v2--h2, --v1
Bottom Right--h2, --v2--h1, --v1

We can use inset shadows to create yet more variations. Unlike drop shadows that make an element appear to be raised from beneath the background, an inset shadow gives the appearance that the element is being pressed into it.

We can change if the element is extruded from the background or inset into the background by applying the initial (not apply the option at all) or inset, respectively.

Let’s keep our light source as the top left and only toggle the inset option to see the difference.

Background colors

You might have noticed that the box-shadow values change the look of the edges of a neumorphic element. So far, we haven’t changed the background-color because it needs to be transparent or have the same (or similar) color as a background color of an underlying element, such as the element’s parent. 

We can use both solid and gradient backgrounds. Using a solid color background on the element can create a flat surface sort of look, when that solid color is the same as the color of the underlying element. 

On the other hand, using subtle gradients can change how the surface is perceived. As with the box-shadow property, there is alight and a dark value in a gradient. The gradient angle needs to be adjusted to match the light source. We have the following two variations when using gradients:

  • Convex surface variation:  The surface curves outwards where the gradient’s lighter section is aligned with the shadow’s lighter section, and the gradient’s darker section is aligned to the shadow’s darker section.
  • Concave surface variation:  The surface curves inward where the gradient’s lighter section is aligned to the shadow’s darker section, and the gradient’s darker section is aligned to the shadow’s lighter section.
.element {
  background: linear-gradient(var(--bg-angle), var(--bg-start), var(--bg-end));
  box-shadow: var(--h1) var(--v1) var(--color-dark), 
              var(--h2) var(--v2) var(--color-light);
}

Neumorphism in practice

Let’s see how Neumorphism performs when applied to a simple button. The main characteristic of a neumorphic interface is that it blends with the background and does so by having a similar or same background color as the underlying element. The main purpose of many buttons, especially a primary call-to-action, is to stand out as much as possible, usually with a prominent background color in order to separate it from other elements and other buttons on the page.

The background color constraint in neumorphism takes away that convenience. If the background color of the button matches the background color of what it’s on top of, we lose the ability to make it stand out visually with a unique color.

We can try and adjust text color, add a border below the text, add an icon or some other elements to increase the visual weight to make it stand out, etc. Whatever the case, a solid background color on a neumorphic button seems to stand out more than a gradient. Plus, it can be paired with an inset shadow on the active state to create a nice “pressed” effect.

Even though the solid color on a neumorphic button calls more attention than a gradient background, it still does not beat the way an alternate color makes a button stand out from other elements on the page.

Taking some inspiration from the real-world devices, I’ve created the following examples as an attempt to improve on the neumorphic button and toggle concept. Although the results look somewhat better, the regular button still provides a better UX, has much fewer constraints, is more flexible, is simpler to implement, and does a better job overall.

The first example was inspired by a button on my router that extrudes from the device and has a sticker with an icon on it. I added a similar “sticker” element with a solid color background as well as a slight inset to add more visual weight and make it stand out as closely as possible to the ideal button. The second example was inspired by a car control panel where the button would light up when it’s in an active (pressed) state.

Let’s take a look at some more HTML elements. One of the downsides of neumorphism that has been pointed out is that it shouldn’t be applied to elements that can have various states, like inputs, select elements, progress bars, and others. These states include:

  • User interaction: Hover, active, focus, visited
  • Validation states: Error, success, warning, disabled

UX and accessibility rules require some elements to look different in each of their respective validation states and user interaction states. Neumorphism constraints and restrictions severely limit the customization options that are required to achieve the different styles for each possible state. Variations will be very subtle and aren’t possibly able to cover every single state.

Everything looks like a button! Notice how the input and button look similar and how the progress bar looks like a scrollbar or a really wide toggle.

It’s hard to see which elements are clickable! Even though this is the simplest possible example that showcases the issue, we could have added extra elements and styles to try and mitigate the issues. But as we’ve seen with the button example, some other types of elements would still perform better in terms of UX and accessibility.

It’s important to notice that Neumorphic elements also take more space (inside padding and outside margin) due to the shadow and rounded corners. A neumorphic effect wouldn’t look so good on a small-sized element simply because the visual effects consume the element.

The ideal element for neumorphism are cards, or any other static container element that doesn’t have states based on user interaction (e.g. hover, active and disabled) or validation (e.g. error, warning, and success).

In his highly critical article on neumorphism, Michal Malewicz (who helped coin “Neumorphism” as a term) suggests adding Neumorphic effects to the cards that already look good without it.

So the only way it works OK is when the card itself has the right structure, and the whole extrusion is unnecessary for hierarchy.

See?

It works well when it can be removed without any loss for the product.

Accessibility and UX

We’ve seen which elements work well with neumorphism, but there are some important rules and restrictions to keep in mind when adding the effect to elements.

First is accessibility. This is a big deal and perhaps the biggest drawback to neumorphism: color contrast.

Neumorphic UI elements rely on multiple shadows that help blend the element into the background it is on. Using subtle contrasts isn’t actually the best fit for an accessible UI. If a contrast checker is scanning your UI, it may very well call you out for not having high enough contrast between the foreground and background because shadows don’t fit into the equation and, even if they did, they’d be too subtle to make much of a difference.

Here are some valid criticisms about the accessibility of a neumorphic design:

  • Users with color blindness and poor vision would have difficulty using it due to the poor contrast caused by the soft shadows.
  • Page hierarchy is difficult to perceive when the effect is overused on a page. No particular element stands out due to the background color restrictions.
  • Users can get confused when the effect is overused on a page. Due to the extrusion effect, it’s difficult to determine which elements users can interact with and which are static.

In order to achieve a good contrast with the shadow, the background color of what a neumorphic element sits on shouldn’t get too close to the edges of RGB extremes (white and black).

Let’s talk UX for a moment. Even though Neumorphic UI looks aesthetically pleasing, it shouldn’t be a dominant style on a page. If used too often, the UI will have an overwhelmingly plastic effect and the visual hierarchy will be all out of whack. The page could easily lose its intended structure when directing users to the most important content or to the main flow.

My personal take is that neumorphism is best used as an enhancement to another style. For example, it could be paired with Material Design in a way that draws distinctions between various component styles. It’s probably best to use it sparsely so that it adds a fresh alternative look to something on the screen — there’s a diminishing return on its use and it’s a good idea to watch out for it.

Here’s an  example where neumorphic qualities are used on card elements in combination with Materialize CSS:

See, it can be pretty nice when used as an accent instead of an entire framework.

That’s a wrap

So that was a deep look at neumorphism. We broke down what makes the style distinct from other popular styles, looked at a few ways to re-create the effect in CSS, and examined the implications it has on accessibility and user experience.

In practice, a full-scale neumorphic design system probably cannot be used on a website. It’s simply too restrictive in what colors can be used. Plus, the fact that it results in soft contrasts prevents it from being used on interactive elements, like buttons and toggle elements. Sure, it’s aesthetically-pleasing, modern and unique, but that shouldn’t come at the expense of usability and accessibility. It should be used sparsely, ideally in combination with another design system like Material Design.

Neumorphism is unlikely to replace the current design systems we use today (at least in my humble opinion), but it may find its place in those same design systems as a fresh new alternative to existing cards and static container styles.

References