/* Smart Autonomous Systems — MCQ Test */
:root {
  --ink: #17233b;
  --paper: #f6f7f9;
  --card: #ffffff;
  --line: #dde2ea;
  --muted: #66718a;
  --accent: #0e7c7b;
  --accent-dark: #0a5c5b;
  --danger: #b3261e;
  --ok: #2e7d32;
  --warn: #9a6b00;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, Arial, sans-serif;
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.45;
}
.topbar {
  background: var(--ink);
  color: #fff;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  position: sticky;
  top: 0;
  z-index: 50;
}
.topbar .brand { font-weight: 700; letter-spacing: .3px; }
.topbar .who { font-size: .9rem; opacity: .9; }
.timer {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: 1.15rem;
  background: rgba(255,255,255,.12);
  padding: 4px 14px;
  border-radius: 6px;
}
.timer.low { background: var(--danger); }
.wrap { max-width: 900px; margin: 0 auto; padding: 20px 16px 80px; }
.wrap-wide { max-width: 1200px; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 16px;
}
h1 { font-size: 1.4rem; margin: 0 0 12px; }
h2 { font-size: 1.15rem; margin: 0 0 10px; }
p.muted, .muted { color: var(--muted); }
label { display: block; font-weight: 600; margin: 12px 0 4px; }
input[type=text], input[type=password] {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 1rem;
}
input:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 10px 20px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
}
.btn:hover { background: var(--accent-dark); }
.btn.secondary { background: #fff; color: var(--ink); border: 1px solid var(--line); }
.btn.secondary:hover { background: #eef1f5; }
.btn.danger { background: var(--danger); }
.btn.small { padding: 6px 12px; font-size: .9rem; }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.error { color: var(--danger); font-weight: 600; margin: 10px 0; }
.notice { color: var(--warn); font-weight: 600; }

/* question blocks */
.question { border-bottom: 1px solid var(--line); padding: 16px 0; }
.question:last-child { border-bottom: none; }
.qhead { font-weight: 700; margin-bottom: 8px; }
.opt {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 8px 10px;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
}
.opt:hover { background: #f0f6f6; }
.opt input { margin-top: 4px; }
.opt.selected { background: #e5f2f1; border-color: var(--accent); }
.optletter { font-weight: 700; min-width: 20px; }
.savemark { font-size: .8rem; color: var(--ok); margin-left: 8px; }

/* pagination */
.pager { display: flex; flex-wrap: wrap; gap: 6px; margin: 14px 0; align-items: center; }
.pager .pg {
  min-width: 42px;
  padding: 7px 8px;
  text-align: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  cursor: pointer;
  font-weight: 600;
  font-size: .9rem;
}
.pager .pg.cur { background: var(--ink); color: #fff; border-color: var(--ink); }
.pager .pg.done { border-color: var(--accent); color: var(--accent-dark); }

.progressline { font-weight: 600; margin: 6px 0 2px; }

/* offline banner */
.netbanner {
  display: none;
  position: fixed;
  left: 0; right: 0; bottom: 0;
  background: #9a6b00;
  color: #fff;
  font-weight: 600;
  text-align: center;
  padding: 10px;
  z-index: 90;
}
.netbanner.show { display: block; }

/* overlay */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(20, 26, 40, .92);
  color: #fff;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
  text-align: center;
  padding: 24px;
}
.overlay.show { display: flex; }
.overlay .box { max-width: 520px; }
.overlay h2 { font-size: 1.5rem; }

/* admin tables */
table.grid { border-collapse: collapse; width: 100%; background: #fff; }
table.grid th, table.grid td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; font-size: .93rem; }
table.grid th { background: #eef1f5; }
tr.violated td { background: #fbd9d7; color: #7a130d; font-weight: 600; }
.pill { display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: .8rem; font-weight: 700; }
.pill.idle { background: #e4e7ee; color: #4a556e; }
.pill.running { background: #dcefdc; color: var(--ok); }
.pill.ended { background: #fbe3e1; color: var(--danger); }
.pill.in_progress { background: #dff0ef; color: var(--accent-dark); }
.pill.submitted { background: #e4e7ee; color: #4a556e; }
.pill.not_started { background: #fff4d6; color: var(--warn); }
.statrow { display: flex; gap: 24px; flex-wrap: wrap; margin-bottom: 16px; }
.stat { background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 12px 18px; }
.stat .n { font-size: 1.6rem; font-weight: 800; }
.stat .l { font-size: .85rem; color: var(--muted); }
.adminnav { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 16px; }