:root {
  --primary: #1565c0;
  --primary-dark: #0d47a1;
  --cyan: #18a0fb;
  --bg: #f4f6fb;
  --card: #ffffff;
  --text: #1a1a1a;
  --muted: #6b7280;
  --ok: #137333;
  --err: #c5221f;
  --border: #e3e8f0;
}

* { box-sizing: border-box; }

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

/* ---------- Login ---------- */
.login-bg {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--cyan), var(--primary-dark));
  padding: 20px;
}
.login-card {
  background: var(--card);
  width: 100%;
  max-width: 380px;
  padding: 32px;
  border-radius: 16px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.18);
}
.login-card h1 { margin: 0 0 4px; font-size: 22px; }
.subtitle { color: var(--muted); margin: 0 0 20px; font-size: 14px; }
.login-card label { display: block; font-size: 13px; margin: 12px 0 4px; font-weight: 600; }
.login-card input {
  width: 100%; padding: 12px; border: 1px solid var(--border);
  border-radius: 8px; font-size: 15px;
}
.login-card button {
  width: 100%; margin-top: 20px; padding: 13px;
  background: var(--primary); color: #fff; border: none;
  border-radius: 8px; font-size: 15px; font-weight: 600; cursor: pointer;
}
.login-card button:hover { background: var(--primary-dark); }

/* ---------- Topbar ---------- */
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  background: var(--primary); color: #fff; padding: 14px 22px;
}
.brand { font-weight: 700; font-size: 17px; }
.topbar-right { display: flex; align-items: center; gap: 12px; }
.topbar-right .muted { color: #dbe7ff; font-size: 13px; }

/* ---------- Dashboard grid ---------- */
.grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 18px; padding: 22px; max-width: 980px; margin: 0 auto;
}
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 14px; padding: 20px;
}
.card-wide { grid-column: 1 / -1; }
.card h2 { margin: 0 0 6px; font-size: 16px; }
.card h3 { margin: 18px 0 8px; font-size: 14px; }
.muted { color: var(--muted); font-size: 13px; }

.card input {
  width: 100%; padding: 11px; margin-top: 10px;
  border: 1px solid var(--border); border-radius: 8px; font-size: 14px;
}
.row { display: flex; gap: 10px; flex-wrap: wrap; }
.row > * { flex: 1; min-width: 160px; }

.card button {
  margin-top: 12px; padding: 11px 16px; background: var(--primary);
  color: #fff; border: none; border-radius: 8px; font-size: 14px;
  font-weight: 600; cursor: pointer;
}
.card button:hover { background: var(--primary-dark); }
.card button.secondary { background: var(--cyan); }
.btn-small {
  padding: 7px 12px; font-size: 13px; background: var(--primary);
  color: #fff; border: none; border-radius: 7px; cursor: pointer; margin: 0;
}
.btn-small.danger { background: var(--err); }
.btn-small:disabled { background: #9aa6b2; cursor: default; }

.status { font-size: 13px; margin: 10px 0 0; min-height: 16px; }
.status.ok { color: var(--ok); }
.status.err { color: var(--err); }

/* ---------- QR + list ---------- */
.qr-area {
  display: flex; flex-direction: column; align-items: center;
  gap: 10px; margin-top: 16px;
}
.qr-area canvas { border: 1px solid var(--border); border-radius: 8px; background: #fff; }

.exam-list { list-style: none; padding: 0; margin: 8px 0 0; }
.exam-list li {
  display: flex; align-items: center; justify-content: space-between;
  gap: 10px; padding: 10px 12px; border: 1px solid var(--border);
  border-radius: 8px; margin-bottom: 8px;
}
.exam-info { display: flex; flex-direction: column; overflow: hidden; }
.exam-info span { color: var(--muted); font-size: 12px; word-break: break-all; }
.exam-actions { display: flex; gap: 8px; flex-shrink: 0; }

@media (max-width: 720px) {
  .grid { grid-template-columns: 1fr; }
}