/* --- Base --- */
:root {
  --bg: #f7f8fa;
  --fg: #1a1d24;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #dc2626;
  --ok: #15803d;
  --card: #fff;
  --shadow: 0 1px 3px rgba(0,0,0,0.05), 0 1px 2px rgba(0,0,0,0.06);
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--fg);
  font-size: 16px;
  line-height: 1.5;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
.mt { margin-top: 1rem; }
.hidden { display: none !important; }

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  background: #fff;
  border-bottom: 1px solid var(--border);
}
.topbar .logo { font-weight: 600; color: var(--fg); }
.topbar nav { display: flex; gap: 1rem; align-items: center; }
.topbar .email { color: var(--muted); font-size: 0.9rem; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem;
}

h1 { margin: 0.5rem 0 1rem; }
h2 { margin: 0 0 0.75rem; font-size: 1.25rem; }
h3 { margin: 0.75rem 0 0.5rem; font-size: 1.05rem; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow);
}
.narrow { max-width: 460px; margin-left: auto; margin-right: auto; }

.card-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1rem; }
.card-link { color: inherit; text-decoration: none; }
.card-link .card { transition: border-color 0.15s; }
.card-link:hover .card { border-color: var(--primary); }

.grid.two { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 760px) { .grid.two { grid-template-columns: 1fr; } }

label { display: block; margin-bottom: 0.75rem; font-size: 0.9rem; color: #374151; }
input[type=text], input[type=email], input[type=password], input[type=search], input[type=file], select {
  width: 100%;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1rem;
  background: #fff;
  margin-top: 0.25rem;
}
input:focus, select:focus { outline: 2px solid var(--primary); outline-offset: -1px; }
.checkbox { display: flex; align-items: center; gap: 0.5rem; }
.checkbox input { width: auto; margin: 0; }

.btn {
  display: inline-block;
  padding: 0.55rem 1rem;
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 6px;
  color: var(--fg);
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
}
.btn:hover { background: #f3f4f6; text-decoration: none; }
.btn.primary { background: var(--primary); color: white; border-color: var(--primary); }
.btn.primary:hover { background: var(--primary-hover); border-color: var(--primary-hover); }
.btn.danger { color: var(--danger); border-color: #fecaca; }
.btn.danger:hover { background: #fef2f2; }
.btn.small { padding: 0.3rem 0.6rem; font-size: 0.85rem; }
.btn.big { padding: 0.85rem 1.25rem; font-size: 1.1rem; }
.btn-link { background: none; border: 0; color: var(--primary); cursor: pointer; padding: 0; font-size: 0.85rem; }
.btn-link.danger { color: var(--danger); }

.row-form { display: flex; gap: 0.5rem; align-items: flex-end; flex-wrap: wrap; }
.row-form input, .row-form select { width: auto; flex: 1; min-width: 200px; }

.flash { padding: 0.75rem 1rem; border-radius: 6px; margin-bottom: 1rem; }
.flash-error { background: #fef2f2; color: #991b1b; border: 1px solid #fecaca; }
.flash-ok { background: #f0fdf4; color: #166534; border: 1px solid #bbf7d0; }
.flash-message { background: #eff6ff; color: #1e40af; border: 1px solid #bfdbfe; }

.back { color: var(--muted); font-size: 0.9rem; }

table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
th, td { text-align: left; padding: 0.5rem 0.75rem; border-bottom: 1px solid var(--border); }
th { font-weight: 600; color: var(--muted); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em; }
table.tight th, table.tight td { padding: 0.3rem 0.5rem; font-size: 0.85rem; }
code { background: #f3f4f6; padding: 0.1rem 0.35rem; border-radius: 3px; font-size: 0.85rem; }
.check { color: var(--ok); font-weight: 700; }
.dash { color: var(--muted); }

.pill {
  display: inline-block; padding: 0.15rem 0.55rem; border-radius: 999px;
  font-size: 0.75rem; background: #f3f4f6; color: var(--muted);
}
.pill.open { background: #dcfce7; color: var(--ok); }
.pill.closed { background: #f3f4f6; color: var(--muted); }
.pill.subtle { background: #eff6ff; color: var(--primary); margin-left: 0.25rem; }
.pill.warning { background: #fef3c7; color: #92400e; margin-left: 0.25rem; }

/* --- Live session view --- */
.live-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 900px) { .live-grid { grid-template-columns: 1fr; } }

.qr-card { text-align: center; }
.qr-wrap {
  display: flex; align-items: center; justify-content: center; gap: 1.5rem;
  margin: 1rem 0;
}
.qr-wrap img { width: 280px; height: 280px; image-rendering: pixelated; background: white; padding: 8px; border-radius: 6px; border: 1px solid var(--border); }
.controls { display: flex; gap: 0.5rem; flex-wrap: wrap; justify-content: center; }
.big-number { font-size: 2.5rem; font-weight: 700; margin: 0.5rem 0; }
.recent-list { list-style: none; padding: 0; margin: 0; max-height: 400px; overflow-y: auto; }
.recent-list li { padding: 0.4rem 0; border-bottom: 1px solid var(--border); font-size: 0.9rem; }
.recent-list .time { color: var(--muted); font-variant-numeric: tabular-nums; margin-right: 0.5rem; }

/* --- Check-in page (student) --- */
.checkin h1 { text-align: center; }
.checkin input[type=search] {
  font-size: 1.25rem;
  padding: 0.85rem 1rem;
}
.match {
  margin-top: 1rem;
  padding: 1rem;
  background: #eff6ff;
  border: 2px solid var(--primary);
  border-radius: 8px;
  text-align: center;
}
.match-name { font-size: 1.5rem; font-weight: 600; }
.match-id { margin-bottom: 0.75rem; }
.suggestions { margin-top: 0.75rem; display: flex; flex-direction: column; gap: 0.4rem; }
.suggestion {
  background: #fff; border: 1px solid var(--border); border-radius: 6px;
  padding: 0.65rem 0.85rem; text-align: left; cursor: pointer; font-size: 1rem;
}
.suggestion:hover { background: #f3f4f6; }
.result { text-align: center; padding: 1rem 0; }
.big-ok { font-size: 4rem; color: var(--ok); line-height: 1; }
.error { color: var(--danger); margin-top: 1rem; text-align: center; }