:root {
  --bg: #f4f0ea;
  --panel: #fffdf8;
  --text: #211916;
  --muted: #766d66;
  --line: #ded2c7;
  --primary: #8f211c;
  --primary-dark: #6f1714;
  --danger: #b42318;
  --warning: #9a5b00;
  --ok: #237348;
  --ink: #0b0605;
  --shadow: 0 2px 8px rgba(33, 25, 22, .08);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background:
    radial-gradient(circle at 18% 0%, rgba(143, 33, 28, .10), transparent 26%),
    linear-gradient(180deg, #f9f6f1 0%, var(--bg) 42%, #eee8df 100%);
  color: var(--text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  letter-spacing: 0;
}

header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: linear-gradient(90deg, rgba(11, 6, 5, .98), rgba(42, 33, 29, .96)), var(--ink);
  border-bottom: 3px solid var(--primary);
  padding: 12px 16px;
  color: #fff;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  max-width: 1180px;
  margin: 0 auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-mark {
  width: 46px;
  height: 46px;
  border-radius: 8px;
  object-fit: cover;
  border: 1px solid rgba(255, 255, 255, .22);
  background: #000;
  box-shadow: 0 4px 18px rgba(0, 0, 0, .25);
  flex: 0 0 auto;
}

h1 {
  margin: 0;
  font-size: 19px;
  line-height: 1.25;
  font-weight: 750;
  color: #fff;
}

.brand-subtitle {
  color: rgba(255, 255, 255, .72);
  font-size: 13px;
  margin-top: 3px;
}

main {
  width: min(1180px, 100%);
  margin: 0 auto;
  padding: 16px;
}

.tabs {
  display: inline-grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  padding: 3px;
  background: rgba(255, 255, 255, .08);
  border: 1px solid rgba(255, 255, 255, .18);
  border-radius: 8px;
}

.tab {
  border: 0;
  border-radius: 6px;
  padding: 9px 14px;
  background: transparent;
  color: rgba(255, 255, 255, .68);
  cursor: pointer;
  font-weight: 650;
  min-width: 88px;
}

.tab.active {
  background: var(--panel);
  color: var(--text);
  box-shadow: var(--shadow);
}

.grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, .9fr);
  gap: 16px;
  align-items: start;
}

section {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 14px;
  margin-bottom: 16px;
}

h2 {
  margin: 0 0 12px;
  font-size: 17px;
  line-height: 1.3;
}

label {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}

select,
input,
textarea {
  width: 100%;
  border: 1px solid #cdbfb3;
  border-radius: 6px;
  background: #fff;
  color: var(--text);
  font: inherit;
  padding: 10px 11px;
  min-height: 42px;
}

textarea {
  resize: vertical;
  min-height: 86px;
}

button {
  border: 1px solid #cdbfb3;
  border-radius: 6px;
  background: #fff;
  color: var(--text);
  font: inherit;
  font-weight: 650;
  min-height: 40px;
  padding: 9px 12px;
  cursor: pointer;
}

button.primary {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

button.primary:hover { background: var(--primary-dark); }

button:disabled {
  opacity: .55;
  cursor: not-allowed;
}

.row {
  display: flex;
  gap: 8px;
  align-items: center;
}

.row > * { min-width: 0; }

.stack { display: grid; gap: 12px; }

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.full { grid-column: 1 / -1; }

.student-list {
  display: grid;
  gap: 8px;
}

.student-item {
  display: grid;
  grid-template-columns: 22px minmax(0, 1fr) auto;
  gap: 10px;
  align-items: center;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fffaf3;
  min-height: 48px;
}

.student-item input {
  width: 18px;
  min-height: 18px;
  height: 18px;
}

.muted {
  color: var(--muted);
  font-size: 13px;
}

.pill {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 3px 9px;
  background: #efe5dc;
  color: #423631;
  font-size: 12px;
  white-space: nowrap;
}

.pill.ok { background: #e4f2e8; color: var(--ok); }
.pill.warn { background: #fff0d0; color: var(--warning); }
.pill.danger { background: #f9ded9; color: var(--danger); }

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

.chip {
  display: inline-grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 7px;
  align-items: center;
  max-width: 100%;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 8px 6px 11px;
  background: #fffaf3;
  font-size: 14px;
}

.chip span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chip button {
  width: 24px;
  height: 24px;
  min-height: 24px;
  padding: 0;
  border-radius: 999px;
  line-height: 1;
}

.stats {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
}

.stat {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fffaf3;
}

.stat strong {
  display: block;
  font-size: 24px;
  line-height: 1;
  margin-bottom: 6px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

th,
td {
  text-align: left;
  border-bottom: 1px solid var(--line);
  padding: 9px 7px;
  vertical-align: top;
}

th {
  color: var(--muted);
  font-weight: 650;
  background: #f6efe7;
}

.action-buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.status {
  position: fixed;
  left: 50%;
  bottom: 18px;
  transform: translateX(-50%);
  width: min(520px, calc(100% - 28px));
  padding: 12px 14px;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  box-shadow: 0 8px 30px rgba(0,0,0,.18);
  display: none;
  z-index: 20;
}

.status.show { display: block; }

.hidden { display: none !important; }

@media (max-width: 860px) {
  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .form-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  main { padding: 12px; }
  section { padding: 12px; }
  .row { flex-direction: column; align-items: stretch; }
  .tabs { width: 100%; }
  .stat strong { font-size: 21px; }
  table { font-size: 13px; }
}