iOS/iMessage gradient effect, with css/svg

and good performance

Scroll down to better see the effect.

well, since I need to add some messages here so it scrolls, i might as well explain how it works

it's a bit tricky.

there's a big gradient background, that spans the entire window

the white background you see is actually being added on each message

the bubble shape itself is not a blue bubble, but a white border with a transparent center

Effectively, each message is a "window" through which one can take a peek at the background

A little trick is used to give the bubble shape to the messages.

they have an svg image as a border

using the (little known?) "border-image-source" and "border-image-slice" css properties

for performance reasons

fixed background makes the browser redraw things every time it scrolls

while doing it this way makes the browser do only a composite operation

that's it, just move things around instead of redrawing them

that's what I gather, anyway

not completely sure

might depend on the browser, gotta test a bit more