:root {
  --bg: #f4f6f8;
  --card: #ffffff;
  --text: #1a1f2e;
  --muted: #5c667a;
  --primary: #1d4ed8;
  --primary-hover: #1e40af;
  --border: #e2e8f0;
  --ok: #166534;
  --ok-bg: #dcfce7;
  --bad: #991b1b;
  --bad-bg: #fee2e2;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.container {
  width: min(960px, 100% - 2rem);
  margin-inline: auto;
}

.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.5rem;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  text-decoration: none;
}

.nav {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.nav a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}

.main-content {
  padding-bottom: 2rem;
}

.site-footer {
  padding: 1.5rem 0;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

h1, h2, h3 { margin-top: 0; }

.muted { color: var(--muted); }
.small { font-size: 0.9rem; }
.bn { font-size: 1.05rem; }

.btn {
  display: inline-block;
  padding: 0.6rem 1rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  text-decoration: none;
  cursor: pointer;
  font: inherit;
}

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

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

.stack { display: grid; gap: 1rem; }

.field {
  display: grid;
  gap: 0.35rem;
}

.field input {
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
}

.search-form {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
  align-items: end;
}

.status-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.75rem;
  margin-top: 1rem;
}

.status-item {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem;
  display: grid;
  gap: 0.25rem;
}

.status-item.ok { background: var(--ok-bg); color: var(--ok); }
.status-item.bad { background: var(--bad-bg); color: var(--bad); }

.alert {
  padding: 0.75rem 1rem;
  border-radius: 8px;
  margin: 1rem 0;
}

.alert.ok { background: var(--ok-bg); color: var(--ok); }
.alert.bad { background: var(--bad-bg); color: var(--bad); }

.student-header {
  display: flex;
  gap: 1rem;
  align-items: center;
  margin-bottom: 1rem;
}

.avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--border);
}

.avatar.placeholder {
  display: grid;
  place-items: center;
  font-size: 0.75rem;
  color: var(--muted);
  background: #f8fafc;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin-bottom: 1rem;
}

.details {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.35rem 1rem;
  margin: 0;
}

.details dt { color: var(--muted); font-weight: 600; }
.details dd { margin: 0; }

.table-wrap { overflow-x: auto; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th, td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.65rem;
  text-align: left;
}

th { background: #f8fafc; }

.warnings { padding-left: 1.25rem; }

code {
  background: #f1f5f9;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-size: 0.9em;
}

.scan-preview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  margin: 1rem 0;
}

.scan-figure {
  margin: 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: #f8fafc;
}

.scan-figure figcaption {
  padding: 0.6rem 0.75rem;
  font-weight: 600;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--border);
  background: #fff;
}

.scan-image {
  display: block;
  width: 100%;
  height: auto;
  max-height: 70vh;
  object-fit: contain;
  background: #111;
}

.overlay-legend.subtle {
  background: #f8fafc;
  margin-bottom: 1rem;
}

.overlay-legend h2 {
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

.legend-list {
  list-style: none;
  padding: 0;
  margin: 0 0 0.75rem;
  display: grid;
  gap: 0.4rem;
}

.legend-list li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.92rem;
}

.swatch {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  border: 1px solid rgba(0, 0, 0, 0.15);
  flex-shrink: 0;
}

.swatch.cyan { background: #00b4ff; }
.swatch.green { background: #00ff00; }
.swatch.red { background: #ff3c3c; }
.swatch.orange { background: #ffb400; }
.swatch.purple { background: #7850ff; }
.swatch.gray { background: #b4b4b4; }
.swatch.blue { background: #1478ff; }

.answers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
  gap: 0.5rem;
  margin: 1rem 0;
}

.answer-cell {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.45rem 0.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #fff;
  font-size: 0.9rem;
}

.answer-cell.filled {
  background: #ecfdf5;
  border-color: #86efac;
}

.answer-cell .qnum {
  color: var(--muted);
  font-weight: 600;
}

.answer-cell .ans {
  font-weight: 700;
}

.details.inline {
  margin-top: 1rem;
}