design-fundamentals

design-fundamentals is a skill for Claude Code, Codex from plugin87/full-stack-design-skills. It costs 86 tokens per session (3,777 once invoked), scanned A, original, MIT.

A reference guide to core design principles for interfaces, websites, and applications. It explains how color, typography, layout, spacing, contrast, and visual hierarchy affect what users see and understand.

In plain words
What is it for?
Use it when designing or reviewing user interfaces, choosing colors and type, arranging page layouts, building design systems, or checking accessibility-related contrast.
Why use it?
It provides a shared basis for design decisions instead of relying only on personal taste or framework-specific conventions.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/plugin87/full-stack-design-skills/design-fundamentals
Any agent
npx skills add plugin87/full-stack-design-skills --skill design-fundamentals
Clone the repo
git clone --depth 1 https://github.com/plugin87/full-stack-design-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for design-fundamentals

README.md
[![agentmods](https://agentmods.dev/badge/skills/plugin87/full-stack-design-skills/design-fundamentals.svg)](https://agentmods.dev/skills/plugin87/full-stack-design-skills/design-fundamentals)
Your own site
<a href="https://agentmods.dev/skills/plugin87/full-stack-design-skills/design-fundamentals"><img src="https://agentmods.dev/badge/skills/plugin87/full-stack-design-skills/design-fundamentals.svg" alt="Measured on agentmods" height="20"></a>
Per session 86 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,777 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00086 $0.03777
Opus 5 $0.00043 $0.01888
Sonnet 5 $0.00017 $0.00755
Haiku 4.5 $0.00009 $0.00378

Measured 5d ago against content hash 303bc7b26b3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

design-fundamentals scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/design-fundamentals/SKILL.md · 417 lines

How it starts

The opening of the file, as written. The whole thing — 417 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Design Fundamentals

A comprehensive guide to universal design principles applicable across all digital products, frameworks, and platforms.

Core Principles Overview

Design fundamentals are the bedrock of every digital product. They transcend frameworks, tools, and trends. Whether you're designing in Figma, building components in React, or architecting a design system, these principles apply universally.

The five pillars:

  1. Color — How color creates meaning, contrast, hierarchy, and mood
  2. Typography — Font selection, sizing, weight, and spacing for readability
  3. Layout & Grid — Structural systems that organize information
  4. Spacing & Scale — Visual breathing room and proportion
  5. Contrast & Hierarchy — Guiding attention and creating relationships

1. Color Theory & Application

Color Fundamentals

Color Dimensions (HSL model):

  • Hue (0-360°) — The color itself (red, blue, yellow, etc.)
  • Saturation (0-100%) — Color intensity (gray is 0%, pure color is 100%)
  • Lightness (0-100%) — Brightness (0% = black, 100% = white, 50% = pure color)

Web designers typically work in:

  • HEX — #FF5733 (shorthand: #F57)
  • RGB/RGBA — rgb(255, 87, 51) with opacity
  • HSL — hsl(10, 100%, 60%)

Color Relationships

Complementary — Colors opposite on the color wheel. High contrast, use for CTAs and accents.

Analogous — Colors adjacent on the wheel. Harmonious, calming, use for neutral palettes.

Triadic — Three colors evenly spaced. Vibrant, balanced, use for playful interfaces.

Monochromatic — One hue in different saturations/lightnesses. Elegant, professional, use for coherent systems.

Accessibility & Contrast

WCAG Standards (minimum contrast ratios):

  • Normal text — 4.5:1 (AA) or 7:1 (AAA)
  • Large text (18pt+ or 14pt+ bold) — 3:1 (AA) or 4.5:1 (AAA)
  • UI Components & borders — 3:1 (AA)

Checking contrast:

  • Use WebAIM Contrast Checker, Accessible Colors, or browser DevTools
  • Never rely on color alone; pair with icons, patterns, or text
  • Dark mode requires separate contrast checks — don't assume 1:1 translations

Read the full file on GitHub · 417 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 417 lines · 86 tokens per session scan A 303bc7b26b3c

Subscribe to this mod's changes

design-fundamentals is a skill published in the GitHub repository plugin87/full-stack-design-skills (10 stars, last pushed 1mo ago), licensed MIT. It adds 86 tokens to every session and 3,777 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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