Design System Inspiration of Studysapuri (スタディサプリ)

1. Visual Theme & Atmosphere

Studysapuri is Recruit's online learning service — recorded lectures from well-known cram-school teachers, for students from elementary school through university entrance exams, and English for adults. It began in an internal business contest: in March 2012 the idea won the grand prize of Recruit's New RING competition, and in October 2012 it launched as 受験サプリ ("exam supplement"), an online prep school aimed at a specific problem the company names on its own history page — that family income and region shape who gets into university. In March 2013 it dropped to ¥980 a month.

The "supplement" name multiplied: 勉強サプリ for grades 4–9 in 2015, then 英語サプリ and 英単語サプリ. In April 2015 Recruit bought Quipper, a London-founded learning company, and in February 2016 every サプリ service was folded into one brand, スタディサプリ. A teachers' edition followed that April, and in 2017 Recruit's university-guide brand リクナビ進学 was renamed スタディサプリ進路 — the learning brand absorbing the older information business.

The hub page reads like that history: a deep sapuri blue #0b41a0 carries the name and every primary action, a charcoal-navy #24243f carries the text, and a set of bright secondary colours — sky #0ca5e6, turquoise #3ec1bd, pink #de30ca — marks the separate services. Surfaces are white and pale blue. Set mostly at 14px.

Three things make it worth reading:

• Two colour generations live side by side. --cl_sapuri_blue (flat, underscore) and --cl-text-primary-darkblue700 (semantic, hyphen) are the same #0b41a0.
• School subjects have colours. --cl-subject-math #436fba, -english #f56ca3, -japanese #e7cc4c, -science #b551e0, -social #33aab2, -informatics #69cbf5, -practical #8eaee5.
• Hover is a fade, and every control fades by a different amount — 0.9, 0.8, 0.7, 0.5.

Primary tasks

• Choose a school level or grade and find its course.
• Start the 14-day free trial; sign in.

2. Color Palette & Roles

Measured with getComputedStyle on studysapuri.jp. About 190 custom properties resolve. The page is built with Panda CSS — --made-with-panda is literally "🐼" — and Panda's own scaffolding is excluded: --breakpoints-* and --sizes-breakpoint-* (5 each) and 36 utility variables (--blur, --translate-x, --skew-y, --gradient-from-position …). What remains is Studysapuri's: 45 --cl_*, 60 --cl-*, and about 37 component-scoped values.

Sapuri blue — the brand and the action

• Primary (#0b41a0) — --cl_sapuri_blue, and in the newer layer both --cl-text-primary-darkblue700 and --cl-background-primary-darkblue700. The label on the sign-up button, the login link and the grade pills.
• Primary Dark (#093788) — --cl_sapuri_blue_plus / -darkblue800.
• Primary Light (#275ab3) — --cl-background-primary-darkblue600.

The flat layer has a five-step naming habit: _minus2 #4978c2 · _minus #3c67b3 · base · _plus #093788 · _plus2 #05266f.

Ink

• Foreground (#24243f) — --cl_black / --cl-text-primary-gray900. Body text. Of text elements on the page, 105 are white (on the dark header, footer and blue bands), 41 are this ink and 35 are sapuri blue — a hub page is mostly labels and links, so the ink leads the blue only narrowly.
• Text Secondary (#808d96) — --cl-text-secondary-gray500.
• Text Spot (#adb8be) — --cl-text-spot-gray400.

Action colours — the semantic layer

--cl-action-* is where the newer layer puts interactive colour, in 500/600/700 triples:

• Action Primary (#0ca5e6) — --cl-action-primary-skyblue600, with #30b6f0 (500) and #0c8dd8 (700).
• Action Secondary (#3ec1bd) — --cl-action-secondary-turquoise600, with #64cdca (500) and #33aab2 (700).
• Spot — Spot Gray #67717a (the most-painted non-white background, on 10 elements) · Spot Pink #de30ca · Spot Purple #aa30de · Spot Violet #b551e0.

Note the naming: the semantic layer calls sky blue "action primary", while the brand's own blue is filed under text and background. On the measured controls the sapuri blue does the primary work; the sky blue appears on 8 text elements.

• Ultra Blue (#1c80e7) — --cl_ultra_blue / --cl-background-primary-ultrablue600.

Surfaces and lines

Canvas (#ffffff) · Surface Gray (#fafafa, -gray50) · Surface Sky (#f0f8ff, -skyblue50) · Surface Sky Strong (#e1f4ff, -skyblue100) · Line (#e9eeef, --cl-line-primary-gray100).

Surface Tint (#e3eefa) — the fill on the grade pills. It is not a token: neither layer contains it; it is written directly.

Sales promotion

A separate group for campaign colour, each with pale 200-step backgrounds: Promo Red #f0307d · Promo Pink #f56ca3 · Promo Yellow #fcda21 · Promo Orange #ff8c5a.

Subjects

--cl-subject-math #436fba · -english #f56ca3 (the promo pink) · -japanese #e7cc4c · -science #b551e0 (spot violet) · -social #33aab2 (turquoise 700) · -informatics #69cbf5 · -practical #8eaee5. Three reuse a colour from elsewhere in the set; four are unique to the subject group.

Things recorded as found

• --cl_pink_week #b433c2 sits beside --cl_pink_strong — "week" where the siblings say weak.
• The course-card tokens --cl_course_header and --cl_course_bg write three hexes directly — #0D3F94, #31938E, #2BAAA3 — that belong to neither layer.

3. Typography Rules

Font family

Open Sans is the loaded webfont — 400 and 700, self-hosted from /_next/static/media/ (no request to Google's font CDN), declared through --font_open_sans as "Open Sans", "Open Sans Fallback". It is a Google-published open face, recorded as what is served, not as a proprietary brand face. Open Sans has no Japanese glyphs; Japanese text falls through the stack to operating-system faces (Hiragino Sans, Meiryo, MS PGothic), which are not recorded as brand fonts.

StudySapuriNumbers — a numerals face of the brand's own — is declared: --font_ss_numbers names it, and an @font-face points at StudySapuri_Numbers-Regular.otf on assets.studysapuri.jp. It did not load on the measured page, so there is no specimen and it is not a token. It exists; it was not seen rendering.

Scale

Rendered on text elements: 14px ×104 · 12px ×61 · 16px ×12 · 11px ×6 · 20px ×5 · 13px ×5 · 24px ×2 · 19px ×2 (the sign-up label). Component-scoped --heading-font-size takes 14/16/18/20, --font-size 10/12/14.

4. Component Stylings

Four controls measured, every state on its own page load, focus read before the mouse moved.

Hover is a fade — and each control has its own depth

No measured control changes colour on hover. Instead each fades, over opacity 0.3s:

Pressed matches hover on all four. The white text links in the dark header change none of background, text colour, border, shadow, outline, transform or opacity on hover; whether they underline was not read, so they are not declared.

• Sign-up — #ffffff, #0b41a0 label at 19px/700, 10px radius, 69px tall, and the page's one offset shadow, rgba(0,0,0,0.15) 0 3px 6px.
• Login — transparent, #0b41a0 12px/700, 32px tall.
• Audience card — #ffffff, #24243f 14px, 8px radius, a centred rgba(0,0,0,0.1) 0 0 10px shadow.
• Grade pill — #e3eefa, #0b41a0 14px/700, 8px radius, 60px tall.

Focus is the browser's

Every control shows outline: rgb(0, 95, 204) auto 1px under :focus-visible — Chrome's default ring, unchanged. No focus colour is recorded.

Radius

Rendered: 8px ×11 (cards, pills) · 10px (the sign-up button, and a split control's two halves as 10px 0 0 10px / 0 10px 10px 0) · 1440px ×3 (circles). The component tokens --buttonSolid-borderRadius and --buttonOutline-borderRadius are both 4px, and no measured control renders at 4px — they govern buttons not on this page.

Also excluded as not Studysapuri's control: a course button that renders #efefef with #000000 text at 13.33px — the browser's own <button> defaults, left unstyled behind an image.

5. Layout Principles

• The header is a token: --header-height 54px, --header-container-size 1230px.
• Carousels carry their own spacing: --slide-spacing 8/16/20/24/32/36px and --slide-size per slider. No global spacing scale is published.
• Illustration offsets are tokens too: --illustHeightPc / --illustHeightSp, --illustTopPosPc 7px — the page tunes its artwork separately for desktop and phone.

6. Depth & Elevation

Two shadows on the page: rgba(0,0,0,0.1) 0 0 10px on cards (centred, soft) and rgba(0,0,0,0.15) 0 3px 6px on the sign-up button (offset down). No shadow token is published.

7. Do's and Don'ts

Do

• Use #0b41a0 for the primary label and #24243f for body text.
• Signal hover with opacity, not a colour change — and fade less on large targets than on small links.
• Give each school subject its own colour from the --cl-subject-* set.

Don't

• Don't count --breakpoints-*, --sizes-* or the utility variables as Studysapuri's — they are Panda CSS.
• Don't use StudySapuriNumbers as though it rendered; it was declared and not loaded.
• Don't take the unstyled #efefef course button as a component.

8. Responsive Behavior

Not measured. Desktop 1440×1000 only. The Pc/Sp token pairs show the page is tuned for phones separately.

9. Agent Prompt Guide

Quick Color Reference

#0b41a0 primary · #24243f ink · #808d96 secondary text · #0ca5e6 sky · #3ec1bd turquoise · #de30ca pink · #67717a spot gray · #ffffff / #fafafa / #f0f8ff / #e1f4ff surfaces · #e9eeef lines · subjects #436fba #f56ca3 #e7cc4c #b551e0 #33aab2 #69cbf5 #8eaee5

Example Component Prompts

• "A 69px sign-up button: white, #0b41a0 19px/700 label, 10px radius, rgba(0,0,0,0.15) 0 3px 6px shadow; hover fades to 0.9 over 0.3s."
• "A grade pill: #e3eefa, #0b41a0 14px/700, 8px radius; hover fades to 0.7."

10. Voice & Tone

Not assessed as authored voice. 1,832 characters on the measured surface, mostly school levels, grades and course names.

11. Brand Narrative

Studysapuri started as a price and access argument — famous teachers' lectures, unlimited, for ¥980 a month, so that where a student lives and what the family earns matter less. The brand then grew by accretion: a サプリ for each audience, until 2016 folded them into one name and 2017 folded Recruit's university-guide brand in too.

The token set carries that layering. An older flat palette named for the brand (--cl_sapuri_blue) survives beside a newer semantic one organised by role, and the newer one adds what a multi-service learning brand needs — a colour per school subject, a separate campaign palette — while keeping the sapuri blue as the one colour that means Studysapuri.

12. Principles

• One blue means the brand. Everything else is a service, a subject or a campaign.
• Colour a subject, not just a state. Math is #436fba wherever it appears.
• Fade to respond. Hover changes opacity, never hue.

13. Personas

Not researched. No persona claim is made from a UI capture.

14. States

Four components, every state measured. Hover and pressed are opacity fades — 0.9, 0.8, 0.7, 0.5 — with no colour change. Focus is the browser's auto ring on all of them. No disabled state was observed.

15. Motion & Easing

Measured controls compute transition: background-color 0.3s, color 0.3s, opacity 0.3s; only the opacity step is used. Separately the set declares --transition-prop: opacity, --transition-duration: 1s and --transition-easing: ease-in — a slower fade whose target on the page was not identified.

Tier 1 sources: https://studysapuri.jp/ (live service hub — about 190 custom properties read via getComputedStyle, Panda CSS scaffolding excluded; four controls measured at rest, hover, pressed and focus, captured 2026-09-23); https://studysapuri.jp/zz-this-does-not-exist (nonsense-path control — a real HTTP 404 with a 112-character body, establishing the host is not a catch-all, captured 2026-09-23); https://brand.studysapuri.jp/about/history/ (first-party brand history — New RING grand prize 2012-03, launch as 受験サプリ 2012-10, ¥980/month 2013-03, Quipper acquisition 2015-04, unification as スタディサプリ 2016-02, read 2026-09-23)

Regional sources: https://resemom.jp/article/2016/02/26/29934.html (リセマム, 2016-02-26 — reports the unification of 受験サプリ and the other サプリ services under スタディサプリ); https://diamond.jp/articles/-/148799 (ダイヤモンド・オンライン — adoption beyond students, by teachers and working adults)