:root {
  --surface-1: #fcfcfb;
  --page-plane: #f9f9f7;
  --text-primary: #0b0b0b;
  --text-secondary: #52514e;
  --text-muted: #898781;
  --gridline: #e1e0d9;
  --border: rgba(11, 11, 11, 0.1);
  --series-1: #2a78d6;
  --seq-100: #cde2fb;
  --seq-250: #86b6ef;
  --seq-400: #3987e5;
  --seq-500: #256abf;
  --seq-650: #104281;
  --good: #0ca30c;
  --critical: #d03b3b;
  --warning-bg: #fff6df;
  --warning-border: #eda100;
}


* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--page-plane);
  color: var(--text-primary);
  min-height: 100vh;
}

.muted { color: var(--text-muted); }

.screen {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 16px 64px;
}

/* Login */
#login-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

#login-screen[hidden],
#dashboard-screen[hidden] {
  display: none;
}

.login-card {
  width: 100%;
  max-width: 340px;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.login-card h1 { margin: 0; font-size: 1.25rem; }
.login-card p { margin: 0 0 4px; }

/* Topbar */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}
.topbar h1 { font-size: 1.25rem; margin: 0; }

/* Stat grid */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 12px;
  margin-bottom: 28px;
}

.stat-tile {
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}

.stat-tile .stat-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  margin-bottom: 6px;
}

.stat-tile .stat-value {
  font-size: 1.75rem;
  font-weight: 600;
  line-height: 1.1;
}

.stat-tile .stat-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Panel */
.panel {
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.panel-header h2 { margin: 0; font-size: 1.05rem; }

/* Table */
.table-wrap { overflow-x: auto; }

table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }

th {
  text-align: left;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  color: var(--text-muted);
  padding: 8px 10px;
  border-bottom: 1px solid var(--gridline);
}

td {
  padding: 10px;
  border-bottom: 1px solid var(--gridline);
  vertical-align: middle;
}

tr:last-child td { border-bottom: none; }

.grade-badge {
  display: inline-block;
  min-width: 2.4em;
  text-align: center;
  padding: 2px 8px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.85rem;
  color: #ffffff;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

.status-pill.pending {
  background: var(--warning-bg);
  border-color: var(--warning-border);
  color: var(--text-primary);
}

.status-pill.excluded {
  opacity: 0.7;
}

.row-actions { display: flex; gap: 6px; justify-content: flex-end; }

/* Buttons */
button {
  font-family: inherit;
  font-size: 0.9rem;
  cursor: pointer;
  border-radius: 8px;
  border: 1px solid transparent;
  padding: 9px 14px;
}

.primary-btn {
  background: var(--series-1);
  color: #ffffff;
  border-color: var(--series-1);
}
.primary-btn:hover { filter: brightness(1.05); }

.ghost-btn {
  background: transparent;
  border-color: var(--border);
  color: var(--text-primary);
}
.ghost-btn:hover { background: var(--gridline); }

.icon-btn {
  background: transparent;
  border-color: var(--border);
  color: var(--text-secondary);
  padding: 5px 9px;
  font-size: 0.8rem;
}
.icon-btn:hover { background: var(--gridline); }
.icon-btn.danger:hover { border-color: var(--critical); color: var(--critical); }

input[type="text"],
input[type="number"],
input[type="password"] {
  font-family: inherit;
  font-size: 0.9rem;
  padding: 9px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--page-plane);
  color: var(--text-primary);
  width: 100%;
}

label { display: flex; flex-direction: column; gap: 4px; font-size: 0.85rem; color: var(--text-secondary); }

.checkbox-row {
  flex-direction: row;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
}
.checkbox-row input { width: auto; }

.error-text {
  color: var(--critical);
  font-size: 0.85rem;
  margin: 0;
}

/* Dialog */
dialog {
  border: none;
  border-radius: 12px;
  padding: 0;
  background: var(--surface-1);
  color: var(--text-primary);
  width: 100%;
  max-width: 420px;
}
dialog::backdrop { background: rgba(0, 0, 0, 0.4); }

#exam-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px;
}
#exam-form h2 { margin: 0 0 4px; font-size: 1.1rem; }

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 8px;
}

#grade-fields { display: flex; flex-direction: column; gap: 10px; }
#grade-fields.hidden { display: none; }

@media (max-width: 520px) {
  .row-actions { flex-direction: column; }
}