CSS para impacientes

CSS como usar o Counter

January 04, 2020

Counters are, in essence, variables maintained by CSS whose values may be incremented by CSS rules to track how many times they’re used.

<ul>
  <li>List item</li>
  <li>List item</li>
  <li>
    List item
    <ul>
      <li>List item</li>
      <li>List item</li>
      <li>List item</li>
    </ul>
  </li>
</ul>
ul {
  counter-reset: counter;
}

li::before {
  counter-increment: counter;
  content: counters(counter, '.') ' ';
}

Explanation

  • You can create a ordered list using any type of HTML.
  • counter-reset Initializes a counter, the value is the name of the counter. By default, the counter starts at 0. This property can also be used to change its value to any specific number.
  • counter-increment Used in element that will be countable. Once counter-reset initialized, a counter’s value can be increased or decreased.
  • counter(name, style) Displays the value of a section counter. Generally used in a content property. This function can receive two parameters, the first as the name of the counter and the second one can be decimal or upper-roman (decimal by default).
  • counters(counter, string, style) Displays the value of a section counter. Generally used in a content property. This function can receive three parameters, the first as the name of the counter, the second one you can include a string which comes after the counter and the third one can be decimal or upper-roman (decimal by default).
  • A CSS counter can be especially useful for making outlined lists, because a new instance of the counter is automatically created in child elements. Using the counters() function, separating text can be inserted between different levels of nested counters.

Browser support

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