Design of buttons with sliding background in HTML and CSS

Button design in HTML and CSS goes far beyond "adding a color and a hover." A well-designed button guides the user, communicates action, and improves the user experience. Over time, I've realized that with very few well-understood CSS properties, you can create modern, animated, and reusable buttons without relying on libraries or JavaScript.

In this guide, I'm going to show you how to design attractive buttons using only HTML and CSS, specifically a type of design such as the one with a sliding background among other examples; from the basics to more advanced animations like animated backgrounds with box-shadow.

Buttons are a fundamental element in any system and allow for various actions; they are also an icon of customization in every system. In CSS, it's easy to create a highly styled button without needing to add many lines of code or be a CSS expert.

What makes a button well-designed in HTML and CSS

A button is not just a visual element. It is a key interaction point.

The button as an interaction element

A good button should:

• Be recognizable as clickable
• Have sufficient contrast
• Respond visually to hover and click
• Maintain consistency with the overall design

In my case, many of the problems I had at first weren't technical, but design-related: buttons that were too flat, exaggerated animations, or effects that added nothing to usability.

Visual design vs. behavior

Visual design attracts, but behavior convinces. States like hover, active, and focus are just as important as color or typography.

Common mistakes

• Using animations that are too slow
• Not defining a focus state
• Relying on JavaScript for simple effects
• Overloading the button with unnecessary shadows

The first thing we will define is a series of basic CSS to style our button: size, shape, position, background color, font format, and an inner shadow on the border using the box-shadow property:

.boton_fondo_corredizo_base {
    color: #FFF;
    background: #0BF;
    padding: 20px;
    margin: 25px auto;
    font-family: 'OpenSansBold', sans-serif;
    font-size: 14px;
    font-weight: bold;
    letter-spacing: 1px;
    text-transform: uppercase;
    display: block;
    text-align: center;
    cursor: pointer;
    width: 300px;
    box-shadow: inset 0 0 0 0 #0BF;
    transition: all ease 0.8s;
}

The box-shadow property for inner shadows

Taking a brief detour, we will see how the box-shadow property works, which, as mentioned at the beginning of this post, is a fundamental property for this exercise; its syntax is as follows:

Syntax of the box-shadow property in our exercise

box-shadow: inset offset-x offset-y blur-radius spread-radius color

• inset: This value indicates that the shadow will appear inside the container rather than outside of it.
• offset-x and offset-y: Indicate the shadow's displacement on the horizontal and vertical axes, respectively.
• blur-radius: Indicates the degree of blurring, which for our example is zero in all cases.
• spread-radius: Allows for increasing or decreasing the size of the shadow; in our example, it is always zero.
• color: Determines the color of the shadow in its hexadecimal representation or any other supported by CSS.

As we can see, the box-shadow property, in addition to being used to create the typical shadows we are used to:

 .boton_sombra { box-shadow: 0 0 10px 2px #F00;}

Is also used to generate "inner shadows" or shadows inside the container like the following using the inset value:

.boton_sombra_interna { box-shadow: inset 0 0 10px 2px #F00;}

But if we decide not to add blur to the shadow whose state is handled by the inset value:

.boton_sombra_sindifuminado { box-shadow: inset 0 0 0 7px #F00;}

It looks as if we were defining a background color for the button.

Why use the box-shadow property instead of background?

Simply because we can "play" with the displacement of the background color or define where we want to start painting the color by using displacements through animations or transitions and the offset-x and offset-y values.

The key is control:

• You can animate directions
• You can “paint” from a specific side
• You don't need extra pseudo-elements

Returning to the creation of buttons with sliding backgrounds

Now that the operation of the box-shadow property has been explained, it will be easier for us to understand how a specific background color can be changed through the box-shadow property; for example, if we wanted to apply a background color change giving a top-to-bottom effect through CSS transitions:

.example .boton_fondo_corredizo_arriba:hover { box-shadow: inset 0 70px 0 0 #08B;}

Bottom to top:

.example .boton_fondo_corredizo_abajo:hover { box-shadow: inset 0 -70px 0 0 #08B;}

Right to left:

.example .boton_fondo_corredizo_derecha:hover { box-shadow: inset -340px 0 0 0 #08B;}

Left to right:

.example .boton_fondo_corredizo_izquierda:hover { box-shadow: inset 340px 0 0 0 #08B;}

Closing effect:

.example .boton_fondo_corredizo_abajo:hover { box-shadow: inset 0 -70px 0 0 #08B;}

Diagonals:

.example .boton_fondo_corredizo_abajo:hover { box-shadow: inset 340px 50px 0 0 #08B;}

.example .boton_fondo_corredizo_diagonal1:hover { box-shadow: inset -340px 50px 0 0 #08B;}

.example .boton_fondo_corredizo_diagonal2:hover { box-shadow: inset -340px -50px 0 0 #08B;}

.example .boton_fondo_corredizo_diagonal3:hover { box-shadow: inset 340px -50px 0 0 #08B;}

.example .boton_fondo_corredizo_diagonal4:hover { box-shadow: inset 340px -50px 0 0 #08B;}

Designing CSS buttons without JavaScript: advantages and performance

Using only CSS has clear benefits:

• Better performance
• Less complexity
• Easier maintenance
• Smoother animations

In real projects, I avoid JavaScript for buttons unless strictly necessary. For visual effects, CSS is usually more than enough.

Accessibility and usability in web button design

• A pretty button that cannot be used properly is a problem.
• Contrast and readability
  • Make sure the text is always legible, even during the animation.
• Focus state:

• .boton:focus { outline: 2px solid #000;}

• Responsible animations
  • Avoid excessive durations and distracting effects. A good design accompanies, it doesn't bother.

Examples of reusable and customizable CSS buttons

Once you have the system set up:

• Changing colors is trivial
• Adjusting sizes doesn't break the animation
• You can reuse the same base class

Frequently asked questions about button design in HTML and CSS

• How to create attractive buttons using only CSS?
  • By properly understanding properties like box-shadow, transition, and button states.
• Is it better to use box-shadow or background for animations?
  • For directional animated backgrounds, box-shadow offers more control.
• Do these animations affect performance?
  • No, as long as they are used in moderation and without recalculating layouts.
• Do I need JavaScript for animated buttons?
  • In most cases, no.

Conclusion

Button design in HTML and CSS does not depend on frameworks or complex code. By understanding a few properties well, you can create modern, animated, and usable buttons. In my case, discovering that box-shadow could be used as an animated background completely changed the way I design them.

A menu is always useful, and a mobile menu is essential in modern development. Learn how to create an animated hamburger menu button with CSS and a little HTML.