# Underdot Tab Bar

> A minimal five-slot mobile bottom bar whose only marker is a small travelling disc that glides under the active label, on a quiet card with a hairline border.

- Category: Navigation
- Frameworks: Vanilla, React + CSS, React + Tailwind
- Design system: Aperture
- Dark mode: yes
- Access: premium (Atheros AI Pass)
- Tags: tab-bar, bottom-nav, mobile
- Page: https://builder.atheros.ai/components/underdot-tab-bar
- Preview: https://d17nmjscumqk5d.cloudfront.net/builder/templates/tpl_builder_underdot_tab_bar/preview-92b402fdd274.webp

## Features

- Five labelled slots — Home, Explore, Projects, Saved, Profile — each a real 24x24 Tabler icon above a micro label
- A small disc marker glides under the active slot on a 0.42s cubic-bezier curve, positioned from measured slot geometry rather than hardcoded offsets
- The disc carries a soft accent halo ring so it reads as a marker rather than a stray dot
- Idle labels rest in a blended neutral ink; hover previews the selection colour and the active slot takes the readable accent ink at weight 600
- The bar is a card frame on the system `--cards-radius`, with a hairline border and the system elevation tier
- Roving `tabindex` with Arrow/Home/End key navigation and `aria-current="page"` on the active link
- Fully respects `prefers-reduced-motion`

## Accessibility

- **Navigation landmark** — `<nav aria-label="Primary">` wraps the slot list
- **Current slot** — `aria-current="page"` on the active link
- **Decorative icons** — All SVGs marked `aria-hidden="true"` and `focusable="false"`
- **Focus indicators** — `:focus-visible` outlines on every link and control, never composed into a `box-shadow` list
- **Keyboard navigation** — Roving tabindex with Arrow, Home and End keys
- **Reduced motion** — `prefers-reduced-motion: reduce` disables all animations

## Keyboard shortcuts

- `Tab` — Move focus into and out of the slot list
- `ArrowLeft` — Move to the previous slot
- `ArrowRight` — Move to the next slot
- `Home` — Move to the first slot
- `End` — Move to the last slot

## Common questions

**Which frameworks is Underdot Tab Bar available in?**

Underdot Tab Bar ships as Vanilla, React + CSS and React + Tailwind — HTML, CSS, JS and React source you can copy, download or clone into Atheros AI Builder.

**Is the Underdot Tab Bar navigation component free?**

Underdot Tab Bar is a premium component. Anyone can preview it; the source, downloads and AI customisation are included with Atheros AI Pass.

**Does Underdot Tab Bar support dark mode?**

Yes. Underdot Tab Bar ships light and dark themes, both drawn from the Aperture design system's tokens. Switch the preview to dark mode to compare them.

## Get the code

Preview Underdot Tab Bar live, then sign in to copy or download the source, apply another design system, or ask the AI assistant to change it: https://builder.atheros.ai/components/underdot-tab-bar

Every component on https://builder.atheros.ai is also reachable from Claude Code, Cursor and Codex through the Atheros MCP server (paid plans). Component index: https://builder.atheros.ai/llms-components.txt