design-philosophy

# VS Code Design Philosophy This skill is the **canonical VS Code design philosophy** — the single source of truth for how we reason about UI, for both developers and agents. As more and more of the UI is implemented via agents and tooling, the pixels increasingly take care of themselves, and the scarce, human part becomes the design judgment behind them. This is about *shifting left* - talking about UI in design terms, not pixels, and having that conversation early. When something looks off, "this is 8px, should be 6px" fixes one number; "this surface is rounded at the wrong *elevation tier*" names the rule, so the fix lands everywhere and we catch it on a mockup or screenshot rather than in code review. The aim is to agree on *what the UI should be and why*, in language a designer and an engineer can share - the implementation (which token, which file) tends to follow once the design is settled. --- ## How to read this: three layers The hardest part of any design language is getting from *"this feels off"* to a clear, shared fix everyone agrees on. This bridges that in three steps, each explaining the one below it: | Layer | What it is | Example | |-------|------------|---------| | **Values** | what we want people to *feel*, and why it's at stake | *Focused* | | **Principles** | evaluative rules you can hold a design up against, phrased as a question | *"One thing leads; the rest supports" - where does the eye go first?* | | **Moves** | the concrete mechanics, each with a rule for *which one and why* | *demote the secondary panel to a recessed background token / a quieter type role* | Read top-down when you're learning the system, and bottom-up when you're fixing a bug: name the **feeling**, find the **principle** it breaks, then reach for the **move** that restores it. > **Worked example - a busy panel** > > - **See:** a panel feels busy and keeps pulling your eye off the editor. > - **Feeling:** not *Calm*, not *Focused*. > - **Principle:** breaks *Quiet at rest* (it carries a permanent fill it shouldn't) and *One thing leads* (secondary chrome competing with the editor). > - **Move:** drop the panel to a recessed/transparent background token, reveal its border only on hover, and demote its labels to a quieter type role. --- ## The values: what we design for These four values name what we want people to *feel* using VS Code - they're the top layer, the thing every principle and move below is ultimately in service of. Learn them and you can describe almost any bug. Each is a *feeling* the UI should give; each is upheld by one or more **principles** below. Reach for the value first, the principle second, the move last. | Value | Means | When it's broken it feels… | Principles | |------|-------|----------------------------|------------| | **Calm** | quiet at rest, uncluttered; room to breathe; soft, not sharp; plain-spoken and human | busy, noisy, cramped, jagged, cryptic, shouty | 1, 2, 3 | | **Focused** | clear hierarchy; one thing leads, the rest supports | flat, samey, the eye has nowhere to go | 4, 5 | | **Consistent** | everything sits on the same ramps and tiers | random, off-grid, drifting | 5, 6 | | **Delightful** | small moments that *do a job* - guide, confirm, orient | lifeless, abrupt, or gimmicky | 7 | > Say *"this feels noisy, it's not **Calm**"* before *"the background should be transparent."* The value points everyone at the same principle. ### Why these four? It's fair to ask: who would ever *want* a UI that isn't calm, focused, consistent, and delightful? That's exactly the point. These aren't differentiators we're claiming over other products - they're the qualities most **under threat in a tool like ours**, and naming them is how we defend them. We chose them because they're the values VS Code is structurally inclined to *lose*: - **Calm** is the first casualty of an IDE. VS Code is information-dense and lived in for hours; every feature team has a good reason to add one more affordance, and the sum is noise. Calm is the value that pushes back on our own gravity. - **Focused** matters because our surfaces are *deep*. A screen full of equally-weighted, equally-valid controls is the default failure mode of a power tool. Naming focus forces us to decide what leads. - **Consistent** has the largest surface area to defend. VS Code is built by many hands over many years; drift is the natural state. Consistency is less an aspiration than a maintenance discipline. - **Delightful** is the one we deliberately **ration**. It earns its place only by doing a job (Principle 7). We name it not to add more polish but to keep it honest, so delight guides and confirms rather than decorates. And each value names a real **tension**, not a free win - which is what makes it a choice worth stating rather than a platitude: - **Calm** trades against **density** - how much do we surface at rest? - **Focused** trades against **equal access** - what do we demote so one thing can lead? - **Consistent** trades against the **genuinely special case** - when is a difference earned rather than drift? - **Delightful** trades against **restraint** - when does a flourish cross into noise? So the useful question isn't *"would we ever not want these?"* but *"which one is this surface trading away, and did we mean to?"* When a value really must yield - say, a critical warning that *should* break calm to seize attention - that's a deliberate, named exception, not a reason to drop the value. --- ## Principles Principles are **evaluative**: each one is a question you can ask of any surface, and the answer tells you whether the design is right - independent of any pixel value. They're grouped by the value they uphold. --- ### Calm #### 1. Quiet at rest, present on intent > **Ask:** *is anything shouting when nothing is happening?* Chrome should recede until you engage it. A surface carrying a permanent fill, border, or focus ring it hasn't earned is competing with the user's content for attention it doesn't need. The modern look is **restrained**: things reveal themselves *on intent* - hover, focus, interaction - and sit quietly otherwise. When this is wrong it sounds like *"this is loud at rest / should be quiet until hover"* or *"the focus ring is firing on click"* - a behavioral description, not a color value. *Carried out by:* [reveal-on-intent behaviors](#reveal-on-intent), [one stroke](#one-stroke), [theme color](#theme-color). #### 2. Room to breathe > **Ask:** *does this feel cramped, tight, or jagged?* Calm UI is generous and soft. Space isn't wasted; it's what lets the eye rest and groups things without drawing a single line. Edges are rounded rather than sharp. When a surface feels boxed-in or busy, the fix is usually more breathing room on the spacing ramp, not smaller content. *Carried out by:* [the spacing ramp](#spacing-ramp), [elevation tiers](#elevation-tiers) (rounded, not sharp). #### 3. The interface explains itself, plainly and kindly > **Ask:** *could someone understand this at a glance, without guessing?* The UI should read like a person talking. Prefer a word to a mystery glyph; write in sentence case; keep the tone human. A lone unlabeled icon, or a Title-Cased Marketing Headline, makes the user work harder than they should - never cryptic, never shouting. *Carried out by:* [words & casing](#words-casing). > **Worked example - a boxed-in toolbar** > - **See:** a toolbar sits on a solid filled bar, separator lines between every button, the buttons pushed up against each other. > - **Feeling:** not *Calm* - busy and boxed-in. > - **Principle:** breaks *Quiet at rest* (the fill and separators are permanent > chrome that hasn't earned its place) and *Room to breathe* (buttons jammed together). > - **Move:** let the bar read transparent at rest, drop the separators (one stroke - and here the answer is *no*), and space the buttons out on the ramp. ### Focused #### 4. One thing leads; the rest supports > **Ask:** *where does the eye go first - and is anything secondary competing with it?* Every view should have a clear **center of attention** - the one thing the eye should land on first. Keep secondary information *out* of that spot: demote it with a quieter type role, a recessed surface, or a smaller icon, so the thing that matters leads and everything else supports it. A view where everything has equal weight is *flat* - the eye has nowhere to go. *Carried out by:* [type roles](#type-ramp), [elevation tiers](#elevation-tiers), [icon size by context](#icon-sizes). #### 5. Elevation is encoded, not eyeballed > **Ask:** *does this surface's roundness match how far it floats above what's beneath it?* How rounded - and how raised - a surface is *means something*: it tells you where the surface sits in the stack. A floating overlay reads as more rounded than a control sitting flat inside a pane. Radius is chosen by the surface's role in the hierarchy, never by taste. (This serves both **Focused** and **Consistent**.) *Carried out by:* [elevation tiers](#elevation-tiers), [reveal-on-intent](#reveal-on-intent) (scroll shadows). > **Worked example - a flat settings row** > - **See:** a settings row shows its label, its help text, and a "Reset" action all at the same size and weight. > - **Feeling:** not *Focused* - flat; the eye doesn't know where to land. > - **Principle:** breaks *One thing leads* - nothing is the center of attention. > - **Move:** lift the label to the leading type role, demote the help text to `body2`, and make "Reset" a quiet secondary action so the row reads top-down. ### Consistent #### 6. Sameness signals sameness > **Ask:** *do two like things look identical - and is any difference here intentional?* Equivalent elements must look equivalent, because they pull from the same named scale. When two similar things differ, that difference should *mean* something; accidental drift is the enemy. This is why every size, radius, weight, and color is a **named token with a role**, not a literal - the literal is only ever a stand-in for the token it lands on. *Carried out by:* every move below - they *are* the shared scales. See especially [design tokens](#design-tokens), [the spacing ramp](#spacing-ramp), [the type ramp](#type-ramp), [icon sizes](#icon-sizes), [one stroke](#one-stroke). > **Worked example - two mismatched dialogs** > - **See:** two dialogs open side by side; one has 8px corners, the other 6px - > both are floating overlays. > - **Feeling:** not *Consistent* - the UI feels like it's drifting. > - **Principle:** breaks *Sameness signals sameness* (two equivalent surfaces look > different for no reason) and *Elevation is encoded* (an overlay belongs on the > Outer tier). > - **Move:** point both at the Outer radius token; the 6px was a literal someone > typed instead of naming the tier. ### Delightful #### 7. Delight earns its keep > **Ask:** *what does this help the user do?* Motion, reveals, and finishing touches are welcome - but each must **do a job**: guide the eye, confirm an action, orient the user, or smooth a jump. If there's no answer to the question, it's decoration, and decoration reads as noise (back to **Calm**). Keep it subtle, short, and interruptible; honor `prefers-reduced-motion`; never animate for its own sake. A delight bug sounds like *"this transition is doing nothing for me"* (cut it) or *"this jump is disorienting - it needs a functional transition"* (add one) - not a duration or easing value to fiddle with. *Carried out by:* [reveal-on-intent behaviors](#reveal-on-intent). > **Worked example - a bouncing panel** > - **See:** a side panel slides in with a 600ms bounce every time you toggle it. > - **Feeling:** not *Delightful* (gimmicky) and not *Calm* (slow and shouty). > - **Principle:** breaks *Delight earns its keep* - the bounce isn't doing a job, > and the toggle is already obvious. > - **Move:** if nothing needs orienting, cut the animation; if the panel's arrival > genuinely needs explaining, replace it with a short, subtle, interruptible fade > that honors `prefers-reduced-motion`. --- ## The moves: the mechanical toolbox Moves are the **concrete mechanics** - the tokens, ramps, and tiers. On their own they're just lists of allowed values; what makes each one usable is the **decision rule** that says *which value, and why*, plus the **principle** it serves. When you reach for a move, lead with the rule, not the literal. This is the one section that touches implementation - and even here, the goal is to keep the *conversation* about design. Treat the Moves as the **shared vocabulary that lets an agreed design be built consistently**, not as the opening move in a review. Reach for them *after* you've named the feeling and the principle, never instead of it. The size and font tokens live in [`baseSizes.ts`](../../../src/vs/platform/theme/common/sizes/baseSizes.ts); the full reference is in [design-tokens.instructions.md](../../instructions/design-tokens.instructions.md). <a id="design-tokens"></a> ### Tokens are the source of truth, not the pixel Design-system spacing, radii, type roles, and colors should use a named token or ramp where one exists. Raw literals remain valid for structural measurements. - **Decision rule:** when something looks wrong, find the token it should be expressing and reason about *that* - not the literal. - **Serves:** *Sameness signals sameness* (6). > An `8px` corner isn't "8px." It's an **Outer surface radius** that someone > typed as a literal. Name the role and the fix follows. <a id="elevation-tiers"></a> ### Elevation tiers - round by role, not by literal Corner radius encodes **how far a surface floats above the one beneath it**. Every rounded thing belongs to exactly one tier: | Tier | Radius | Token | What it is | |------|--------|-------|------------| | **Control** | 4px | `--vscode-cornerRadius-small` | interactible elements - buttons, inputs, list rows, tabs | | **Inner** | 6px | `--vscode-cornerRadius-medium` | non-control containers sitting *inside* a surface | | **Outer** | 8px | `--vscode-cornerRadius-large` | floating / overlay surfaces - menus, hovers, dialogs, toasts | Pills (radius ≈ half the height) are **fully round** (`--vscode-cornerRadius-circle`), not "a big radius." - **Decision rule:** pick the tier by the surface's **role in the stack**, not by how the corner looks. A bug here sounds like *"this overlay is rounded at the control tier,"* never *"this needs more border-radius."* - **Serves:** *Elevation is encoded* (5), *Room to breathe* (2). <a id="spacing-ramp"></a> ### The spacing ramp - on-scale or off-scale Padding, margin, and gap come from the **spacing ramp** (0, 2, 4, 6, 8, 10, 12, 16, 20, 24, 28, 32, 36, 40). - **Decision rule:** a value either lands *on* the ramp or it doesn't. Off-scale values (3, 5, 7, 14, 26…) break the rhythm; snap to the nearest step, ties rounding up. Report rhythm bugs as *"this is off the spacing ramp,"* not *"add a couple of pixels."* - **Serves:** *Room to breathe* (2), *Sameness signals sameness* (6). <a id="type-ramp"></a> ### The type ramp - roles and two weights, not free sizes Text styles are **roles**, not arbitrary sizes: `heading1–3`, `body1–2`, `label1–3`. There are exactly **two weights** - `regular` (400) and `semiBold` (600). There is no medium (500). "Strong" is not a bigger size; it is the *same role token at `semiBold`*.