Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices. Use when building responsive websites, optimizing for mobile users, or implementing adaptive layouts.
/plugin marketplace add secondsky/claude-skills/plugin install mobile-first-design@claude-skillsThis skill inherits all available tools. When active, it can use any tool Claude has access to.
Design interfaces starting with mobile as the foundation, then enhance for larger screens.
| Name | Width | Devices |
|---|---|---|
| Mobile | 320-480px | iPhone SE, small Android |
| Tablet | 481-768px | iPad mini |
| Desktop | 769-1024px | iPad Pro, laptops |
| Large | 1025px+ | Desktop monitors |
/* Base styles (mobile) */
.container {
padding: 1rem;
}
.nav {
display: none; /* Hidden on mobile */
}
.nav-toggle {
display: block; /* Hamburger visible */
}
/* Tablet and up */
@media (min-width: 768px) {
.container {
padding: 2rem;
max-width: 720px;
margin: 0 auto;
}
.nav {
display: flex;
}
.nav-toggle {
display: none;
}
}
/* Desktop */
@media (min-width: 1024px) {
.container {
max-width: 960px;
}
}
/* Minimum touch target: 48x48px */
.button {
min-height: 48px;
min-width: 48px;
padding: 12px 24px;
}
/* Adequate spacing */
.list-item {
padding: 16px;
margin-bottom: 8px;
}
| Metric | Target |
|---|---|
| First Contentful Paint | <3s on 3G |
| JS bundle | <100KB gzipped |
| Total page weight | <500KB |
<!-- Layer 1: Semantic HTML (works without CSS/JS) -->
<nav>
<a href="/home">Home</a>
<a href="/about">About</a>
</nav>
<!-- Layer 2: CSS enhances appearance -->
<!-- Layer 3: JS adds interactivity -->
This skill should be used when the user asks to "create an agent", "add an agent", "write a subagent", "agent frontmatter", "when to use description", "agent examples", "agent tools", "agent colors", "autonomous agent", or needs guidance on agent structure, system prompts, triggering conditions, or agent development best practices for Claude Code plugins.
This skill should be used when the user asks to "create a slash command", "add a command", "write a custom command", "define command arguments", "use command frontmatter", "organize commands", "create command with file references", "interactive command", "use AskUserQuestion in command", or needs guidance on slash command structure, YAML frontmatter fields, dynamic arguments, bash execution in commands, user interaction patterns, or command development best practices for Claude Code.
This skill should be used when the user asks to "create a hook", "add a PreToolUse/PostToolUse/Stop hook", "validate tool use", "implement prompt-based hooks", "use ${CLAUDE_PLUGIN_ROOT}", "set up event-driven automation", "block dangerous commands", or mentions hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification). Provides comprehensive guidance for creating and implementing Claude Code plugin hooks with focus on advanced prompt-based hooks API.