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UwayxtUwayxt/agent-skills/.agents/skills/responsive-breakpoint-strategy/SKILL.md

responsive-breakpoint-strategy

Skill4 starsChanged 2 months agoMITView on GitHub

Define the breakpoint system and grid strategy for cross-device layouts. Use when setting up responsive design, breakpoints, mobile-first layout, fluid grid, or container queries.

The file

We split this skill into the rules it gives an agent

3 rules. About 0 are common, 2 are distinctive, and 1 is very specific to this project.

  • ≈0

    Common · estimate

    Many files like this have a rule of this kind.

  • ≈2

    Distinctive · estimate

    This author's own choices. Worth a look.

  • 1

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Document which breakpoints are "content breakpoints" (layout changes) vs "fine-tune breakpoints" (minor adjustments).

    line 19
  2. Very specific:

    Add breakpoints to design-tokens output (bp-* token set).

    line 28
  3. Distinctive:

    Every breakpoint has a name, value, and documented purpose

    line 34

≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

A breakpoint is a contract, not a guess. Define it once, reference it everywhere — never hard-code a pixel value that already has a token.

1. Choose the layout approach

Mobile-first (default, recommended) or desktop-first (only for admin-heavy tools where mobile is explicitly secondary). Document the choice and its rationale.

2. Define the breakpoint scale

Standard 5-point system:

  • bp-xs: < 480px (small phones)
  • bp-sm: 480px (phones, landscape)
  • bp-md: 768px (tablets, portrait)
  • bp-lg: 1024px (tablets landscape, small laptops)
  • bp-xl: 1280px (desktops)
  • bp-2xl: 1536px (large desktops, widescreen) Document which breakpoints are "content breakpoints" (layout changes) vs "fine-tune breakpoints" (minor adjustments).

3. Define the grid system

Columns per breakpoint (e.g., 4-col mobile, 8-col tablet, 12-col desktop), gutter size (token reference), max-content-width. Use CSS Grid or framework equivalent.

4. Evaluate container queries

For components that need to adapt based on their container width (not the viewport), flag them for container query usage. These are components that appear in multiple layout contexts (e.g., a card that appears in a sidebar AND in a main grid).

5. Output the breakpoint token file

Add breakpoints to design-tokens output (bp-* token set). Provide CSS custom properties + framework config (Tailwind, CSS-in-JS, or native CSS as appropriate to the project).

6. Document the decision

Which breakpoints trigger layout changes vs style adjustments. This feeds into adaptive-component-behavior.

Completion Criteria

  • Every breakpoint has a name, value, and documented purpose
  • Grid system defined for all breakpoints
  • Breakpoints added to design-tokens
  • Container query candidates identified
  • mobile-first vs desktop-first decision documented

Output

Breakpoint token set (JSON) + grid spec + CSS custom properties block + framework config.

Anti-patterns

  • Defining breakpoints by device name ("iPhone breakpoint") instead of content needs
  • Hardcoding pixel values in components that should reference bp-* tokens
  • Adding a breakpoint for every pixel difference — 5–6 breakpoints is almost always enough
  • Forgetting to handle the space between breakpoints (the "in-between" states)

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