:root {
  --bg: #0f141b;
  --panel: #1a212b;
  --panel2: #222b37;
  --border: #2c3744;
  --text: #e6edf3;
  --muted: #8b98a8;
  --accent: #ff9900;
  --green: #2ecc71;
  --red: #e74c3c;
  --blue: #4aa3ff;
  --yellow: #f1c40f;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 22px; background: #11171f; border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10; flex-wrap: wrap; gap: 12px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.logo {
  background: var(--accent); color: #11171f; font-weight: 800; padding: 6px 9px;
  border-radius: 6px; font-size: 18px; letter-spacing: .5px;
}
.brand h1 { font-size: 18px; margin: 0; }
.sub { margin: 0; font-size: 12px; color: var(--muted); }
.tabs { display: flex; gap: 6px; }
.tab {
  background: transparent; color: var(--muted); border: 1px solid transparent;
  padding: 8px 16px; border-radius: 8px; cursor: pointer; font-size: 14px;
}
.tab:hover { color: var(--text); }
.tab.active { background: var(--panel2); color: var(--accent); border-color: var(--border); }

main { max-width: 920px; margin: 22px auto; padding: 0 16px; }
.view.hidden, .hidden { display: none !important; }

.panel {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 18px 20px; margin-bottom: 18px;
}
.panel h2 { margin: 0 0 8px; font-size: 16px; }
.muted { color: var(--muted); font-size: 13px; }

.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px,1fr)); gap: 12px; margin-bottom: 14px; }
.stat {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 14px 16px; cursor: pointer; transition: transform .08s, border-color .15s;
}
.stat:hover { transform: translateY(-2px); border-color: var(--accent); }
.stat .num { font-size: 28px; font-weight: 800; }
.stat .lbl { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .4px; }
.stat.correct .num { color: var(--green); }
.stat.wrong .num { color: var(--red); }
.stat.review .num { color: var(--yellow); }
.stat.unanswered .num { color: var(--muted); }
.stat.total .num { color: var(--accent); }
.stat.discrepancy .num { color: var(--blue); }

.progressbar { height: 10px; background: var(--panel2); border-radius: 6px; overflow: hidden; border: 1px solid var(--border); }
#progressFill { height: 100%; width: 0; background: linear-gradient(90deg, var(--green), var(--accent)); transition: width .4s; }

.row { display: flex; gap: 10px; align-items: center; margin-top: 10px; }
.row.wrap { flex-wrap: wrap; }
.btn {
  background: var(--panel2); color: var(--text); border: 1px solid var(--border);
  padding: 9px 16px; border-radius: 8px; cursor: pointer; font-size: 14px;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); color: #11171f; font-weight: 700; border-color: var(--accent); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.ghost { background: transparent; }
.btn.danger { background: var(--red); border-color: var(--red); color: #fff; }
.btn.small { padding: 5px 10px; font-size: 12px; }
.btn:disabled { opacity: .4; cursor: not-allowed; }
.check { font-size: 13px; color: var(--muted); display: inline-flex; align-items: center; gap: 6px; margin-top: 10px; cursor: pointer; }
.custom-test { display: inline-flex; gap: 6px; }
input[type=number], input[type=search], select {
  background: var(--panel2); border: 1px solid var(--border); color: var(--text);
  padding: 8px 10px; border-radius: 8px; font-size: 14px;
}
input[type=number] { width: 80px; }
input[type=search] { flex: 1; min-width: 160px; }
.danger-zone { border-color: #43302f; }

/* browse list */
.browse-controls { gap: 12px; }
.qlist { display: flex; flex-direction: column; gap: 8px; }
.qrow {
  background: var(--panel); border: 1px solid var(--border); border-left-width: 4px;
  border-radius: 8px; padding: 12px 14px; cursor: pointer; display: flex; gap: 12px; align-items: flex-start;
}
.qrow:hover { border-color: var(--accent); }
.qrow .qn { font-weight: 700; color: var(--muted); min-width: 46px; }
.qrow .qs { flex: 1; font-size: 14px; }
.qrow.correct { border-left-color: var(--green); }
.qrow.wrong { border-left-color: var(--red); }
.qrow.review { border-left-color: var(--yellow); }
.qrow.unanswered { border-left-color: var(--border); }
.tagicons { font-size: 12px; color: var(--muted); white-space: nowrap; }

/* question detail */
.qhead { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 10px; }
.qmeta { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; }
.chip { background: var(--panel2); border: 1px solid var(--border); border-radius: 20px; padding: 3px 12px; font-size: 12px; color: var(--muted); }
.chip.warn { background: #3a2e12; color: var(--yellow); border-color: #5a4715; }
.chip.img { background: #12303a; color: var(--blue); border-color: #1c4a5a; }
.qtext { font-size: 15px; white-space: pre-wrap; margin-bottom: 14px; }
.qimg-warn { background: #12303a; border: 1px solid #1c4a5a; color: var(--blue); padding: 10px 12px; border-radius: 8px; font-size: 13px; margin-bottom: 14px; }
.choices { display: flex; flex-direction: column; gap: 8px; margin-bottom: 14px; }
.choice {
  display: flex; gap: 10px; align-items: flex-start; background: var(--panel2);
  border: 1px solid var(--border); border-radius: 8px; padding: 11px 13px; cursor: pointer;
}
.choice:hover { border-color: var(--accent); }
.choice input { margin-top: 3px; }
.choice .letter { font-weight: 700; color: var(--accent); min-width: 18px; }
.choice.selected { border-color: var(--accent); }
.choice.correct { border-color: var(--green); background: #16301f; }
.choice.incorrect { border-color: var(--red); background: #301717; }
.choice.disabled { cursor: default; }
.choice.disabled:hover { border-color: var(--border); }

/* answer panel */
.answer-panel { border-top: 1px solid var(--border); padding-top: 14px; margin-top: 4px; }
.verdict { font-size: 18px; font-weight: 800; margin-bottom: 10px; }
.verdict.ok { color: var(--green); }
.verdict.bad { color: var(--red); }
.ans-block { background: var(--panel2); border: 1px solid var(--border); border-radius: 8px; padding: 12px 14px; margin-bottom: 10px; }
.ans-block h4 { margin: 0 0 6px; font-size: 13px; color: var(--muted); text-transform: uppercase; letter-spacing: .4px; }
.disc-warn { background: #3a2412; border: 1px solid #6b3d12; color: var(--accent); padding: 12px 14px; border-radius: 8px; margin-bottom: 10px; font-size: 14px; }
.ai-note { background: #15263a; border: 1px solid #1f3f63; color: var(--blue); padding: 12px 14px; border-radius: 8px; margin-bottom: 10px; font-size: 14px; }
.votebar-wrap { display: flex; flex-direction: column; gap: 6px; }
.votebar { display: flex; align-items: center; gap: 8px; font-size: 13px; }
.votebar .vb-letter { min-width: 34px; font-weight: 700; }
.votebar .vb-track { flex: 1; background: var(--bg); border-radius: 4px; height: 16px; overflow: hidden; border: 1px solid var(--border); }
.votebar .vb-fill { height: 100%; background: var(--blue); }
.votebar.most .vb-fill { background: var(--green); }
.votebar .vb-cnt { min-width: 64px; text-align: right; color: var(--muted); }

.status-badge { font-size: 12px; padding: 3px 10px; border-radius: 20px; font-weight: 700; }
.status-badge.correct { background: #16301f; color: var(--green); }
.status-badge.wrong { background: #301717; color: var(--red); }
.status-badge.review { background: #3a2e12; color: var(--yellow); }
.status-badge.unanswered { background: var(--panel2); color: var(--muted); }

.toast {
  position: fixed; bottom: 22px; left: 50%; transform: translateX(-50%);
  background: var(--panel2); border: 1px solid var(--accent); color: var(--text);
  padding: 10px 18px; border-radius: 8px; font-size: 14px; z-index: 50;
}
.summary-big { font-size: 34px; font-weight: 800; color: var(--accent); }

/* AI verification block */
.stat.ai_flagged .num { color: var(--blue); }
.ai-block { border-radius: 8px; padding: 12px 14px; margin-bottom: 10px; border: 1px solid var(--border); }
.ai-block .ai-head { font-size: 14px; margin-bottom: 6px; }
.ai-block .ai-reason { font-size: 13px; }
.ai-block .ai-opt { font-size: 12px; margin-top: 8px; background: rgba(0,0,0,.25); padding: 8px 10px; border-radius: 6px; font-family: ui-monospace, monospace; white-space: pre-wrap; }
.ai-block .ai-src { font-size: 12px; margin-top: 8px; color: var(--muted); }
.ai-block .ai-src a { color: var(--blue); margin-right: 4px; text-decoration: none; }
.ai-tag { font-size: 11px; background: rgba(255,255,255,.08); border-radius: 10px; padding: 1px 8px; margin-left: 6px; color: var(--muted); }
.ai-block.agree { background: #122a1a; border-color: #1f5034; }
.ai-block.agree .ai-head { color: var(--green); }
.ai-block.disagree { background: #3a1a12; border-color: #7a2d12; }
.ai-block.disagree .ai-head { color: #ff7a45; font-weight: 700; }
.ai-block.disputed { background: #3a2e12; border-color: #6b5215; }
.ai-block.disputed .ai-head { color: var(--yellow); font-weight: 700; }