DEV Community: FSCSS tutorial

patterns.fscss: a demo module for styling CSS in plain English

FSCSS tutorial — Sun, 23 Aug 2026 00:10:15 +0000

FSCSS v1.1.25 shipped pattern() — a method that matches a plain-English phrase against a stored description and injects the matching CSS. I wrote about the mechanics of pattern() itself in an earlier post. This one is about what I built with it: patterns.fscss, a small demo module you can import today.

What it is

patterns.fscss is a pattern library. It bundles a set of design tokens and a set of pattern() definitions for common UI needs, cards, buttons, hover effects, animations, a few components, so you can write a class body like this:

.card {
  beautiful gradient hello world card
}

.btn-primary {
  solid purple primary button with white label
}

and get real CSS out, without calling a mixin by an exact name.

It is explicitly a demo. It does not try to cover every pattern you might want. It exists to show what a pattern library looks like in practice, and to give people a working repo to fork and extend.

How it's structured

The module is two @define blocks:

@define pattern-root(sel: root) {
  /* declares design tokens as CSS custom properties */
}

@define patterns(thr: 0.65) {
  /* declares the pattern library, using @use(thr) as
     the shared threshold for every pattern() call */
}

Calling @pattern-root() sets up the tokens. Calling @patterns(0.7) registers the library at whatever threshold you want. Everything after that is just writing phrases inside your selectors.

Using it

Import the published module directly:

@import((pattern-root, patterns) from patterns)

@pattern-root()
@patterns(0.7)

Or fork the repo and import your own copy, which is the better option once you start adding patterns of your own:

@import((pattern-root, patterns) from "./patterns.fscss")

A note on threshold and collisions

Every pattern in the module shares one threshold, set at the @patterns() call site. That keeps the call simple, but it means pattern descriptions need to stay lexically distinct from each other. Two descriptions that share most of their words, for example an early draft of this module had "rounded primary white button with purple text" next to "solid purple primary button with white text", can end up close enough in similarity score that which one wins depends on small wording differences in the phrase you actually write. The fix isn't a smarter algorithm, it's writing descriptions that don't overlap that much in the first place.

Contributing

The repo is set up for contribution. If you have a pattern you use often, plain-English description plus the CSS it should produce, a pull request is the way to get it in. The README has the full guidelines, including the distinctness rule above.

Repo: github.com/fscss-ttr/patterns.fscss

Open-source, MIT Licensed

FSCSS @define, pattern(), and @import — Explained in Plain English

FSCSS tutorial — Sat, 22 Aug 2026 17:08:59 +0000

FSCSS @define, pattern(), and @import

Explained in plain English

FSCSS gives you three powerful ways to write less and reuse more.

Here’s what each one actually means — without the complicated words.

1. `@define` — Create your own shortcut

Think of @define as saying to FSCSS:

“Hey, look here! I’m creating a brand new shortcut command that I want to reuse later.”

Example:

@define card(bg, color) {
  background: @use(bg);
  color: @use(color);
  border-radius: 12px;
  padding: 24px;
}

card → the custom name of your shortcut
(bg, color) → the placeholders (like empty boxes) where you will later put real values
@use(bg) and @use(color) → how you use those placeholders inside the shortcut

How you use it later:

.box {
  @card(#667eea, white)
}

FSCSS fills in the placeholders and gives you real CSS.

You can also give default values:

@define button(bg: #764ba2, text: white) {
  background: @use(bg);
  color: @use(text);
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
}

Now you can call it with or without values.

2. `pattern()` — Describe what you want in normal words

pattern() is the more flexible cousin of @define.

Instead of calling a shortcut by its exact name, you just write a normal sentence that describes the style.

FSCSS looks at your sentence, finds the closest matching pattern, and injects the CSS for you.

Example:

pattern(0.6: "rounded primary button", `
  border: none;
  border-radius: 8px;
  padding: 10px 20px;
  background: #ffffff;
  color: #764ba2;
  font-weight: 600;
  cursor: pointer;
`)

Then later you can write:

.btn {
  rounded primary button
}

or even:

.btn {
  nice rounded purple button
}

As long as the words are close enough (the number 0.6 is the confidence threshold), FSCSS understands what you mean.

When to use which?

Feature	Best for	How strict?
`@define`	Exact, reusable components	Very precise
`pattern()`	Fast writing & natural language	Flexible / fuzzy

3. `@import` — Bring shortcuts from other files

@import lets you pull in the shortcuts (@define or patterns) you already created in another file.

Basic selective import:

@import((card, button) from "./components.fscss")

Only card and button are brought in — nothing else.

Wildcard (bring everything):

@import((*) from "./components.fscss")

The powerful part — renaming on the fly:

@import((card as my-card, button as btn) from "./components.fscss")

.box {
  @my-card(#8f6bff, white)
}

.action {
  @btn()
}

You can give the imported shortcuts new names that fit the current file better.

This is especially useful when different modules use similar names, or when you just want cleaner code.

Quick mental model

@define → “I’m inventing a new reusable command”
pattern() → “I’m describing the style in normal English”
@import → “Bring those commands from another file (and rename them if I want)”

Together they let you write less CSS, keep things organized, and still stay 100% compatible with normal CSS at the end.

Try it yourself

Extension is vailable on vscode

Docs: fscss.devtem.org

Learning hub: hub.devtem.org

npm: npmjs.com/package/fscss

Happy coding ❤️

FSCSS tutorial Follow

Figured Shorthand Cascading Style Sheet

Looking back at my 2024 article 😅

FSCSS — Sat, 22 Aug 2026 00:44:57 +0000

2024 FSCSS vs 2026 FSCSS — still moving, still light, still backward-compatible

Looking back at my 2024 article 😅

https://dev.to/figsh/my-rotate-animation-css-fscss-46b

2024 FSCSS vs 2026 FSCSS

Still moving with FSCSS 😕

Code written for v1.1.3 still runs fine on v1.1.26.

No breaking changes.

Backward compatibility is still a real thing here.

What was already there early:

Animation compact - since 1.1.0
Arrays - since 1.1.2
%n(), $variables, -* vendor prefixing… - since the unreleased days

What came later:

v1.1.24 - @define + selective @import
v1.1.25 – 1.1.26 - pattern() (write what you mean, let the compiler match it) - https://dev.to/fscss/pattern-in-fscss-write-what-you-mean-let-the-compiler-match-it-541m

The hardest recent release (and my favorite)

The real upgrade was the @import that can pull @define blocks and rename them on the fly:

@import((yourname as myname, brother as bro) from "/me.fscss")

@bro()
@myname()

Because it works directly with @define:

load - read - edit - paste…

Still light. Still pure CSS at the end.

Where everything lives

Docs - fscss.devtem.org
Learning hub - hub.devtem.org
npm - npmjs.com/package/fscss
One of the modules - github.com/fscss-ttr/st-core.fscss

A small note on the JavaScript journey

I’ve been simplifying some possibilities ❤️

Less noise. More direct paths.

Thank you to everyone who keeps sending heads ♥️❤️

I see you.

Still building.

Still light.

Still moving. 🎉

FSCSS tutorial Follow

Figured Shorthand Cascading Style Sheet

How ProvChart Makes Your Pages Faster, Crawlable, and Still Dynamic

FSCSS tutorial — Fri, 21 Aug 2026 08:04:36 +0000

Charts without the JavaScript tax.

Most charting libraries force a trade-off:

You get beautiful interactive charts
…but you also ship 40–150 kb of JavaScript
…and the chart only appears after JS executes
…and search engines often struggle to see the content

ProvChart takes a different path.

It turns your data into CSS custom properties. The browser then paints the chart using native CSS (clip-path, gradients, etc.). The result is a chart that:

Loads with the first paint
Requires zero chart library on the page
Is fully visible to crawlers
Can still be updated dynamically

And with the Developer API, you can generate these charts from your own backend or frontend.

The Performance Problem with Traditional Charts

A typical JS charting library does this:

Download the library
Wait for JavaScript to parse and execute
Create DOM / Canvas / SVG elements
Render the chart
Re-render on every data change

This creates several issues:

Problem	Impact
Heavy JS payload	Slower LCP & TTI
Render-blocking	Chart appears late
Client-side only	Harder for crawlers to index
Re-render cost	Jank on data updates

ProvChart removes almost all of this.

How ProvChart Works

You send data to the API (or use the visual builder)
ProvChart compiles the data into CSS variables
It returns pure HTML + CSS
You drop that into your page

The browser then paints the shape using CSS. No charting library is shipped to the user.

When you need to update the chart, you just change the CSS custom properties. The browser handles the transition natively.

Connecting Your Data to the ProvChart API

Here’s a real example that generates a multi-series chart:

<div id="chart-container"></div>

<script type="module">
  try {
    const res = await fetch("https://provchart-api.devtem.org/api/v1/generate", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        "X-API-Key": "YOUR_API_KEY"
      },
      body: JSON.stringify({
        type: "line",
        series: [
          { name: "Organic",  color: "#8b7bff", points: [18, 28, 35, 42, 48, 55, 62] },
          { name: "Direct",   color: "#4fd8c4", points: [12, 22, 30, 38, 45, 50, 58] },
          { name: "Referral", color: "#f0a860", points: [8, 15, 22, 28, 33, 40, 46] },
          { name: "Social",   color: "#ff5e7d", points: [5, 12, 18, 25, 30, 36, 42] },
          { name: "Email",    color: "#5ea8ff", points: [3, 9, 14, 20, 26, 32, 38] }
        ],
        axisX: ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"],
        theme: "dark"
      })
    });

    const data = await res.json();

    if (data.success) {
      // Inject the chart
      document.getElementById("chart-container").innerHTML = data.html;

      // Inject the CSS
      document.querySelector("head").insertAdjacentHTML(
        "beforeend",
        `<style>${data.css}</style>`
      );
    } else {
      console.error("API Error:", data.error);
    }
  } catch (err) {
    console.error("Fetch Error:", err);
  }
</script>

That’s all you need. The chart is now pure HTML + CSS on the page.

Why This Is Great for SEO & Crawlability

Because the chart is delivered as normal HTML and CSS:

Search engines see the content on the first crawl
No need to wait for JavaScript execution
No hydration delay
Works perfectly with static site generators

This is especially valuable for:

Documentation sites
Marketing pages
Dashboards that need to be shareable / indexable
Content that should appear in search results

Developer API Highlights

Feature	Details
Endpoint	`POST /api/v1/generate`
Authentication	API Key (`X-API-Key` header)
Response	`{ html, css }`
Chart types	line, area, bar, stackedbar, hbar, scatter, combo, gauge
Free tier	5 generations so you can test
Pro	500 generations / month
Business	5,000 generations / month

You can create an API key and try it immediately from the Pro Dashboard — even on the free plan you get 5 test generations.

Supported Chart Types

line – Multi-series line charts
area – Filled area charts
bar / stackedbar – Vertical bars
hbar – Horizontal bars
scatter – Scatter plots
combo – Mixed bar + line
gauge – Circular KPI gauges

All of them are rendered with pure CSS.

When to Use ProvChart

Great fit when you care about:

Performance (LCP, TTI, bundle size)
SEO / crawlability
Static or mostly-static pages
Simple live updates without heavy re-renders

Less ideal when you need:

Extremely complex interactions
Real-time streaming with thousands of points
Heavy chart animations driven by JavaScript

Getting Started

Try the free visual builder (no signup)

→ chart.devtem.org/get-started
Create an API key (free users get 5 test generations)

→ chart.devtem.org/dashboard
Read the full API docs

→ chart.devtem.org/docs

The rendering core is open source (st-core.fscss). The hosted API and Pro features are provided by DevTemple.

Final Thought

You don’t always need a heavy charting library.

Sometimes the best chart is the one that:

Loads instantly
Weighs almost nothing
Is fully visible to both users and search engines
Still lets you connect real data

That’s what ProvChart is built for.

Happy building.

pattern() in FSCSS: Write What You Mean, Let the Compiler Match It

FSCSS — Tue, 18 Aug 2026 10:42:42 +0000

FSCSS v1.1.25 ships a new core method: pattern().

It's the first FSCSS feature that doesn't ask you to remember an exact name. Instead of calling @card() or @btn-primary(), you describe what you want in plain language, and FSCSS matches the closest pattern at compile time.

pattern(0.5: "Hello World Card", `
  border-radius: 12px;
  padding: 24px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
  box-shadow: 0 8px 24px rgba(0,0,0,0.25);
`)

.card {
  hello world card
}

Compiles to:

.card {
  border-radius: 12px;
  padding: 24px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
  box-shadow: 0 8px 24px rgba(0,0,0,0.25);
}

Notice .card doesn't call anything — it just contains a phrase close enough to "Hello World card" to trigger the match.

Why this exists

@define is precise but rigid. You call it by exact name, with exact arguments. That's great for a library you built yourself, but it breaks down in a few real situations:

Design handoffs. A designer or junior dev writes dark card with rounded corners inside a rule instead of hunting through your define library for the right call signature.
AI-generated markup. Tools that generate FSCSS from natural-language prompts can emit descriptive phrases instead of needing to know your exact mixin names.
Fast prototyping. You don't always remember what you named something six months ago. pattern() lets close-enough phrasing still resolve correctly.

pattern() doesn't replace other variable methods — it sits next to it, for cases where flexibility matters more than precision.

The syntax

pattern(threshold: "description", `
  css to inject
`)

threshold — a number from 0 to 1. The minimum similarity score a phrase must reach to trigger this pattern. Omit it and it defaults to 1 (near-exact match only).
description — the plain-language phrase you're matching against.
css — what gets injected when a phrase matches. Use backticks so the CSS can freely contain single or double quotes.

Threshold uses a colon, deliberately — 0.5: reads as a labeled parameter, distinct from a plain comma-separated argument. It's there so the number's purpose is visually obvious to anyone reading your stylesheet.

How matching works

Every phrase in your code gets compared against every pattern description using similarity scoring (Dice coefficient, if you're curious — it compares word overlap between the phrase and the description). The pattern with the highest score that also clears its own threshold wins.

That means:

pattern(0.8: "dark background and light color", `
  background: #212121;
  color: #ffffff;
`)

.chip {
  style dark background and light color
}

.tooltip {
  dark background light color
}

Both .chip and .tooltip resolve to the same CSS, even though neither phrase matches the description word-for-word. That's the point — you're not looking up a name, you're describing an outcome.

Tuning the threshold

High threshold (0.8–1) → strict. Good for short, generic descriptions where you don't want accidental matches ("button" alone would be too easy to trigger by accident).
Low threshold (0.4–0.6) → forgiving. Good for longer, more specific descriptions where a few words might vary but the intent is clearly the same.

If two patterns could plausibly match the same phrase, the highest-scoring one wins — so keep descriptions distinct from each other, especially at lower thresholds.

Property patterns vs. block patterns

Same split as @define:

Property patterns inject a group of declarations inside a rule:

pattern(0.6: "rounded primary button", `
  border: none;
  border-radius: 8px;
  padding: 10px 20px;
  background: #ffffff;
  color: #764ba2;
  font-weight: 600;
  cursor: pointer;
`)

.btn {
  rounded primary button
}

Block patterns inject full structures — keyframes, media queries, whole at-rules — and can stand alone outside any selector:

pattern(0.7: "animated keyframe for spin", `
  @keyframes spin {
    0% { transform: rotate(0); }
    100% { transform: rotate(360deg); }
  }
`)

an Animated keyframe for spin

Content injection example

Because the CSS argument is just a string, pattern() isn't limited to properties — it can inject anything valid at that point in your stylesheet, including pseudo-element content:

pattern(0.9: "hello world heading", `h1:before{content: 'Hello World';}`)

.title {
  hello world heading
}

What's shipped in v1.1.25

CDN
API
CLI
VSCode Extention

Try it

pattern() is live now on v1.1.25

Docs: fscss.devtem.org/pattern

FSCSS v1.1.25: pattern() is here 🎉

FSCSS tutorial — Tue, 18 Aug 2026 07:35:25 +0000

New in this release: pattern() — semantic pattern matching for your stylesheets.

Instead of memorizing exact selectors or class names, describe what you want in plain language, set a confidence threshold, and let FSCSS match it to reusable CSS.

Basic example

pattern(0.5: "Hello World card", `
  border-radius: 12px;
  padding: 24px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
  box-shadow: 0 8px 24px rgba(0,0,0,0.25);
`)

.card {
  hello world card
}

Write the phrase anywhere inside a selector, and FSCSS matches it against your defined patterns using similarity scoring — no exact match required, just close enough to clear the threshold.

Buttons

pattern(0.6: "rounded primary button", `
  border: none;
  border-radius: 8px;
  padding: 10px 20px;
  background: #ffffff;
  color: #764ba2;
  font-weight: 600;
  cursor: pointer;
`)

.btn {
  rounded primary button
}

Dark theme surfaces

pattern(0.8: "dark background and light text", `
  background: #212121;
  color: #ffffff;
`)

.chip {
  dark background and light text
}

.tooltip {
  dark background light text
}

Two different phrasings, same pattern — because it's matched on meaning, not exact wording.

Animations

pattern(0.7: "animated keyframe for spin", `
  @keyframes spin {
    0% { transform: rotate(0); }
    100% { transform: rotate(360deg); }
  }
`)

animated keyframe for spin

Patterns aren't limited to selector bodies — they can resolve to full at-rules too.

Content injection

pattern(0.9: "hello world heading", `h1:before{content: 'Hello World';}`)

hello world heading

What's shipped

✅ CDN
✅ API
✅ CLI
✅ Available now on v1.1.25

What's coming

VS Code extension support (syntax highlighting + autocomplete for pattern()) isn't live yet — landing August 20, 2026.

Full explanation coming soon. Try it out and let me know what patterns you build 👇

St-core.fscss Multi-Line Chart Pure CSS

FSCSS tutorial — Mon, 17 Aug 2026 17:01:49 +0000

st-core.fscss is a pure-CSS charting system that renders line charts with no SVG, no Canvas, and no JavaScript charting library. It uses:

clip-path: polygon() for the line shapes
CSS custom properties (--st-p1 … --st-p8) for the 8 data points
FSCSS mixins that expand at compile/runtime into the required CSS

How Multi-Line Charts Work

You declare one @st-chart-line renderer. Every element that matches the class becomes an independent line.

The chart container can hold a default dataset (@st-chart-points).
Line 1 inherits that default.
Additional lines override with their own @st-chart-points.
Each line gets its own color via background or color.

X positions are fixed (0 %, 14 %, 28 %, 42 %, 57 %, 71 %, 85 %, 100 %).

Y values are given on a 0–100 scale (100 = top of the chart). The library inverts them internally for CSS coordinates.

Complete Multi-Line Chart Example

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.24/exec.min.js" async></script>

<style>
@import((*) from st-core)

@st-root()

.chart {
  position: relative;
  height: 200px;
  background: var(--st-surface);
  border-radius: var(--st-radius-lg);
  overflow: hidden;
  /* default dataset – inherited by line-1 */
  @st-chart-points(20, 25, 21, 37, 30, 60, 27, 50)
}

/* single renderer for all lines */
@st-chart-line(.chart-line)

.chart-line {
  @st-chart-line-width(2.5px)
}

/* line-1 inherits container data */
.line-1 {
  background: #32D8D4;
}

/* line-2 has its own dataset */
.line-2 {
  background: #E8A030;
  @st-chart-points(10, 20, 16, 15, 66, 50, 80, 54)
}

/* line-3 has its own dataset */
.line-3 {
  background: #B840C8;
  @st-chart-points(5, 39, 20, 30, 27, 70, 60, 70)
}

/* optional grid + axes */
@st-chart-grid(.chart-grid, 10, 7)
@st-chart-axis-y(.y-axis)

.chart-grid {
  opacity: 0.08;
}
</style>

<div class="chart">
  <div class="chart-line line-1"></div>
  <div class="chart-line line-2"></div>
  <div class="chart-line line-3"></div>
  <div class="chart-grid"></div>
  <div class="y-axis">
    <span>0</span><span>20</span><span>40</span>
    <span>60</span><span>80</span><span>100</span>
  </div>
</div>

Key Rules

Rule	Explanation
One renderer	`@st-chart-line(.chart-line)` is declared once
Default data	Container’s `@st-chart-points` is inherited by the first line
Overrides	Later lines set their own `@st-chart-points`
Color	Set with `background` (or `color` + `currentColor`)
Line thickness	`@st-chart-line-width(2.5px)` (default is 1.5 px)
Grid / axes	Optional helpers for visual polish

Design Tokens (`@st-root`)

Call @st-root() once (usually at the top of your stylesheet). It injects these CSS custom properties:

Colors

Token	Default	Purpose
`--st-bg`	`#0e0d14`	Page background
`--st-surface`	`#161422`	Chart / surface background
`--st-card`	`#1c1a2e`	Card background
`--st-accent`	`#9d7eff`	Primary accent
`--st-accent-2`	`#c4a8ff`	Secondary accent
`--st-accent-dim`	`#3a2e6e`	Dimmed accent
`--st-green`	`#4fffb0`	Positive / up
`--st-red`	`#ff5e7d`	Negative / down
`--st-text`	`#e8e3ff`	Primary text
`--st-muted`	`#6b6488`	Muted text / axis labels
`--st-border`	`rgba(157,126,255,.15)`	Borders

Radius & Spacing

Token	Default
`--st-radius-xl`	`40px`
`--st-radius-lg`	`16px`
`--st-radius-md`	`12px`
`--st-radius-sm`	`10px`
`--st-pad`	`24px`

Chart-specific

Token	Default	Purpose
`--st-p1` … `--st-p8`	sample values	Y data points
`--st-chart-line-width`	`1.5px`	Stroke thickness

You can override any token globally or scoped to a single chart:

.chart {
  --st-accent: #32D8D4;
}

HTML Structure Summary

<div class="chart">                 <!-- container + default data -->
  <div class="chart-line line-1"></div>  <!-- inherits default data -->
  <div class="chart-line line-2"></div>  <!-- own @st-chart-points -->
  <div class="chart-line line-3"></div>  <!-- own @st-chart-points -->
  <div class="chart-grid"></div>         <!-- optional -->
  <div class="y-axis">…</div>            <!-- optional -->
</div>
<div class="x-axis">…</div>              <!-- optional, usually outside -->

Runtime Data Updates (optional JS)

Because data lives in CSS variables, you can update any line by writing properties:

const line2 = document.querySelector('.line-2');
[15, 30, 25, 40, 55, 45, 70, 60].forEach((v, i) => {
  line2.style.setProperty(`--st-p${i + 1}`, `${100 - v}%`);
});

The browser repaints the clip-path automatically — no redraw library needed.

Sources

Repository and examples:
Help us star the repo if it helps 🙏

This gives you a zero-JS-runtime (or near-zero) multi-series line chart that stays extremely lightweight.

Creating modern forms with form.fscss — pure CSS

FSCSS tutorial — Fri, 14 Aug 2026 12:42:40 +0000

Floating labels. Inline validation. Custom checkboxes, radios, and a toggle switch. A gradient button with a press-down micro-interaction. Every bit of it below is CSS — no form library, no useState, no event listener wiring up a class toggle.

That's form.fscss — the module in the FSCSS ecosystem. Same philosophy each time: solve the hard visual problem once, ship it as importable mixins, let the browser do the actual work.

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.24/exec.min.js" defer></script>

<style>
@import((*) from form)

@form-root()
@form-group(.form-group)
@form-input(.form-input)
@form-label(.form-label)
@form-float(.form-group, .form-input, .form-label)
@form-checkbox(.form-checkbox)
@form-btn(.form-btn)
@form-btn-primary(.form-btn-primary)
</style>

<div class="form-group">
  <input class="form-input" type="text" placeholder=" ">
  <label class="form-label">Full name</label>
</div>

<label class="form-checkbox">
  <input type="checkbox" checked><span></span> I agree to the Terms
</label>

<button class="form-btn form-btn-primary">Create account</button>

The two tricks doing all the work

Forms feel like they need JavaScript because most tutorials reach for it immediately. Two native CSS mechanisms cover almost everything a "modern" form needs.

Floating labels run entirely on :placeholder-shown. Give the input placeholder=" " — a literal space, not empty — and the browser now knows, purely in CSS, whether the field is empty and unfocused:

.form-input:focus + .form-label,
.form-input:not(:placeholder-shown) + .form-label {
  top: -9px;
  font-size: 11px;
  color: var(--form-accent);
}

No state, no class toggling on keyup. The label just reacts to what the browser already knows about the input.

Checkboxes, radios, and the switch all use the classic checkbox-hack: the real <input> stays in the DOM (so it keeps native keyboard support and form submission) but is visually hidden, and a sibling <span> becomes the thing you actually see:

.form-checkbox input { opacity: 0; position: absolute; }
.form-checkbox input:checked + span::after {
  transform: rotate(45deg) scale(1); /* the checkmark, drawn from two borders */
}

The checkmark itself isn't an icon font or an SVG — it's two border sides on a pseudo-element, rotated 45 degrees. Same trick powers the radio dot and the switch thumb slide, just with different shapes and transforms.

Validation

Add .is-error or .is-success straight to the field wrapper. One mixin call registers the rule; every field just reacts to its own class:

<div class="form-group is-error">
  <input class="form-input" type="email" placeholder=" ">
  <label class="form-label">Email address</label>
  <span class="form-help">Please enter a valid email</span>
</div>

Your actual validation logic — regex, an API check, whatever — still needs real JS somewhere. But the presentation layer of "this field is wrong, here's why" needs nothing but toggling one class name. no state management for something.

Full example

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.24/exec.min.js" defer></script>

<style>
@import((*) from form)

@form-root()

body {
  min-height: 100vh;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--form-bg);
  font-family: 'Syne', sans-serif;
}

.card {
  width: 100%;
  max-width: 380px;
  background: #1c1a2e;
  border: 1px solid var(--form-border);
  border-radius: 20px;
  padding: 32px;
}

@form-group(.form-group)
@form-input(.form-input)
@form-label(.form-label)
@form-float(.form-group, .form-input, .form-label)
@form-help(.form-help)
@form-validation(.form-group)
@form-select(.form-select)
@form-select-arrow(.form-select-wrap)
@form-checkbox(.form-checkbox)
@form-switch(.form-switch)
@form-btn(.form-btn)
@form-btn-primary(.form-btn-primary)
</style>

<div class="card">
  <div class="form-group">
    <input class="form-input" type="text" placeholder=" ">
    <label class="form-label">Full name</label>
  </div>

  <div class="form-group is-success">
    <input class="form-input" type="text" placeholder=" " value="devtemple_creator">
    <label class="form-label">Username</label>
    <span class="form-help">Username is available</span>
  </div>

  <div class="form-select-wrap">
    <select class="form-select">
      <option>Creator</option>
      <option>Buyer</option>
    </select>
  </div>

  <label class="form-checkbox">
    <input type="checkbox" checked><span></span> I agree to the Terms
  </label>

  <button class="form-btn form-btn-primary" style="width:100%;">Create account</button>
</div>

Every visual state in that form — resting, focused, filled, valid, invalid, checked, hovered, pressed — is handled by CSS pseudo-classes doing what they were always built to do. JavaScript's only job left is your logic: submit handling, async validation, whatever's actually specific to your product.

Try it

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.24/exec.min.js" defer></script>
<style>
  @import((*) from form)
</style>

Full docs, token reference, and markup gotchas (input-before-label ordering, the placeholder=" " requirement, sibling-selector rules):

github.com/fscss-ttr/form.fscss

Pure CSS 3D dice cube module: FSCSS

FSCSS tutorial — Fri, 07 Aug 2026 21:58:09 +0000

cube.fscss — a module for FSCSS, Here's the whole thing rendered live, nothing but <div>s and CSS:

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.24/exec.min.js" defer></script>

<style>
@import((*) from cube)

@cube-root()
@cube-wrapper(.my-cube)
@cube-face(.my-cube div)
@cube-face-front(.my-cube .f1)
@cube-face-back(.my-cube .f2)
@cube-face-left(.my-cube .f3)
@cube-face-right(.my-cube .f4)
@cube-face-top(.my-cube .f5)
@cube-face-bottom(.my-cube .f6)
@cube-micro-dice(.my-cube .cube)

.my-cube {
  @cube-size(80px)
  transform: rotateY(50deg) rotateX(30deg);
  animation: spin 5s linear infinite;
}

@keyframes spin {
  0%   { transform: rotateX(20deg) rotateY(40deg); }
  100% { transform: rotateX(380deg) rotateY(400deg); }
}
</style>

<div class="my-cube">
  <div class="cube f1 dice-1"></div>
  <div class="cube f2 dice-2"></div>
  <div class="cube f3 dice-3"></div>
  <div class="cube f4 dice-4"></div>
  <div class="cube f5 dice-5"></div>
  <div class="cube f6 dice-6"></div>
</div>

No dice PNGs. No SVG paths. No canvas draw calls. Every pip is a radial-gradient.

Why build this

Already had a chart/dashboard module (st-core.fscss) built on clip-path polygons — no JS charting library, just CSS custom properties driving the shape. I wanted to see how far that "CSS does the visual math" philosophy could stretch into actual 3D space. A cube felt like the right next test: real perspective, real preserve-3d, real face geometry — not a flat illusion.

How the geometry works

A cube is 6 absolutely-positioned faces sharing one parent set to transform-style: preserve-3d. Each face gets pushed out from the center by half the cube's edge length, then rotated to face outward:

front  → translateZ(half)
back   → rotateY(180deg) translateZ(half)
top    → rotateX(90deg)  translateZ(half)
bottom → rotateX(-90deg) translateZ(half)
right  → rotateY(90deg)  translateZ(half)
left   → rotateY(-90deg) translateZ(half)

The entire cube's dimensions live in two CSS variables: --cube-size and --cube-half (always size ÷ 2). Resize the whole thing with one call:

.my-cube {
  @cube-size(150px)
}

Faces, offsets, and dice dot size all scale together — no manually recalculating six translateZ values by hand.

Dice pips, no font glyphs

I originally reached for Unicode dice characters (⚀⚁⚂⚃⚄⚅) for the pips, but font rendering for those glyphs is wildly inconsistent across platforms — some Android/Chrome stacks show them thin, outlined, or as tofu boxes. Stacked radial-gradients solved it instead:

.dice-3 {
  background-image:
    radial-gradient(circle var(--cube-dot-size) at 25% 25%, var(--cube-dot-color) 99%, transparent 100%),
    radial-gradient(circle var(--cube-dot-size) at 50% 50%, var(--cube-dot-color) 99%, transparent 100%),
    radial-gradient(circle var(--cube-dot-size) at 75% 75%, var(--cube-dot-color) 99%, transparent 100%);
}

Font-independent, crisp at any size, and the dot radius is itself a variable — so it scales automatically with @cube-size() instead of overflowing on a big cube or vanishing on a small one.

It's not just dice

Faces and face content are decoupled on purpose. The face mixins only handle position — what renders inside is a separate "micro" you apply on top. Right now there are eight:

cube-micro-fire — pulsing gradient-text fire
cube-micro-matrix — scrolling digital rain
cube-micro-neon — pulsing cyan/magenta glow border
cube-micro-float — subtle bounce, stacks with anything
cube-micro-glass — frosted backdrop-filter panel
cube-micro-holo — holographic shifting gradient text
cube-micro-glitch — RGB-split glitch shift
cube-micro-dice — the pips above

Mix and match per face on the same cube:

@cube-micro-fire(.my-cube .f1)
@cube-micro-matrix(.my-cube .f2)
@cube-micro-neon(.my-cube .f3)
@cube-micro-glass(.my-cube .f5)
@cube-micro-holo(.my-cube .f6)

Try it

CDN, drop-in:

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.24/exec.min.js" defer></script>
<style> 
  @import((*) from cube)
  /* your mixins here */
</style>

Or compile ahead of time with the CLI for a plain .css file, zero runtime:

npm install -g fscss
fscss style.fscss style.css

Full docs, token reference, and more examples: github.com/fscss-ttr/cube.fscss

If you build something with it — I'd love to see. And if you hit issue, open an issue, it's open-source.

Stay tuned for more upcoming useful modules ❤️

DevTemple: a marketplace for developers and designers to sell code, templates & assets

FSCSS — Wed, 15 Jul 2026 00:21:37 +0000

We built DevTemple (devtem.org) — a live digital marketplace where developers and designers sell code templates, UI kits, graphics, and other digital assets, with instant downloads for buyers.

Why We built it

I make and sell digital products myself, and kept hitting the same frustrations on other platforms — fees that don't make sense for smaller creators, no real visibility into earnings, and buyers having to trust a screenshot instead of actually seeing the thing work before paying.

DevTemple is my answer to that: a place built specifically for code/design assets, where sellers get a proper profile, real-time earnings and referral tracking, and buyers can preview a template live in the browser before they buy — not just look at static images.

How it works

Sellers create an account, and upload their products (templates, kits, graphics, snippets, etc.)
Buyers browse, preview live where available, and check out securely via Paystack
Live Preview runs the actual HTML/CSS/JS in-browser so buyers know exactly what they're getting
Referral program lets anyone earn commission (7%, or 10% for Pro members) by sharing links
Seller dashboard tracks earnings, subscribers, and withdrawals in one place — payouts go straight to your bank

Not trying to replace any other platform — it's its own thing, built around instant-download digital assets for the developer/designer crowd.

Will it help?

That's what I'm putting out there to find out. If you build things — templates, kits, snippets, assets — and want a place to sell them where buyers can actually try before they buy, I think it's worth checking out. And if you're buying, the live preview alone should save you from a few bad surprises.

Would genuinely appreciate people trying it out — as a seller or buyer — and telling me what's missing.

🔗 devtem.org

🔗 FAQ

I Built a Live Trading Dashboard With Zero Chart.js — Just CSS Custom Properties

FSCSS — Tue, 30 Jun 2026 09:19:25 +0000

Every time I needed a chart on a dashboard, the playbook was the same: pull in Chart.js or Recharts, fight with canvas sizing, write a wrapper component, and ship 40-80kb of JS just to draw a line. So with st-core.fscss — a library for FSCSS, CSS preprocessor — I went the other way: charts that are pure clip-path: polygon() shapes, animated with native CSS transitions, and driven entirely by CSS custom properties.

To prove it holds up outside a toy demo, I built Vela, a full portfolio/trading dashboard UI — KPI cards, a live performance chart with a benchmark overlay, allocation bars, sparklines, the works. You can poke at it live here:

🔗 Live preview: https://i.devtem.org/preview?id=5b5e4957-765b-4969-b1a0-3a4d0de495b4

No build step, no bundler — just index.html, dashboard.fscss, and main.js.

The core idea

A line chart is just a shape. If you have 8 data points on a 0-100 scale, you can describe the filled area under that line as a clip-path: polygon() with 8+2 coordinate pairs. st-core generates that polygon for you from CSS custom properties:

@st-chart-fill(.chart-fill)
@st-chart-line(.chart-line)
@st-chart-dots(.chart-dot-, 9px)
@st-chart-grid(.chart-grid, 6, 8)

.chart {
  @st-chart-points(28, 42, 35, 55, 48, 72, 60, 78)
}

Those four @st-chart-* directives wire up a filled area, a stroked line, positioned dot markers, and a background grid — all from the same underlying point data. Swap the numbers in @st-chart-points, or update the matching --st-p1 through --st-p8 custom properties at runtime, and the shape redraws.

JS never touches a canvas

This is the part that actually matters for integration. main.js in Vela has zero charting logic — it only ever writes custom properties:

function setChartData(el, vals) {
  vals.forEach((v, i) => {
    el.style.setProperty(`--st-p${i + 1}`, `${100 - v}%`);
  });
}

Because the chart shapes are driven by transition: clip-path 700ms cubic-bezier(.4,0,.2,1), animating between datasets is just... setting new values. There's a small easing loop in animateTo() for smoother interpolation, but even that is optional — CSS will tween clip-path changes on its own.

animateTo(mainChart, oldPoints, newPoints, 700);

Swap a REST call in and you have live data:

const res = await fetch('/api/portfolio/history?period=1w');
const { points } = await res.json();
setChartData(document.getElementById('chart-line-portfolio'), points);

Allocation bars and stat cards work the same way

st-core ships a few other primitives that follow the same pattern — a directive that hooks a custom property to a visual property:

@st-cat-bar-fill(.bar-fill)
@st-stat-card(.st-stat-card)

function setBar(id, pct) {
  document.getElementById(id).style.setProperty('--st-cat-bar-fill-range', `${pct}%`);
}

One CSS variable in, one bar width out. No JS animation library needed because the width transition lives in the stylesheet.

Why this matters

A few things fall out of this approach almost for free:

No JS dependency for rendering. The charts render even before main.js runs — they're just CSS shapes with default values baked into the stylesheet.
Themeable by design. Every color in Vela is a custom property (--st-accent, --st-green, --st-red...). Retheme the whole dashboard by overriding tokens in :root.
Animations are declarative. Hover tooltips, dot reveals, fade-ins — all transition and @keyframes, not requestAnimationFrame spaghetti (except where I wanted extra easing control).
Tiny footprint. No charting library payload. st-core compiles in the browser via the FSCSS runtime, or precompiles to plain CSS if you don't want runtime compilation at all.

Try it

The live preview link above is the full zip running as-is — sidebar nav, period switching (1D/1W/1M/3M/1Y), live-ticking BTC/ETH sparklines, the lot. Click around the period tabs and watch the chart redraw with the same clip-path mechanism described above.

Github repository: https://github.com/fscss-ttr/st-core.fscss

st-core.fscss is an open source MIT Licensed if you want to dig into the source, and Vela itself is listed as a template over on DevTemple if you'd rather skip straight to wiring up your own data.

Questions, pushback, "this is insane, why not just use a library"

Build a Stunning Developer Portfolio in Minutes with devtemDesign

FSCSS tutorial — Tue, 23 Jun 2026 09:15:18 +0000

A step-by-step tutorial on building an animated, glassmorphic developer portfolio using the devtemDesign declarative page engine — zero boilerplate, one JS call.

Most developer portfolios take hours to set up. You pick a template, fight with CSS, tweak the layout, and eventually settle for something that looks like every other portfolio on the internet.

What if you could describe your portfolio as a config object and have a JavaScript engine paint the whole thing for you — animated, glassmorphic, responsive?

That's exactly what devtemDesign does.

In this tutorial, we'll build a complete developer portfolio from scratch using devtemDesign@0.0.2. By the end, you'll have a live, production-ready portfolio page — and you'll understand every config option that powers it.

What is devtemDesign?

devtemDesign is a lightweight, declarative page engine. You call one function with a config object, and it renders a full animated page: hero section, navbar, feature grid, info panels, footer — all of it.

No build tools. No framework. Just a CDN import and a JS object.

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/devtemdesign@0.0.2/style.css">
<script src="https://cdn.jsdelivr.net/npm/devtemdesign@0.0.2/script.js"></script>

It ships four built-in themes:

Template	Vibe
`figsh`	Futuristic glassmorphism — cyan / purple / pink
`cyber`	Neon cyberpunk — cyan / magenta / red
`aurora`	Organic nature — emerald / violet / blue
`monochrome`	Minimalist grayscale

Step 1 — The HTML shell

The entire page lives inside one div. That's it.

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Your Name — Developer Portfolio</title>

  <!-- devtemDesign -->
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/devtemdesign@0.0.2/style.css">
  <script src="https://cdn.jsdelivr.net/npm/devtemdesign@0.0.2/script.js"></script>

  <!-- Font Awesome (needed for icons) -->
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">
</head>
<body>
  <div id="app"></div>
  <script src="portfolio.js"></script>
</body>
</html>

Font Awesome is required — devtemDesign uses it for feature icons, social links, and CTA buttons.

Step 2 — Initialize the engine

In portfolio.js, call devtemDesign() with your container ID and config:

devtemDesign("app", {
  template: "figsh",
  logoName: "YOUR NAME",
  // ... rest of config
});

The first argument is the container element's id. The second is your full config object. Let's build it section by section.

Step 3 — Core + Navigation

devtemDesign("app", {
  template: "figsh",        // pick your theme
  logoName: "YOUR BRAND",   // shows in navbar & footer

  navLinks: [
    { label: "About",    href: "#about"    },
    { label: "Projects", href: "#projects" },
    { label: "Skills",   href: "#skills"   },
    { label: "Contact",  href: "#contact"  }
  ],
  ctaText: "<i class='fab fa-github'></i> GitHub",
});

navLinks accepts plain strings ("About") or objects with { label, href }. The ctaText field supports HTML, so you can embed Font Awesome icons directly.

Step 4 — Hero section

The hero is the first thing visitors see. Fill it with clarity and confidence:

heroTag: "fullstack developer · builder · creator",
heroTitleLine1: "Building the",
heroTitleLine2: "Web's Future",
heroSubtitle: "I'm [Your Name] — I build platforms, tools, and open-source projects that help developers ship faster.",
primaryBtnText: "<i class='fas fa-rocket'></i> My Work",
secondaryBtnText: "Read More →",

heroTitleLine1 and heroTitleLine2 split into two animated lines — the engine handles the styling. Keep them short and punchy.

Step 5 — Brands ticker

The scrolling ticker below the hero is great for showing your tech stack:

brands: ["React", "Node.js", "Supabase", "Netlify", "Cloudflare", "PostgreSQL"],
brandsSubtitle: "technologies & platforms I work with daily",

Pass any strings — tool names, frameworks, platforms. The engine animates them as a continuous marquee.

Step 6 — Feature cards (Projects)

Each features entry renders as a glassmorphic card. Use them for your best projects:

featuresSectionLabel: "<i class='fas fa-layer-group'></i> &nbsp; FEATURED PROJECTS",
featuresSectionTitle: "Things I've Built",

features: [
  {
    title: "Project Alpha",
    desc: "A brief description. What problem does it solve? What's the tech stack?",
    icon: "<i class='fas fa-store'></i>"
  },
  {
    title: "Project Beta",
    desc: "Explain the key challenge and how you solved it. Mention notable outcomes.",
    icon: "<i class='fas fa-code'></i>"
  },
  {
    title: "Project Gamma",
    desc: "Is it open source? A commercial product? Include a metric if you have one.",
    icon: "<i class='fas fa-chart-bar'></i>"
  }
  // add up to 6 for a clean 3-column grid
],

Icons are raw HTML strings — any Font Awesome icon class works here.

Step 7 — Panels (About / Context blocks)

Panels are wider info blocks, great for explaining your professional angle:

panels: [
  {
    tag: "Fullstack",
    title: "End-to-End Development",
    desc: "From database schema to polished frontends — I own the whole stack."
  },
  {
    tag: "Open Source",
    title: "Building in Public",
    desc: "I contribute to open-source, write technical articles, and document everything."
  },
  {
    tag: "Creator",
    title: "Products & Templates",
    desc: "I create and sell UI kits, templates, and dev tools for fellow developers."
  }
],

The tag renders as a small label chip above the title. Use it for categories or keywords.

Step 8 — Footer

The v0.0.2 footer is fully declarative with link columns, social icons, and legal links:

footer: {
  tagline: "Fullstack developer · Open source creator · Problem solver.",
  copy: "© 2025 Your Name · Built with devtemDesign",

  columns: [
    {
      heading: "Platforms",
      links: [
        { label: "My App",   href: "https://yourapp.com"  },
        { label: "npm",      href: "https://npmjs.com"    }
      ]
    },
    {
      heading: "Writing",
      links: [
        { label: "dev.to",   href: "https://dev.to"       },
        { label: "LinkedIn", href: "https://linkedin.com" }
      ]
    },
    {
      heading: "Code",
      links: [
        { label: "GitHub",   href: "https://github.com"   }
      ]
    }
  ],

  social: [
    { icon: "fab fa-github",   href: "https://github.com",   label: "GitHub"   },
    { icon: "fab fa-linkedin", href: "https://linkedin.com", label: "LinkedIn" },
    { icon: "fab fa-dev",      href: "https://dev.to",       label: "dev.to"   },
    { icon: "fab fa-npm",      href: "https://npmjs.com",    label: "npm"      },
    { icon: "fab fa-codepen",  href: "https://codepen.io",   label: "CodePen"  }
  ],

  legal: [
    { label: "MIT License", href: "#" }
  ]
}

Step 9 — Optional: Custom accent colors

All visual variables are CSS custom properties. Override them after including the engine stylesheet:

<style>
  :root {
    --accent:    #ff7b2c;  /* primary accent   */
    --accent2:   #ff2c7b;  /* secondary accent */
    --glass-bg:  rgba(20, 20, 40, 0.5);
  }
</style>

This lets you brand the page without touching the engine internals.

The full config at a glance

Here's the complete template — copy it, fill in your details, and you're done:

What you just built

In a single JS config object you defined:

Animated navbar with CTA
Full hero with tag, two-line title, subtitle, and dual buttons
Scrolling tech stack ticker
6-card project grid with custom icons
3 contextual panels
Structured footer with columns, social links, and legal

Zero boilerplate. No bundler. No framework.

Resources

npm: npm i devtemdesign
Docs: design.devtem.org/docs
Live demo: design.devtem.org
GitHub: github.com/devtem-dev/devtemDesign
DevTemple: @devtemDesign

If you build a portfolio with devtemDesign, drop the link in the comments — I'd love to see what you make with it.

DEV Community: FSCSS tutorial

patterns.fscss: a demo module for styling CSS in plain English

What it is

How it's structured

Using it

A note on threshold and collisions

Contributing

FSCSS @define, pattern(), and @import — Explained in Plain English

FSCSS @define, pattern(), and @import

Explained in plain English

1. @define — Create your own shortcut

2. pattern() — Describe what you want in normal words

3. @import — Bring shortcuts from other files

Quick mental model

Try it yourself

FSCSS tutorial Follow

Looking back at my 2024 article 😅

2024 FSCSS vs 2026 FSCSS

The hardest recent release (and my favorite)

Where everything lives

A small note on the JavaScript journey

FSCSS tutorial Follow

How ProvChart Makes Your Pages Faster, Crawlable, and Still Dynamic

The Performance Problem with Traditional Charts

How ProvChart Works

Connecting Your Data to the ProvChart API

Why This Is Great for SEO & Crawlability

Developer API Highlights

Supported Chart Types

When to Use ProvChart

Getting Started

Final Thought

pattern() in FSCSS: Write What You Mean, Let the Compiler Match It

Why this exists

The syntax

How matching works

Tuning the threshold

Property patterns vs. block patterns

Content injection example

What's shipped in v1.1.25

Try it

FSCSS v1.1.25: pattern() is here 🎉

Basic example

Buttons

Dark theme surfaces

Animations

Content injection

What's shipped

What's coming

St-core.fscss Multi-Line Chart Pure CSS

How Multi-Line Charts Work

Complete Multi-Line Chart Example

Key Rules

Design Tokens (@st-root)

HTML Structure Summary

Runtime Data Updates (optional JS)

Sources

Creating modern forms with form.fscss — pure CSS

The two tricks doing all the work

Validation

Full example

Try it

github.com/fscss-ttr/form.fscss

Pure CSS 3D dice cube module: FSCSS

Why build this

How the geometry works

Dice pips, no font glyphs

It's not just dice

Try it

DevTemple: a marketplace for developers and designers to sell code, templates & assets

Why We built it

How it works

Will it help?

I Built a Live Trading Dashboard With Zero Chart.js — Just CSS Custom Properties

The core idea

JS never touches a canvas

Allocation bars and stat cards work the same way

Why this matters

Try it

Build a Stunning Developer Portfolio in Minutes with devtemDesign

1. `@define` — Create your own shortcut

2. `pattern()` — Describe what you want in normal words

3. `@import` — Bring shortcuts from other files

Design Tokens (`@st-root`)