Bold design gets blamed for slow sites. The weight is almost never the design — it is the four analytics scripts, the font you loaded in six weights, and the hero video nobody watches.

Budget before build

Agree a number before the first component: total transfer on the landing page, largest contentful paint on a mid-range phone. Anything that breaks the budget has to displace something else.

Where the weight actually is

• Fonts. Two families, two weights each. Subset them.

• Images. Modern formats, real dimensions, lazy below the fold.

• Third parties. Each tag is someone else's performance decision running on your site.

Motion without jank

Animate transform and opacity. Nothing else. Anything that triggers layout will stutter on the device your customer actually owns.

The part people skip

Test on a throttled connection and a four-year-old phone before launch, not after the first complaint. Loud and fast is a choice you make early or not at all.