css

• MDN Docs

• freeCodeCamp youtube link

Selectors

<selector > {
  <property>: <value>;
}

• Element Selectors h1, body
• ID Selectors #id-name
• Class Selectors .class-name
• Wildcard Selectors [<attr>*="<str>"], ^ = starts with, $ = ends with
• Universal Selector (type of Wildcard) *

Pseudo-Classes

<selector>:<pseudo-class> {...}

• hover
• visited
• checked
• first-child
• last-child
• nth-child - <selector>:nth-child(<n> | even | odd)

Pesudo-Elements

<selector>::<pseudo-element> {...}

• first-letter
• first-line
• before, after
  • { content: "some content to add without changing html" }

Combinators

<selector> <combinator> <selector2> {...}

• direct child >
• all descendants <literal space>
• adjacent siblings +
• general siblings (all) ~

More on Wildcard Selectors

• To select all classes containing str in name:

  [class*="str"] ...

• To select all classes that start with strt or end with end use:

  [class^="strt"] ...
  [class$="end"] ...

Tips

• To center image: margin: 0 auto

• To center text: text-align: center

• Group duplicates: h1, h2, .header-class, #header-id { ... }

Sizing Units

• Absolute units: px, pt, cm, mm, in

• Relative units: em, rem, vw, vh, %

• Standard html size is around 16px

• Use relative units for responsive UI

Colors

• Build-in names white, blue, black, red

• RGB(A) (Red, Blue, Green, Alpha) rgb(x, y, z)

• Hexadecimal #000000 -> #FFFFFF #RRBBGG

• HSL (Hue, Saturation%, Lightness%)

• Adobe Color Wheel

Typography

• font-family
• font-weight
• text-align
• text-shadow
• text-transform
• text-indent
• line-height
• letter-spacing
• word-spacing
• white-space
• background-color (not specific to typography)

Box-model

content, padding, border, margin.

Layouts

Flexbox

• Parent:

  • display: flex
  • flex-direction: row (default on web) | column (default on react-native)
  • justify-content: center | ... (main axis)
  • align-items: center | flex-start | ... (cross axis)
  • flex-wrap: wrap | nowrap

• Children:

  • flex-grow: <number> amount of space an item will take
  • flex-shrink: <number> same as above
  • flex-basis: <value> Initial size
  • Shorthand for grow, shrink and basis: flex: <num> <num> <val>
  • align-self: center | ...

Grid

Frameworks

• Bulma
• Bootstrap
• Ant
• Sementic

Tips n Tricks

• Center Div

  <div class="outer">This text should be in center!</div>
  
  <style>
    .outer {
      display: flex /* grid */;
      justify-content: center;
      align-items: center;
      height: 100%;
    }
  </style>

• Change svg color using css filter

Source

1. Add the SVG image using an <img> tag.

   <img src="dotted-arrow.svg" class="filter-green" />

2. To filter to a specific color, use the following Codepen to convert a hex color code to a CSS filter:

For example, output for #00EE00 is

filter: invert(42%) sepia(93%) saturate(1352%) hue-rotate(87deg) brightness(119%) contrast(119%);

3. Add the CSS filter into this class.

   .filter-green {
     filter: invert(48%) sepia(79%) saturate(2476%) hue-rotate(86deg) brightness(
         118%
       ) contrast(119%);
   }