design-best-practices

name	design-best-practices
description	Comprehensive library of professional document design best practices sourced from top consulting firms (McKinsey, Deloitte, BCG), tech leaders (Stripe, Apple, Google), and typography/layout research. Use this skill when making design decisions, choosing fonts, colors, layouts, or when the user asks for a "professional" or "corporate" look.

Design Best Practices Library

Actionable design guidelines sourced from top companies and research. Use these as the default standard for all generated documents.

1. Proposal Design (McKinsey / Deloitte Style)

Structure

• Cover page: title pushed to upper-center area (not dead center), accent line above title, meta block (prepared by/for, date)
• Executive summary on page 2 — single page max
• Clear section breaks with generous whitespace between major sections
• About/team page near the end, not the beginning

Layout Principles

• Left-aligned body text always (never centered body copy)
• Action titles on every section — articulate the key takeaway, not just the topic
• One idea per page/section — do not stack unrelated content
• Use line-based separators (1px rules) over box-based containers
• Generous whitespace signals sophistication; cluttered layouts signal amateur work

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2. Invoice Design (Stripe / FreshBooks Model)

Layout

1. Subtle top bar (4-5px solid color) — visual anchor without heaviness
2. Header: company name + details left; "INVOICE" label + number + dates right
3. Bill-to section: plain text, uppercase muted labels (9px) above client info (14px bold)
4. Amount Due: right-aligned, large bold (18px)
5. Line items table: dark header row with white text, alternating white/#F8FAFC rows, no vertical inner borders
6. Totals: right-aligned, line-based — subtotal/tax in muted, 1.5px divider, total in bold
7. Payment details: separated by thin rule, 2-column label+value grid
8. Subtle bottom bar (4px)

Principles

• Minimalism outperforms cluttered designs
• White space is "breathing room" — cramped invoices feel chaotic, spacious invoices feel trustworthy
• Sans-serif fonts work best for invoice data
• No colored background cards for info sections — use plain text with thin separators
• No navy fill boxes on totals — bold text + border-top rule instead

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3. Report Design (McKinsey / BCG Style)

Brand Colors (Reference)

• McKinsey: Primary blue #2251FF, dark #051C2C, white #FFFFFF
• Deloitte: Green #86BC24, Black #000000
• BCG: Off-white #F5F5F5, dark #222222, blue #005EB8, gray #A2AAAD

Layout Principles

• Every slide/page needs an "action title" — the key takeaway, not a topic label
• White and dark backgrounds alternated for contrast and hierarchy
• Color used sparsely — vivid colors highlight key data only
• Well-organized layouts with bold headings, bullet points, numbered lists
• Simple, minimalist, monochromatic icons from a consistent set

Report Structure

• Cover page with clear title hierarchy
• Table of contents for 10+ page documents
• Executive summary (1 page)
• Key findings with action titles
• Data tables with dark header rows, light zebra striping
• Appendices separated clearly

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4. Presentation Design (Apple Keynote / TED Style)

Core Principles

• One core message per slide — prevent information overload
• Build slides last — first develop message, structure, supporting points
• Bold typography can serve as the visual element itself
• Use simple, punchy images that amplify spoken words

Text Rules

• 4-5 words per bullet point maximum
• 4-5 bullet points per slide maximum
• Sans-serif fonts for clean screen readability

Sizes

• Title slide heading: 40pt Bold, white on dark background
• Slide header: 16pt Bold, white on navy bar (0.75" height)
• Subtitle: 20-22pt Regular, muted color
• Body/bullets: 16-18pt Regular
• Agenda numbers: 24pt Bold, accent color

Patterns

• Title slide: full navy background + accent stripe + left-aligned text
• Content slides: navy header bar + accent line + white body area
• Agenda slides: numbered items with accent-colored numbers + dividers
• Summary slides: two card boxes with top accent stripe

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5. Contract / Legal Document Formatting

Typography

• Serif fonts preferred for printed legal documents (traditional, authoritative)
• Recommended: Georgia, Garamond, Source Serif 4
• Font size: 12pt standard (courts recommend 12pt)
• Bold for section titles, italics for references/citations, avoid underlining

Spacing

• Line spacing: 1.5-1.7 for legal documents
• Line length: 60-75 characters per line, never more than 90
• 12pt of space between paragraphs
• Hanging indent for numbered sub-clauses: padding-left 2.2em, text-indent -2.2em

Margins

• Standard: 1" on all sides
• Left margin slightly wider (1.25") if bound

Layout

• Centered title block: title in Bold uppercase with letter-spacing 0.08em
• Contract number + date in muted text below title
• Article/section dividers: full-width primary background bars with white uppercase text
• Two-column signature blocks at end
• Page numbering starting on page 2, upper right

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6. Typography Best Practices

Font Pairings by Context

System-safe (DOCX/PPTX):

Use Case	Headings	Body
Proposals, Reports	Georgia (serif)	Arial (sans-serif)
Presentations	Georgia (serif)	Arial (sans-serif)
Contracts, Legal	Georgia (serif)	Georgia (serif)

Embedded/PDF:

Use Case	Headings	Body
Invoices, Reports	Source Serif 4	Inter
Contracts, Acts	Source Serif 4	Source Serif 4

Premium pairings (reference):

• Helvetica + Garamond: authority + elegance (academic, government, law)
• Inter + Garamond: modern screen clarity + warm body text
• Montserrat + EB Garamond: geometric modern + classic (free Google Fonts)

Font Size Scale

Element	Print (pt)	Screen (px)
Document title	28-32	26-32
H1	18-20	20-24
H2	14-16	16-18
H3	12-13	14-15
Body text	11-12	12-16
Captions/meta	8-9	10-11
Table body	10-11	12-13
Table header	10-11	10.5

Spacing

• Line height: 1.3 for business docs, 1.5-1.7 for legal, 1.0 for presentations
• Paragraph spacing: 8-12pt after paragraphs
• Letter spacing: 0.08-0.12em for uppercase labels; 0 for body text

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7. Color Palette Best Practices

The 60-30-10 Rule

• 60% — Dominant (white/off-white page background)
• 30% — Structure (navy headers, table headers, headings)
• 10% — Accent (blue highlights, underlines, key values)

Corporate Palette

Role	Hex	Usage
Primary (Deep Navy)	#1E3A5F	Table headers, title bars, key amounts
Accent (Corporate Blue)	#2563EB	Underlines, bullet markers, highlights
Text (Dark Slate)	#1E293B	Body text, names, amounts
Muted (Slate Gray)	#64748B	Labels, captions, secondary info
Border (Light)	#E2E8F0	Table borders, dividers
Background (Off-white)	#F8FAFC	Alternating table rows only

Guidelines

• 5-8 colors total: 1-2 dark anchors, 1-2 light surfaces, 1 accent, supporting tints
• Use off-white (#F8FAFC) instead of pure white for premium feel
• Keep saturation low for multi-color palettes
• Reserve bright/vivid colors for key data highlights only
• Never use colored fill boxes as section backgrounds in PDFs

Document-Type Variations

• Formal/Legal: darker palette — primary #1E293B, accent #1E3A5F
• Business/Corporate: standard — primary #1E3A5F, accent #2563EB
• Creative/Tech: warmer accent (teal #0D9488, terracotta #C2410C)

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8. Multi-Language Document Design

RTL (Arabic, Hebrew, Persian)

• Entire layout flips: navigation, columns, margins all mirror
• Use CSS logical properties (margin-inline-start not margin-left)
• Numerals, punctuation, brand names, and URLs remain LTR
• Arabic text needs 20-30% more vertical space than Latin
• Arabic fonts: Noto Sans Arabic, Noto Naskh Arabic, Amiri

CJK (Chinese, Japanese, Korean)

• No word spaces in Chinese/Japanese — text is continuous
• CJK text needs larger line-height (1.5-1.8 recommended)
• Recommended: Noto Sans CJK / Noto Serif CJK (covers all three scripts, 7 weights, free)

Cyrillic (Ukrainian, Russian)

• Source Serif 4: designed specifically for Cyrillic+Latin — ideal
• Inter: excellent Cyrillic support for sans-serif body text
• Both embedded as WOFF2 in this plugin's font system

General Guidelines

• Always verify font coverage for target scripts before selecting
• Use font-family stacks with fallbacks
• Allow 20-40% text expansion for translations (German, Finnish expand significantly from English)
• The language field in document data controls localized labels (act headers, table columns, signature blocks)

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9. Logo Placement Best Practices

Primary Placement: Top-Left

• Users are 89% more likely to remember logos placed top-left vs top-right
• Left-aligned matches natural F-pattern eye scanning

Size Guidelines

• Minimum resolution: 300 DPI for print
• Typical size: 120-180px wide for PDFs, 1.5-2.5" for print
• Always maintain clear space around logo equal to at least the height of the logo mark

Placement by Document Type

Document	Logo Position	Notes
Invoice	Top-left of header row	Paired with company info
Proposal/Report	Top-left or on cover page	Can be larger on cover
Contract	Top-center or top-left	Formal centered placement acceptable
Presentation	Title slide + small in header bar	Subtle on content slides

Technical Requirements

• Use SVG or high-res PNG (transparent background) for digital
• Embed as base64 for self-contained PDFs
• Logo is auto-constrained to max-height 56px, max-width 160px in this plugin

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10. White Space and Margins

Margin Standards

Document Type	Top	Bottom	Left	Right
Proposals/Reports (DOCX)	1"	1"	0.75"	0.75"
Contracts (DOCX)	1"	1"	1"	1"
PDFs (via Playwright)	28mm	22mm	18mm	18mm

Spacing Grid (8px base)

Use multiples of 8px for all spacing: 8, 16, 24, 32, 48, 64px.

Section Spacing (DOCX twips)

Element	Before	After
H1	480 (24pt)	60 + accent line
H2	320 (16pt)	120 (6pt)
Body paragraph	0	160 (8pt)
Bullet item	0	80 (4pt)
Cover page title	3000 (150pt) push-down	0

Principles

• White space improves reading comprehension by up to 40%
• Proper spacing improves reading accuracy by 20% and reduces eye strain by 30%
• Optimal line length: 60-75 characters (45-80 acceptable range)
• For two-column layouts: 40-50 characters per line

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Anti-Patterns to Avoid

Anti-pattern	Professional approach
Colored fill boxes for info sections	Plain text + thin separator line
Navy fill on total amounts	Bold text + 1.5px border-top rule
More than 3 colors per document	Primary + muted + accent is sufficient
Centered body text	Left-aligned always (except titles/legal headers)
Dense text, no paragraph breaks	Min 1.3-1.5 line-height; clear paragraph spacing
Mismatched font pairing	Serif headings + sans-serif body, or all-serif for legal
Web UI patterns in PDFs (cards, badges)	Line-based layouts, typographic hierarchy
Decorative fills and gradients	White space + type scale + weight contrast
Logo too large or too small	Proportional to header, 300 DPI, clear space
Pure white backgrounds everywhere	Use #F8FAFC off-white for alternating rows and surfaces