What is the purpose of CSS reset?

CSS reset is necessary to reset or normalize default styles applied by browsers to HTML elements. Different browsers have their own built-in styling rules, which can lead to inconsistent rendering of elements across browsers. CSS reset helps create a uniform baseline for styling, ensuring the same visual appearance across platforms.

Main tasks of CSS reset:

• Removing default margins and paddings: Browsers often add default internal and external margins to elements like <h1>, <p>, <ul>, <li>, etc. Resetting these allows developers to control them.
• Reset list styles: Remove default list markers and margins for <ul>, <ol>, <li>.
• Normalize border sizes: Borders can affect the final size of elements due to the standard box-sizing model. Some resets use box-sizing: border-box.
• Reset typography: Default sizes and fonts for headings, paragraphs, and other text elements can be reset.
• Fix differences: Eliminate other minor rendering differences between browsers.

Example of a simple CSS reset:

/* Reset default margins and paddings */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box; /* Simplifies size calculations */
}

/* Reset list styles */
ul, ol {
  list-style: none;
}

/* Reset table styles */
table {
  border-collapse: collapse;
  border-spacing: 0;
}

/* Reset image styles */
img {
  display: block; /* Remove extra space below images */
  max-width: 100%; /* Images do not overflow their containers */
}

/* Reset link styles */
a {
  text-decoration: none; /* Remove underline */
  color: inherit; /* Inherit color from parent */
}

/* Reset form styles */
button, input, select, textarea {
  margin: 0;
  padding: 0;
  border: none;
  background: none;
  font: inherit;
  color: inherit;
  cursor: pointer;
}

button:focus, input:focus, select:focus, textarea:focus {
  outline: none;
}

In practice, ready-made CSS reset libraries like Normalize.css or Eric Meyer's Reset are often used, offering more comprehensive and tested solutions. Normalize.css, unlike traditional resets, normalizes styles rather than completely resetting them, preserving useful defaults and fixing inconsistencies.