@media (min-width: 992px) {
  /* 1. Expand the outer wrapper that holds the whole website */
  .container, .container-md, .container-lg, .container-xl {
    max-width: 1400px !important; /* Change this to 90% for fluid width, or keep at 1400px */
  }

  /* 2. Target Beautiful Jekyll's specific column classes and remove the empty side margins */
  .container[role="main"] .row > div[class*="col-"] {
    flex: 0 0 100% !important;
    max-width: 100% !important; 
    margin-left: 0 !important; /* This is the key line! It kills the Bootstrap offset */
    padding-left: 15px !important;
    padding-right: 15px !important;
  }
}