Decrease sidebar widget area size

I’m also interested in finding a solution to the sidebar size. . .

Not sure if you’re still looking for a solution, but I added this code to successfully reduce the sidebar:

/* For Large Screen */
#primary { width: 854px; }
#secondary { width: 200px; }
@media screen and (max-width: 1224px) {
#primary { width: 754px; }
#secondary { width: 200px; }
}
@media screen and (max-width: 1060px) {
#primary { width: 630px; }
#secondary { width: 200px; }
}
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px)
and (orientation : landscape) {
#primary { width: 590px; }
#secondary { width: 200px; }
}
@media screen and (max-width: 960px) {
#primary, #secondary { width: 100%; }
}