General

Misc

  • Resources

  • Tools

    • Gradient Generator
    • Widget for testing parameter values for css styling a div box
      • Gradient inside, shadow, border, size, etc.
      • Similar tool mostly for box shadows

  • Margin, Border, and Padding

    • Margin is the space between the edge of the div/border and the rest of the elements
    • Padding is the space between the text and the edge of the div/border
    • Syntax
      • padding: 25px 50px 75px 100px;
        • top padding is 25px
        • right padding is 50px
        • bottom padding is 75px
        • left padding is 100px
      • padding: 25px 50px 75px;
        • top padding is 25px
        • right and left paddings are 50px
        • bottom padding is 75px
      • padding: 25px 50px;
        • top and bottom paddings are 25px
        • right and left paddings are 50px
      • padding: 25px;
        • all four paddings are 25px

  • Column Widths in CSS Grid

  • CSS comment - /* comment */

  • Selector formats

    • Syntax: #<class>.<id><additional-stuff>
    • Example:

      • CSS

        #header.fluid-row::before{
}

      • HTML

        <div class="fluid-row" id="header"> == $0
::before
</div>

  • Include css styling directly into a html page

    • Example: Via HTML style tag

      <style>
body {
  padding: 50px 25px 0px 25px;
  font-family: 'Roboto', sans-serif;
  font-size: 19px;
}
</style>

    • Example: Via R chunk

      htmltools::tags\$link(href = "https://fonts.googleapis.com/css2?family=Libre+Baskerville:ital,wght\@0,400;0,700;1,400&display=swap",
                      rel = "stylesheet")

    • Example: styling of a legend html div

      <style type='text/css'>
  .my-legend .legend-title {
    text-align: left;
    margin-bottom: 8px;
    font-weight: bold;
    font-size: 90%;
    }
  .my-legend .legend-scale ul {
    margin: 0;
    padding: 0;
    float: left;
    list-style: none;
    }
  .my-legend .legend-scale ul li {
    display: block;
    float: left;
    width: 50px;
    margin-bottom: 6px;
    text-align: center;
    font-size: 80%;
    list-style: none;
    }
  .my-legend ul.legend-labels li span {
    display: block;
    float: left;
    height: 15px;
    width: 50px;
    }
  .my-legend .legend-source {
    font-size: 70%;
    color: #999;
    clear: both;
    }
  .my-legend a {
    color: #777;
    }
</style>
      • See link for details on the legend div element that uses this CSS

Centering

  • There are also instructions for placing elements in different positions (e.g. right edge)
  • Notes from How To Center a Div
    • There’s also code/explainer for centering elements (e.g. images) that have to stacked on top of each other

Elements

  • Center Horizontally with auto-margins

    .element {
  max-width: fit-content;
  margin-left: auto;
  margin-right: auto;
  /* margin-inline: auto*/
}
    • Use when you want to horizontally center a single element without disturbing any of its siblings
    • max-width is used because if width is used instead, it would lock it to that size, and the element would overflow when the container is really narrow.
    • Including only margin-left: auto will force the div flush with the right side and vice verse with margin-right
    • margin-inline: auto can replace both margin-left and margin-right to center the div

  • Centering Vertically and Horizontally

    .container {
  align-content: center;
}
.element {
  max-width: fit-content;
  margin-inline: auto;
}

  • Center Vertically and Horizontally with Flexbox

    /* single element */
.container {
  display: flex;
  justify-content: center;
  align-items: center;
}
/* multiple elements */
.container {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 4px;
}
    • The most versatile method; it can be used to center one or multiple children, horizontally and/or vertically, whether they’re contained or overflowing.
    • flex-direction controls the direction in which the items are aligned, and it can have other values: column, row-reverse, column-reverse

  • Text

    container {
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
}
    • Blocks of text can be treated as one element and can be centered using the previous methods. This code (text-align) is for centering the rows of text within a element’s block.

Viewports

  • Useful for elements like dialogs, prompts, and GDPR banners need to be centered within the viewport. (Think pop-ups)

  • Centering With Known Sizes

    .element {
  position: fixed;
  inset: 0px;
  width: 12rem;
  height: 5rem;
  max-width: 100vw;
  max-height: 100dvh;
  margin: auto;
}
    • Complex and has more settings that depend on the element. See article for details but there are four main concepts:
      • Fixed positioning
      • Anchoring to all 4 edges with inset: 0px
      • Constrained width and height
      • Auto margins
    • Omitting top: 0px will anchor the element to the bottom

      • Use calc with max-width to make sure theres a buffer around the element

        max-width: calc(
    100vw - 8px * 2
  );

  • Centering Elements With Unknown Sizes

    .element {
  position: fixed;
  inset: 0;
  width: fit-content;
  height: fit-content;
  margin: auto;
}
    • fit-content is doing the work