/* Legacy/static fallback for gradebook pages when Tailwind runtime is unavailable. */
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; min-height: 100vh; background: #f8fafc; color: #0f172a; font-family: "Microsoft YaHei", Arial, sans-serif; box-sizing: border-box; padding-bottom: 70px; }
*, *:before, *:after { box-sizing: inherit; }
a { color: inherit; }
.hidden { display: none !important; }
.flex { display: -ms-flexbox; display: flex; }
.flex-col { -ms-flex-direction: column; flex-direction: column; }
.flex-wrap { -ms-flex-wrap: wrap; flex-wrap: wrap; }
.items-center { -ms-flex-align: center; align-items: center; }
.justify-between { -ms-flex-pack: justify; justify-content: space-between; }
.justify-center { -ms-flex-pack: center; justify-content: center; }
.gap-1, .gap-1\.5, .gap-2, .gap-4, .gap-6 { gap: 8px; }
.w-full { width: 100%; }
.min-h-screen { min-height: 100vh; }
.bg-white { background: #fff; }
.text-white { color: #fff; }
.text-slate-800 { color: #1e293b; }
header { background: #1e293b; color: #fff; padding: 12px 20px; display: -ms-flexbox; display: flex; -ms-flex-wrap: wrap; flex-wrap: wrap; -ms-flex-align: center; align-items: center; -ms-flex-pack: justify; justify-content: space-between; gap: 10px; position: sticky; top: 0; z-index: 50; box-shadow: 0 8px 24px rgba(15,23,42,.18); }
header > div { display: -ms-flexbox; display: flex; -ms-flex-wrap: wrap; flex-wrap: wrap; -ms-flex-align: center; align-items: center; gap: 8px; }
header h1 { margin: 0; font-size: 19px; font-weight: 900; letter-spacing: 0; }
select, input, button { font: inherit; }
button, select, input[type="text"], input[type="number"], input[type="file"] { border: 1px solid #cbd5e1; border-radius: 8px; min-height: 34px; padding: 6px 10px; background: #fff; color: #0f172a; }
header button { border: 0; background: #334155; color: #fff; font-weight: 800; cursor: pointer; }
header button:hover { background: #475569; }
#classSelector { min-width: 220px; background: #0f172a; color: #fff; border-color: #475569; }
#main { display: block; min-height: calc(100vh - 120px); background: #fff; }
.table-container { width: 100%; overflow: auto; -webkit-overflow-scrolling: touch; background: #fff; padding-bottom: 88px; }
.grade-table { width: 100%; min-width: 780px; border-collapse: collapse; background: #fff; }
.grade-table th { position: relative; background: #f8fafc; font-weight: 800; color: #475569; font-size: 14px; letter-spacing: 0; border-bottom: 2px solid #e2e8f0; padding: 12px 10px; white-space: nowrap; }
.grade-table td { font-size: 15px; padding: 12px 10px; border-bottom: 1px solid #e2e8f0; }
.grade-table tbody tr:nth-child(even) { background: #f9fafb; }
.grade-table tbody tr:hover { background: #eff6ff !important; }
.editable:focus { outline: 2px solid #2563eb; background: #fff; }
footer { position: fixed; left: 0; right: 0; bottom: 0; z-index: 50; display: -ms-flexbox; display: flex; -ms-flex-wrap: wrap; flex-wrap: wrap; -ms-flex-align: center; align-items: center; -ms-flex-pack: justify; justify-content: space-between; gap: 10px; background: #f8fafc; border-top: 1px solid #e2e8f0; padding: 10px 20px; box-shadow: 0 -8px 22px rgba(15,23,42,.06); }
footer > div { display: -ms-flexbox; display: flex; -ms-flex-wrap: wrap; flex-wrap: wrap; -ms-flex-align: center; align-items: center; gap: 10px; }
footer button { background: #334155; color: #fff; border: 0; font-weight: 800; cursor: pointer; }
.student-checkin-overlay { position: fixed; top: 0; right: 0; bottom: 0; left: 0; z-index: 99999; background: #eff6ff; display: none; -ms-flex-align: center; align-items: center; -ms-flex-pack: center; justify-content: center; padding: 16px; }
.student-checkin-card, .checkin-modal-card { background: #fff; border-radius: 20px; box-shadow: 0 20px 60px rgba(0,0,0,.1); overflow: auto; max-height: 92vh; }
.student-checkin-shell { width: 100%; max-width: 420px; }
.fixed { position: fixed; }
.inset-0 { top: 0; right: 0; bottom: 0; left: 0; }
.z-\[100\] { z-index: 100; }
.p-4 { padding: 16px; }
.p-8 { padding: 28px; }
.rounded-2xl { border-radius: 18px; }
.shadow-2xl { box-shadow: 0 24px 60px rgba(15,23,42,.22); }
.max-w-md { max-width: 440px; }
@media (max-width: 900px) {
  body { padding-bottom: 0; }
  header { position: relative; display: block; padding: 12px; }
  header > div { margin-bottom: 8px; }
  #classSelector { width: 100%; min-width: 0; }
  .table-container { padding-bottom: 12px; }
  .grade-table { min-width: 640px; }
  .grade-table th, .grade-table td { font-size: 13px; padding: 9px 6px; }
  .grade-table th:nth-child(5), .grade-table td:nth-child(5),
  .grade-table th:nth-child(6), .grade-table td:nth-child(6),
  .grade-table th:nth-child(7), .grade-table td:nth-child(7) { display: none; }
  footer { position: relative; display: block; padding: 10px 12px; }
  footer > div { margin: 6px 0; }
  footer button { margin: 3px 0; }
}
@media (max-width: 430px) {
  header h1 { font-size: 17px; }
  header button, footer button { display: inline-block; width: 48%; min-width: 0; margin: 3px 1%; padding-left: 6px; padding-right: 6px; }
  .grade-table { min-width: 520px; }
  .grade-table th, .grade-table td { font-size: 12px; }
  .grade-table th:nth-child(2), .grade-table td:nth-child(2) { max-width: 96px; overflow: hidden; text-overflow: ellipsis; }
}