The CSS rule * { box-sizing: border-box; } changes the default CSS box model used to calculate widths and heights of elements. By default, elements use the content-box model, where the width and height you specify apply only to the content of the box, and padding and borders are added to those dimensions. When you apply box-sizing: border-box;, the specified width and height include the content, padding, and border, but not the margin[1][3][5][7][9][10].
Advantages of Using box-sizing: border-box
Simplified Layout Calculation: With border-box, the padding and border of the box are included within the box's specified width and height. This simplification means that when you set an element's width and height, you no longer need to add extra calculations to account for padding and borders. This makes it much easier to size elements precisely without unexpected overflow or additional math[1][3][5][7].
Consistency Across Browsers: Using border-box helps ensure that elements appear the same size across different browsers, regardless of box model differences. This consistency is crucial for responsive design and cross-browser compatibility[1][3].
Easier Responsive Design: It's beneficial for responsive design as it allows elements to better adapt to varying screen sizes. Padding and borders are included in the element's size, so the layout is more likely to remain intact no matter the device[1][3][5].
Integration with Grids and Flexbox: When using CSS frameworks like Flexbox or Grid, border-box makes it easier to manage layouts as the total size of the elements remains consistent regardless of internal spacing[1][3].
Useful for Percentage-Based Layouts: For layouts that rely on percentages, ...
