Forem: FSCSS tutorial

From Static to Real-Time: Data Viz with st-core.fscss (Pure CSS Charts)

FSCSS tutorial — Mon, 06 Apr 2026 20:01:37 +0000

This is a follow-up to my earlier post (Building a trading dashboard UI with zero JavaScript — just st-core.fscss.)If you haven't read that one, the quick summary: st-core is an FSCSS plugin that lets you declare chart infrastructure — fills, lines, dots, axes, grids — entirely at the CSS layer. No canvas, no chart library.

That post showed you the static side. This one shows you how to make it live.

The "Aha" Moment

The thing that unlocks st-core for real data viz is understanding what the chart actually is under the hood.

The chart shape IS a clip-path polygon.

When st-core compiles your FSCSS, it generates CSS that reads from a set of custom properties — --st-p1 through --st-p8 — and uses them to construct the polygon coordinates. That's it. So updating the chart at runtime is just:

element.style.cssText = `--st-p1: 40%; --st-p2: 75%; --st-p3: 55%; ...`;

One line. No DOM surgery. No re-render cycle. The CSS transition handles the rest.

The Demo: Expenses Chart

Here's the full chart we're building — an analytics card with a live-updating area chart, a stat card, and a peak-tracking dot.

CodePen demo

<!DOCTYPE html>
<html lang="en">
<head>
  <script src="https://cdn.jsdelivr.net/npm/fscss@1.1.24/exec.min.js" async></script>
  <style>

    @import((*) from st-core) @st-root() @st-container(body) .wrapper {
      flex-direction: column;
      gap: 16px;
      width: 100%;
    }

    @st-chart-fill(.chart-fill)
    @st-chart-line(.chart-line)
    @st-chart-dot(.chart-dot, 70, 60)
    .chart {
      width: 100%;
      height: 200px;
      border-radius: 20px;
      @st-chart-points(20, 25, 21, 37, 30, 60, 27, 50)
    }

    @st-stat-card(.stat-card)
    @st-chart-axis-x(.x-axis)
    @st-chart-axis-y(.y-axis)
    @st-chart-grid(.chart-grid, 10, 7)
    .chart-fill, .chart-line {
      height: 100%;
      transition: clip-path .9s cubic-bezier(.4, 0, .2, 1);
    }

  </style>
</head>
<body>
  <div class="wrapper">

    <div class="stat-card">
      <div class="st-stat-label">TOTAL EXPENSES</div>
      <div class="st-stat-value">$1,326.03</div>
      <div class="st-stat-delta up">+5.1% vs last week</div>
    </div>

    <div class="chart">
      <div class="chart-fill"></div>
      <div class="chart-line"></div>
      <div class="chart-dot"><span class="tooltip">$405.67</span></div>
      <div class="chart-grid"></div>
      <div class="y-axis">
        <span>0</span><span>10</span><span>20</span><span>30</span>
        <span>40</span><span>50</span><span>60</span><span>70</span>
      </div>
    </div>

    <div class="x-axis days">
      <span>Sun</span><span>Mon</span><span>Tue</span><span>Wed</span>
      <span>Thu</span><span>Fri</span><span>Sat</span><span>Sun</span>
    </div>

  </div>
</body>
</html>

Directive Breakdown

The chart block

@st-chart-fill(.chart-fill)
@st-chart-line(.chart-line)
@st-chart-dot(.chart-dot, 70, 60)
.chart {
  @st-chart-points(20, 25, 21, 37, 30, 60, 27, 50)
}

Directive	What it generates
`@st-chart-fill`	Area fill via `clip-path` polygon, reads `--st-p1..8`
`@st-chart-line`	Stroke-only overlay of the same shape
`@st-chart-dot`	Absolute-positioned peak marker, initial position `(70, 60)`
`@st-chart-points`	Compiles the 8 values into `--st-p1` through `--st-p8`

Support directives

@st-stat-card(.stat-card)        /* label / value / delta slots */
@st-chart-axis-x(.x-axis)        /* wires x-axis label container */
@st-chart-axis-y(.y-axis)        /* wires y-axis label container */
@st-chart-grid(.chart-grid, 10, 7) /* 10 rows × 7 cols grid */

The JS Bridge (19 lines)

This is the entire runtime layer. No chart library, no framework.

const chartFill = document.querySelector(".chart-fill");
const chartLine = document.querySelector(".chart-line");
const chartDot  = document.querySelector(".chart-dot");

// st-core clip-path is top-down, so flip the value
function normalize(n) {
  return (100 - n) + '%';
}

// X positions for the 8 columns
const xStops = ['0%', '14%', '28%', '42%', '57%', '71%', '85%', '100%'];

function update(points) {
  // Set --st-p1..8 directly on the elements
  const vars = points.map((v, i) => `--st-p${i + 1}: ${normalize(v)};`).join(' ');
  chartLine.style.cssText = vars;
  chartFill.style.cssText = vars;

  // Move dot to the peak
  const highest = Math.max(...points);
  const idx = points.indexOf(highest);
  chartDot.style.top  = normalize(highest);
  chartDot.style.left = xStops[idx];
  chartDot.querySelector('.tooltip').textContent = `$${(highest * 5.5).toFixed(2)}`;
}

Call update() with any array of 8 numbers and the chart animates there. That's the whole bridge.

Connecting to Real Data

WebSocket (e.g. financial feed)

const socket = new WebSocket('wss://your-api.com/expenses/stream');

socket.onmessage = (event) => {
  const { daily } = JSON.parse(event.data);
  // daily is an array of 8 values, one per day
  update(daily);
};

REST polling (e.g. every 30 seconds)

async function poll() {
  const res  = await fetch('/api/expenses/weekly');
  const data = await res.json();
  update(data.points); // [20, 45, 33, 60, 27, 51, 38, 44]
}

poll();
setInterval(poll, 30_000);

In both cases your only job is feeding an array of 8 numbers into update(). The CSS does everything else — shape, fill, transition, dot position.

Why `clip-path` Makes This Work

st-core uses clip-path: polygon() which means:

The shape is arbitrary — true area curves, not stepped bars
Transitions are compositor-accelerated — clip-path animates on the GPU, not the main thread
No repaints — changing --st-p* variables doesn't touch the DOM structure at all

The transition declaration is doing a lot of heavy lifting here:

.chart-fill, .chart-line {
  transition: clip-path .9s cubic-bezier(.4, 0, .2, 1);
}

That single line is what makes the chart feel like a live dashboard instead of a static image that gets replaced.

The "Gravy Path": Compiling to Pure CSS

The exec.min.js CDN script is for prototyping and demos. For production — and especially for large-scale projects — you compile your .fscss file down to totally pure, standard CSS.

Two ways to do this:

1. VS Code Extension

Install the FSCSS extension from the VS Code marketplace, and install fscss from npm. It watches your .fscss files and compiles on save — you get instant output CSS right next to your source file. This is the fastest feedback loop for building UIs.

2. FSCSS npm package

npm install -g fscss

fscss "path/to/style.fscss" "path/to/style.css"

More details on that fscss.devtem.org.

The compiled output is 100% standard CSS. No runtime dependency, no JavaScript required for the styles. You ship the .css file and it just works.

Why this matters for large-scale projects

When you're managing a dashboard with dozens of chart components, keeping your chart configuration in .fscss files is a huge advantage:

/* charts/expenses.fscss */
@st-chart-points(20, 25, 21, 37, 30, 60, 27, 50)

/* charts/revenue.fscss */
@st-chart-points(44, 51, 60, 72, 65, 80, 78, 90)

You get a single source of truth for chart shapes, baseline datasets, theming, and responsive behavior — all in .fscss. The compiled CSS is what ships to users. The JS layer stays tiny because it only handles the live variable updates.

The Full Stack, One More Time

.fscss source
  └── compiled via npm
        └── pure CSS output
              ├── clip-path polygon (shape)
              ├── --st-p1..8 variables (data)
              ├── transitions (motion)
              └── stat card / axis / grid layout

Runtime JS (optional, for live data)
  └── update(points[]) → sets --st-p1..8 on elements
        └── CSS transition takes over → smooth animation

The mental model: FSCSS owns the structure and shape. JS owns the numbers. CSS owns the motion.

The core pattern doesn't change for any of these. You're still just feeding --st-p* variables and letting the compiled CSS handle the rest.

fscss.devtem.org

Building a trading dashboard UI with zero JavaScript — just st-core.fscss

FSCSS tutorial — Fri, 03 Apr 2026 01:09:40 +0000

No JS. No SVG. No canvas. Just CSS — and one import.

Here's what that actually looks like in practice.

The problem with dashboard UIs

Every time I need a stats dashboard — chart, bars, stat cards, the whole thing — I end up writing the same boilerplate. CSS variables, clip-path polygons, card layouts. It's not hard, but it's repetitive. And when you're working across multiple projects, copy-pasting that foundation every time gets old fast.

So packaged it.

st-core.fscss is an open source plugin for FSCSS that gives you a complete trading/stats dashboard design system in a single import. MIT licensed, no dependencies besides the FSCSS runtime or cli.

What you get

A full set of @st-* mixins that each generate a production-ready component:

Mixin	Output
`@st-root()`	Design tokens (colors, radius, spacing) on `:root`
`@st-stat-card`	Stat card — label, value, up/down delta
`@st-chart-fill`	Gradient area fill under a chart line
`@st-chart-line`	Glowing line stroke
`@st-chart-dot`	Positioned data point with tooltip support
`@st-chart-grid`	Background grid lines
`@st-chart-axis-x/y`	Axis label rows
`@st-chart-points`	Inject 8 data values into a chart
`@st-cat-bar-fill`	Gradient progress bar fill
`@st-phone`	Mock phone/device frame

How the chart works — pure CSS, no JS

This is the interesting part. The chart is a clip-path: polygon() shape.

You pass 8 Y values to @st-chart-points, which writes them as CSS custom properties — --st-p1 through --st-p8 — on your chart container. The fill and line elements inside read those values and clip themselves accordingly.

.chart {
  position: relative;
  height: 200px;
  overflow: hidden;
  background: var(--st-surface);

  /* your 8 data points */
  @st-chart-points(20, 35, 33, 30, 48, 35, 66, 37)
}

That's it. No JS. No SVG path calculations. The "line" is a thin filled polygon with two rows of points — the front edge and the back edge — separated by --st-chart-line-width. Change the width, the line redraws.

.chart-line {
  @st-chart-line-width(2px)
}

A minimal full example

demo using runtime

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

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

/* ================= INIT ================= */

@st-root()
@st-container(body)

/* ================= COMPONENTS ================= */

@st-chart-fill(.chart-fill)
@st-chart-line(.chart-line)
@st-chart-dot(.chart-dot, 70, 60)

/* ================= CHART ================= */

.chart{
  width: 100%;
  height: 200px;
  border-radius: 25px;
  position: relative;
  overflow: hidden;

  background: var(--st-surface);

  /*  DATA (main power) */
  @st-chart-points(20,25,21,37,30,60,27,50)
}
@st-phone(.wrapper)
/* ================= LINE ================= */

.chart-line{
  /* controlled via helper */
  @st-chart-line-width(2px);

  /* optional override */
  filter: drop-shadow(0 0 8px var(--st-accent));
}

/* ================= FILL ================= */

.chart-fill{
  /* enhance fill visibility */
  opacity: .85;
}

/* ================= DOT ================= */

.chart-dot{
  position: relative;
  overflow: visible;

  /*  local customization */
  --st-accent: #c4a8ff; /* overrides root accent just for dot */
}

/* tooltip */
.chart-dot:after{
  content: attr(data-point);
  background: var(--st-accent);
  padding: 6px 8px;
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  border-radius: var(--st-radius-sm);
  position: absolute;
  top: -40px;
  left: -22px;
  white-space: nowrap;
}

/* arrow */
.chart-dot:before{
  content: '';
  width: 10px;
  height: 10px;
  background: var(--st-accent);
  transform: rotate(45deg);
  position: absolute;
  top: -18px;
  left: 2px;
}

/* ================= EXTRA (USING st-core IDEA) ================= */


@st-stat-card(.stat-card)
@st-chart-axis-x(.x-axis)
@st-chart-axis-y(.y-axis)



@st-chart-grid(.chart-grid, 10, 7)
</style>
<div class="wrapper">
    <div class="stat-card">
    <div class="st-stat-label">TOTAL EXPENSES</div>
    <div class="st-stat-value">$1,326.03</div>
    <div class="st-stat-delta up">+5.1% vs last week</div>
  </div>
<div class="chart">
  <div class="chart-fill"></div>
  <div class="chart-line"></div>
  <div class="chart-dot" data-point="$405.67"></div>
  <div class="chart-grid"></div>
   <div class="y-axis">
   <span>0</span>
   <span>10</span>
   <span>20</span>
   <span>30</span>
   <span>40</span>
   <span>50</span>
   <span>60</span>
   <span>70</span>
   <span>80</span>
   <span>90</span>
   <span>100</span>
 </div>
  </div>
        <div class="x-axis days">
      <span>Sun</span>
      <span>Mon</span>
      <span>Tue</span>
      <span>Wed</span>
      <span>Thu</span>
      <span>Fri</span>
      <span>Sat</span>
      <span>Sun</span>
    </div>

  </div>

A full chart with a stat card and axis labels. That's the entire CSS. No custom polygon math, no JavaScript data binding.

Token overrides — it's just CSS variables

All the colors, spacing, and radii are CSS custom properties. Override any of them locally — they cascade normally.

/* global theme tweak */
:root {
  --st-accent: #00d4ff;
  --st-bg: #0a0f1e;
}

/* local override — just for the dot */
.chart-dot {
  --st-accent: var(--st-accent-2);
}

Multiple charts on the same page? Each container has its own --st-p1–--st-p8, so they're fully independent.

Category bars

The @st-cat-bar-fill mixin builds a gradient progress bar. You set the fill per element using a CSS variable — no extra params needed once the mixin is declared.

@st-cat-bar-fill(.bar-fill, 0)

/* per-bar widths */
.equities { --st-cat-bar-fill-range: 82%; }
.crypto   { --st-cat-bar-fill-range: 61%; }
.forex    { --st-cat-bar-fill-range: 45%; }

<div class="bar-track">
  <div class="bar-fill equities"></div>
</div>

See it live

Live demo

GitHub — fscss-ttr/st-core.fscss (MIT)

FSCSS NPM (MIT)

The full demo includes stat cards, a chart with fill + line + dot + grid + axes, category bars, and a phone frame — all driven by @st-* mixins with no custom CSS beyond the mixin calls themselves.

Why FSCSS?

FSCSS is a lightweight modern CSS preprocessor.

If you're unfamiliar with FSCSS, the docs are a good starting point.

Drop a ⭐ on the repo if it's useful, and feel free to open issues or PRs — it's MIT, go wild.

Building a Data-Driven Chart UI with Zero JavaScript (Pure CSS + FSCSS)

FSCSS — Wed, 01 Apr 2026 23:35:28 +0000

Most modern web charts rely on heavy JavaScript libraries. While powerful, they often come with a performance cost and complex integration steps.
What if you could build a fully styled, data-driven chart UI using Pure CSS?
By using FSCSS and its utility system, st-core (statistic core)_, we can transform raw data into visual interfaces directly within our stylesheets.

1. The Setup

First, include the FSCSS runtime and import the st-core helpers.

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

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

/* Initialize design tokens, layout base, and colors */
@st-root() 
@st-container(body) 
</style>

2. Attaching the Components

st-core.fscss uses directive-like helpers to generate the complex logic needed for backgrounds, lines, and markers.

@st-chart-fill(.chart-fill)    /* Area under the line */
@st-chart-line(.chart-line)    /* The actual trend line */
@st-chart-dot(.chart-dot, 70, 60) /* Data point marker at x=70, y=60 */

3. Mapping Data to UI

This is where the magic happens. The @st-chart-points helper maps your numeric data points into CSS variables. These variables are then used to calculate a clip-path that draws the chart.

.chart {
  width: 300px;
  height: 400px;
  border-radius: 25px;
  border: 2px solid var(--st-accent);
  position: relative;
  overflow: hidden;
  background: var(--st-surface);

  /* The Data: These points define the shape of the graph */
  @st-chart-points(20, 25, 21, 37, 30, 60, 27, 50)
}

4. Customizing the Visuals

Because this is CSS, customization is trivial. You can use filters, transitions, and standard properties to polish the UI.

/* Add a glow to the line */
.chart-line {
  @st-chart-line-width(2px);
  filter: drop-shadow(0 0 8px var(--st-accent));
}

/* Style the tooltip and point */
.chart-dot {
  position: relative;
  --st-accent: #c4a8ff; /* Local theme override */
}

.chart-dot:after {
  content: attr(data-point); /* Pulls data from HTML attribute */
  background: var(--st-accent);
  padding: 6px 8px;
  border-radius: var(--st-radius-sm);
  /* ... positioning ... */
}

5. The Final HTML Structure

The HTML remains incredibly clean. No Canvas elements, no complex SVG strings—just a few semantic divs.

<div class="chart">
  <div class="chart-fill"></div>
  <div class="chart-line"></div>
  <div class="chart-dot" data-point="$405.67"></div>
</div>

Why This Matters

Zero JS Overhead: The browser handles the rendering logic via CSS variables and clip-paths.
Declarative Data: You define data where you define your styles.
Fully Themeable: Since it uses CSS variables (--st-accent, etc.), switching to dark mode or changing brand colors is instantaneous. This approach shifts the paradigm: CSS isn't just styling the UI, it’s generating the UI from data.

Check out the project here: st-core on GitHub

Build a 360 Starburst Animation Using FSCSS

FSCSS tutorial — Mon, 30 Mar 2026 11:47:29 +0000

Traditional CSS struggles when you need to generate hundreds of repeated elements with dynamic transformations.

With FSCSS, you can do this elegantly using arrays, loops, and computed values — all inside your styles.

In this guide, we’ll build a 360-degree radial starburst animation using FSCSS.

What We’re Building

A circular pattern made of 360 elements, each rotated slightly to form a full radial burst.

Each ray ends with a small geometric shape, creating a complex animated structure.

HTML

<div class="box"></div>

JavaScript (Generate 360 Elements)

const box = document.querySelector(".box");

for (let i = 0; i < 360; i++) {
  const star = document.createElement("div");
  star.className = "star";
  box.appendChild(star);
}

Instead of writing 360 elements manually, JavaScript handles it.

FSCSS Code

@import((*) from snake_case)
@import((*) from themes)
@import((flex-wrap-center as flex_wrap) from flex-control)

body {
  background_color: #233332;
}

.box {
  %2(width, height [: 400px;])
  position: absolute;
  transform_style: preserve-3d;
  @flex_wrap()
}

@arr pos[count(360, 10)]

.box .star:nth-child(@arr.pos[]) {
  $pos: @arr.pos[];

  background: #2FF200;
  padding: 1px;
  width: 100px;
  position: absolute;

  transform_origin: right;
  transform: rotate($pos!deg);
}

.star:before {
  content: " ";
  position: absolute;
  width: 20px;
  height: 20px;
  background: #C800F2;

  top: -8.5px;
  left: -7px;

  transform: rotate(60deg);

  tr Shape: @event.shape(star);
}

$(@keyframes rotate,.star &[360s linear infinite alternate]) {
  to {
    transform: rotate(0);
  }
}

How It Works

1. Array Generation

@arr pos[count(360, 10)]

This creates a sequence:

10, 20, 30 ... 350

Each value is used to rotate an element.

Dynamic nth-child Targeting

.box .star:nth-child(@arr.pos[])

FSCSS maps each array value to a corresponding element automatically.

3. Rotation Per Element

transform: rotate($pos!deg);

Each .star rotates based on its assigned value, forming a full circle.

4. Shape Injection via Event from the imported themes

tr Shape: @event.shape(star);

This dynamically applies a shape transformation, allowing reusable geometric logic.

5. Animation Binding

$(@keyframes rotate,.star &[360s linear infinite alternate])
FSCSS binds animation directly to the selector in one line.

Why This Is Powerful

With FSCSS, you get:

Looping without preprocessors
Dynamic selectors
Inline logic and transformations
Reusable event-driven styling
Zero runtime overhead

Final Result

You now have a fully procedural radial animation, built with:

1 HTML element
1 loop in JavaScript
FSCSS handling all styling logic

codepen demo

https://codepen.io/David-Hux/pen/gbwvqGb

FSCSS changes how you think about CSS.

Instead of writing repetitive rules, you define behavior — and let the system generate the rest.

You can extend this into:

loaders
charts
generative UI
data-driven visuals

Want more like this?

Why kebab-case is Outdated — And How FSCSS Fixes It

FSCSS tutorial — Fri, 27 Mar 2026 18:58:26 +0000

CSS naming hasn’t evolved.

Everything else in development has — JavaScript, Python, APIs — but CSS is still stuck in:

background-color: #111;
border-radius: 8px;

Hyphens. Everywhere.

Meanwhile, the rest of your stack uses:

camelCase (JavaScript)

snake_case (Python, databases)

That mismatch is not just annoying — it’s inefficient.

The Real Problem: Context Switching

Every time you write CSS, your brain does a silent conversion:

backgroundColor → background-color

user_name → user-name

That’s friction.

And friction slows teams down.

Even modern systems still enforce kebab-case in CSS — meaning developers constantly translate between conventions.

FSCSS Changes the Rule

With FSCSS (Figured Shorthand Cascading Style Sheets), you don’t adapt to CSS…

CSS adapts to you.

Write CSS Like Your Actual Code

camelCase (Frontend-friendly)

@import((*) from camelCase)

.card {
  backgroundColor: #111;
  borderRadius: 12px;
}

snake_case (Backend-friendly)

@import((*) from snake_case)

.card {
  background_color: #111;
  border_radius: 12px;
}

What Happens Behind the Scenes

Both become:

background-color: #111;
border-radius: 12px;

FSCSS maps naming styles directly to valid CSS — no hacks, no runtime overhead.

Why This Is a Bigger Deal Than It Looks

1. Your Brain Stops Translating

Camel case uses capital letters to separate words
Snake case uses underscores instead

FSCSS lets you stick to one mental model.

2. Your Stack Becomes Consistent

React / Next.js → use camelCase

Django / APIs → use snake_case

CSS → now matches both

3. Teams Move Faster

No more:

“Wait, what’s the CSS version of this?”

“Is it borderRadius or border-radius again?”

You already know the answer because you’re already using it.

Extend Beyond Naming

FSCSS isn’t just about syntax - it lets you build reusable styling logic:

@define glassEffect(){
  backdrop-filter: blur(12px);
  background: rgba(255,255,255,0.2);
} 

.hero {
  @glassEffect()
}

Now your CSS behaves more like a system.

Learn More

If you want to go deeper into each approach:

Snake case guide:
https://figsh.devtem.org/how_to_use_snakecase_fscss

Camel case guide:
https://figsh.devtem.org/how_to_use_camelcase_fscss

Final Thought

Kebab-case made sense when CSS was isolated.

But modern development is interconnected.

FSCSS brings CSS into alignment with the rest of your stack —
and removes one of the most subtle productivity killers in frontend development.

FSCSS @random() - Making CSS Feel Alive

FSCSS tutorial — Wed, 25 Mar 2026 18:59:38 +0000

There was a time when CSS felt… predictable.

Every color was chosen.
Every position was fixed.
Every animation behaved exactly the same—every single time.

Then came FSCSS… and suddenly, randomness became a design tool.

What is `@random()` in FSCSS?

The @random() function in Figured Shorthand Cascading Style Sheets (FSCSS) allows you to generate dynamic, non-deterministic values at runtime.

Instead of hardcoding styles, you let the browser decide—from a list you provide.

color: @random([red, blue, green]);

Each render can produce a different result. Same code, different vibe.

How It Works

@random() accepts an Array of values and randomly selects one.

Numbers

width: @random([100, 200, 300])px;

Colors

background: @random([lightgreen, yellow, orange]);

Transforms

transform: translateX(@random([10, 30, 40, -60])px);

Why This Matters

Traditional CSS is static.
FSCSS introduces controlled randomness.

That opens doors to:

Procedural UI design
Organic-looking animations
Dynamic backgrounds (stars, particles, noise)
Unique user experiences on every load

Real-World Use Cases

Randomized Star Field

.star{
  left: @random([10,20,30,40,50,60,70,80,90])%;
  top: @random([10,20,30,40,50,60,70,80,90])%;
}

Dynamic Button Colors

.btn{
  background: @random([#ff6b6b, #6bcB77, #4d96ff, #ffd93d]);
}

Organic Motion

@keyframes float{
  to{
    transform: translateY(@random([-20, -40, -60])px);
  }
}

Best Practices

Use CDN runtime when working with @random() (it runs in the browser).

Combine with:

@arr → reusable value sets

@define → reusable logic blocks

@event → conditional styling

Avoid overusing randomness in critical UI elements (keep UX predictable where needed).

A Quick Note

Random doesn’t mean chaos.

Good design still needs constraints.
Think of @random() as guided creativity, not pure unpredictability.

Final Thoughts

@random() is one of those features that quietly changes how you think about CSS.

It’s no longer just styling it’s behavior.

And once you start using it…
you’ll wonder why CSS was ever fully static.

FSCSS Toast System (Dynamic UI Without Repetition)

FSCSS — Sun, 22 Mar 2026 17:39:25 +0000

A clean, scalable toast/notification system built with FSCSS using events + arrays + dynamic selectors.

No repeated classes. No manual variants.
Just structured, reusable styling.

Features

Dynamic toast types (success, error, warning, info)
Centralized color logic using @event
Auto-generated class variants with @arr
Clean and scalable structure
Modern UI styling (glass + soft colors)

Define Toast Color Logic

@event toast-color(type){

if type:success{
  return: #38d9a9;
}

el-if type:error{
  return: #ff6b6b;
}

el-if type:warning{
  return: #f7b267;
}

el{
  return: #74c0fc;
}

}

This acts like a function:

type → color

Base Toast Component

.toast{
  padding: 12px 16px;
  border-radius: 10px;
  color: #fff;
  font-size: 14px;

  background: rgba(255,255,255,0.05);
  backdrop-filter: blur(8px);

  border-left: 4px solid currentColor;

  display: flex;
  gap: 10px;
  align-items: center;

  min-width: 220px;
}

Generate Toast Variants

@arr toast-types[success,error,warning,info]
@arr i[1,2,3,4]

.toast-@arr.toast-types[@arr.i[]]{

  $type: @arr.toast-types[@arr.i[]];

  color: @event.toast-color($type);
}

💡 Why the Index Mapping?

FSCSS currently resolves:

Selector → index ("1, 2, 3...")
Value → actual array value ("success, error...")

So we map them together:

index → value → selector

Result:

.toast-success { color: ... }
.toast-error { color: ... }

Usage

<div class="toast toast-success">Operation successful</div>

<div class="toast toast-error">Something went wrong</div>

<div class="toast toast-warning">Check your input</div>

<div class="toast toast-info">New update available</div>

✨ Optional: Add Icons

<div class="toast toast-success">✔ Operation successful</div>
<div class="toast toast-error">✖ Something went wrong</div>
<div class="toast toast-warning">⚠ Check your input</div>
<div class="toast toast-info">ℹ New update available</div>

🔥 How It Works

Flow:

Class → Array Mapping → Event Logic → Final Style

Example:

toast-success
→ mapped to "success"
→ passed into @event
→ returns color
→ applied to UI

Why This Pattern Matters

Avoids repetitive CSS
Centralizes UI logic
Scales easily as types grow
Keeps styling consistent

Takeaway

This approach shows how FSCSS can:

Handle UI state
Generate variants automatically
Apply logic inside styling

Without relying on JavaScript.

Next Ideas

Add animations (slide-in, fade)
Create stacked notifications (top-right)
Build theme variations (dark/light)
Auto-inject icons via "@event"

Clean. Scalable. Powerful.

Welcome to structured CSS ❤️

FSCSS tutorial Follow

Figured Shorthand Cascading Style Sheet

Turning CSS Into a Smart UI Engine (Without JavaScript)

FSCSS tutorial — Sat, 21 Mar 2026 14:26:19 +0000

Modern UI development keeps pushing toward more dynamic, responsive, and intelligent interfaces. But what if some of that “logic” didn’t need JavaScript at all?

Today, I experimented with something interesting: building a fully dynamic circular progress system where values, colors, and styles are generated and computed directly inside CSS.

No loops in JS. No conditionals in JS.
Everything happens in styling.

⚡ The Goal

Create a circular progress component that:

Supports values from 0 → 100
Automatically generates classes like .p-0, .p-1, .p-2, to p-100
Dynamically changes color based on the value
Feels like a real UI component system

🧩 Setup

FSCSS CDN or it extention + npm

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.20/exec.min.js" async></script>

@import(exec(_init circle-progress))
@progress-root()
@circle-progress(.progress)

This initializes a reusable circular progress component.

🧠 Adding Logic to Styling

Instead of hardcoding colors, we define a reusable event:

@event range-color(range){

if range<=10{
    return: #ff6b6b;
}

el-if range<=30{
    return: #f7b267;
}

el-if range<=60{
    return: #74c0fc;
}

el-if range<=99{
    return: #63e6be;
}

el{
    return: #38d9a9;
}

}

This acts like a function:

«Input → progress value
Output → corresponding UI color»

🔁 Generating 100 Classes Automatically

Instead of writing ".p-1", ".p-2", ".p-3" manually:

@arr p-ranges[count(100)]

Now we loop through them:

.p-@arr.p-ranges[]{
    $range: @arr.p-ranges[];

    @progress-range($range)

    --progress-color-glow: @event.range-color($range);
    --progress-color-arc: @event.range-color($range);
}

This generates:

.p-1 { ... }
.p-2 { ... }
...
.p-100 { ... }

Automatically.

🎨 Styling

body{
  background: #131213;
}

🧪 Usage

<div class="progress p-10">10</div>
<div class="progress p-30">30</div>
<div class="progress p-55">55</div>
<div class="progress p-89">89</div>
<div class="progress p-100">100</div>

✨ What’s Happening Here?

Each element:

Gets its value from the class ("p-55")
That value is passed into "@progress-range"
The same value is sent into "@event range-color"
The UI updates automatically

So the system becomes:

Class → Value → Logic → Style → UI

💡 Why This Is Interesting

This fscss approach introduces a different way to think about styling:

CSS with Logic

You’re not just styling — you’re deciding behavior

No Repetition

No need to manually define 100 variations

Reusable Patterns

The same "@event" can power multiple components

Component Thinking

Styles start behaving like UI modules

Example

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.20/exec.min.js"  async></script>

<style>

@import(exec(_init circle-progress))
@progress-root()
@circle-progress(.progress)

@event range-color(range){

if range<=10{
    return: #ff6b6b; /* soft red */
}

el-if range<=30{
    return: #f7b267; /* warm orange */
}

el-if range<=60{
    return: #74c0fc; /* light blue */
}

el-if range<=99{
    return: #63e6be; /* soft teal */
}

el{
    return: #38d9a9; /* fresh green */
}

}

body{
  background: #131213;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  padding: 20px;
  gap: 15px;
}
@arr p-ranges[count(100)]

.p-0 {
    @progress-range(0) 
    --progress-color-glow: @event.range-color(0);
    --progress-color-arc: @event.range-color(0); 
}

.p-@arr.p-ranges[]{
    $range: @arr.p-ranges[];
    @progress-range($range) 
    --progress-color-glow: @event.range-color($range);
    --progress-color-arc: @event.range-color($range); 
}


</style>

<div class="progress p-10">10</div>
<div class="progress p-30">30</div>
<div class="progress p-55">55</div>
<div class="progress p-89">89</div>
<div class="progress p-100">100</div>

🔥 Real Use Cases

This pattern can be extended to:

Skill meters
File upload progress
Health/status indicators
Dashboard analytics
Gamification systems

We usually separate logic (JavaScript) and styling (CSS).
But this shows something interesting:

Styling itself can become expressive enough to handle structured logic.

🚀 FSCSS Extension for VS Code is Now Live

FSCSS tutorial — Tue, 17 Mar 2026 00:39:07 +0000

I'm excited to announce that the FSCSS Support extension for VS Code is now available on the Visual Studio Marketplace!

Making developer experience smoother inside VS Code.

The extension provides syntax highlighting and tooling for .fscss files.

Install the Extension

You can install it directly from the marketplace:

https://marketplace.visualstudio.com/items?itemName=Figsh.fscss

Or search “FSCSS” inside VS Code extensions.

✨ Features

The extension currently includes:

FSCSS syntax highlighting
Support for .fscss and .xfscss files
FSCSS snippets
Custom language icon
Grammar support for the FSCSS syntax

This makes it easier to write and explore FSCSS directly in VS Code.

What is FSCSS?

FSCSS (Figured Shorthand Cascading Style Sheets) is a CSS-inspired system designed to make stylesheets shorter, more expressive, and more programmable.

Example:

@define button(){
  padding: 10px;
  background: blue;
  color: white;
}

.btn{
  @button()
}

Project Repository

The extension source code is available here:

https://github.com/Figsh/fscss-vscode-extension

Feel free to explore, suggest improvements, or contribute.

What's Next?

Future improvements may include:

IntelliSense for FSCSS functions
auto-completion
FSCSS → CSS compile helpers
improved syntax rules

If you try the extension, I'd love to hear your feedback.

Happy coding!

Building 200+ CSS Utility Classes in 6 Lines with FSCSS 🤯

FSCSS tutorial — Fri, 13 Mar 2026 22:04:53 +0000

One of the fun things about FSCSS is how easily you can generate large utility systems without writing repetitive CSS.

Instead of manually creating dozens or hundreds of classes like:

.radius-1 { border-radius:1px; }
.radius-2 { border-radius:2px; }
.radius-3 { border-radius:3px; }
/* ... */
.radius-200 { border-radius:200px; }

FSCSS can generate all of them automatically.

Let's look at a simple example.

The Setup

First include the FSCSS CDN:

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.17/exec.min.js" async></script>

Now we can write FSCSS directly inside <style>.

Generate 200 Border Radius Utilities

@arr radius[count(200)]

.radius-@arr.radius[]{
  border-radius: @arr.radius[]px;
}

That's it.

Just two lines of logic.

What This Generates

FSCSS will automatically compile it into something like this:

.radius-1 { border-radius:1px; }
.radius-2 { border-radius:2px; }
.radius-3 { border-radius:3px; }
.radius-4 { border-radius:4px; }

/* ... */

.radius-200 { border-radius:200px; }

You just created 200 utility classes instantly.

Creating Padding Utilities

You can repeat the same idea for padding:

@arr padding[count(200)]

.padding-@arr.padding[]{
  padding: @arr.padding[]px;
}

Now you have:

.padding-1
.padding-2
.padding-3
...
.padding-200

All generated automatically.

Example Usage

<div class="card radius-25 padding-30">
  <h3>Hello World</h3>
</div>

With a simple card style:

.card{
  background: rgba(48, 56, 145, 1);
  %2(width, height [:200px;])
  color:#ddd;
}

Result:

• radius-25 → border-radius:25px
• padding-30 → padding:30px

Why This Is Useful

Utility systems like this normally require huge CSS files.

But FSCSS lets you generate them dynamically using logic like:

arrays
loops
functions
macros
imports

Which means you write logic instead of repetition.

The Crazy Part

You can scale this even further.

Example:

@arr size[count(1000)]

Now you can generate 1000 spacing utilities instantly.

Instead of writing CSS line by line, FSCSS lets you design CSS generators.

Things like:

utility frameworks

design systems

component libraries

reusable style functions

All become easier.

<script src="https://cdn.jsdelivr.net/npm/fscss@1.1.17/exec.min.js" async></script>

<style >
 @arr radius[count(200)]

.radius-@arr.radius[]{
  border-radius: @arr.radius[]px;
}

 @arr padding[count(200)]

.padding-@arr.padding[]{
  padding: @arr.padding[]px;
}


.card{
  background: rgba(48, 56, 145, 1);
  margin: 10px;
  %2(width, height [: 200px;]) 
  color: #ddd;
}

</style>

<div class="card radius-25 padding-30">
  <h3>Hello World</h3>
</div>


<div class="card radius-15 padding-20">
  <h3>Hello World</h3>
</div>

<div class="card radius-40 padding-55">
  <h3>Hello World</h3>
</div>

FSCSS Randomness, Arrays, and Better control

FSCSS tutorial — Tue, 10 Mar 2026 21:53:18 +0000

Some powerful features that make styling more dynamic and expressive.

Random value generation using arrays.

@random() — True Random Selection

FSCSS allows selecting a random value from an array using @random().

Example:

@arr colors[#1E2783, #8C29B2, #C41348]

body{
  background:@random(@arr.colors);
}

h1{
  background:@random(@arr.colors);
}

h2{
  background:@random(@arr.colors);
}

Each call to @random() is independent, meaning every selector can receive a different value.

Possible compile result:

body{ background:#8C29B2; }
h1{ background:#1E2783; }
h2{ background:#C41348; }

And on the next compile (or page reload if used CDN), the results may change again.

Inline Arrays

You can also use inline arrays directly inside @random().

border-width:@random([1,2,3])px;

Possible outputs:

1px
2px
3px

This makes it easy to quickly introduce variation into styles.

`array!.randint` — One Random Value Per Compile

FSCSS also provides a different behavior using:

array!.randint

Example:

@arr colors[red, blue, green]

h1{
  color:@arr.colors!.randint;
}

h2{
  color:@arr.colors!.randint;
}

body{
  color:@arr.colors!.randint;
}

In this case, one random value is selected for the entire compile.

Example result:

h1{ color:red; }
h2{ color:red; }
body{ color:red; }

On the next compile, it may change:

h1{ color:blue; }
h2{ color:blue; }
body{ color:blue; }

Why This Matters

These two behaviors allow different design strategies:

Global random theme

@arr.colors!.randint

Entire UI gets one random color.

Randomized UI elements

@random(@arr.colors)

Each element gets a different color.

Small Features, Big Possibilities

FSCSS Import System You Actually Wanted

FSCSS — Tue, 10 Mar 2026 15:09:22 +0000

FSCSS v1.1.16+: Import System

JavaScript-Style Imports

@import((
flex-center,
flex-wrap, 
flex-x
) from flex-control)
@import((
circle-progress as clp,
progress-range as pr,
progress-root as p-root
) from circle-progress)
@import((*) from st-core)

@p-root() 
@clp(.progress)
.p-72{
  @pr(72) 
}
.container {
  @flex-center()
}

Named imports. Aliases.

5 Ways to Import

Named imports

@import((flex-x, flex-center) from flex-control)

Aliases (when names clash)

@import((circle-progress as cp) from circle-progress)

Everything (when you're lazy)

@import((*) from themes)

Remote (CDN friendly)

@import((btn) from "https://cdn.example/buttons.fscss")

Built-in libs (no quotes needed)

@import((*) from icon-mask)

Also: It's Faster Now

v1.1.16+ CDN loads quicker than older versions.

The Error Messages Actually Make Sense

@import((* as all) from "style.fscss")
// Warning: syntax error at @import((* as all) from "style.fscss"): unexpected *

No more cryptic parser errors at 2am.

Same modular architecture. Way less noise.

Forem: FSCSS tutorial

From Static to Real-Time: Data Viz with st-core.fscss (Pure CSS Charts)

The "Aha" Moment

The Demo: Expenses Chart

CodePen demo

Directive Breakdown

The chart block

Support directives

The JS Bridge (19 lines)

Connecting to Real Data

WebSocket (e.g. financial feed)

REST polling (e.g. every 30 seconds)

Why clip-path Makes This Work

The "Gravy Path": Compiling to Pure CSS

1. VS Code Extension

2. FSCSS npm package

Why this matters for large-scale projects

The Full Stack, One More Time

Building a trading dashboard UI with zero JavaScript — just st-core.fscss

The problem with dashboard UIs

What you get

How the chart works — pure CSS, no JS

A minimal full example

Token overrides — it's just CSS variables

Category bars

See it live

Why FSCSS?

Building a Data-Driven Chart UI with Zero JavaScript (Pure CSS + FSCSS)

1. The Setup

2. Attaching the Components

3. Mapping Data to UI

4. Customizing the Visuals

5. The Final HTML Structure

Why This Matters

Build a 360 Starburst Animation Using FSCSS

What We’re Building

HTML

JavaScript (Generate 360 Elements)

FSCSS Code

How It Works

1. Array Generation

3. Rotation Per Element

4. Shape Injection via Event from the imported themes

5. Animation Binding

Why This Is Powerful

codepen demo

Why kebab-case is Outdated — And How FSCSS Fixes It

The Real Problem: Context Switching

FSCSS Changes the Rule

Write CSS Like Your Actual Code

What Happens Behind the Scenes

Why This Is a Bigger Deal Than It Looks

1. Your Brain Stops Translating

2. Your Stack Becomes Consistent

3. Teams Move Faster

Extend Beyond Naming

Learn More

Final Thought

FSCSS @random() - Making CSS Feel Alive

What is @random() in FSCSS?

How It Works

Why This Matters

That opens doors to:

Real-World Use Cases

Best Practices

A Quick Note

Final Thoughts

FSCSS Toast System (Dynamic UI Without Repetition)

Features

Define Toast Color Logic

Base Toast Component

Generate Toast Variants

Usage

✨ Optional: Add Icons

🔥 How It Works

Why This Pattern Matters

Takeaway

Next Ideas

FSCSS tutorial Follow

Turning CSS Into a Smart UI Engine (Without JavaScript)

Why `clip-path` Makes This Work

What is `@random()` in FSCSS?

`array!.randint` — One Random Value Per Compile