Design System: Uber Bold Transit

1. Visual Theme & Atmosphere

Estilo Uber Bold Transit com dualidade preto-branco, tipografia billboard e navegação pill. Ideal para mobilidade, logística e plataformas urbanas. Inspirado no design do Uber, que usa dualidade preto-branco com confiança de marca estabelecida e geometria pill como linguagem tátil.

• Density: 3/10 — Airy
• Variance: 3/10 — Restrained
• Motion: 4/10 — Subtle

2. Color Palette & Roles

• Preto Uber (#000000) — Dark surface, primary background
• Branco (#ffffff) — Light surface, card backgrounds
• Cinza Hover (#e2e2e2) — Secondary text, borders, muted elements
• Cinza Chip (#efefef) — Secondary text, borders, muted elements
• Cinza Body (#4b4b4b) — Primary text color
• Cinza Muted (#afafaf) — Secondary text, borders, muted elements
• Sombra (rgba(0,0,0,0.12)) — Extended palette, decorative use
• Sombra Média (rgba(0,0,0,0.16)) — Extended palette, decorative use

3. Typography Rules

• Display / Hero: system-ui — Weight 700, tight tracking, used for headline impact
• Body: system-ui — Weight 400, 16px/1.6 line-height, max 72ch per line
• UI Labels / Captions: system-ui — 0.875rem, weight 500, slight letter-spacing
• Monospace: JetBrains Mono — Used for code, metadata, and technical values

Scale:

• Hero: clamp(2.5rem, 5vw, 4rem)
• H1: 2.25rem
• H2: 1.5rem
• Body: 1rem / 1.6
• Small: 0.875rem

4. Component Stylings

• Primary Button: Pill-shaped (9999px) shape. Accent color fill. Hover: 8% darken + subtle lift shadow. Active: -1px translate tactile press. Font weight 600. No outer glows.
• Secondary / Ghost Button: Outline variant. 1.5px border in muted color. Text in primary color. Hover: subtle background fill.
• Cards: Pill-shaped (9999px) corners. Surface background. Subtle shadow (0 2px 12px rgba(0,0,0,0.06)). 1px border stroke.
• Inputs: Label above input. 1px border stroke. Focus ring: 2px accent color offset 2px. Error text below in semantic red. No floating labels.
• Navigation: Primary surface background. Active item: accent color indicator. Font weight 500 when active.
• Skeletons: Shimmer animation matching component dimensions. No circular spinners.
• Empty States: Icon-based composition with descriptive text and action button.

5. Layout Principles

• Grid: CSS Grid primary. Max-width containment: 1280px centered with 1.5rem side padding.
• Spacing rhythm: Balanced. Base unit: 0.5rem (8px).
• Section vertical gaps: clamp(4rem, 8vw, 8rem).
• Hero layout: Split-screen (text left, visual right).
• Feature sections: Zig-zag alternating text+image rows. No 3-equal-columns.
• Mobile collapse: All multi-column layouts collapse below 768px. No horizontal overflow.
• z-index contract: base (0) / sticky-nav (100) / overlay (200) / modal (300) / toast (500).

6. Motion & Interaction

• Physics: Ease-out curves, 200-300ms duration. Smooth and predictable.
• Entry animations: Fade + translate-Y (16px → 0) over 420ms ease-out. Staggered cascades for lists: 80ms between items.
• Hover states: Subtle color shift + shadow adjustment over 200ms.
• Page transitions: Fade only (200ms).
• Performance: Only transform and opacity animated. No layout-triggering properties.

7. Anti-Patterns (Banned)

• No emojis in UI — use icon system only (Lucide, Heroicons)
• No pure black (#000000) — use off-black or charcoal variants
• No oversaturated accent colors (saturation cap: 80%)
• No 3-column equal-width feature layouts — use zig-zag or asymmetric grid
• No h-screen — use min-h-[100dvh]
• No AI copywriting clichés: "Elevate", "Seamless", "Unleash", "Next-Gen"
• No broken external image links — use picsum.photos or inline SVG
• No generic lorem ipsum in demos