Fix LED Dress video html centering

content/led-dress.md

@@ -22,9 +22,7 @@ seven LEDs that form the Big Dipper continually scroll through a gradient of
 three colors. Instead of calculating the values of each color in the gradient as
 the program runs, a lookup table is used.
 
-<center>
-  <video autoplay muted loop>
-  <source src="{static}/videos/dress/dress3.mp4" type="video/mp4">
-  Your browser does not support the video tag.
-  </video> 
-</center>
+<video autoplay muted loop style="display:block; margin: 0 auto;">
+<source src="{static}/videos/dress/dress3.mp4" type="video/mp4">
+Your browser does not support the video tag.
+</video>