Datum
Design system · Rev A
A design system for civil engineering, built for the field and the model

Built to
tolerance.

Datum treats every screen like a drawing sheet: a fixed grid, a title block, dimensions you can trust. Two accents carry the firm's two worlds — survey orange for what is poured and bolted, laser cyan for what is measured and modelled.

44 000 23 800 clear span 12 000 SCAN 2026-08-14 · Δ 3 mm SECTION A–A · SCALE 1:200
0+00

Foundations

Four principles decide every choice below. If a new pattern can't cite one, it doesn't ship.

Everything is a drawing

Screens sit on a visible grid, carry a title block, and dimension what they show. A client should feel the same rigour on the website as on the stamped set.

Two accents, two worlds

Survey orange marks the physical: sites, crews, safety, primary actions. Laser cyan marks the digital: sensors, models, live data. Never mix them on one element.

Numbers are the brand

Tolerances, spans, loads, dates. Numbers are set in mono, tabular, with units. They are never rounded to sound impressive.

Cut, don't mould

2 px radii, square line caps, hard borders. Surfaces read as plate steel and cast concrete, not soft plastic. Shadows are almost never used.

1+00

Colour

Neutrals come from materials on site. The two accents are the only saturated colours allowed outside status states.

Concrete#E9E7E2Page ground. Cured, slightly warm grey — not cream.
Formwork#DDD9D2Panels, wells, disabled fills.
Blueprint#12263AInk. Text, primary buttons, dark surfaces.
Steel#5B6770Secondary text, rules, dimension lines.
Galvanised#9AA3AAHairlines, disabled text.
Survey#F26B1DField accent. Stake paint, hi-vis, action.
Laser#2FB8CFDigital accent. Total station beam, LiDAR, live data.
Status#3E8F5A · #D9A21B · #C23B3BPass, watch, fail. Only on tags and charts.

Field

Survey orange. Used on light surfaces, sparingly — a page should have one orange primary action and a handful of orange marks.

  • Primary CTAs on public pages
  • Site, crew, safety, schedule
  • Dimensions on drawings
  • Progress along a chainage

Digital

Laser cyan. Lives on Blueprint navy — dashboards, monitoring, model viewers. Never used as a button on light backgrounds (contrast fails).

  • Sensor readings, live tags
  • Point clouds, scan overlays
  • Focus rings across the system
  • Links on dark surfaces

Theme diff — light vs dark

Ink and ground swap. The two accents keep their hex values but trade roles: on a dark ground, laser cyan becomes the primary action and survey orange steps back to marking. Status colours are lifted for contrast. Everything else — type, spacing, radii, rules — is identical.

Token / roleLightDark
Page ground#E9E7E2 Concrete#0F1F30 Night pour
Panel / surface#FFFFFF#16304A
Wells, disabled fill#DDD9D2 Formwork#1B3550
Ink / primary text#12263A Blueprint#E9E7E2 Concrete
Secondary text, rules#5B6770 Steel#9AA3AA Galvanised
Hairlines#9AA3AA#4B5A68
Primary action#F26B1D Survey#2FB8CF Laser
Secondary accentLaser (dark surfaces only)Survey (marks, tags)
Status pass / watch / fail#3E8F5A · #D9A21B · #C23B3B#5FB57C · #E0B03A · #E36B6B
Focus ring#2FB8CF#2FB8CF (unchanged)
Sheet gridrgba(18,38,58,.06)rgba(233,231,226,.06)
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Typography

A condensed display face with road-sign lineage, a sober body face, and a mono for anything that is a measurement.

Display
Barlow Condensed 700
uppercase · lh .92 · ls .01em
64–96 px
Load rated
to 2050
Heading 2
Barlow Condensed 600
uppercase · 40 px

Stormwater retrofit, Ward 6

Heading 3
Barlow Condensed 600
uppercase · 20 px · ls .03em

Geotechnical summary

Lede
IBM Plex Sans 400
20 px · lh 1.4

We design, model, and inspect the infrastructure a city depends on — and publish the numbers.

Body
IBM Plex Sans 400
16 px · lh 1.55 · max 68ch

The pier caps were scanned at 2 mm resolution on 14 August and compared against the federated model. Deviations exceeding 5 mm were flagged for the site engineer before the next pour.

Data
IBM Plex Mono 400/500
12–14 px · tabular

STA 12+40.00 · EL 214.62 m · Δ +0.003 · N 5 128 934.21 E 341 208.77

Eyebrow / label
IBM Plex Mono
12 px · caps · ls .08em
Drawing set · Issued for construction
Do

Set numbers, coordinates, IDs and dates in mono. Keep display type to two or three words per line. Use sentence case in body and UI.

Don't

Don't run body copy in the condensed face. Don't letter-space uppercase display beyond .02em. Don't use italics anywhere — the system has none.

3+00

Grid & spacing

Everything sits on an 8 mm module — 8 px on screen. The page background shows a 64 px sheet grid; components snap to it.

8pxBase module
64pxSheet grid
12 / 24colLayout, 24 px gutter

Space tokens: 8 · 16 · 24 · 32 · 48 · 64 · 96. Sections use 64, panels use 24, controls use 8/16. Content measures 1180 px max; text 68ch max. Breakpoint at 800 px collapses multi-column layouts to one.

4+00

Components

Enough to build a marketing site, a project dashboard, and a field-inspection form without inventing anything.

Buttons — light surface

One orange button per view. Labels are verbs. Condensed caps, 16 px, 2 px radius.

Buttons — dark surface

Live · 3 sensors

On Blueprint, cyan takes the primary role. Orange is not used on dark backgrounds.

Form fields

mm
Clear span between bearings.
Use YYYY-MM-DD. Month must be 01–12.

Status tags

PassWatchFailLiveOn site

Progress — chainage

0+005+0010+0015+0020+00

Progress is shown as distance along a station line, not a percentage. The diamond marks the current head.

Project · Bridges

Millrace Crossing

Two-span steel girder replacement
Span
44 000 mm
Client
County DOT
Status
On site
Monitoring · Pier 2

Settlement

Tilt + strain, 15 min interval
Last
+0.3 mm
Limit
5.0 mm
State
Pass
Document

Set C-201

Issued for construction, Rev 3
Sheets
42
Issued
2026-08-11
Stamp
PE #48812
StationElementScan ΔToleranceResult
12+40.00Pier cap P2+3 mm±5 mmPass
12+62.50Bearing seat B4−6 mm±5 mmFail
13+05.00Deck edge, west+4 mm±5 mmWatch

Iconography

Bridge
Survey
Site
Sensor
Model

40 px grid, 1.5 px stroke, square caps, mitre joins. Drawn like a drafting symbol, not an emoji. A single accent stroke allowed.

Motion

One page-load sequence: eyebrow, headline, lede rise 8 px and fade in over 500 ms, staggered 100 ms, easing cubic-bezier(.2,.7,.2,1). Live tags pulse. Nothing else moves. Reduced-motion turns everything off.

Hover states change colour only (150 ms). No lifts, no glows, no parallax.

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Voice

Write like a stamped drawing note: specific, active, measured. Confidence comes from numbers, not adjectives.

Do

"Scanned 14 Aug. Pier cap P2 within 3 mm of model."

"Request a proposal" · "Download the set" · "Open live monitoring"

Errors: "Month must be 01–12."

Don't

"Leveraging cutting-edge technology to deliver world-class infrastructure solutions."

"Learn more" · "Submit" · "Get started"

Errors: "Oops! Something went wrong."