Sistema de diseño de github.com

---
version: alpha
name: "github.com"
description: "Design system extracted from https://github.com/ on 2026-09-28"
colors:
  background: "#000000"
  surface: "#0d1117"
  surface-2: "#1c1f25"
  foreground: "#ffffff"
  muted-foreground: "#a4aea6"
  primary: "#08872b"
  on-primary: "#ffffff"
  secondary: "#1f6feb"
  border: "#25292e"
typography:
  headline-display:
    fontFamily: "Mona Sans"
    fontSize: "64px"
    fontWeight: 425
    lineHeight: "1.08"
    letterSpacing: "-2.24px"
  headline-lg:
    fontFamily: "Mona Sans"
    fontSize: "40px"
    fontWeight: 460
    lineHeight: "1.2"
  headline-md:
    fontFamily: "Mona Sans"
    fontSize: "22px"
    fontWeight: 480
    lineHeight: "1.4"
  body-md:
    fontFamily: "Mona Sans"
    fontSize: "16px"
    fontWeight: 400
    lineHeight: "1.69"
  label-md:
    fontFamily: "Mona Sans"
    fontSize: "16px"
    fontWeight: 400
    lineHeight: "1.5"
    letterSpacing: "0.21px"
  button:
    fontFamily: "Mona Sans VF"
    fontSize: "14px"
    fontWeight: 400
    lineHeight: "1.5"
  code:
    fontFamily: "Mona Sans Mono"
    fontSize: "11px"
    fontWeight: 400
    lineHeight: "0.91"
    letterSpacing: "0.21px"
rounded:
  none: "0px"
  md: "6px"
  xl: "16px"
  2xl: "60px"
  full: "9999px"
spacing:
  unit: "4px"
  1: "4px"
  2: "8px"
  3: "12px"
  4: "16px"
  5: "20px"
  6: "24px"
  7: "32px"
  8: "40px"
  9: "48px"
  10: "64px"
  11: "96px"
components:
  button-ghost:
    backgroundColor: "#0d1117"
    textColor: "#ffffff"
    typography: "{typography.button}"
    rounded: "0px"
    height: "40px"
    padding: "8px 8px"
  button-secondary:
    backgroundColor: "#0d1117"
    textColor: "#ffffff"
    typography: "{typography.button}"
    rounded: "6px"
    height: "32px"
    padding: "1px 12px"
  button-primary:
    backgroundColor: "{colors.primary}"
    textColor: "{colors.on-primary}"
    typography: "{typography.button}"
    rounded: "6px"
    height: "48px"
    padding: "6px 20px"
  input:
    backgroundColor: "transparent"
    rounded: "8px"
    height: "41px"
  card:
    backgroundColor: "transparent"
    rounded: "16px"
    padding: "0px"
---

# github.com

## Overview

GitHub · Change is constant. GitHub keeps you ahead. · GitHub: Join the world's most widely adopted, AI-powered developer platform where millions of developers, businesses, and the largest open source community build software that advances humanity.

Gently rounded controls, one soft shadow for depth, large display type at 64px / 425, a single green accent on neutrals. The site ships in dark mode by default (dark surfaces, light type). Measured from 1600 rendered elements at 1440px wide on 2026-09-28.

Reference screenshots live beside this file; look at them before writing any layout, they carry the composition, density and image treatment that tokens cannot:

- `screenshots/desktop-1440-fold.png`: Desktop 1440, above the fold
- `screenshots/desktop-1440-full.jpg`: Desktop 1440, full page
- `screenshots/desktop-1440-light.png`: Desktop 1440, light mode
- `screenshots/laptop-1024-fold.png`: Laptop 1024, above the fold
- `screenshots/tablet-768-fold.png`: Tablet 768, above the fold
- `screenshots/phone-390-fold.png`: Phone 390, above the fold
- `screenshots/phone-390-full.jpg`: Phone 390, full page

## Colors

| Token | Value | Use |
| --- | --- | --- |
| background | `#000000` | Page background |
| surface | `#0d1117` | Cards, panels, raised or recessed surfaces |
| surface-2 | `#1c1f25` | Secondary surface |
| foreground | `#ffffff` | Primary text |
| muted-foreground | `#a4aea6` | Secondary text, captions |
| primary | `#08872b` | Accent: primary buttons, links, focus |
| on-primary | `#ffffff` | Text on the accent |
| secondary | `#1f6feb` | Secondary accent (blue) |
| border | `#25292e` | Hairlines, dividers, input borders |

Full painted palette by area (largest first): `#000000`, `#0d1117`, `#1c1f25`, `#3d4145`, `#31353a`, `#08872b`, `#5fed83`, `#1f6feb`.

Gradients in use: `linear-gradient(rgb(0, 2, 64), rgba(0, 0, 0, 0))`; `radial-gradient(circle at 0px 100%, rgb(230, 183, 254) 10%, rgb(80, 73, 194) 20%, rgba(87, 78, 255, 0) 60%)`; `linear-gradient(rgb(0, 2, 64), rgb(0, 0, 0) 117%)`.

The accent `#08872b` is used sparingly: primary buttons, links and focus rings. Everything else stays neutral.

## Typography

- **Mona Sans** for h1, h2, h3, body, label: self-hosted webfont, not freely available; use **Inter** from Google Fonts as the stand-in.
- **Mona Sans VF** for button: self-hosted webfont, not freely available; use **Inter** from Google Fonts as the stand-in.
- **Mona Sans Mono** for code: self-hosted webfont, not freely available; use **Inter** from Google Fonts as the stand-in.

| Role | Family | Size | Weight | Line height | Tracking |
| --- | --- | --- | --- | --- | --- |
| headline-display | Mona Sans | 64px | 425 | 1.08 | -2.24px |
| headline-lg | Mona Sans | 40px | 460 | 1.2 | normal |
| headline-md | Mona Sans | 22px | 480 | 1.4 | normal |
| body-md | Mona Sans | 16px | 400 | 1.69 | normal |
| label-md | Mona Sans | 16px | 400 | 1.5 | 0.21px |
| button | Mona Sans VF | 14px | 400 | 1.5 | normal |
| code | Mona Sans Mono | 11px | 400 | 0.91 | 0.21px |

Type scale in use: 11px, 12px, 14px, 16px, 18px, 22px, 24px, 40px, 64px. Base body size 16px.

The H1 renders at 64px / 425, center aligned, up to 924px wide, tracking -2.24px. Sample: "The future of building happens together".

## Layout

- Spacing unit: 4px. Scale in use: 4, 8, 12, 16, 20, 24, 32, 40, 48, 64, 96 (px).
- Flex and grid gaps: 4, 8, 12, 16, 24, 32, 44, 48 px.
- Content max width: 1280px, centred.
- Header: 72px tall, fixed, background `rgba(0, 0, 0, 0)`; 12 nav links at 16px / 400 (GitHub CopilotWrite better code with AI · GitHub Copilot appDirect agents from issue to merge · MCP RegistryIntegrate external tools · ActionsAutomate any workflow · CodespacesInstant dev environments · IssuesPlan and track work · Code ReviewManage code changes · Code QualityEnforce quality at merge).

## Elevation & Depth

Shadows in use, most common first:

- shadow-1: `rgb(25, 31, 27) 0px -1px 0px 0px inset`

## Shapes

- Buttons: 6px
- Inputs: 8px
- Cards and panels: 16px
- Images and media: 0px
- Radius scale: none 0px, md 6px, xl 16px, 2xl 60px, full 9999px

## Components

### Button, ghost

Background transparent (it sits on `#0d1117`, so place it on that colour), text `#ffffff`, border none, radius 0px, height 40px, padding 8px 8px, 16px / 500. Sample label: "Platform".

### Button, secondary

Background transparent (it sits on `#0d1117`, so place it on that colour), text `#ffffff`, border 1px solid #262c28, radius 6px, height 32px, padding 1px 12px, 16px / 400. Sample label: "Search/".

### Button, primary

Background `#08872b`, text `#ffffff`, border 1px solid transparent, radius 6px, height 48px, padding 6px 20px, 14px / 400. Sample label: "Sign up for GitHub".

### Input

Height 41px, background `transparent`, border 0px solid #000000, radius 8px, 16px text, padding 18px 12px.

### Card

Background `transparent`, border 1px solid #484f5880, radius 16px, padding 0px, no shadow. Typical size about 378×332px.

### Link

Colour `#ffffff`, no underline at rest, weight 400.

## Dark Mode

Both themes exist; the default render is dark and the light theme was reached via data-color-mode=light. Token pairs, light → dark:

| Token | Light | Dark |
| --- | --- | --- |
| background | `#000000` | `#000000` |
| surface | `#0d1117` | `#0d1117` |
| surface-2 | `#151a22` | `#1c1f25` |
| foreground | `#ffffff` | `#ffffff` |
| muted-foreground | `#a4aea6` | `#a4aea6` |
| primary | `#08872b` | `#08872b` |
| on-primary | `#ffffff` | `#ffffff` |
| secondary | `#0969da` | `#1f6feb` |
| border | `#ffffff` | `#25292e` |

Light-theme shadows: `rgb(25, 31, 27) 0px -1px 0px 0px inset`

The light pass changed the page but the result still reads as dark; check the light screenshot.

## Responsive Behavior

| Viewport | Content width | Gutter | Body | H1 | Header | Hero | Grids | Buttons |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| desktop 1440px | 1280px | 258px | 14px | 64px, 2 lines, center | 72px, 3 links, 3 CTA | text only | 2→2 col; 2→1 col; 2→2 col | content-width |
| laptop 1024px | 928px | 50px | 14px | 64px, 2 lines, center | 72px, 3 links, 3 CTA | text only | 2→2 col; 2→1 col; 2→2 col | content-width |
| tablet 768px | 574px | 48px | 14px | 56px, 2 lines, center | 65px, hamburger (Toggle navigation), 1 CTA | text only | 2→2 col; 2→1 col; 2→2 col | content-width |
| phone 390px | 342px | 48px | 14px | 40px, 4 lines, center | 65px, hamburger (Toggle navigation), 1 CTA | text only | 4→2 col | 13 full-width |

- H1 goes 64px → 40px (63%), 2 → 4 lines.
- Nav collapses to a hamburger by 390px (first seen at 768px); header 72px → 65px.
- Body text stays 14px at every width.
- Phone side gutter 48px.
- 13 buttons stretch full-width on phones.
- Section top padding 72px → 65px.

## Interaction & Motion

99 elements carry transitions; typical 0.2s with cubic-bezier(0.165, 0.84, 0.44, 1), mostly on opacity, transform, background-color. 1 running keyframe animations (Primer_Brand__LogoSuite-module__LogobarScrollX___eGhi4 60s infinite).

- Hover on button-primary ("Search/"): background transparent → #ffffff29, border #262c28 → #ffffff1f; cursor pointer; transition background-color, border-color | 0.2s, 0.2s | ease, ease | delay 0s, 0s.
- Hover on button-secondary ("Sign in"): background transparent → #ffffff29, border #262c28 → #ffffff1f; cursor pointer; transition background-color, border-color | 0.2s, 0.2s | ease, ease | delay 0s, 0s.
- Hover on nav-link ("Pricing"): text #ffffff → #a4aea6, border #ffffff → #a4aea6; cursor pointer.
- Hover on input: no visible change; cursor text; transition color, background-color, box-shadow | 0.08s | cubic-bezier(0.33, 1, 0.68, 1).
- Focus on button-primary: outline 2px solid rgb(48, 148, 255).
- Focus on input: no visible focus style measured (may rely on :focus-visible with keyboard only).
- No tooltip could be triggered from the first viewport, but the stylesheet defines tooltip rules (.tooltipped): position: relative.
- Hover/click menus: below the trigger, 1496px gap, shifted right; transparent, radius 0px, padding 0px 0px, shadow none; appears instantly (no fade); stays open after the pointer leaves (click-away or hover-intent grace).
- 14 sizable elements sit at opacity 0 before scrolling: scroll-reveal animations are in use (reveal on enter, fade + rise is the usual recipe).

Full detail (every overlay, table, form, scroll and text rule measured) is in `BEHAVIOR.md`; raw evidence in `evidence.json`.

## Do's and Don'ts

- Do use 4px multiples for every padding, margin and gap; the site does not use odd values.
- Do reserve `#08872b` for actions and focus; never paint large areas with it.
- Do keep body text at 16px in Mona Sans.
- Do match corner radii per element class (buttons 6px, cards 16px); do not pick one radius for everything.
- Do use the measured shadows above; do not invent heavier ones.
- Don't substitute a different accent hue or introduce gradients that are not listed above.
- Don't rebuild from the tokens alone; open the screenshots for composition, density and image treatment.