Jobb Smooth

CSS Trick 🤙 You can create these tab bar controls by using :has() to count the number of tabs ⭐️ .tabs:has(input:nth-of-type(3)){--count: 3;} .tabs:has(:checked:nth-of-type(3)){--active: 200%;} .tabs::after{ translate:var(--active) 0;} Let's break it down in this <noscript>! 📼 Couple of CSS :has() tricks here combined with custom properties 😎 First things first, lay out the tabs using display: grid. This gives you a way to create equal-width tabs 🙏 .tabs { display: grid; grid-auto-flow: column; } Then you use :has() to count the number of tabs and store that in a custom property 🤓 .tabs:has(input:nth-of-type(3)) { --count: 3; } .tabs:has(input:nth-of-type(4)) { --count: 4; } Using the cascade, the last valid :has() gives you the number of tabs 🫶 Using the tab count, you can size the tab indicator. For the tab indicator, use the tabs pseudoelement: .tabs::after { content: ""; position: absolute; height: 100%; width: calc(100% / var(--count)); } See how you can use --count to determine its size 📏 Next, use :has() to determine which tab is active or :checked with input [type=radio] .tabs:has(:checked:nth-of-type(2)) { --active: 1; } .tabs:has(:checked:nth-of-type(3)) { --active: 2; } You can use a zero-indexed translation here. If the second input is :checked, set --active: 1, then translate the pseudoelement on the tabs to that position 👉 .tabs::after { translate: calc(var(--active, 0) * 100%) 0; } Or you could set active to the translation: .tabs:has(:checked:nth-of-type(2)) { --active: 100%; } Setting the custom property allows you to use the index elsewhere if you need it 🤙 The final piece is using mix-blend-mode 👀 The tabs have a black background-color, the pseudoelement is white, and the label text is white. When you use mix-blend-mode: difference on the pseudoelement it will give this effect that the text transitions from white to black sliding across 😎 .tabs::after { color: hsl(0 0% 100%); mix-blend-mode: difference; } You can totally mix up the colors here though and go with a different effect. The mechanics of how you can use CSS :has() is the main point here 🙏 As always, any questions, suggestions, etc. let me know @CodePen link below! 👇 (There's even a @tailwindcss play for this one too 👀)