Selectstar DESIGN.md

Overview

Visual Theme & Atmosphere

Selectstar (셀렉트스타) is a Korean AI-evaluation and data company whose homepage reads like a serious research-grade product rather than a flashy startup pitch. The atmosphere is calm, institutional, and blue — a light cool-grey canvas (#f8f9fa) carries white content cards while a single confident royal blue (#0c5fdb) does all the work of "action," appearing on every CTA, link, and interactive accent. Text sits in a soft Bootstrap-family neutral ladder — near-black #212529 for the strongest labels, slate #495057 for headings, and a muted grey #6c757d for the vast majority of body copy — which keeps the page quiet, legible, and trustworthy without ever reaching for pure black except on occasional maximum-contrast headings (#000000).

The typographic personality is deliberately restrained and Western-technical: everything is set in Inter (with Noto Sans KR carrying hangul), and the signature move is the hero headline running at an unusually light weight 300 — "Solution for Trustworthy AI" at 72px with tight -1.44px tracking. This whisper-weight display is the opposite of the bold-hero convention; it signals research confidence rather than marketing volume. Below the hero, section headings snap back to weight 600 (48px, -0.96px) so the hierarchy reads as "quiet authority up top, firm structure below." Body text is a generous 16px at a relaxed 1.8 line-height, giving the dense bilingual content room to breathe.

Depth is soft and sparing. Most surfaces are flat white cards on the grey canvas, separated by subtle grey (#e9ecef) fills and light shadows (rgba(0, 0, 0, 0.15) 0px 3px 8px 0px); the floating white pill CTA earns a two-layer ambient shadow. Accents beyond the primary blue are minimal — a lighter blue tint (#5797f6 at 15% alpha) for highlight surfaces, a soft sky cyan (#6ec1e4) for illustration touches, and a deep near-black navy (#00001a) for immersive dark sections. Geometry is conservative: 4px radius on the workhorse buttons and inputs, 10px on cards, and full pills (24px–50px, 9999px) reserved for softer CTAs and circular controls.

Key Characteristics:

• Single royal blue (#0c5fdb) as the only action color — CTAs, links, active nav
• Inter everywhere (Noto Sans KR for hangul); light weight 300 hero at 72px is the signature
• Bootstrap-family neutral ladder: #212529 → #495057 → #6c757d → #adb5bd
• Cool light-grey canvas (#f8f9fa) with flat white cards and light rgba(0,0,0,0.15) shadows
• Conservative geometry: 4px workhorse radius, 10px cards, pill (24px–50px) softer CTAs
• Light-blue tint (#5797f6 @15%) + sky cyan (#6ec1e4) as the only secondary accents
• Deep navy (#00001a) dark sections for brand immersion
• Relaxed 1.8 body line-height for dense bilingual (KO/EN) reading

Primary tasks

• Benchmark model quality with Datumo Eval before shipping
• Commission training data collection and labeling for a model
• Check the conference publications before trusting the data methodology
• Compare the product lines named in the top navigation

Brand Narrative

Selectstar (셀렉트스타) is a Korean AI company built around a single premise: AI is only as trustworthy as the data and evaluation behind it. Founded in 2018 (CEO 김세엽 / Kim Se-yeop), the company began by solving the hard, unglamorous problem of high-quality training-data construction — crowdsourced collection and labeling — and grew into a full "data-centric AI" platform spanning dataset construction, a dataset store, data-voucher programs, and verification consulting. (Founding year and leadership are widely documented public facts; see the sources comment below.)

As large language models moved from research into production, Selectstar extended the same rigor from data into evaluation — the product line marketed globally under the Datumo brand (Datumo Eval for LLM evaluation, plus an AI Red Team offering). The homepage's proof-first framing — "세계 최고 권위 AI 학회 등재" ("published at the world's top AI conferences") — reflects a company that treats academic credibility as a product feature, not a vanity metric.

What Selectstar refuses, visible in its design: the hype aesthetic of consumer AI marketing (no neon gradients, no breathless superlatives) and the intimidating opacity of enterprise software. What it embraces: a clean grey-and-white research canvas, a single trustworthy blue, a light-weight hero that signals confidence over volume, and copy that leads with evidence. The design is the argument — "trustworthy AI" rendered as calm, precise, credible interface.

Principles

1. Trust is the product. Everything ladders up to "Trustworthy AI." UI implication: lead with proof (conferences, benchmarks, scope); keep the interface calm and credible, never salesy.
2. Evidence over hype. The brand cites rather than claims. UI implication: pair every benefit statement with concrete proof; forbid superlatives in copy.
3. One action, one color. Blue (#0c5fdb) means "do this." UI implication: reserve the saturated blue exclusively for CTAs, links, and active states.
4. Quiet confidence. The weight-300 hero says "we don't need to shout." UI implication: lightness at the top, firm weight-600 structure below; restraint reads as authority.
5. Clarity for a technical audience. ML engineers and data teams are peers. UI implication: decode jargon, keep density readable (16px / 1.8 body), and respect the reader's expertise.

Personas

Personas below are fictional archetypes informed by publicly observable Selectstar user segments (ML engineers, enterprise AI leads, data-team managers), not individual people.

정민석, 33, 서울. An ML engineer at a large-model team who needs high-quality Korean evaluation sets. Chose Selectstar because the credibility signals (top-conference publications) told him the data methodology was rigorous, not crowdsourced noise.

Grace Lee, 41, Seoul/San Jose. Head of AI at a mid-market enterprise adopting LLMs. Uses Datumo Eval to benchmark model quality before shipping. Values the calm, evidence-first surface — it reads like a research partner, not a vendor.

한지우, 29, 판교. A data-operations manager coordinating labeling and dataset construction. Appreciates that the product names are plain ("데이터 구축", "데이터셋 스토어") and that the interface stays legible under dense, bilingual content.

Colors

Primary

• Selectstar Blue (#0c5fdb): Primary brand color and the single action color — CTA backgrounds, link text, active nav, interactive accents.
• Blue Hover (#1274e7): Slightly brighter blue for hover states and secondary link emphasis.
• On Primary (#ffffff): White text/icon on blue CTAs and dark surfaces.

Accent

• Accent Blue (#5797f6): Light-blue tint used at ~15% alpha for highlight surfaces and soft callout backgrounds.
• Sky Cyan (#6ec1e4): Soft cyan for illustration touches and decorative accents.

Neutral & Surface

• Pure White (#ffffff): Card surfaces, nav bar, and text on blue/dark.
• Canvas Grey (#f8f9fa): Page background — a cool light grey that segments content into airy zones.
• Surface Alt (#e9ecef): Slightly darker grey for circular icon chips, dividers, and alternating fills.
• Navy Dark (#00001a): Near-black navy background for immersive dark brand sections.

Text Hierarchy

• Ink (#212529): Strongest labels, nav items, dark headings.
• Slate (#495057): Primary heading color for hero and section titles.
• Body Grey (#6c757d): The dominant body-text grey — descriptions, paragraphs, captions.
• Muted Grey (#adb5bd): Faint tertiary text, placeholders, lowest-emphasis labels.
• Pure Black (#000000): Occasional maximum-contrast headings and search-field text.
• Slate 333 (#333333): Text on the floating white pill CTA.

Typography

Font Family

• Sans (primary): Inter — used for all English display, headings, body, nav, and UI labels.
• Korean: Noto Sans KR — carries hangul headings and body where Inter lacks glyphs.
• Weights in use: 300 (hero display), 400 (body, softer CTAs), 600 (headings, nav, primary buttons).

Hierarchy

Principles

• Light hero, firm structure: the 72px weight-300 hero is the defining choice; every headline below it uses weight 600. Lightness at the top signals research confidence, not marketing hype.
• Tight tracking scales with size: -1.44px at 72px, -1.2px at 60px, -0.96px at 48px, -0.72px at 36px; body stays at normal tracking.
• One family, two scripts: Inter for Latin, Noto Sans KR for hangul — they never swap roles.
• Generous body leading: 16px body at 1.8 line-height keeps dense bilingual content readable.

Layout

Spacing System

• Base unit: ~4px, Bootstrap-family scale
• Scale: 4px, 8px, 12px, 16px, 18px, 24px, 38px, 64px
• Notable: button horizontal padding lands at 18px (compact) or 38px (pill CTA); section rhythm at 64px

Grid & Container

• Centered content column with a large hero anchored by the weight-300 headline
• Feature sections use white cards on the grey #f8f9fa canvas, often in 2–3 column grids
• Full-width dark navy (#00001a) sections for product/brand immersion
• Blog uses a search bar plus a card grid of posts

Whitespace Philosophy

• Breathing room: despite being a dense, data-heavy AI product, the marketing surface is airy with generous vertical rhythm.
• Flat segmentation: content separates by background tint (#f8f9fa vs #ffffff) and light shadows rather than heavy borders.
• Restraint with color: white and grey dominate; blue is spent only on the action layer.

Border Radius Scale

• Small (4px): buttons, inputs, badges — the workhorse
• Medium (10px): cards and content containers
• Large (24px–26px): rounded/soft CTAs
• Pill / Full (50px, 9999px): floating CTA, circular icon chips

Responsive Behavior

Breakpoints

Touch Targets

• Primary CTA at 45px height with 18px horizontal padding
• Floating pill CTA at 64px height, unmistakable target
• Nav dropdown items at 45px row height
• Circular icon chips at 50px diameter

Collapsing Strategy

• Hero: 72px headline scales down on mobile, weight 300 maintained
• Nav: horizontal dropdowns collapse to a hamburger menu
• Feature card grids: multi-column → stacked single column
• Dark navy sections maintain full-width treatment, reduce internal padding

Image Behavior

• Product screenshots and illustration accents sit on white cards with soft shadow
• Cards maintain 10px radius across breakpoints
• Sky-cyan (#6ec1e4) illustration touches scale with the section

Elevation & Depth

Shadow Philosophy: Selectstar keeps depth soft and neutral. Shadows are low-opacity black (rgba(0, 0, 0, 0.15)) rather than brand-tinted — the brand identity lives in the blue action layer and the clean grey canvas, not in elevation. Most surfaces stay flat; a shadow appears only to lift interactive chrome (cards, the floating CTA) a small, believable distance off the page. Dark navy (#00001a) sections create depth through background contrast instead of shadow.

Values kept in prose

Measured values the DESIGN.md token grammar cannot carry, kept verbatim:

• shadow.soft: rgba(0, 0, 0, 0.15) 0px 1px 5px 0px
• shadow.card: rgba(0, 0, 0, 0.15) 0px 3px 8px 0px
• shadow.float: rgba(0, 0, 0, 0.05) 0px 2px 6px 0px, rgba(0, 0, 0, 0.1) 0px 8px 19.2px 0px

Motion & Easing

Durations:

Easings:

Motion rules: Motion is functional and restrained — consistent with the calm, research-grade aesthetic. Nav dropdowns and cards fade/rise a few pixels at motion-standard / ease-enter; the floating pill CTA lifts subtly on hover. No bounce or spring — a trustworthy-AI product signals steadiness, not playfulness. Under prefers-reduced-motion: reduce, all transitions collapse to instant and the product remains fully functional.

Components

Buttons

Primary CTA

• Background: #0c5fdb
• Text: #ffffff
• Radius: 4px
• Padding: 9px 18px
• Height: 45px
• Font: 14px Inter weight 600
• Hover: #1274e7
• Use: Header and primary call-to-action — "문의하기" / "CONTACT"

Floating White Pill

• Background: #ffffff
• Text: #333333
• Radius: 50px
• Padding: 16px 38px
• Height: 64px
• Font: 20px Inter weight 400
• Shadow: rgba(0, 0, 0, 0.05) 0px 2px 6px 0px, rgba(0, 0, 0, 0.1) 0px 8px 19.2px 0px
• Use: Prominent floating CTA — "문의하기"

Rounded Subscribe

• Background: #0c5fdb
• Text: #ffffff
• Radius: 26px
• Padding: 10px 24px
• Height: 50px
• Font: 16px Inter weight 400
• Use: Newsletter "Subscribe" / "뉴스레터 구독하기" rounded CTA

Inputs

Search Field

• Background: #ffffff
• Text: #000000
• Radius: 4px
• Padding: 9px 18px
• Height: 47px
• Font: 16px Inter
• Use: Blog search input, paired with a blue #0c5fdb Search button

Cards & Containers

Feature Card

• Background: #ffffff
• Radius: 10px
• Shadow: rgba(0, 0, 0, 0.15) 0px 3px 8px 0px
• Use: Content / feature card sitting on the grey #f8f9fa canvas

Tinted Highlight Surface

• Background: #5797f6
• Text: #0c5fdb
• Radius: 10px
• Use: Light-blue callout surface, rendered at ~15% alpha (base #5797f6)

Badges

Icon Chip (Circular)

• Background: #e9ecef
• Text: #0c5fdb
• Radius: 9999px (full circle)
• Height: 50px
• Use: Circular icon chip / carousel prev-next control

Navigation

• Background: #ffffff
• Text: #212529
• Font: 14px Inter weight 600 (dropdown items), 16px weight 600 (top-level)
• Active: blue #0c5fdb text
• Use: Top horizontal nav with Products / Resources / IR dropdowns ("데이터 구축", "데이터셋 스토어", "검증 솔루션 Datumo Eval", "AI 레드팀")

Verified: 2026-07-02 (omd:add-reference CREATE — Tier 1 live inspect, 2 surfaces) Tier 1 sources: https://selectstar.ai/ , https://blog.datumo.com/ Tier 2 sources: getdesign.md/selectstar — no entry ("0 DESIGN.md files"); styles.refero.design/?q=selectstar — no specific entry (generic browse grid) Conflicts unresolved: none

States

Do's and Don'ts

Do

• Use the single royal blue (#0c5fdb) for every action — CTAs, links, active nav
• Set the primary hero light (Inter weight 300) at large sizes for research-grade confidence
• Use weight 600 for all headings below the hero and for primary buttons
• Keep body text in muted grey (#6c757d) at 16px / 1.8 line-height
• Separate content with the grey canvas (#f8f9fa) and light rgba(0,0,0,0.15) shadows
• Use 4px radius on workhorse buttons/inputs, 10px on cards
• Reserve pills (24px–50px) for softer CTAs and circular icon chips
• Use Inter for Latin and Noto Sans KR for hangul

Don't

• Introduce a second saturated accent — blue is the only action color
• Set the hero in a heavy weight — the weight-300 lightness is the signature
• Use pure black (#000000) for body text — the neutral ladder tops out at #212529
• Add heavy or colored drop shadows — depth stays soft and neutral
• Spread blue across decorative elements — keep it on the action layer
• Use large pill radius on content cards — cards are 10px, not rounded
• Apply positive letter-spacing on display headings — Selectstar tracks tight

Voice & Tone

Selectstar's voice is credible, precise, and reassuring — the register of a research-grade AI company that sells trust, not hype. The hero line "Solution for Trustworthy AI" sets the tone: a plain, confident claim rather than a superlative. Korean copy is equally measured, naming what the product does ("AI 개발을 가속하세요" — "Accelerate your AI development") and backing it with proof ("세계 최고 권위 AI 학회 등재" — "Published at the world's top AI conferences"). The audience is technical — ML engineers, data teams, enterprise AI leads — so the voice respects the reader as a peer and leads with evidence.

Voice samples (verbatim from live surfaces):

• "Solution for Trustworthy AI" — hero H1, selectstar.ai (mission-framed). (verified live 2026-07-02)
• "AI 개발을 가속하세요" — section H2, selectstar.ai (benefit claim). (verified live 2026-07-02)
• "세계 최고 권위 AI 학회 등재" — section H2, selectstar.ai (proof / credibility). (verified live 2026-07-02)
• "Data-Centric AI Insights: Trends, Innovations, and Practical Advice" — blog page title, datumo.com/blog. (verified live 2026-07-02)

Forbidden register: hype superlatives ("revolutionary", "game-changing"), fear-based AI-risk marketing, undefined jargon left unexplained, exclamation-heavy urgency.

Agent Prompt Guide

Quick Color Reference

• Primary / CTA / link: Selectstar Blue (#0c5fdb)
• Hover: Blue Hover (#1274e7)
• Accent tint: Accent Blue (#5797f6) at 15% alpha
• Decorative cyan: Sky (#6ec1e4)
• Background canvas: Canvas Grey (#f8f9fa)
• Cards / nav: Pure White (#ffffff)
• Surface alt / chips: #e9ecef
• Headings: Slate (#495057) / Ink (#212529)
• Body text: Body Grey (#6c757d)
• Muted: #adb5bd
• Dark section: Navy (#00001a)

Example Component Prompts

• "Create a hero on a light grey #f8f9fa canvas. English headline at 72px Inter weight 300, line-height 1.25, letter-spacing -1.44px, color #495057. Below it a primary blue CTA: #0c5fdb background, white text, 4px radius, 9px 18px padding, 14px Inter weight 600 — hover #1274e7."
• "Design a feature card: white #ffffff background, 10px radius, shadow rgba(0,0,0,0.15) 0px 3px 8px. Title 36px Inter weight 600, letter-spacing -0.72px, #212529. Body 16px Inter weight 400, #6c757d, line-height 1.8."
• "Build a blog search bar: white #ffffff input, 4px radius, 9px 18px padding, 16px Inter, black #000000 text, paired with a #0c5fdb Search button (white text, 4px radius)."
• "Create top nav on white: Inter 16px weight 600 top-level items in #212529, dropdown items 14px weight 600, active item in blue #0c5fdb. Primary blue CTA 'CONTACT' right-aligned."
• "Design a dark section: #00001a background, white text. Display heading 60px Inter weight 600, letter-spacing -1.2px. Body 16px, rgba(255,255,255,0.7)."

Iteration Guide

1. Blue (#0c5fdb) is the single action color — never spread it decoratively
2. Hero is Inter weight 300; everything else weight 600 (headings) or 400 (body)
3. Body text is muted grey #6c757d at 16px / 1.8, never pure black
4. 4px radius for buttons/inputs, 10px for cards, pills for soft CTAs and circular chips
5. Depth is soft neutral shadow (rgba(0,0,0,0.15)), never brand-tinted
6. Canvas is grey #f8f9fa; cards are white #ffffff
7. Noto Sans KR for hangul, Inter for Latin

Governance

Known Gaps

• Contrast, tint-surface. Text #0c5fdb on #5797f6 measures 1.95:1, below the WCAG AA 4.5:1 minimum for normal-size text. Recorded as measured, not adjusted.