:root{
  --bg:#f6f7fb;
  --card:#ffffff;
  --text:#1f2937;
  --muted:#6b7280;
  --line:#dbe0ea;
  --primary:#1d4ed8;
  --primary-dark:#1e40af;
  --success:#047857;
  --warn:#b45309;
  --danger:#b91c1c;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
  background:var(--bg);
  color:var(--text);
}
.wrap{max-width:1200px;margin:0 auto;padding:0 16px}
.topbar{background:#0f172a;color:#fff}
.topbar-inner{display:flex;justify-content:space-between;align-items:center;min-height:64px}
.brand{font-weight:700}
.nav a{color:#cbd5e1;text-decoration:none;margin-left:16px}
.nav a:hover{color:#fff}
.page{padding:24px 16px 48px}
.card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:14px;
  padding:20px;
  margin-bottom:18px;
  box-shadow:0 1px 3px rgba(15,23,42,.04);
}
.inner-card{background:#fafcff}
.narrow{max-width:460px;margin:0 auto}
h1,h2,h3{margin-top:0}
.muted{color:var(--muted)}
.small{font-size:12px}
.strong{font-weight:600}
.stack{display:flex;flex-direction:column;gap:12px}
.large-gap{gap:20px}
.toolbar{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.space-between{justify-content:space-between}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:38px;padding:0 14px;border-radius:10px;
  background:var(--primary);color:#fff;text-decoration:none;border:0;cursor:pointer;font-weight:600
}
.btn:hover{background:var(--primary-dark)}
.btn-secondary{background:#eef2ff;color:#1e3a8a}
.btn-secondary:hover{background:#e0e7ff}
.btn-primary{background:var(--success)}
.small-btn{min-height:32px;padding:0 10px;font-size:13px}
input[type="text"], input[type="password"], textarea{
  width:100%;
  border:1px solid var(--line);
  border-radius:10px;
  padding:10px 12px;
  font-size:14px;
  background:#fff;
}
textarea{resize:vertical}
.inline-check{display:flex;gap:10px;align-items:center}
.flash{
  border-radius:10px;padding:12px 14px;margin-bottom:16px;border:1px solid;
}
.flash-info{background:#eff6ff;color:#1e3a8a;border-color:#bfdbfe}
.flash-success{background:#ecfdf5;color:#065f46;border-color:#a7f3d0}
.flash-warning{background:#fffbeb;color:#92400e;border-color:#fde68a}
.flash-error{background:#fef2f2;color:#991b1b;border-color:#fecaca}
.grid{display:grid;gap:18px}
.grid.two{grid-template-columns:1fr 1fr}
.list{display:flex;flex-direction:column;gap:10px}
.list-item{
  display:flex;justify-content:space-between;gap:12px;align-items:center;
  border:1px solid var(--line);border-radius:12px;padding:12px;background:#fff
}
.table{width:100%;border-collapse:collapse}
.table th,.table td{padding:10px;border-bottom:1px solid var(--line);vertical-align:top;text-align:left}
.pill{display:inline-block;padding:4px 8px;border-radius:999px;font-size:12px;margin-right:4px}
.pill-green{background:#dcfce7;color:#166534}
.pill-yellow{background:#fef3c7;color:#92400e}
.pill-blue{background:#dbeafe;color:#1d4ed8}
.pill-gray{background:#e5e7eb;color:#374151}
.student-list{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.student-list.compact{grid-template-columns:1fr 1fr}
.student-item{
  display:flex;gap:10px;align-items:flex-start;border:1px solid var(--line);
  border-radius:12px;padding:10px;background:#fff
}
.student-item.disabled{opacity:.55;background:#f3f4f6}
.danger{color:var(--danger)}
.dynamic-row,.dynamic-grid{margin-bottom:10px}
.dynamic-grid{display:grid;gap:10px}
.dynamic-grid.two{grid-template-columns:1fr 1fr}
.dynamic-grid.three{grid-template-columns:1.2fr .8fr 1fr}
.row-head{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:10px}
.suggestions{margin-top:8px;display:flex;flex-direction:column;gap:6px}
.suggestion-item{
  border:1px solid var(--line);background:#fff;padding:10px;border-radius:10px;
  text-align:left;cursor:pointer
}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:12px 0}
.stat{background:#f8fafc;border:1px solid var(--line);border-radius:12px;padding:14px}
.stat span{display:block;font-size:24px;font-weight:700}
.stat small{color:var(--muted)}
.pre{white-space:pre-wrap;line-height:1.45}
.detail-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-bottom:14px}
@media (max-width: 900px){
  .grid.two,.detail-grid,.student-list,.student-list.compact,.dynamic-grid.two,.dynamic-grid.three,.stats{grid-template-columns:1fr}
  .topbar-inner{flex-direction:column;align-items:flex-start;padding:12px 0}
  .nav a{margin:0 14px 0 0}
}