Bootstrap template & box-sizing

Click the border-box button to fix the layout with the power of Box Sizing!

Parent div with 50% width.

Child div with 90% width, 4px black border, and 15% padding

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.

Child div with 50% width, 4px black border, and 1em padding

Lord, have mercy.

Child div with 50% width, 4px black border, and 1em padding

Glory to the Father, and to the Son, and to the Holy Spirit, both now and ever, and unto the ages of ages. Amen.

For the reference: Bootstrap's global default is box-sizing: border-box. Vanilla html's default is content-box.