Terminal UI Design System

A comprehensive design system for creating terminal-inspired user interfaces with macOS-style window decorations, monospace typography, and a warm, developer-friendly color palette. This design system is optimized for developer tools, code marketplaces, technical documentation, and any interface that benefits from a command-line aesthetic.

Design Philosophy

Core Principles:

Terminal Aesthetic: Mimics macOS terminal windows with colored dots, monospace fonts, and command-line syntax
Developer-First: Uses syntax highlighting colors, code-like structures, and terminal metaphors
Warm & Approachable: Warm terracotta primary color (#cc7a60) creates a friendly, non-intimidating feel
High Contrast: Clear visual hierarchy with distinct text colors and backgrounds
Functional Beauty: Every design element serves a purpose while maintaining visual appeal

Color System

Primary Palette

Main Brand Color:

--primary: #cc7a60 - Warm terracotta/orange-brown, used for primary actions, accents, and highlights
--primary-foreground: #fff - White text on primary backgrounds
--primary-dark: #b56850 - Darker shade for hover states
--primary-light: #d8907a - Lighter shade for subtle accents
--ring: #cc7a60 - Focus ring color (same as primary)

Warm Accent:

--warm-red: #c85a3f - Used for code block borders and warm accents

Semantic Colors

Backgrounds:

--background: #fff - Pure white for main backgrounds
--bg-main: #f8f8f8 - Light gray for page background (with subtle grid pattern)
--bg-card: #fff - White for card components
--bg-code: #fafafa - Very light gray for code blocks and window headers
--secondary: #f9fafb - Light gray for secondary backgrounds
--muted: #f3f4f6 - Muted gray for subtle backgrounds

Text Colors:

--foreground: #111827 - Near-black for primary text (excellent readability)
--text-primary: #111827 - Primary text color
--text-secondary: #666666 - Medium gray for secondary text
--text-muted: #5b6370 - Muted gray for less important text
--muted-foreground: #5b6370 - Foreground on muted backgrounds

Borders:

--border: #8b929e - Medium gray for main borders
--border-light: #e5e7eb - Light gray for subtle dividers
--input: #8b929e - Input border color

Status Colors:

--success: #22c55e - Green for success states
--warning: #f59e0b - Amber for warnings
--danger: #ef4444 - Red for errors/destructive actions
--accent: #f59e0b - Amber accent color

Syntax Highlighting Colors

Code Syntax:

--syntax-keyword: #cc7a60 - Primary color for keywords (const, export, etc.)
--syntax-string: #22c55e - Green for strings
--syntax-number: #cc7a60 - Primary color for numbers
--syntax-comment: #6a9955 - Muted green for comments
--syntax-function: #dcdcaa - Light yellow for function names

Command Prefix:

Command prefix ($) uses fluorescent green: #39ff14 - Creates terminal-like appearance

Code Elements:

--text-comment: #6a9955 - Comment text color

macOS Window Dots

Terminal Window Controls:

--dot-red: #ff5f57 - Close button (macOS red)
--dot-yellow: #febc2e - Minimize button (macOS yellow)
--dot-green: #28c840 - Maximize button (macOS green)

Color Usage Guidelines

Primary Color (#cc7a60) Usage:

Command keywords in navigation
Prompt symbols (>)
Active states and highlights
Focus rings
Hover borders
Primary buttons when active
Chart lines and data visualization

Fluorescent Green (#39ff14) Usage:

Command prefix ($) - creates authentic terminal feel
Only used for dollar signs, never for other elements

Green (#22c55e) Usage:

Success indicators
Status dots (online/ready)
String literals in code
Positive actions

Blue (#3b82f6) Usage:

Command keywords (cd, watch, man, api)
Code keywords (const, let, var)
Links and interactive elements

Typography System

Font Families

Primary Font Stack:

--font-mono: "JetBrains Mono", "JetBrains Mono Fallback", 'Fira Code', 'Consolas', monospace;

Primary: JetBrains Mono (400-800 weights)
Fallbacks: Fira Code, Consolas, system monospace
Used for: All UI text, navigation, buttons, code blocks

Sans-serif Fallback:

--font-sans: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";

Used as fallback only, monospace is preferred

Font Size Scale

Base Unit System:

--text-xs: 0.75rem (12px) - Small labels, hints, window status
--text-sm: 0.875rem (14px) - Secondary text, descriptions
--text-base: 1rem (16px) - Body text, default size
--text-lg: 1.125rem (18px) - Slightly emphasized text
--text-xl: 1.25rem (20px) - Subheadings
--text-2xl: 1.5rem (24px) - Section titles
--text-3xl: 1.875rem (30px) - Large numbers, stats
--text-4xl: 2.25rem (36px) - Hero numbers
--text-5xl: 3rem (48px) - Large headings
--text-6xl: 3.75rem (60px) - Extra large headings

Font Weights:

--font-weight-normal: 400 - Body text
--font-weight-medium: 500 - Medium emphasis
--font-weight-semibold: 600 - Semibold (keywords, labels)
--font-weight-bold: 700 - Bold (headings, important text)
--font-weight-extrabold: 800 - Extra bold (hero text)

Line Heights:

--leading-tight: 1.25 - Tight spacing for headings
--leading-relaxed: 1.625 - Relaxed spacing for body text

Typography Usage

Headings:

Hero titles: 3.5rem, weight 700, line-height 1.1
Section titles: 2.5rem, weight 700
FAQ titles: 2rem, weight 700

Body Text:

Default: 1rem, weight 400, line-height 1.5
Secondary: 0.875rem, color --text-secondary
Muted: 0.75rem, color --text-muted

Code/Command Text:

Always use monospace font
Command prefix: fluorescent green (#39ff14)
Keywords: primary color (#cc7a60) or blue (#3b82f6)
Flags/arguments: default foreground color

Spacing System

Base Unit: --spacing: 0.25rem (4px)

Spacing Scale:

--spacing-xs: 4px (0.25rem) - Tight spacing, icon padding
--spacing-sm: 8px (0.5rem) - Small gaps, button padding
--spacing-md: 16px (1rem) - Standard spacing, card padding
--spacing-lg: 24px (1.5rem) - Large gaps, section spacing
--spacing-xl: 32px (2rem) - Extra large gaps, major sections
--spacing-2xl: 48px (3rem) - Maximum spacing, page sections

Usage Guidelines:

Use consistent spacing multiples (4px base)
Card padding: --spacing-md to --spacing-lg
Section margins: --spacing-xl to --spacing-2xl
Button padding: --spacing-sm to --spacing-md
Gap between related elements: --spacing-sm to --spacing-md

Border Radius System

Radius Scale:

--radius-xs: 2px (0.125rem) - Minimal rounding
--radius-sm: 4px (0.25rem) - Small elements
--radius-md: 6px (0.375rem) - Buttons, inputs
--radius-lg: 8px (0.5rem) - Cards, windows (most common)
--radius-xl: 12px (0.75rem) - Large cards
--radius-2xl: 16px (1rem) - Extra large elements
--radius: 10px (0.625rem) - Default radius

Usage:

Terminal windows: --radius-lg (8px)
Buttons: --radius-lg (8px)
Cards: --radius-lg (8px)
Inputs: --radius-md (6px)
Avatar: 9999px (fully rounded)

Shadow System

Shadow Scale:

--shadow-sm: 0 1px 2px rgba(0,0,0,0.05) - Subtle elevation
--shadow-md: 0 4px 6px rgba(0,0,0,0.07) - Medium elevation (cards on hover)
--shadow-lg: 0 10px 25px rgba(0,0,0,0.1) - Large elevation (floating buttons)

Usage:

Default cards: --shadow-sm
Hover states: --shadow-md
Floating elements: --shadow-lg
Primary-colored shadows: rgba(204, 122, 96, 0.1) for primary-themed elements

Component Specifications

Terminal Window Component

Structure:

<div class="terminal-window">
  <div class="window-header">
    <div class="window-dots">
      <span class="dot red"></span>
      <span class="dot yellow"></span>
      <span class="dot green"></span>
    </div>
    <span class="window-title">filename.ext</span>
    <span class="window-status">ready</span>
  </div>
  <div class="window-content">
    <!-- Content -->
  </div>
</div>

Styling:

Background: --bg-card (#fff)
Border: 1px solid --border (#8b929e)
Border radius: --radius-lg (8px)
Box shadow: --shadow-sm
Header background: --bg-code (#fafafa)
Header border-bottom: 1px solid --border-light (#e5e7eb)
Header padding: --spacing-sm --spacing-md (8px 16px)
Content padding: --spacing-lg (24px)

Window Dots:

Size: 12px × 12px
Gap: 6px
Colors: Red (#ff5f57), Yellow (#febc2e), Green (#28c840)
Fully rounded (border-radius: 50%)

Window Title:

Font size: 0.85rem
Color: --text-secondary (#666666)
Font: Monospace

Window Status:

Font size: 0.75rem
Color: --text-muted (#5b6370)
Position: Right side of header

Navigation Bar

Structure:

<nav class="navbar">
  <div class="navbar-container">
    <div class="navbar-content">
      <!-- Logo, commands, actions -->
    </div>
  </div>
</nav>

Styling:

Position: sticky, top: 0
Background: rgba(255, 255, 255, 0.8) with backdrop-filter: blur(8px)
Border-bottom: 1px solid --border
Height: 64px (desktop), 56px (mobile)
Max width: 80rem (1280px), centered

Logo:

Status indicator: Green dot (8px) + "ready" text
Path prefix: ~/ in primary color (#cc7a60)
Path name: Bold, foreground color
Cursor blink: 2px width, primary color, animated

Navigation Commands:

Display: Flex, gap --spacing-md
Button style: Monospace font, small padding (6px 12px)
Border: 1px solid --border
Border radius: --radius-lg
Active state: Primary border color with pulse animation
Hover: Border color changes to primary with 50% opacity

Command Button Structure:

<button class="nav-cmd">
  <span class="cmd-prefix">$</span>
  <span class="cmd-keyword">ai</span>
  <span class="cmd-flag">--search</span>
</button>

Command Colors:

Prefix ($): Fluorescent green (#39ff14)
Keyword: Primary color (#cc7a60) or blue (#3b82f6)
Flag: Default foreground color

Card Components

Skill Card:

Background: --bg-card (#fff in light, #111 in dark)
Border: 1px solid --border
Border radius: --radius-xl (12px)
Height: 100% with flex column layout
Hover: Border changes to primary with 50% opacity, shadow increases (0 25px 50px -12px rgba(204, 122, 96, 0.1)), translateY(-4px)
Active: translateY(0) scale(0.99)
Transition: all 0.3s ease
Line Numbers: Absolute positioned on left, 2rem width, subtle background
Avatar: 24px × 24px, bordered, scales on hover
Star Icon: 10px × 10px, warning color
Like Button: SVG heart icon, changes color on hover

Category Card:

Same base styling as skill card
Color Themes: Cyan, Blue, Purple, Amber variants
Folder Icon: SVG icon, color varies by theme, scales on hover
Category Dot: Small indicator dot, changes on hover
Arrow Icon: Appears on hover, positioned bottom-right
JSON Display: Key-value pairs with theme-colored hover effects
Command Line: Footer with command-style text

Mention Card:

Same base styling
Blockquote styling with quotation marks
Source attribution with border-top separator

Button Components

Primary Button (Active):

Background: --primary (#cc7a60)
Color: --primary-foreground (#fff)
Border: 1px solid --primary
Border radius: --radius-lg
Padding: 6px 12px (small) or --spacing-md --spacing-lg (medium)
Font: Monospace, --text-xs or --text-sm

Secondary Button:

Background: --bg-card
Border: 1px solid --border
Color: --foreground
Hover: Border color changes to primary with 50% opacity
Active: transform: scale(0.95)

Icon Button:

Square or rounded
Padding: 6px 12px
Icon size: 14px or 16px
Same hover/active states as secondary button

Input Components

Search Input:

Background: Transparent
Border: None
Font: Monospace
Placeholder: --text-muted color
Focus: No visible border (minimal design)

Text Input:

Background: --bg-card
Border: 1px solid --border
Border radius: --radius-sm or --radius-md
Padding: --spacing-sm
Font: Monospace

Code Display Components

Code Block:

Background: rgba(255, 255, 255, 0.5) with backdrop blur
Border: 1px solid --border
Border radius: --radius-lg
Padding: --spacing-md
Font: Monospace
Line height: --leading-relaxed

Code Line:

Display: Flex, align baseline
Gap: --spacing-sm
Syntax colors applied to different elements

Description Block (Comment Style):

Border-left: 4px solid rgba(204, 122, 96, 0.5)
Background: rgba(204, 122, 96, 0.05)
Padding-left: --spacing-md
Border-radius: Right side only (--radius-lg)
Font: Monospace

Grid Layouts

Skills Grid:

Display: Grid
Columns: repeat(3, 1fr) (desktop), repeat(2, 1fr) (tablet), 1fr (mobile)
Gap: --spacing-lg (24px)

Categories Grid:

Display: Grid
Columns: repeat(4, 1fr) (desktop), repeat(2, 1fr) (tablet), 1fr (mobile)
Gap: --spacing-lg

Mentions Grid:

Display: Grid
Columns: 1fr 1fr (desktop), 1fr (mobile)
Gap: --spacing-lg

Animation System

Transitions

Default Transition:

Duration: 0.15s or 0.2s
Timing: cubic-bezier(.4,0,.2,1) (ease-in-out)
Properties: all or specific properties

Common Transitions:

Hover states: all 0.2s ease
Active states: transform 0.2s ease
Color changes: color 0.2s ease or background-color 0.2s ease

Keyframe Animations

Blink Animation (Cursor):

@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}

Duration: 1s
Iteration: infinite
Used for: Cursor blink effect

Pulse Border Animation:

@keyframes pulse-border {
  0%, 100% { border-color: rgba(204, 122, 96, 0.5); }
  50% { border-color: var(--ring); }
}

Duration: 2s
Timing: ease-in-out
Iteration: infinite
Used for: Active navigation items

Fade In Up Animation:

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

Duration: 0.5s
Timing: ease
Used for: Card entrance animations
Staggered delays: 0.1s increments for grid items

Interactive States

Hover States:

Buttons: Border color changes, background lightens
Cards: Border changes to primary, shadow increases, slight lift
Links: Color changes to primary
Scale: No scaling on hover (maintains stability)

Active States:

Buttons: transform: scale(0.95) - subtle press effect
Duration: 0.2s

Focus States:

Outline: 2px solid --ring with 2px offset
Used for: Accessibility, keyboard navigation

Background Patterns

Grid Pattern (Page Background)

background-image: 
  linear-gradient(rgba(0, 0, 0, 0.02) 1px, transparent 1px),
  linear-gradient(90deg, rgba(0, 0, 0, 0.02) 1px, transparent 1px);
background-size: 20px 20px;

Very subtle grid (2% opacity black)
20px × 20px grid cells
Creates texture without distraction
Applied to body background

Gradient Backgrounds

Avatar Gradient:

background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);

Warm peach gradient
135-degree angle
Used for: User avatars

Chart Gradient:

linearGradient: #cc7a60 with opacity stops (0%: 0.6, 100%: 0)

Primary color gradient
Used for: Area charts, data visualization

Responsive Design

Breakpoints

Mobile: < 640px

Single column layouts
Reduced font sizes
Simplified navigation
Stacked grids

Tablet: 640px - 1024px

Two column layouts
Medium font sizes
Collapsed navigation menu

Desktop: 1024px - 1200px

Three column layouts
Full navigation visible
Standard spacing

Large Desktop: > 1200px

Four column layouts (where applicable)
Maximum content width: 1400px
Generous spacing

Responsive Adjustments

Navigation:

Desktop (>1024px): Full command menu visible
Tablet/Mobile: Hamburger menu, simplified layout
Status indicator: Hidden on mobile, visible on tablet+

Hero Section:

Desktop: Two column grid (text + chart)
Mobile: Single column, stacked

Grids:

Skills: 3 → 2 → 1 columns
Categories: 4 → 2 → 1 columns
Mentions: 2 → 1 columns

Typography:

Hero title: 3.5rem → 2.5rem (mobile)
Section titles: 2.5rem → 2rem (mobile)
Body text: Maintains readability

Implementation Guidelines

CSS Variable Usage

Always use CSS variables for:

Colors (never hardcode hex values)
Spacing (use spacing scale)
Typography (use text size scale)
Border radius (use radius scale)
Shadows (use shadow scale)

Example:

.button {
  background: var(--bg-card);
  color: var(--foreground);
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

Component Structure

Terminal Window Pattern:

Container with border and radius
Header with dots, title, status
Content area with padding
Consistent spacing throughout

Command-Line Pattern:

Prefix ($) in fluorescent green
Keyword in primary or blue
Flags/arguments in default color
Monospace font throughout

Color Application Rules

Primary Color (#cc7a60):

Use for: Active states, highlights, keywords, prompts
Avoid: Large background areas (too intense)
Opacity variants: Use rgba(204, 122, 96, 0.5) for borders, rgba(204, 122, 96, 0.05) for backgrounds

Fluorescent Green (#39ff14):

Use ONLY for: Command prefix ($)
Never use for: Other text, backgrounds, or accents

Green (#22c55e):

Use for: Success states, positive indicators, string literals
Avoid: Primary actions (use primary color instead)

Typography Rules

Always use monospace font for:

Navigation elements
Buttons
Code blocks
Command-line interfaces
Window titles
Status text

Font weight guidelines:

Body text: 400 (normal)
Labels/keywords: 600 (semibold)
Headings: 700 (bold)
Hero text: 700-800 (bold-extrabold)

Spacing Consistency

Use spacing scale:

Never use arbitrary values (e.g., 13px, 27px)
Stick to: 4px, 8px, 16px, 24px, 32px, 48px
For gaps between related items: --spacing-sm to --spacing-md
For section separation: --spacing-xl to --spacing-2xl

Animation Best Practices

Keep animations subtle:

Duration: 0.15s - 0.3s maximum
Easing: Use provided cubic-bezier curves
Avoid: Bouncy animations, long durations
Prefer: Fade, translate, scale (small amounts)

Performance:

Use transform and opacity for animations (GPU accelerated)
Avoid animating width, height, margin, padding

Common Patterns

Terminal Window Card

<div class="terminal-window">
  <div class="window-header">
    <div class="window-dots">
      <span class="dot red"></span>
      <span class="dot yellow"></span>
      <span class="dot green"></span>
    </div>
    <span class="window-title">filename.ext</span>
    <span class="window-status">ready</span>
  </div>
  <div class="window-content">
    <!-- Content here -->
  </div>
</div>

Command Button

<button class="nav-cmd">
  <span class="cmd-prefix">$</span>
  <span class="cmd-keyword">command</span>
  <span class="cmd-flag">--flag</span>
</button>

Code Block Display

<div class="stats-code-block">
  <div class="code-line">
    <span class="keyword">const</span>
    <span class="variable-name">variable</span>
    <span class="operator">=</span>
    <span class="number">123</span>
    <span class="operator">;</span>
  </div>
  <div class="code-comment">
    <span class="comment-symbol">// </span>Comment text
  </div>
</div>

Description Block (Comment Style)

<div class="description-block">
  <div class="comment-start">/**</div>
  <div class="comment-text">
    <span class="comment-asterisk"> * </span>Description text
  </div>
  <div class="comment-end"> */</div>
</div>

Accessibility Considerations

Color Contrast:

Primary text (#111827) on white: WCAG AAA compliant
Secondary text (#666666) on white: WCAG AA compliant
Primary color (#cc7a60) on white: WCAG AA compliant for large text

Focus States:

All interactive elements have visible focus indicators
Focus ring: 2px solid primary color with 2px offset

Keyboard Navigation:

All interactive elements are keyboard accessible
Tab order follows visual hierarchy
Enter/Space activate buttons

Screen Readers:

Semantic HTML structure
ARIA labels where needed
Status indicators use appropriate roles

Dark Mode Implementation

The design system includes a complete dark mode implementation using [data-theme="dark"] attribute selector. Dark mode is fully integrated with smooth transitions and maintains all design principles.

Dark Mode Color System

Primary Colors (Dark Mode):

--primary: #d99178 - Lighter terracotta for better contrast on dark backgrounds
--primary-foreground: #0a0a0a - Dark text on primary backgrounds
--primary-dark: #c57f66 - Darker shade for hover states
--primary-light: #e5a890 - Lighter shade for subtle accents
--ring: #d99178 - Focus ring color (lighter primary)

Backgrounds (Dark Mode):

--background: #0a0a0a - Deep black for main backgrounds
--bg-main: #0a0a0a - Dark background with subtle white grid pattern
--bg-card: #111 - Slightly lighter black for card components
--bg-code: #18181b - Dark gray for code blocks and window headers
--secondary: #1a1a1a - Dark gray for secondary backgrounds
--muted: #262626 - Muted dark gray for subtle backgrounds

Text Colors (Dark Mode):

--foreground: #ededed - Light gray for primary text
--text-primary: #ededed - Primary text color
--text-secondary: #a3a3a3 - Medium gray for secondary text
--text-muted: #a3a3a3 - Muted gray for less important text
--muted-foreground: #a3a3a3 - Foreground on muted backgrounds

Borders (Dark Mode):

--border: #606068 - Lighter gray for visibility on dark backgrounds
--border-light: #27272a - Subtle dark gray for dividers

Syntax Highlighting (Dark Mode):

--syntax-keyword: #d99178 - Lighter primary for keywords
--syntax-string: #22c55e - Green (same as light mode)
--syntax-number: #d99178 - Lighter primary for numbers
--syntax-comment: #6a9955 - Muted green (same as light mode)
Blue keywords: #60a5fa (blue-400) - Brighter blue for better contrast
Purple keywords: #c084fc (purple-400) - Brighter purple for better contrast

Shadows (Dark Mode):

--shadow-sm: 0 1px 2px rgba(0,0,0,0.3) - Stronger shadows for depth
--shadow-md: 0 4px 6px rgba(0,0,0,0.4) - Medium shadows
--shadow-lg: 0 10px 25px rgba(0,0,0,0.5) - Large shadows

Dark Mode Background Pattern

Dark mode uses a subtle white grid pattern instead of black:

[data-theme="dark"] body {
  background-image: 
    linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
}

Theme Toggle Implementation

HTML Structure:

<button class="theme-toggle-btn theme-toggle" title="切换主题" aria-label="切换主题">
  <svg class="icon-sun theme-icon"><!-- Sun icon --></svg>
  <svg class="icon-moon theme-icon" style="display: none;"><!-- Moon icon --></svg>
</button>

JavaScript Implementation:

Uses localStorage to persist theme preference
Detects system preference on first load
Smoothly transitions between themes
Updates icon visibility (sun/moon)
Listens to system theme changes (when no manual preference set)

Key Features:

Automatic system preference detection
Manual override with localStorage persistence
Smooth CSS transitions (0.2s ease-in-out)
Icon state management (sun for light, moon for dark)

Dark Mode Component Adaptations

Navigation Bar:

Background: rgba(10, 10, 10, 0.8) with backdrop blur
Status indicator: Darker background with adjusted border

Terminal Windows:

Card background: #111 (slightly lighter than main background)
Window headers: rgba(38, 38, 38, 0.3) for subtle contrast
All borders use darker mode colors

Skill Cards:

Line numbers background: rgba(38, 38, 38, 0.2)
Footer background: rgba(38, 38, 38, 0.2)
Hover effects maintain same behavior with adjusted colors

Category Cards:

Each category has theme-specific hover colors:
- Cyan: #22d3ee (dark) vs #06b6d4 (light)
- Blue: #60a5fa (dark) vs #3b82f6 (light)
- Purple: #c084fc (dark) vs #a855f7 (light)
- Amber: #fbbf24 (dark) vs #f59e0b (light)

Charts:

Grid lines: #27272a with 0.5 opacity
Chart container: rgba(17, 17, 17, 0.3)
All text colors adapt to dark mode

FAB Button:

Light mode: Dark background #1a1a1a with white icon
Dark mode: White background with dark icon (inverted)

Dark Mode Best Practices

Color Contrast:

All text maintains WCAG AA compliance in dark mode
Primary color is lightened for better visibility
Borders are lighter for clear definition

Transitions:

All color changes use transition: color 0.2s ease-in-out
Background changes use transition: background-color 0.2s ease-in-out
Smooth theme switching without jarring changes

Implementation Pattern:

/* Light mode (default) */
.component {
  background: var(--bg-card);
  color: var(--foreground);
}

/* Dark mode */
[data-theme="dark"] .component {
  background: var(--bg-card); /* Automatically uses dark value */
  color: var(--foreground); /* Automatically uses dark value */
}

Maintains:

Same spacing system
Same typography scale
Same component structure
Same animation timing
Enhanced shadows for depth perception

Performance Optimization

CSS Variables:

All colors/spacing use CSS variables for easy theming
Variables defined in :root for global access

Animations:

Use transform and opacity (GPU accelerated)
Avoid layout-triggering properties
Keep durations short (0.15s - 0.3s)

Font Loading:

Preconnect to Google Fonts
Use font-display: swap for better performance
Provide fallback fonts in stack

Browser Support

Modern Browsers:

Chrome/Edge: Full support
Firefox: Full support
Safari: Full support (with -webkit- prefixes for backdrop-filter)

Features Used:

CSS Grid: Full support in modern browsers
CSS Variables: Full support
Backdrop Filter: Requires -webkit- prefix for Safari
Flexbox: Full support

Design Tokens Summary

Quick Reference:

/* Colors - Light Mode */
Primary: #cc7a60
Fluorescent Green: #39ff14 (command prefix only)
Success: #22c55e
Blue: #3b82f6
Foreground: #111827
Border: #8b929e

/* Colors - Dark Mode */
Primary: #d99178
Foreground: #ededed
Background: #0a0a0a
Card: #111
Border: #606068
Blue: #60a5fa (brighter for contrast)

/* Spacing */
xs: 4px, sm: 8px, md: 16px, lg: 24px, xl: 32px, 2xl: 48px

/* Typography */
Font: JetBrains Mono
Sizes: 0.75rem - 3.75rem scale
Weights: 400, 500, 600, 700, 800

/* Radius */
xs: 2px, sm: 4px, md: 6px, lg: 8px, xl: 12px, 2xl: 16px

/* Shadows - Light Mode */
sm: 0 1px 2px rgba(0,0,0,0.05)
md: 0 4px 6px rgba(0,0,0,0.07)
lg: 0 10px 25px rgba(0,0,0,0.1)

/* Shadows - Dark Mode */
sm: 0 1px 2px rgba(0,0,0,0.3)
md: 0 4px 6px rgba(0,0,0,0.4)
lg: 0 10px 25px rgba(0,0,0,0.5)

Theme Toggle JavaScript Implementation

Complete Implementation:

(function() {
  const themeToggles = document.querySelectorAll('.theme-toggle');
  const html = document.documentElement;
  
  // Get initial theme from localStorage or system preference
  function getInitialTheme() {
    const savedTheme = localStorage.getItem('theme');
    if (savedTheme) {
      return savedTheme;
    }
    // Check system preference
    if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
      return 'dark';
    }
    return 'light';
  }
  
  // Set theme and update icons
  function setTheme(theme) {
    if (theme === 'dark') {
      html.setAttribute('data-theme', 'dark');
      document.querySelectorAll('.icon-sun').forEach(icon => {
        icon.style.display = 'none';
      });
      document.querySelectorAll('.icon-moon').forEach(icon => {
        icon.style.display = 'block';
      });
    } else {
      html.removeAttribute('data-theme');
      document.querySelectorAll('.icon-sun').forEach(icon => {
        icon.style.display = 'block';
      });
      document.querySelectorAll('.icon-moon').forEach(icon => {
        icon.style.display = 'none';
      });
    }
    localStorage.setItem('theme', theme);
  }
  
  // Toggle theme
  function toggleTheme() {
    const currentTheme = html.getAttribute('data-theme');
    const newTheme = currentTheme === 'dark' ? 'light' : 'dark';
    setTheme(newTheme);
  }
  
  // Initialize
  const initialTheme = getInitialTheme();
  setTheme(initialTheme);
  
  // Add event listeners
  themeToggles.forEach(button => {
    button.addEventListener('click', toggleTheme);
  });
  
  // Listen to system theme changes (only if no manual preference)
  if (window.matchMedia) {
    const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
    mediaQuery.addEventListener('change', (e) => {
      if (!localStorage.getItem('theme')) {
        setTheme(e.matches ? 'dark' : 'light');
      }
    });
  }
})();