css3
Cascading Style Sheets (CSS) is a simple mechanism for adding style (e.g., fonts, colors, spacing) to Web documents.
clamp
Specify a range of values min, computed value, max
clamp(0.78rem, calc(0.71rem + 0.35vw), 0.96rem);
ch
Unit specifying the width of the 0 character.
  max-width: 30ch;
root
Define Variables
:root {
  /* Colors */
  --theme-primary: hsl(0, 0%, 5%);
  --theme-on-primary: hsl(0, 0%, 90%);
  --theme-primary-hover: hsl(0, 0%, 10%);
  --theme-primary-light: hsl(0, 0%, 80%);
  --theme-background: hsl(0, 0%, 98%);
  --theme-on-background: hsl(0, 0%, 5%);
  --theme-surface-1: hsl(0, 0%, 93%);
  --theme-on-surface-1: hsl(0, 0%, 10%);
  --theme-footer-background: hsl(0, 0%, 3%);
  --theme-on-footer-background: hsl(0, 0%, 90%);
  /* Typography */
 /* @link https://utopia.fyi/type/calculator?c=320,18,1.2,1140,24,1.25,5,2,&s=0.75|0.5|0.25,1.5|2|3|4|6,s-l */
  --step--2: clamp(0.78rem, calc(0.71rem + 0.35vw), 0.96rem);
  --step--1: clamp(0.94rem, calc(0.84rem + 0.51vw), 1.20rem);
  --step-0: clamp(1.13rem, calc(0.98rem + 0.73vw), 1.50rem);
  --step-1: clamp(1.35rem, calc(1.15rem + 1.02vw), 1.88rem);
  --step-2: clamp(1.62rem, calc(1.34rem + 1.41vw), 2.34rem);
  --step-3: clamp(1.94rem, calc(1.56rem + 1.92vw), 2.93rem);
  --step-4: clamp(2.33rem, calc(1.81rem + 2.59vw), 3.66rem);
  --step-5: clamp(2.80rem, calc(2.11rem + 3.47vw), 4.58rem);
  --font-family-heading: '', sans-serif;
  --font-family-body: 'Open Sans', sans-serif;
  --body-max-width: 1920px;
  /* Container */
  --container-padding: 0 1rem;
  --container-max-width: 860px;
  --header-height: 76px;
  /* Transitions */
  --ease-out-soft: cubic-bezier(0.28, 0, 0.49, 1);
}
white-space
Control how elements wrap. pre-wrap breaks lines at newlines.
white-space: pre-wrap;
word-break
Control where lines break. break-all will break on any character. This is helpful for long words.
word-break: break-all;
background
Set background color of an element
background: #ddd;
border-left
Set a left border
border-left:0.3rem solid #bbb;