.skeleton {
  background: linear-gradient(90deg, rgba(0,0,0,0.06) 25%, rgba(0,0,0,0.10) 37%, rgba(0,0,0,0.06) 63%);
  background-size: 400% 100%; animation: skeleton-shimmer 1.4s ease infinite; border-radius: 0.375rem;
}
@keyframes skeleton-shimmer { 0% { background-position: 100% 50%; } 100% { background-position: 0 50%; } }
:focus-visible { outline: 2px solid #C17F3E; outline-offset: 2px; }
.card-hover { transition: transform 0.15s ease, box-shadow 0.15s ease; }
.card-hover:hover { transform: translateY(-1px); box-shadow: 0 6px 18px -8px rgba(22,48,43,0.15); }
.modal-backdrop { background: rgba(22,48,43,0.45); }
.grade-A { color: #2F6F4F; } .grade-B { color: #2F6F4F; } .grade-C { color: #C17F3E; } .grade-D, .grade-F { color: #A23E2E; }
table.gradebook-grid th { font-family: 'IBM Plex Mono', monospace; text-transform: uppercase; font-size: 0.7rem; color: #C17F3E; }
table.gradebook-grid td, table.gradebook-grid th { padding: 0.6rem 0.75rem; }