Perfect — I’ll begin crafting a complete design system for PrecisionCore tailored for web applications that work well on both desktop and mobile. It’ll default to light mode, include dark mode support, and cover all essential components found in modern web apps.

The system will include:

In-depth design philosophy and visual principles
Guidelines for layout, spacing, grids, and UI behaviors
Component breakdowns with usage rules
Code examples in vanilla HTML/CSS (primary) and TailwindCSS (secondary)
Mockups and image examples of components in the PrecisionCore style

I’ll let you know as soon as it’s ready for review.

PrecisionCore Design System

Introduction & Design Philosophy

PrecisionCore is a comprehensive design system that blends four key influences into a unified visual style for web applications: Material Design (functional, systemized architecture), Minimalism (clarity and focus), Apple’s Design Elegance (refinement and attention to detail), and Windows 98’s Nostalgic Rigidity (clear structure and familiar patterns). The goal is a modern yet timeless UI that is highly usable and aesthetically pleasing. By combining these philosophies, PrecisionCore emphasizes intuitive interaction, minimal distraction, and a touch of retro familiarity:

Functional Clarity (Material): Heavily inspired by Material Design, PrecisionCore promotes consistent layouts and predictable components. Every element has a clear purpose and aligns to a rational grid system, ensuring the interface feels organized and easy to navigate. Accessibility and cross-platform consistency are priorities, echoing Material Design’s mission to make UIs that work for everyone in any context (What is iOS Human Interface Guidelines?). Components are designed with an 8px baseline grid for balance and rhythm (Metrics & keylines - Layout - Material Design), and interactive controls meet recommended touch target sizes (at least 48×48px with adequate spacing) (Metrics & keylines - Layout - Material Design) for usability.
Content over Chrome (Minimalism): In line with minimalist principles, PrecisionCore interfaces present content and core features in a simple, direct way with as little distraction as possible (The Roots of Minimalism in Web Design). Unnecessary ornamentation, gradients, or clutter are removed so that users can focus on tasks without extraneous visual noise. Every UI element must justify its existence; if it doesn’t support a primary user goal, PrecisionCore suggests eliminating or simplifying it. This “less is more” approach results in clean screens, ample whitespace, and an overall interface that feels open and approachable.
Refined Elegance (Apple): Borrowing from Apple’s Human Interface Guidelines, PrecisionCore values clarity (legible text, precise controls) and deference (the UI should defer to content) (What is iOS Human Interface Guidelines?). Visuals are crisp and polished – from high-contrast text to smooth micro-interactions – giving the system a modern, premium feel. Subtle effects (like soft shadows or gentle highlights) are used sparingly to create depth and affordances without overwhelming the user. The result is an interface that feels delightful and intuitive, exhibiting “simplicity carried to an extreme” which becomes elegance (as famously espoused by Apple’s design ethos).
Nostalgic Structure (Windows 98): Finally, PrecisionCore infuses a hint of nostalgia by channeling the pragmatic rigidity of classic late-90s interfaces. In those UIs, everything had clear boundaries and states – things were “so frickin obvious” to the user (98.css – design system for building faithful recreations of Windows 98 UIs | Hacker News). PrecisionCore revives that sense of obviousness through clearly delineated panels, buttons with distinct states, and straightforward iconography. For example, buttons have clear outlines or shadows to indicate pressability, and modal dialogs resemble classic window frames (complete with a title bar), instantly signaling their function. This throwback to “classic UI” is done with subtlety – providing familiarity and predictability (users never have to guess if something is clickable) without looking dated or heavy. As one observer noted, older UIs minimized cognitive load by avoiding ambiguity (98.css – design system for building faithful recreations of Windows 98 UIs | Hacker News); PrecisionCore embraces that lesson, ensuring every interactive element is visually distinctive and every state change (hover, active, disabled) is unambiguous.

Light-first, Dark-ready: By default, PrecisionCore is designed in a light mode aesthetic (bright backgrounds, dark text, vibrant accent colors), as light mode tends to be the most common environment for general-purpose apps. However, from its inception the system is built to support an equally robust dark mode. This means color palettes, component designs, and shadows have been chosen to invert gracefully. The design philosophy encourages using a dark gray (not pure black) for dark backgrounds to reduce eye strain and preserve depth (e.g., shadows on pure black are hard to see) (docs/theming/Dark.md · mevermore/material-components-android - Gitee). All guidelines – from color contrast to elevation – have been considered in both light and dark contexts, and developers are given clear instructions on how to implement theme switching. (See Color & Theming for details.)

Overall, the PrecisionCore philosophy is about precision in execution and core essentials in experience. Users should find interfaces built with PrecisionCore familiar yet fresh – as if the best ideas of past and present UI design have been distilled into one system. By following this design system, designers and developers can create apps that are visually consistent, easily extensible, and appealing to a broad range of users. The following sections detail the specifics of this system – from grids and spacing to components and code examples – providing a foundation as polished and complete as official design guidelines from Google, Apple, and Microsoft.

Color & Theming

PrecisionCore uses a carefully chosen color palette that works in both light and dark themes. The system defines a set of core colors (with recommended defaults) and guidelines for their usage:

Primary Color: A vivid but not overwhelming hue used for main interactive elements, highlights, and emphasis. By default, PrecisionCore’s primary color is a medium blue (#3388FF) – evoking the classic Windows 98 selection blue, but with a modern vibrancy. This blue serves as the accent for buttons, links, selection states, and active indicators. It contrasts well against light backgrounds and is adjusted for dark mode (slightly desaturated or brightened as needed) to maintain clarity.
Secondary Color: An optional accent or complementary color (for example, a green or orange) used sparingly for secondary actions, highlights or to distinguish different types of messages (like success or warning states). The secondary palette is meant to complement the primary blue and adhere to the minimalist approach (e.g., used in icons or subtle backgrounds rather than large areas).
Neutrals (Backgrounds & Surfaces): In light mode, the background is generally a clean white or very light gray (#FFFFFF or #F8F8F8) for a fresh, minimal canvas. Surface elements (cards, navbars, modals) use neutral grays (ranging from #FAFAFA to #E0E0E0) to differentiate layers. In dark mode, instead of pure black, a dark gray (e.g., #121212 or #1E1E1E) is used for backgrounds (docs/theming/Dark.md · mevermore/material-components-android - Gitee). This dark gray improves shadow visibility and reduces the stark contrast of pure black on modern displays, thereby easing eye strain (docs/theming/Dark.md · mevermore/material-components-android - Gitee). Surfaces in dark mode are slightly lighter dark grays (#2A2A2A, #333) to stand out from the background. Text in dark mode is a near-white (#EAEAEA) rather than pure white, to avoid glare.
Text Colors: High contrast is a must. Standard body text in light mode is charcoal/black (#212121) on white, meeting at least WCAG AA contrast. In dark mode, body text is a light gray-white (#E0E0E0) on dark backgrounds. Muted or secondary text can use mid-grays (#666 in light mode, #AAA in dark) but always ensure readability (never falling below a 4.5:1 contrast ratio against the background) (Dark Mode | Apple Developer Documentation). PrecisionCore follows accessibility guidance that even non-text elements (like icons or borders) should have sufficient contrast – e.g. an outline or icon should be at least 3:1 against its background (Color contrast - Accessibility designing – Material Design 3).
States and Feedback Colors: Standard semantic colors are included for states like success (e.g., a green #28A745), warning (amber/orange), error (red #DC3545), and info (blue or cyan). These are used for icons or text messages (e.g., error text for form validation). They are designed to be legible on both light and dark backgrounds by slightly adjusting their brightness/saturation between themes (for instance, error red might be slightly lighter in dark mode to appear vibrant on a dark surface).

Dark Mode Guidelines: Designers should design in light mode first, then invert to dark mode and adjust. When creating a dark theme, avoid pure black backgrounds; use dark gray as mentioned (e.g., Material’s baseline is #121212) (docs/theming/Dark.md · mevermore/material-components-android - Gitee). Ensure that text and UI elements in dark mode meet contrast standards (ideally ≥ 4.5:1 for body text) (Dark Mode | Apple Developer Documentation). Additionally, consider using “on-dark” variants for shadows or dividers – e.g., a semi-transparent white at 15% opacity for dividers on dark backgrounds (instead of a gray) to achieve a subtle separation without harsh lines. Primary and secondary colors can generally remain the same hue, but check their vibrancy on dark backgrounds; sometimes increasing the brightness or adding a slight outer glow can maintain their visibility.

For example, PrecisionCore’s primary blue (#3388FF) in dark mode might be tweaked to a slightly lighter blue (#5B9DFF) for links or buttons, ensuring it stands out on near-black. The design system provides tokenized color definitions for both modes.

CSS Custom Properties Example: PrecisionCore provides CSS variables to manage theming easily. In the light mode stylesheet (or :root), variables define the palette. For dark mode, a .dark class or [data-theme="dark"] attribute on a parent element can override those variables:

:root {
  --pcore-bg: #FFFFFF;
  --pcore-surface: #F8F8F8;
  --pcore-text: #212121;
  --pcore-text-muted: #666666;
  --pcore-primary: #3388FF;
  --pcore-primary-text: #FFFFFF;
  --pcore-border: #CCCCCC;
  /* ...other vars */
}
.dark {
  --pcore-bg: #121212;
  --pcore-surface: #1E1E1E;
  --pcore-text: #EAEAEA;
  --pcore-text-muted: #AAAAAA;
  --pcore-primary: #5B9DFF;    /* slightly brighter blue for dark mode */
  --pcore-primary-text: #FFFFFF;
  --pcore-border: #444444;
}

In your HTML, you could then toggle dark mode by adding the dark class to <html> or <body>, and all components will adapt automatically by using these variables for colors.

TailwindCSS Theming: If using Tailwind, PrecisionCore’s color palette can be integrated via Tailwind’s configuration (tailwind.config.js). Define a custom theme with the above colors (e.g., as primary, surface, etc.) and enable Tailwind’s built-in dark mode class strategy (dark class). For example:

// tailwind.config.js (excerpt)
module.exports = {
  theme: {
    colors: {
      primary: '#3388FF',
      'primary-dark': '#5B9DFF',
      surface: '#F8F8F8',
      'surface-dark': '#1E1E1E',
      text: '#212121',
      'text-dark': '#EAEAEA',
      /* ... */
    }
  },
  darkMode: 'class'
}

Then in HTML you can use classes like bg-surface text-text dark:bg-surface-dark dark:text-text-dark. Tailwind also provides dark: variants for utility classes, so you might write: <div class="bg-white text-gray-900 dark:bg-gray-900 dark:text-gray-100">...</div> to manually implement dark mode styles.

Theming Summary: PrecisionCore supplies light and dark design tokens, encouraging developers to implement theme toggling either via CSS classes or media queries (prefers-color-scheme). All components and examples in this document are provided in light mode by default, but include notes or examples for dark mode adjustments. By adhering to these color and theming guidelines, your app will be comfortable to use in a variety of environments (bright office, dark room, OLED mobile screen, etc.), all while preserving a consistent brand identity.

Typography

Typography in PrecisionCore is chosen for legibility, scalability, and a hint of nostalgia. The default typeface is a clean sans-serif, aligning with the system fonts of each platform for familiarity and optimal rendering. For example, the recommended font stack might be:

font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

This stack uses the user’s system UI font (San Francisco on Apple devices, Segoe UI on Windows, Roboto on Android, etc.), ensuring text feels native on every device. It also pays homage to classic GUI fonts (Segoe UI was a cornerstone of Windows design).

Font Sizes & Scale: PrecisionCore uses a modular scale derived from an 8px baseline grid for vertical rhythm (Metrics & keylines - Layout - Material Design). Base body text is typically 14px (roughly 0.875rem) for desktop for a dense but readable display, and can scale up to 16px (1rem) for mobile devices for readability. Heading styles increment by roughly 1.25× to 1.333× ratios:

Body/Text: 14px (0.875rem) – primary content, forms, labels.
Small Text/Caption: 12px (0.75rem) – secondary info, hints.
H3/Subsection Title: ~16px (1rem) – section headings.
H2/Modal Title: ~20px (1.25rem).
H1/Page Title: ~24px (1.5rem) – used sparingly for page headers.

These sizes are guidelines; the system is flexible as long as the baseline grid is maintained (e.g., line-heights in multiples of 4px). Line-height is set around 1.4 for body text for comfortable reading (e.g., 14px text -> ~20px line-height). Headings have tighter line-heights (~1.2) to keep them tied to their content block.

Weight & Style: Use a minimal set of font weights to avoid confusion and maintain performance. Regular (400) for body, Medium/Semi-bold (500–600) for headings or emphasis, and perhaps Bold (700) for very important numbers or labels. Italics are rarely used except for occasional emphasis or terminology. Underlines are reserved for actual links (as per web convention), and even then, a subtle colored underline or dotted underline can be used to reduce visual noise unless needed for clarity.

Tone & Aesthetic: The overall typographic tone is utilitarian meets elegant. It should remind users of productivity software (clear and focused) but with the polish of a modern app. Apple’s influence means text is given ample margin and is never too cramped; minimalism means we don’t use excessive font variants or decorative type. If a custom font is desired for branding, it should be high-legibility and tested in various sizes. (Think of Google’s use of Roboto or Apple’s use of San Francisco – functional yet distinct.)

Responsive Typography: PrecisionCore recommends slightly adjusting font sizes at extreme breakpoints. For instance, on very large screens (desktop HD), bump base font to 15px or 16px for readability. On very small screens, ensure captions/labels don’t go below 12px, and consider using relative units (rem/em) so that user browser settings for font size can gracefully scale the UI. The design system’s typography is designed to work with user preferences – if a user has increased their base font size for accessibility, the UI should scale accordingly (thanks to using rem units).

Vertical Rhythm: All text sits on a 4px baseline grid (Metrics & keylines - Layout - Material Design). This means margin/padding around text elements come in increments of 4px or 8px to ensure consistent spacing. For example, a heading might have 8px margin-top and 4px margin-bottom, aligning neatly with the spacing system. Consistent line heights (e.g., 20px for 14px text, 24px for 16px text) also snap to the grid to avoid misalignment between text lines and other UI elements.

Examples:

A form label might be 14px, semi-bold, with 4px letter-spacing in uppercase for a subtle nod to old-school form labels (which were often all-caps), but this is optional.
Button text is typically 14px Medium, using uppercase for primary buttons to resemble Material Design and classic buttons (again, optional based on preference).

In code, a simple example for a heading and body text:

<h1 class="page-title">Analytics Dashboard</h1>
<p class="body-text">Welcome back, user! Here are your stats for this week.</p>

.page-title {
  font-size: 1.5rem; /* 24px */
  font-weight: 600;
  margin: 0 0 0.5rem 0;
}
.body-text {
  font-size: 0.875rem; /* 14px */
  line-height: 1.4;
  margin: 0;
}

TailwindCSS Equivalent: Using Tailwind’s utilities and perhaps custom font sizing:

<h1 class="text-3xl font-semibold mb-2">Analytics Dashboard</h1>
<p class="text-base leading-6 mb-0">Welcome back, user! Here are your stats for this week.</p>

(Tailwind’s default text-base is 1rem/16px, so one might configure text-base to 0.875rem in Tailwind config to match our 14px base.)

By following these typography rules, PrecisionCore ensures text is always readable and harmonious with the overall design, whether on a small mobile screen or a 4K monitor.

Layout, Grid & Spacing

A solid layout foundation is critical. PrecisionCore uses a responsive 12-column grid (like many modern systems) with an 8px base unit for spacing and sizing (Metrics & keylines - Layout - Material Design):

8px Grid System: All measurements – margins, paddings, component dimensions, and placements – align to an 8px increment. This doesn’t mean every gap is 8px, but rather that all spacing values are multiples of 8 (or 4, for finer adjustments). For instance, a card might have 16px padding (2 × 8), a gutter between columns might be 24px (3 × 8) on desktop, or 8px on mobile. Using an 8px grid simplifies layout decisions and keeps visual harmony (Metrics & keylines - Layout - Material Design). (Material Design also uses 8dp extensively for this reason.)
12-Column Responsive Grid: The page layout is divided into 12 columns with adjustable gutters. This allows flexibility – e.g., a form might use 6 of 12 columns (50% width) on desktop, but 12 of 12 (full width) on mobile. We provide breakpoint guidelines:
- Mobile (≤ 600px): Simplified, mostly single-column or two-column layouts. Use full-bleed content with 16px padding margins on the sides by default. The grid can collapse to 4 columns for finer control if needed (each ~25% width) on mobile, but generally a single column flow is preferred.
- Tablet (601px–1024px): 12-column grid with gutters ~16px. You might use 2–3 columns for content. E.g., a sidebar might take 3 cols and content 9 cols.
- Desktop (≥ 1025px): 12-column grid with wider gutters (24px). Content often centers with a max width (e.g., 1200px container) for readability on large screens. Side navigation (if present) can be a fixed 240px width column, and the remaining content uses the rest of the grid.

PrecisionCore’s grid is flexible: you can nest grids for card layouts or split layouts into halves, thirds, etc., as long as you stick to the base spacing. Use CSS Flexbox or CSS Grid for actual implementation (the system is agnostic to method; you could use floats in older setups, though Flex/Grid is recommended).

Spacing Scale: We define spacers like 4px (minor), 8px (small), 16px (medium), 24px (large), 32px (x-large), etc. This scale is used for margin/padding of components:
- Small elements (buttons, icons) often have 4px or 8px gaps.
- Medium components (input fields, cards) might have 16px internal padding.
- Large sections (between form sections or large grid gaps) use 24px or more. This consistent scale keeps the design cohesive. For example, a form label might have 4px bottom margin (to the input), fields 16px bottom margin to the next field, and form sections separated by 32px.
Alignment & Keylines: Align content to the grid and keylines. For instance, text baselines line up horizontally across columns when possible. Icons and text within a toolbar align on a 4px baseline grid for a neat appearance (Metrics & keylines - Layout - Material Design). PrecisionCore encourages using soft keylines – subtle vertical rhythm lines at consistent intervals to guide placement (these aren’t visible, but you can imagine a vertical grid every 8px). This helps ensure consistent padding inside containers and alignment of elements in complex layouts.
Example Layout Usage: A typical page might have a header (taking full width), a content area using a 12-col centered grid, and a footer. Within the content, you could have a 2-column layout for desktop (8 cols for main content, 4 cols for a sidebar). On mobile, those would stack. PrecisionCore’s spacing guidelines ensure that the gutter between these columns is at least 24px on desktop (for clear separation) and maybe 16px on tablet, 8px on mobile. All of these follow the 8px rule.
Visual Rhythm: To avoid a dead, overly rigid look, not everything must be an exact multiple of 8px (e.g., 12px is allowed for line-height or subtle adjustments). But such exceptions are used intentionally. Most of the time, sticking to 8px increments (and sometimes 4px for fine tuning) will create a natural rhythm that users subconsciously appreciate.

Navigation & Structure will be discussed next, but note that layout-wise, navigation elements (like sidebars or top bars) integrate with this grid system. For example, a sidebar might span 2 columns of the grid in a desktop layout, and the remaining 10 columns are the main content area.

Code Example – Responsive Grid: Here’s how you might structure a basic responsive grid in HTML/CSS:

<div class="container">
  <div class="row">
    <div class="col col-4 col-sm-12">Sidebar content</div>
    <div class="col col-8 col-sm-12">Main content</div>
  </div>
</div>

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 16px; /* gutter padding */
}
.row {
  display: flex;
  flex-wrap: wrap;
  margin: -8px; /* negate child padding/gutter */
}
.col {
  padding: 8px;
}
.col-4 { width: 33.333%; }
.col-8 { width: 66.667%; }
@media (max-width: 600px) {
  .col-sm-12 { width: 100%; }
}

In this example, .col-4 and .col-8 are using a 12-col grid (4/12 and 8/12 respectively). On small screens, we override to full width (col-sm-12). We use 8px gutters. In real use, you might use CSS Grid with grid-template-columns: repeat(12, 1fr) and span columns as needed, or a framework’s grid.

TailwindCSS Equivalent: Tailwind makes grids easy with its utility classes:

<div class="max-w-screen-xl mx-auto px-4">
  <div class="flex flex-wrap -mx-2">
    <aside class="w-1/3 px-2 sm:w-full">Sidebar content</aside>
    <main class="w-2/3 px-2 sm:w-full">Main content</main>
  </div>
</div>

Here we used w-1/3 and w-2/3 for 33%/66% columns (Tailwind also has a 12-column fraction utilities like w-4/12, etc.), and sm:w-full to stack them on small screens. We simulate gutters with padding (px-2 which is 0.5rem, i.e. 8px, in Tailwind’s default config, aligning to our 8px grid). The container uses px-4 (16px padding) and is centered.

Navigation Structure

Navigation components in PrecisionCore are designed to be straightforward, responsive, and consistent across desktop and mobile. The system supports common navigation patterns:

Top App Bar / Header,
Sidebar / Drawer,
Tabs,
Breadcrumbs (for secondary navigation),
Footer (for supplemental links).

The Top App Bar is usually a full-width horizontal bar at the top of the app (or page). It typically contains the application’s logo or title on the left, and important actions or menu toggles on the right. PrecisionCore’s top bar draws from Apple’s simplicity and Material’s functionality:

It’s usually a solid color (often white or a light neutral in light mode, or a dark neutral in dark mode) or can optionally use the primary color for emphasis (like Material’s colored app bars).
It has a subtle shadow or a 1px bottom border to separate it from content (to echo Windows 98’s delineation of toolbars, we often use a simple border line).
The height is around 56px on mobile and 64px on desktop (to accommodate status bars and comfortably fit icons and touch targets (Metrics & keylines - Layout - Material Design)).

For example, a header might look like this:

(image) Example of a PrecisionCore header (top navigation bar with a title on the left and icons on the right), and a set of tabs below it for secondary navigation. (The header uses a white background with a bottom border, while the active tab is underlined in blue.)

The image above illustrates a top navbar with the app title “PrecisionApp” on the left, and two icon placeholders on the right. Below it is a tab bar with three tabs (“Home”, “Profile”, “Settings”), where “Home” is active (underlined in the primary blue). This structure is typical: a persistent top bar for global nav, and optional tabs for different views or sub-sections.

Sidebar / Drawer: On larger screens, an app may use a left sidebar for navigation (e.g., a list of sections or a menu). PrecisionCore sidebars are plain and functional:

Typically a fixed width (say 240px) with a neutral background distinct from main content (light gray in light mode).
Menu items are arranged vertically, each item with an icon and label (if needed). Active item can be highlighted with the primary color background or an indicator bar on the side.
The style can subtly mimic classic menus (e.g., slight 3D pressed effect for active item, or just a solid highlight). However, by default it stays flat/minimal.
On mobile, this sidebar turns into a drawer that slides in from the left or appears as a hamburger menu. A hamburger icon in the top bar triggers it. The drawer covers the content with a semi-transparent overlay background when open.

Tabs: As shown, tabs in PrecisionCore appear as a horizontal strip of text labels (or icons+text) that allow switching between views. The active tab is indicated by:

A bold text and a colored underline (Material influence),
Or alternatively, a pill-shaped highlight behind the active tab (for a more prominent look, though that’s less minimal).
In a nod to older interfaces, if appropriate, the active tab could also have a slight raised look (like Windows 98 tabs). This is optional and generally the flat style is preferred for modernity.
Tabs overflow smoothly to a dropdown or scroll if there are too many to fit, ensuring responsiveness.

Breadcrumbs: If the app has deep navigation, breadcrumbs can be used (e.g., “Projects / Project Alpha / Settings”). PrecisionCore breadcrumbs are simple text links separated by “/” or chevron icons. They use the primary color for links and a muted color for the current page. Spacing around them aligns to the grid (maybe 8px between items).

Footer: For web apps that need a footer (less common in app-like interfaces), PrecisionCore footers are minimal – typically a thin bar with secondary links or copyright info, using a very light background.

Responsive Behavior: Navigation adapts to screen size:

On mobile, the top bar often contains a menu button (to open the sidebar as a drawer) and maybe a single context action (like a search or profile icon). Tabs can scroll horizontally if too many, or collapse into a dropdown.
On desktop, the sidebar can be persistent (always shown) and tabs display fully since there’s space. The top bar might show more actions with text labels (since hover is available for tooltips).
PrecisionCore encourages using the appropriate component per platform conventions: e.g., on mobile, a bottom navigation bar (like iOS’s tab bar with icons) could be used instead of top tabs if it makes more sense for the app. The design system supports that pattern too, with similar styling (icons, labels, primary color highlight for active).

Code Example – Top Bar and Tabs:

HTML:

<header class="app-header">
  <h1 class="app-title">MyApp</h1>
  <nav class="app-actions">
    <button class="icon-button">☰</button>
    <button class="icon-button">🔔</button>
  </nav>
</header>
<div class="tab-bar">
  <button class="tab active">Home</button>
  <button class="tab">Profile</button>
  <button class="tab">Settings</button>
</div>

CSS:

.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #fff;
  border-bottom: 1px solid #ccc;
  padding: 0 16px;
  height: 56px;
}
.app-title {
  font-size: 1rem;
  font-weight: bold;
  margin: 0;
}
.app-actions .icon-button {
  background: none;
  border: none;
  font-size: 20px;
  margin-left: 16px;
  cursor: pointer;
}
.tab-bar {
  display: flex;
  background: #f8f8f8;
  padding: 0 8px;
}
.tab {
  flex: 1;
  padding: 12px 0;
  border: none;
  background: transparent;
  font: 1rem sans-serif;
  cursor: pointer;
  color: #555;
  border-bottom: 3px solid transparent;
}
.tab.active {
  color: #000;
  font-weight: 600;
  border-bottom: 3px solid #3388FF;
}

This snippet creates a responsive header with a menu and notification icon, and a tab bar. On mobile, you might hide the words “MyApp” in favor of just an icon due to space, or vice versa show more icons on desktop.

TailwindCSS Equivalent:

<header class="flex items-center justify-between bg-white border-b border-gray-300 px-4 h-14">
  <h1 class="text-base font-bold m-0">MyApp</h1>
  <nav>
    <button class="text-2xl ml-4">☰</button>
    <button class="text-2xl ml-4">🔔</button>
  </nav>
</header>
<div class="flex bg-gray-100 px-2">
  <button class="flex-1 py-3 text-gray-600 font-medium border-b-4 border-transparent">Home</button>
  <button class="flex-1 py-3 text-gray-600 font-medium border-b-4 border-transparent">Profile</button>
  <button class="flex-1 py-3 text-gray-600 font-medium border-b-4 border-transparent">Settings</button>
</div>

You would then add a class (e.g., border-blue-600 text-black) to the active tab via a script or a server-side render for the active page. Tailwind’s utility classes allow quick styling; here we used border-b-4 to mimic the underline. (Note: 4 corresponds to 4px in default Tailwind, not 3px, but that’s fine, or Tailwind can be configured.)

Using these navigation patterns, your app will have a clear and familiar structure. Users will find the menu locations and behaviors unsurprising, which is exactly the intention – predictable navigation = better UX.

Components

PrecisionCore provides a rich library of UI components, each designed with detailed styles, states, and behaviors. Below we cover the major components, including design guidelines and code examples in both standard HTML/CSS and TailwindCSS. Each component in PrecisionCore is designed to be accessible, responsive, and easily themeable.

Buttons & Actions

Buttons are fundamental interactive elements. In PrecisionCore, buttons combine the flat, modern look of Material Design with subtle retro cues (like clear borders or inset shadows on click) from classic GUIs. The design system defines several types of buttons:

Primary Button: Used for the main call-to-action. Visually distinguished with a solid fill (usually the primary color) and white or light text.
Secondary Button: Used for secondary actions. Typically has a softer style – often a light background (gray or neutral) with a border, or an outline style.
Outline (Ghost) Button: Transparent background, colored border (usually primary color) and primary-colored text. Used for less emphasis or tertiary actions.
Text Button: No border, no background, just text (often primary-colored text). Used for the least emphasis (like a “Cancel” action or inline link-style button).
Disabled state: Any button type can be disabled, which in PrecisionCore means it is visibly faded (lower opacity) and non-interactive (no hover effects). The style often includes a dashed or gray-out text to communicate disuse.

These buttons all share consistent shape and spacing: a small border-radius (e.g., 4px) for slightly rounded corners (to soften the look, avoiding harsh 90° corners of pure Win98, but still squarer than overly-round modern buttons), and padding that provides a comfortable touch target (8px tall padding typically, resulting in ~36px tall buttons, meeting the ~48px including text height and paddi (Metrics & keylines - Layout - Material Design)0】). Buttons have clear focus indicators for keyboard users – e.g., an outline or glow when focused.

States: PrecisionCore buttons have distinct states:

Default: As described (filled or outlined).
Hover: In light mode, the primary button might darken slightly on hover (e.g., #3388FF to #2A76D2) or gain a subtle shadow. Secondary/outline buttons might get a light gray background on hover to indicate interactiveness.
Active/Pressed: When clicked or tapped, buttons might use an inset shadow to mimic a pressed look (a nod to Windows 98) or simply become a slightly darker shade. For example, a filled button might momentarily show an inset 2px shadow (giving a “pushed in” fee (98.css – design system for building faithful recreations of Windows 98 UIs | Hacker News)2】. This reinforces the action feedback.
Disabled: Reduced opacity (e.g., 50%) and no shadow or hover change. The cursor also becomes default (not pointer) to indicate it’s not interactive. (image)e】 Examples of various button styles in PrecisionCore’s light theme: a blue primary button, a gray secondary button, an outline button, and a disabled button.

The image above shows (from left to right) a Primary Button (filled blue), a Secondary Button (gray background, for a less prominent action), an Outline Button (white background with blue border and text), and a Disabled primary button (faded). These demonstrate the default appearance of each type.

Notice the Primary button has a slight shadow and solid fill, Secondary has a bordered rectangle style (almost like a classic UI button but flat), the Outline is very minimal until hover (not shown), and Disabled is semi-transparent. All have 4px rounded corners and consistent padding.

HTML/CSS Example (Button):

<button class="btn primary">Save Changes</button>
<button class="btn secondary">Cancel</button>

.btn {
  font: 14px "Segoe UI", sans-serif;
  padding: 8px 16px;
  border: 1px solid transparent;
  border-radius: 4px;
  cursor: pointer;
}
.btn.primary {
  background-color: #3388FF;
  border-color: #2A76D2;
  color: #fff;
}
.btn.primary:hover { background-color: #2A76D2; }
.btn.primary:active {
  /* simulate pressed with inset shadow */
  box-shadow: inset 2px 2px 4px rgba(0,0,0,0.2);
}
.btn.secondary {
  background-color: #F5F5F5;
  border-color: #CCCCCC;
  color: #222;
}
.btn.secondary:hover { background-color: #E0E0E0; }
.btn.outline {
  background: #fff;
  border-color: #3388FF;
  color: #3388FF;
}
.btn.outline:hover { background: #E6F0FF; }
.btn:disabled, .btn.disabled {
  background: #DDD;
  border-color: #CCC;
  color: #888;
  cursor: not-allowed;
}

In this CSS:

.btn sets base style (padding, font).
.btn.primary etc. set variants. We use a slightly darker border on primary for contrast (blue on blue).
The :active state of primary uses an inset shadow to give that pressed effect.
Disabled style grays everything out.

TailwindCSS Example: Using Tailwind utility classes, the equivalent of a primary and secondary button:

<button class="px-4 py-2 bg-blue-600 hover:bg-blue-700 text-white font-semibold rounded focus:outline-none focus:ring-2 focus:ring-blue-300">
  Save Changes
</button>
<button class="px-4 py-2 bg-gray-100 hover:bg-gray-200 text-gray-800 font-medium rounded border border-gray-400">
  Cancel
</button>

Here:

Primary: bg-blue-600 (blue), hover:bg-blue-700 for hover darken, focus:ring-2 focus:ring-blue-300 for focus outline. Tailwind doesn’t have an inset shadow utility by default, but one could add a custom style or use active:shadow-inner if configured.
Secondary: gray background and border via bg-gray-100 border border-gray-400, etc.

In summary, Buttons in PrecisionCore are accessible (use <button> or <a> with proper roles), have sufficient contrast (blue on white, etc.), and a clear visual hierarchy (primary vs secondary). They work equally well with mouse, touch, or keyboard (with focus styles visible). They also adapt to dark mode (e.g., the primary button in dark mode might be blue 500 instead of 600 to pop on dark, and secondary buttons might use a darker gray background).

Form Inputs & Controls

Forms include text inputs, text areas, dropdowns (select), checkboxes, radio buttons, toggles (switches), and sliders. PrecisionCore form controls are designed for clarity and ease of use, following both web standards and common UX patterns:

Text Fields: A basic text input in PrecisionCore is styled with a clear rectangular outline. We avoid purely underlined style (Material’s default) to improve discoverability (a box is an obvious input, aligning with the Windows 98 approach of input fields):

Light mode: white background, 1px solid gray border (#AAA) by default.
On focus: the border (or outline) turns the primary blue and maybe increases to 2px or adds an outer glow, making the focus state very apparent. For example, a focused text field might show a blue shadow or outline ri (What is iOS Human Interface Guidelines?)8】.
Placeholder text is slightly lighter gray (#999) and disappears on focus or as user types, as usual.
We include a label for every text field (for accessibility). The label can be above the field (with a small margin) or floating. PrecisionCore often prefers the label above or to the left rather than floating inside the field, to keep things simple (floating labels can be an optional enhancement).

Multi-line Textareas: Similar style to text inputs, but top-aligned label and a resize handle if content is expected to grow (we allow browser default resizing or provide our own corner resize indicator).

Select (Dropdown): Styled to look like a text input with an arrow indicator. On modern browsers, this often defaults to native UI for the dropdown list, which is fine. The field itself has the same height as a text input, with an added icon (caret) on the right. In dark mode, select dropdowns invert colors accordingly (dark background, etc.). We ensure the text and arrow have enough contrast (the arrow icon often using the text color).

Checkboxes and Radio Buttons: PrecisionCore keeps these simple:

Checkboxes: square boxes, 16px or 20px in size, with a 1px border (#AAA). When checked, a checkmark (✓) or an inset fill of primary color with a check icon appears. The old Windows 98 style 3D checkbox (with beveled edges) is simplified to a flat box that changes background when checked (blue background, white check icon perhaps). We still make it distinct (the presence of the checkmark icon itself is clear).
Radios: circles (again ~16px diameter) with a 1px border. When selected, a dot fills the circle (usually black dot on light background, or white dot on blue background if we fill it). We might fill the radio with primary color when selected as well.
Both checkboxes and radios have an adjacent label (clickable) with some spacing (like 4px or 8px). We ensure the label has proper for attribute linking to input id for accessibility.

Toggle Switches: A toggle (for settings on/off) is essentially a stylized checkbox. PrecisionCore toggles appear as a small slider:

Off state: a gray track and a knob (circle) on the left.
On state: the track switches to primary bl (What is iOS Human Interface Guidelines?)8】, and the knob moves to the right, often with a subtle transition animation. The knob itself might have a slight shadow.
We might add a slight border on the track to echo a subtle groove (like older UI switches had an inset track), but it’s largely flat.
The size is about 40px x 20px (common size to be easily clickable on mobile).
The toggle also has an accessible label (visible or hidden) to indicate what it controls (never rely solely on color or position).

Other Controls (Slider, etc.): Sliders have a track and thumb; by default we use the browser’s styling but can customize: e.g., a blue filled track to the left of the thumb, gray to the right, and a thumb circle with a border.

Overall Form Layout: We recommend a vertical form layout: labels on top of fields (left-aligned). Spacing: 4px between label and field, 16px between form fields vertically (to give a comfortable touch ar (Metrics & keylines - Layout - Material Design)9】). Use 8px or 12px of horizontal padding inside text fields. Group related fields together with a section label if needed.

Accessibility in Forms: All form controls use proper <label> elements. The designs use not just color but also shape/icons to indicate state (e.g., required fields could have an asterisk, error states show an icon or message in addition to red outline).

Example – Form Inputs HTML/CSS: (image)e】 A collection of form elements: a text field and dropdown with labels, a group of checkboxes and radio buttons with labels, and a toggle switch (Dark Mode on/off).

In the image above:

The “Name” field (text input) and “Country” field (select) are shown with labels on top. They have a light gray border and subtle rounded corners. The Name field is empty (showing placeholder text), the Country select is showing a chosen option.
Below, there’s a “Subscribe” checkbox (unchecked), and two radio options for Plan (Basic and Premium, with neither selected in the image).
Finally, a “Dark Mode” label with a toggle switch (which is in the ON position, colored blue).

This illustrates default (unfocused) states. If the Name field were focused, we’d see its outline glow blue. If a checkbox was checked, a checkmark would appear. These controls are all vertically spaced for clarity.

HTML:

<div class="form-group">
  <label for="name">Name</label>
  <input type="text" id="name" placeholder="Enter your name">
</div>
<div class="form-group">
  <label for="country">Country</label>
  <select id="country">
    <option>United States</option>
    <option>Canada</option>
    <option>Australia</option>
  </select>
</div>
<div class="form-group">
  <div>
    <input type="checkbox" id="subscribe">
    <label for="subscribe">Subscribe</label>
  </div>
  <div>
    <input type="radio" id="basic" name="plan">
    <label for="basic">Basic Plan</label>
  </div>
  <div>
    <input type="radio" id="premium" name="plan">
    <label for="premium">Premium Plan</label>
  </div>
</div>
<div class="form-group">
  <label for="dark-mode">Dark Mode:</label>
  <label class="switch">
    <input type="checkbox" id="dark-mode" checked>
    <span class="slider round"></span>
  </label>
</div>

CSS:

.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-weight: 500; margin-bottom: 4px; }
input[type=text], select {
  width: 100%;
  padding: 6px 8px;
  font-size: 14px;
  color: #222;
  background: #FFF;
  border: 1px solid #AAA;
  border-radius: 2px;
}
input[type=text]:focus, select:focus {
  outline: 2px solid #3388FF;
  outline-offset: 0;
}
input::placeholder { color: #999; }
.checkbox-group, .radio-group {
  margin: 4px 0;
}
input[type=checkbox], input[type=radio] {
  margin-right: 4px;
  /* default styling is used for simplicity; can customize if needed */
}
.switch {
  position: relative; display: inline-block;
  width: 40px; height: 20px;
  margin-left: 4px; /* gap between label and switch */
}
.switch input { opacity: 0; width: 0; height: 0; }
.slider {
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background-color: #CCC;
  border: 1px solid #AAA;
  border-radius: 10px;
  transition: 0.2s;
}
.slider:before {
  content: "";
  position: absolute;
  left: 1px; bottom: 1px;
  width: 16px; height: 16px;
  background: #FFF;
  border: 1px solid #AAA;
  transition: 0.2s;
}
input:checked + .slider {
  background-color: #3388FF;
  border-color: #2A76D2;
}
input:checked + .slider:before {
  transform: translateX(20px);
  border-color: #2A76D2;
}
.slider.round:before {
  border-radius: 50%;
}

In this CSS:

We style text inputs and selects similarly, with padding and border. The focus outline uses outline for simplicity (could also change border-color instead).
Checkboxes/radios use default appearance (which will vary by OS, but generally acceptable). One could enhance them with custom styling (using :checked:before for a checkmark, etc.), but simplicity and native clarity is fine.
The .switch classes define a custom toggle slider. The checkbox is hidden (opacity: 0) and the .slider span is the visible track. The :checked + .slider:before moves the knob to simulate on/off. We gave the track a rounded full border (border-radius: 10px) and the knob a slightly smaller radius (we made it round by 50%).
Labels are block to sit above fields, and inline for the checkbox/radio lines.

TailwindCSS Example: Using Tailwind, much of this can be done with utilities, but often one might still write custom CSS for things like switches. For a quick example:

<div class="mb-4">
  <label for="name" class="block font-medium mb-1">Name</label>
  <input type="text" id="name" placeholder="Enter your name"
         class="w-full px-2 py-1 border border-gray-400 rounded focus:outline-none focus:ring-2 focus:ring-blue-500" />
</div>
<div class="mb-4">
  <label for="country" class="block font-medium mb-1">Country</label>
  <select id="country"
          class="w-full px-2 py-1 border border-gray-400 rounded focus:outline-none focus:ring-2 focus:ring-blue-500">
    <option>United States</option>
    <option>Canada</option>
  </select>
</div>
<div class="mb-4">
  <label class="mr-2"><input type="checkbox" class="mr-1 align-middle"/> Subscribe</label>
  <label class="mr-2"><input type="radio" name="plan" class="mr-1 align-middle"/> Basic Plan</label>
  <label><input type="radio" name="plan" class="mr-1 align-middle"/> Premium Plan</label>
</div>
<div class="mb-4">
  <span class="font-medium">Dark Mode:</span>
  <!-- Custom switch still likely needs custom CSS or a plugin -->
  <label class="relative inline-block align-middle w-10 h-5 ml-2">
    <input type="checkbox" checked class="peer opacity-0 w-0 h-0" />
    <span class="absolute cursor-pointer top-0 left-0 right-0 bottom-0 bg-gray-400 rounded-full peer-checked:bg-blue-600 transition"></span>
    <span class="absolute left-[2px] bottom-[2px] h-4 w-4 bg-white rounded-full transition peer-checked:translate-x-[20px]"></span>
  </label>
</div>

This uses some Tailwind tricks (like peer classes for the toggle to style sibling elements when checkbox is checked). The rest are straightforward classes for spacing and border.

By adhering to these form styles, forms in PrecisionCore are highly usable and consistent. Users can quickly understand where to type or click, labels are clearly associated with inputs, and the overall look is clean. The slight influences from retro design (e.g., clearly outlined inputs, tactile switch) make forms feel reliable and familiar.

Modals & Overlays

Modals (dialog windows) and overlay components (like tooltips, dropdown menus, popovers) in PrecisionCore follow a layered approach: they appear above the main UI with a clear backdrop, much like classic desktop dialogs, but with modern styling.

Modal Dialogs: A modal is a focused interface that requires user interaction before returning to the main app (for example, a confirmation dialog or a settings popup). PrecisionCore modals are designed to be highly visible and familiar:

The modal window often has a distinct header bar at the top containing a title and an optional close button (an “X”). This is inspired by traditional window design (especially Windows 95/98 dialogs) which had title bars. In PrecisionCore, the header bar might be colored (e.g., the primary color or a dark neutral) to stand out, with the rest of the modal content on a contrasting surface.
The modal content area (body) uses the app’s surface background (white in light mode) with standard content (text, form inputs, etc.) and perhaps a bit of padding (16px).
The modal has a drop shadow to separate it from the background content, and the entire screen behind it is dimmed out by an overlay (backdrop).

Behavior: When a modal opens, a semi-transparent dark backdrop covers the page (usually 40–50% opacity black) to draw focus to the modal. The backdrop also intercepts clicks, requiring the user to explicitly interact with the modal’s buttons. The modal typically animates in (fade or slide down slightly) to attract attention gracefully.

Modal Buttons: Actions like “OK” or “Cancel” are placed at the bottom-right (for LTR languages) or bottom-left (for RTL) of the modal, in a footer area. The primary action button is styled as a Primary button, secondary as Secondary. There’s usually a small gap (8px) between them. The footer might have a light gray background or simply be part of the body with right-aligned buttons.

Size: Modals should be appropriately sized to their content – often a small dialog (300–500px width) for simple alerts, up to perhaps 800px for complex forms. On mobile, modals typically take full width (and often nearly full height, like a bottom sheet or fullscreen dialog) due to limited space. PrecisionCore modals are responsive: at smaller screens, they may stretch to fill more of the screen and the border radius might be removed (for a seamless fit).

Tooltip and Popovers: These are small overlays used for additional info or small actions, not covered by the backdrop (non-modal). E.g., a tooltip on hover appears with text, or a context menu appears on right-click. PrecisionCore styles them with a subtle shadow, a background color that contrasts with the environment (often a dark tooltip on light mode, or light tooltip on dark mode), and clear, small text. They often have a slight fade-in animation. Arrow pointers (for popovers) can be included if needed.

Example – Modal Dialog HTML/CSS: (image)e】 A modal dialog example (light mode): it shows a title bar “Modal Title” in blue with a close “X” button, a white content area with text, and a footer with “Cancel” and “OK” buttons.

The image demonstrates a typical PrecisionCore modal:

A semi-transparent dark backdrop covers the entire viewport.
The modal box has a blue header (with the title and an “X” close button on the right).
The body has a short message.
The footer has two buttons: a secondary “Cancel” and a primary “OK”.

This design clearly separates the modal as a foreground element. The title bar being blue is an optional accent (one could also use a neutral dark header or no distinct header bar, but here we chose blue as a strong indicator of focus).

HTML:

<div class="backdrop"></div>
<div class="modal">
  <div class="modal-header">
    <span class="title">Modal Title</span>
    <button class="close-btn">×</button>
  </div>
  <div class="modal-body">
    <p>This is a modal dialog. It appears on top of the main content, requiring user interaction.</p>
  </div>
  <div class="modal-footer">
    <button class="btn secondary">Cancel</button>
    <button class="btn primary">OK</button>
  </div>
</div>

CSS:

.backdrop {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.4);
  /* a semi-transparent black overlay */
}
.modal {
  position: fixed;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 320px;
  background: #F0F0F0;
  border: 1px solid #888;
  box-shadow: 2px 2px 8px rgba(0,0,0,0.5);
}
.modal-header {
  background: #3388FF;
  color: #FFF;
  padding: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.modal-header .title { font-size: 14px; font-weight: bold; }
.close-btn {
  background: #FFF;
  color: #3388FF;
  border: none;
  width: 20px; height: 20px;
  text-align: center;
  line-height: 18px;
  font-size: 18px;
  border-radius: 4px;
  cursor: pointer;
}
.modal-body {
  background: #FFF;
  color: #222;
  padding: 16px;
  font-size: 14px;
}
.modal-footer {
  background: #F0F0F0;
  text-align: right;
  padding: 8px;
}
.modal-footer .btn { margin-left: 8px; }

Notes on this CSS:

The modal is fixed positioned (so it stays centered even on scroll) and uses a CSS transform to center it.
We gave it a slight border and a shadow to lift it off the backdrop.
The header is blue with white text – we also styled the close “X” as a white square button to fit the retro style a bit (white button on blue bar, akin to old Windows title bars which had a gray “X” button). This close-btn changes color on hover perhaps (could add .close-btn:hover { background: #e0e0e0; } for effect).
The body and footer are separated just by background colors here: body white, footer light gray. You could also keep them unified and just have the buttons at bottom.
The buttons reuse the earlier .btn styles (with classes primary and secondary).

Behavior & JavaScript: Not shown here, but the close button × would be wired to close the modal (removing it and the backdrop from DOM). Clicking the backdrop could also close the modal (if allowed), except for critical confirmations where you might require an explicit choice. Ensure focus is trapped inside the modal when open (using JS to loop tab focus or using inert attribute on background content in modern browsers). Also, pressing Esc should close the modal for accessibility.

TailwindCSS Example: Tailwind utilities can style a modal quickly:

<div class="fixed inset-0 bg-black bg-opacity-50"></div>
<div class="fixed top-1/2 left-1/2 w-80 bg-gray-100 rounded shadow-lg transform -translate-x-1/2 -translate-y-1/2">
  <div class="bg-blue-600 text-white px-4 py-2 flex justify-between items-center rounded-t">
    <span class="text-sm font-bold">Modal Title</span>
    <button class="w-6 h-6 text-blue-600 bg-white rounded flex items-center justify-center">×</button>
  </div>
  <div class="bg-white text-gray-900 p-4 text-sm">
    <p>This is a modal dialog. It appears on top of the main content, requiring user interaction.</p>
  </div>
  <div class="bg-gray-100 flex justify-end px-4 py-2 rounded-b">
    <button class="px-3 py-1 bg-white border border-gray-400 text-gray-800 rounded mr-2">Cancel</button>
    <button class="px-3 py-1 bg-blue-600 text-white rounded">OK</button>
  </div>
</div>

This uses Tailwind’s utilities for layout and spacing. We used rounded-t and rounded-b to give the modal a slightly rounded top and bottom corners (though in our CSS above we didn’t round the corners explicitly). One could also remove rounding for a more rectangular look. The close button is styled inline (white circle with blue X, here we did blue background text on white just to illustrate).

PrecisionCore modals are designed to ensure the user’s focus is not lost: the backdrop prevents interaction with background, the active elements are clearly in the modal. By following these patterns, modals will feel native and user-friendly. They combine the best of old-school dialogs (title bars, clear separation) with modern simplicity (flat design, smooth animations).

Other Overlays: For completeness, tooltips might be implemented simply as:

.tooltip {
  position: absolute;
  background: #333;
  color: #FFF;
  padding: 4px 8px;
  font-size: 12px;
  border-radius: 4px;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.2s;
}
.tooltip.show { opacity: 1; }

And dropdown menus (context menus) as:

.menu {
  position: absolute;
  background: #FFF;
  border: 1px solid #CCC;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
  list-style: none;
  margin: 0; padding: 4px 0;
}
.menu-item {
  padding: 4px 12px;
  font-size: 14px;
  color: #222;
  cursor: pointer;
}
.menu-item:hover { background: #F0F0F0; }

These follow similar styling philosophies – flat, lightly bordered, subtle shadows, and clear highlight on hover. They can be theme-adjusted (dark menus on dark mode, etc.).

With modals and overlays, accessibility is key: always provide aria-labels, role="dialog" for modals, focus management, etc. PrecisionCore’s provided code ensures these attributes are considered (though not all are shown in the snippet, developers should include them).

Additional Components

(Beyond the major components above, PrecisionCore includes patterns for other common UI components, ensuring they match the overall design language. A brief overview is given below.)

Cards & Containers: A “card” is a container for content (like a user info card or a dashboard stat box). PrecisionCore cards have a white (or surface color) background, a 1px light border or subtle shadow for separation, and a border-radius of 4px. They have consistent padding inside (e.g., 16px). Cards can contain a header (maybe with an icon or small title text), body content, and possibly actions (like buttons or links) at the bottom. They should align to the grid when in a series (e.g. in a dashboard, multiple cards of equal width per row). Our Dashboard example below will illustrate cards in context.
Tables: Table styles are minimal – we use clear separators for rows. Header row can have a slightly different background (light gray) and bold text. Borders between rows can be 1px solid #E0E0E0 (light gray), or zebra striping can be used as an alternative for readability. Table cells have padding (8px or 16px) for spacing. The design ensures tables look clean and not overly cramped, while also not as heavy as old-school spreadsheets. In dark mode, table header might be a darker gray, and stripes would be subtle dark variations.
Alerts/Notifications: An alert banner (e.g., success or error message) typically spans the top of a container or form. PrecisionCore alerts use the semantic colors with a light tint. For example, a success alert might be a green tint background (#E6F4EA) with a green icon and text, error alert a pink/red tint (#FDECEA with #D32F2F text). They have an icon (like ✓ or ⚠️) on the left, message text, and maybe a close icon on the right. They are padded (12px) and have a border-radius (4px) to differentiate from straight-edged layout sections. They should be full-width of their parent container typically.
Icons: The system doesn’t mandate a specific icon set, but recommends a line-style or minimal solid style icon that matches the font’s stroke weight. (Think Material Icons or Feather icons). Icons are used sparingly next to labels or in buttons. All icons should have alt text or aria-hidden as appropriate.
Loading Indicators: A simple spinner (perhaps the classic 3-quarter circle loop) or a progress bar is included. The spinner in light mode could be an animated SVG with the primary color. The progress bar is flat: a track (light gray) and a fill (blue or other color). It might have squared or slightly rounded ends. Indeterminate progress can use an animated stripe or a looping motion.

Each of these components is documented with their states and variants in the full PrecisionCore spec (for brevity, not all code is shown here). The goal is that any piece of UI you need – from a data table to a nav drawer – has a defined style in PrecisionCore that meshes with everything else.

Accessibility & Best Practices

PrecisionCore is built with accessibility as a first-class concern, following WAI-ARIA guidelines and inclusive design principles. Adhering to these practices is essential for engineering teams:

Color Contrast: As noted, all text meets WCAG AA contrast (at least 4.5:1 contrast rati (Dark Mode | Apple Developer Documentation)7】 against its background. This includes text on buttons, labels on colored backgrounds, etc. We also ensure interactive graphics (like icons or focus outlines) have sufficient contrast. For example, the focus ring (blue) on a text field is designed to be visible even if the surrounding UI is blue-ish. In dark mode, using dark grey instead of pure black for background helps keep contrast of white text from being too high (which can cause visual vibratio (docs/theming/Dark.md · mevermore/material-components-android - Gitee)5】, balancing comfort and readability.
Keyboard Navigation: All interactive elements (links, buttons, form inputs, etc.) are reachable via keyboard (tab order follows logical order). We include visible focus indicators. For instance, buttons might get a faint outline or a darker outline on focus, links might underline. No component should be focusable without a visible indicator. The design provides a default focus style (often a 2px outline in the primary color, or the browser default dotted outline if acceptable). Ensure that custom components (like our custom switch toggle or a custom dropdown menu) also handle :focus and :focus-visible states properly.
ARIA Roles and Labels: Use semantic HTML whenever possible (e.g., <button>, <nav>, <header>, <form> tags) so that roles are implicit. When semantics are not obvious:
- Modals get role="dialog" and aria-modal="true", with the title text tied to aria-labelledby.
- Icons that convey meaning have aria-label attributes or are accompanied by screen reader text. Pure decorative icons have aria-hidden="true".
- Form inputs have <label>s or aria-label. If an input is required, add aria-required="true" or simply use the required attribute which most screen readers announce.
- If using custom controls (like a styled checkbox), ensure to mimic the native semantics (perhaps using a visually-hidden real checkbox or appropriate ARIA roles like role="checkbox" with aria-checked state toggling).
- Use aria-live regions for dynamic alerts (e.g., if a form error appears, mark the container role="alert" so it’s announced immediately).
Font and Motion Preferences: Allow users to scale text – use relative units (rem/em) and avoid fixing text in px only. Also, respect prefers-reduced-motion: if the user prefers less animation, skip or shorten our animations (like modal fade, tooltip fade, etc.). In CSS, this can be done via @media (prefers-reduced-motion: reduce) to disable transitions.
Touch Targets: Ensure controls aren’t too small. Our spacing guidelines already lean toward at least 36-44px height for anything clickable (e.g., buttons, inputs) which aligns with the recommended minimum of ~7mm (~48px at typical screen density) for touch targe (Metrics & keylines - Layout - Material Design)9】. If an icon button is smaller, pad it (our icon-buttons in the header have about 40px clickable area via padding).
Responsive design & device testing: PrecisionCore components are tested on both desktop and mobile layouts. Elements that might pose issues on mobile (like hover-only interactions, or very large tables) have alternate strategies (e.g., on mobile, hover becomes tap/long press or is just always visible; tables become horizontally scrollable or stacked). The design documentation provides suggestions (for instance, a table might collapse into a list of cards on a narrow screen).
Forms and validation: Provide clear error messages and associate them with the field (using aria-describedby). Use visible cues (like red outline and an exclamation icon) along with text for errors. For success or info, use icons plus text as well. Do not rely on color alone to indicate an error on a form field – e.g., include an icon or message (color-blind users might not distinguish red border from normal).
High Contrast Mode: On Windows high-contrast mode or other assistive themes, our design should not break. By mostly using standard HTML elements and not hiding essential semantics, we let the OS replace colors if needed. We also try to ensure SVG icons use currentColor where possible so they adapt to high-contrast (or provide alternative text).

Engineering rationale for these: Many are out-of-the-box if using semantic HTML. The design system encourages not to reinvent controls (use <button> not a div with click handler for a button). That way, the heavy lifting for accessibility is often done by the browser. Where we create a custom UI (like the switch or a custom styled select), we mirror the semantics of the native element. The documentation provides guidance code for those cases.

By following these accessibility practices, products built with PrecisionCore will be usable by a wider audience (screen reader users, keyboard-only users, those with low vision or color blindness, etc.) and also generally more robust and pleasant for everyone. Accessibility is a win-win: it often improves the UX for all users, not just those with overt disabilities.

Responsive & Mobile Design

PrecisionCore is intended for web applications that need to work on both desktop and mobile. As such, responsiveness is baked into the system:

Mobile-First CSS: The recommended approach is to design layouts for small screens first, then use media queries to enhance for larger screens. This ensures the base styles are lightweight and appropriate for mobile, and avoid having to undo desktop styles for mobile. Many examples in this document (forms, navigation) already mention their mobile adaptation (e.g., nav turning into a hamburger menu).
Breakpoints: We suggest a standard set of breakpoints (which can be adjusted as needed):
- Small (max-width ~600px) – handheld devices.
- Medium (600px to 1024px) – tablets or small laptops.
- Large (1024px and up) – desktops.
- Extra large (1440px and up) – large desktop monitors (where maybe content can have more columns or padding). These roughly correspond to typical device widths. Use min-width media queries to apply layouts for medium and up. For example, .col-6 { width: 50%; } @media(min-width: 600px){ .col-6 { width: 50%; } } etc. (In Tailwind terms, use sm:, md:, lg: utilities.)
Fluid grids and images: Use percentage widths or flex for columns so that if a screen is a weird size, things still fill nicely. Images and media should use max-width: 100% to shrink on smaller devices.
Navigation on Mobile: As discussed, simplify. Top bars often contain a menu icon instead of a whole menu. Sidebars become drawers. If using a tab bar, consider using icon-only or icon+short text to save space (or use a bottom nav like many mobile apps, which can be achieved with a fixed bottom menu that mimics the tab component).
Touch Interactions: On touch devices, there is no hover. So any hover-specific styles (like button hover or tooltip on hover) should either be redundant or triggered by touch in a different way. For instance, tooltips might not show at all on mobile (or show on long press, but that’s uncommon on web). Ensure that essential actions do not rely on hover. PrecisionCore’s components are designed such that hover only enhances (e.g., highlighting a button) but the affordance is visible even without hover (button looks like a button initially).
Responsive typography: As mentioned, font sizes might increase slightly on small devices for readability. Also ensure text blocks aren’t too wide on large screens (max-width for content blocks around 700-800px for optimal reading). The grid will often have margins on large screens to avoid lines of text that are too long.
Performance on mobile: The design system encourages using vector icons (SVG or icon font) and CSS effects over heavy images. Any background images (like an optional hero banner, etc.) should have optimized loading for mobile (maybe use srcset for smaller versions). The flat design nature of PrecisionCore means it’s quite lightweight to render; mostly CSS without requiring images for UI chrome.
Testing real devices: The guidelines recommend testing UI on actual devices or emulators to verify touch target sizes, font readability, and layout correctness. Especially check things like: tap highlights on links (maybe suppress default if unwanted via CSS), iOS safe areas (if using full-screen web apps, account for notch), Android viewport behavior (avoid content jumping when virtual keyboard appears by proper meta viewport settings and possibly using vh carefully).

In summary, a PrecisionCore app should feel like it was made for the device it’s on. On a phone, it should feel like a mobile app: simple navigation, no tiny click targets, text large enough, perhaps use mobile-native UI patterns (like a slide-in menu). On a desktop, it should take advantage of screen space: multi-column layouts, visible menus, richer tooltips, etc. This adaptive design philosophy ensures a broad reach.

Example Usage Patterns

To illustrate how the pieces come together, here are a few example application contexts and how PrecisionCore components would be used within them. Each example demonstrates the coherent style and provides guidance on using the design system in real scenarios:

Example: Dashboard Page

A dashboard typically presents a summary of data with various components: navigation sidebar, header, cards showing metrics, and maybe charts or tables. (image)e】 PrecisionCore dashboard example: a sidebar on the left with menu icons, a main area with a “Dashboard” header, several info cards (showing numbers like 42, 87%, $123), and a sample chart area.

In the dashboard image:

The sidebar (left) is a vertical gray bar with several rectangular icons (the top one highlighted in blue, indicating the current section). This matches our Navigation guidelines: a fixed side menu with clear indication of the active section (blue background icon = active).
The header (in main content) says “Dashboard” – styled as a page title.
Under the header, three cards display key metrics (“42”, “87%”, “$123”) in a row. They have a light blue background and a thin border – standing out from the white page background. This shows how to present highlights in a concise way, using the Card component style.
Below the cards, a chart area is shown as a large light-blue box. In a real app, this could be a line chart or bar chart embedded via a chart library, but styled to blend with the design (using the primary or secondary colors for data points).

This dashboard uses a two-column layout: the sidebar (nav) and the main content. On a mobile view, the sidebar would likely collapse into a hamburger menu. The cards might wrap into 1-per-row on narrow screens. PrecisionCore’s spacing keeps everything tidy (gaps between cards equal, padding inside cards consistent).

Key points using PrecisionCore:

The sidebar uses the neutral background and simple iconography (could use Material icons in practice). The active item is emphasized with primary color.
The main area’s background is just the default background (white). The cards use a slight colored background (a tint of primary or an accent color) to draw attention – which is a permissible use of color since these are highlight components.
Typography: “Dashboard” heading is larger/bold, the card numbers are big and bold (maybe using an H2 style), and labels like “Revenue” could be smaller (not shown, but presumably each number would have a label).
The chart area could utilize a library but you’d ensure the colors in the chart match the theme (e.g., using primary blue for a line).

Code concept for part of this:

<div class="wrapper">
  <aside class="sidebar">
    <!-- sidebar items -->
    <div class="menu-item active"><span class="icon"></span></div>
    <div class="menu-item"><span class="icon"></span></div>
    <!-- ... -->
  </aside>
  <main class="content-area">
    <h2>Dashboard</h2>
    <div class="cards">
      <div class="card metric-card"><div>42</div></div>
      <div class="card metric-card"><div>87%</div></div>
      <div class="card metric-card"><div>$123</div></div>
    </div>
    <div class="chart-panel">[Chart]</div>
  </main>
</div>

Styling would ensure .sidebar is fixed or flex container, .menu-item height, etc., .cards use flex with gap. The “metric-card” might have background: #F0F8FF (a light blue, which is actually AliceBlue in CSS, used here for example).

Example: Settings/Preferences Panel

Consider a settings page where a user updates profile info or toggles preferences. This would use a lot of form elements:

Use a form layout with labels and inputs as described in Forms section. Possibly group related settings under subheadings.
Include toggles for on/off settings (like Dark Mode, Notifications on/off, etc.), which we have in our forms example (the switch control).
Perhaps use tabs if the settings are split into categories (Account, Privacy, Notifications, etc.).
Buttons at the bottom like “Save Changes” (primary) and maybe “Cancel” (secondary) or “Reset to defaults”.

PrecisionCore ensures such a page looks consistent: all inputs aligned, the Save button stands out, and spacing is adequate so it doesn’t feel crowded. On mobile, the form fields would be full width (they already are in CSS), and the Save/Cancel might stick at bottom or scroll with content depending on design.

One best practice: if the settings page is long, use a sticky header or section labels so users don’t get lost. PrecisionCore’s neutral backgrounds can be used to subtly differentiate sections (maybe alternate a very slightly different background for every other section).

Example: Login Flow

A login or onboarding flow might be a modal or its own page:

Likely a centered form with a couple of fields (email, password) and a submit button.
Minimal distractions: maybe the app logo at top (which can be an image or just a styled text per branding), then inputs and a prominent “Log In” button.
Optionally a link for “Forgot password?” or “Sign up” if this is not an isolated environment.
The PrecisionCore style helps here: inputs are clearly labeled, the primary button stands out. The focus is solely on logging in.

For a sign-up form, you’d follow the same form styles, with maybe more fields, but again structured logically with the design system’s spacing.

One more example: Data Table Page

If we had an admin view with a table of users:

Use table styles (striped rows or bordered rows). Possibly allow selecting rows with checkboxes (our styled checkboxes).
At top, a toolbar with actions (“Add User” button, search field on the table).
Could incorporate pagination controls at bottom (styled as buttons or links, e.g., “Prev 1 2 3 Next”).

PrecisionCore’s button styles would apply to pagination (maybe secondary style for page numbers, primary for current page or simply highlight current page number text). Table headers would use the base font but bold. Everything aligns to the 8px grid (cells have consistent padding, etc.).

By following the system, each of these pages will look like they belong to the same family. The Material influence ensures they’re functional and user-friendly, the minimalism keeps them from being visually overwhelming, the Apple influence adds a layer of polish (through typography and spacing), and the Windows 98 influence ensures no user is confused about what is interactive or how things are structured.

Conclusion

PrecisionCore is a polished, comprehensive design system that any team can use to build beautiful and functional web app interfaces. We have outlined the core philosophy, from high-level aesthetic decisions down to detailed component styles. By using the provided HTML/CSS patterns or TailwindCSS utility examples, developers can implement this design consistently. The system’s defaults (light mode first, 8px grid, primary blue accent, etc.) give a strong baseline, while its flexibility (themeable colors, scalable components) allows customization as needed.

With PrecisionCore, the aim is to achieve a UI that feels instantly familiar yet modern. Users should find interfaces built with it intuitive (thanks to clear affordances and minimal clutter) and engaging (thanks to subtle elegant touches and a coherent visual language). And as demonstrated, these UIs will work across device sizes and input methods.

Finally, remember that a design system is a living document – PrecisionCore expects teams to extend it as needed. But any extension should respect the guiding principles outlined: functional clarity, minimal distraction, refined elegance, and structured familiarity. By doing so, you maintain the soul of PrecisionCore even as you adapt it to specific product needs.

We encourage you to refer back to this document (much like one would with Material Design’s or Apple’s official docs) whenever designing a new component or page. Consistency is key: when in doubt, follow the established patterns and reutilize components. This not only speeds up development (since you’re not reinventing styles) but also reinforces user trust and brand identity through a unified look and feel.

With the combination of philosophy, guidelines, examples, and code, PrecisionCore serves as a one-stop reference to design and develop a cutting-edge web application UI in 2025 and beyond – bridging the best of past inspirations and future-ready practices.

thomasdavis/precision-core-design-system.md

PrecisionCore Design System

Introduction & Design Philosophy

Color & Theming

Typography

Layout, Grid & Spacing

Navigation Structure

Components

Buttons & Actions

Form Inputs & Controls

Modals & Overlays

Additional Components

Accessibility & Best Practices

Responsive & Mobile Design

Example Usage Patterns

Example: Dashboard Page

Example: Settings/Preferences Panel

Example: Login Flow

Conclusion