Beginner
+20 XP

👋 Start learning JavaScript right now — for free!

📖

Colors and Typography

CSS colors, fonts, sizes and CSS variables

Colors in CSS

CSS supports several color formats:

css
/* HEX — most common */
color: #e44d26;        /* orange */
color: #fff;           /* white (shorthand) */

/* RGB */
color: rgb(228, 77, 38);

/* RGBA — with opacity (0 = transparent, 1 = opaque) */
background: rgba(0, 0, 0, 0.5); /* 50% black */

/* HSL — hue, saturation, lightness */
color: hsl(14, 76%, 52%);

/* Named colors */
color: red;
color: cornflowerblue;

color — text color. background-color (or background) — background color.

Typography

css
/* Font */
font-family: 'Inter', Arial, sans-serif;
/* If 'Inter' didn't load — Arial, if not — any sans-serif */

/* Size */
font-size: 16px;    /* pixels */
font-size: 1rem;    /* relative to root element (16px by default) */
font-size: 1.125em; /* relative to parent element */

/* Weight */
font-weight: 400;   /* normal */
font-weight: 700;   /* bold */

/* Line height */
line-height: 1.6;   /* 1.6× the font-size — a good standard */

/* Alignment */
text-align: left | center | right | justify;

/* Decoration */
text-decoration: none | underline | line-through;
text-transform: uppercase | lowercase | capitalize;
letter-spacing: 0.05em; /* letter spacing */

CSS Variables (Custom Properties)

Let you store values and reuse them throughout your CSS:

css
:root {
  --color-primary: #6070f7;
  --color-text: #1e293b;
  --font-size-base: 16px;
  --border-radius: 8px;
}

.btn {
  background: var(--color-primary);
  border-radius: var(--border-radius);
}

/* To change the primary color — just update it in :root */

Why this is great: change one value in :root and the color scheme updates across the whole site. Perfect for dark mode.

css
💬

This is the CSS this platform uses. rem + CSS variables — the modern standard.

Prefer rem over px for fonts! If a user has increased the browser font size (for readability), rem scales with it, but px does not.

Comments

Log In or Start to leave a comment.