:root {
  --ink: #172033;
  --muted: #5b6577;
  --line: #dbe2ee;
  --bg: #eef2f8;
  --card: #ffffff;
  --brand: #4338ca;
  --brand-dark: #312e81;
  --ok: #15803d;
  --bad: #b91c1c;
  --ring: rgba(67, 56, 202, 0.18);
  color-scheme: light;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}

.wrap {
  width: 100%;
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 18px;
}

.teacher-hero {
  background: linear-gradient(135deg, #312e81, #4338ca 58%, #2563eb);
  color: #fff;
  padding: 28px 0;
  margin-bottom: 22px;
}

.hero-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.24);
  font-weight: 900;
  letter-spacing: 0.04em;
}

.eyebrow {
  margin: 0 0 2px;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.82;
}

h1 {
  margin: 0;
  font-size: clamp(1.35rem, 3vw, 1.9rem);
  line-height: 1.2;
}

h2 {
  margin: 0 0 6px;
  font-size: 1.2rem;
}

.muted { color: var(--muted); }
.status { min-height: 1.4em; color: var(--muted); margin: 12px 0; }
.error { color: var(--bad); font-weight: 700; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 10px 28px rgba(23, 32, 51, 0.07);
  padding: 18px;
}

.login-card {
  max-width: 460px;
  margin: 36px auto;
}

.field {
  display: block;
  margin-bottom: 12px;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 800;
}

.input {
  display: block;
  width: 100%;
  min-height: 44px;
  margin-top: 6px;
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  font: inherit;
}

.input:focus {
  outline: 3px solid var(--ring);
  border-color: var(--brand);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 8px 15px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #f4f6fb;
  color: var(--ink);
  font: inherit;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
}

.btn:hover { filter: brightness(0.98); }
.btn:disabled { opacity: 0.55; cursor: not-allowed; }
.btn.primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn.primary:hover { background: var(--brand-dark); }
.btn.ghost { background: #fff; }
.block { width: 100%; }

.teacher-hero .btn.ghost {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.3);
  color: #fff;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: end;
  justify-content: space-between;
}

.filters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 10px;
  flex: 1 1 560px;
}

.toolbar-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.table-wrap {
  margin-top: 16px;
  padding: 0;
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

th, td {
  padding: 11px 12px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  background: #f7f9fd;
  color: var(--muted);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

tbody tr:hover { background: #fafbff; }
tbody tr:last-child td { border-bottom: 0; }
.num { text-align: right; font-variant-numeric: tabular-nums; }
.empty { padding: 28px 18px; text-align: center; color: var(--muted); }

.pager {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  justify-content: center;
  margin: 18px 0 30px;
}

.page-info { color: var(--muted); font-weight: 700; }

.teacher-footer {
  padding: 22px 0 32px;
  color: var(--muted);
  font-size: 0.86rem;
  text-align: center;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 640px) {
  .teacher-hero { padding: 20px 0; }
  .card { padding: 14px; }
  .toolbar { align-items: stretch; }
  .toolbar-actions .btn { flex: 1 1 150px; }
}