Box width: Each section width can be set from here.

1. Go to admin menu >> appearance >> customizer.
2. Go to theme options >> general layout.
   1. Main page width : Assign a number here which which can set the width of entire whole page of site. It uses a % of total width. This is available in pro version only.
   2. Main header image box width: Assign a number here which can set the width of header image section. It uses a % of total width. Example if you set the number 50 then it will show header image 50% of total width. This is available in pro version only.
   3. Menu box width: Assign a number here which which can set the width of Menu width. It uses a % of total width. Example if you set the number 50 then it will show Menu width 50% of total width.
   4. Frontpage layout 1 area width: Assign a number here which can set the width of Frontpage layout 1 widget area. It uses a % of total width. This is available in pro version only.
   5. Frontpage layout 2 area width: Assign a number here which can set the width of Frontpage layout 2 widget area. It uses a % of total width. This is available in pro version only.
   6. Frontpage layout 3 area width: Assign a number here which can set the width of Frontpage layout 3 widget area. It uses a % of total width. This is available in pro version only.
   7. Footer box width: Assign a number here which can set the width of Footer box width section. It uses a % of total width. This section has site title by default and footer sidebar one and two. This is available in pro version only.