/* ======== Theme ======== */
:root {
  --bg: #0f1115;
  --bg-soft: #161a22;
  --bg-card: #1b2030;
  --bg-elev: #232a3d;
  --border: #2a3245;
  --text: #e6e9f2;
  --text-muted: #9aa3b8;
  --accent: #5b8cff;
  --accent-strong: #4a76e6;
  --good: #34d399;
  --bad: #f87171;
  --warn: #fbbf24;
  --info: #60a5fa;
  --shadow: 0 8px 24px rgba(0,0,0,.25);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

/* ======== Views ======== */
.view { display: none; min-height: 100vh; flex-direction: column; }
.view.active { display: flex; }

/* ======== Topbar ======== */
.topbar {
  display: flex; justify-content: space-between; align-items: center;
  padding: 18px 28px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 5;
}
.brand { display: flex; align-items: center; gap: 14px; }
.logo {
  width: 42px; height: 42px;
  background: linear-gradient(135deg, var(--accent), #8a5bff);
  border-radius: 10px;
  display: grid; place-items: center;
  font-weight: 800; font-size: 20px; color: white;
}
.brand-title { font-weight: 700; font-size: 18px; }
.brand-sub { font-size: 12px; color: var(--text-muted); }
.topnav { display: flex; gap: 6px; }
.nav-link {
  background: transparent; border: 0; color: var(--text-muted);
  padding: 8px 14px; border-radius: 8px; cursor: pointer;
  font-size: 14px; font-weight: 500;
}
.nav-link:hover { color: var(--text); background: var(--bg-card); }
.nav-link.active { color: var(--text); background: var(--bg-card); }

/* ======== Container & tabs ======== */
.container { max-width: 1100px; margin: 0 auto; padding: 28px 24px 60px; flex: 1; width: 100%; }
.tab { display: none; }
.tab.active { display: block; }

/* ======== Hero ======== */
.hero h1 { font-size: 32px; line-height: 1.2; margin: 8px 0 6px; }
.hero p { color: var(--text-muted); margin: 0 0 24px; max-width: 720px; }

/* ======== Grand test card (legacy single) ======== */
.grand-test-card {
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  background: linear-gradient(135deg, rgba(91,140,255,.12), rgba(138,91,255,.10));
  border: 1px solid rgba(91,140,255,.35);
  padding: 22px 24px; border-radius: 14px;
  margin: 8px 0 32px;
}
.grand-test-card h2 { margin: 0 0 4px; font-size: 22px; }
.grand-test-card p { margin: 0; color: var(--text-muted); font-size: 14px; }

/* ======== Grand test grid ======== */
.grand-test-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
  margin-bottom: 32px;
}
.grand-test-card-mini {
  background: linear-gradient(135deg, rgba(91,140,255,.12), rgba(138,91,255,.10));
  border: 1px solid rgba(91,140,255,.35);
  border-radius: 12px;
  padding: 18px;
  display: flex; flex-direction: column; gap: 10px;
  transition: transform .15s, border-color .15s;
}
.grand-test-card-mini:hover { transform: translateY(-2px); border-color: var(--accent); }
.grand-test-card-mini h3 { margin: 0; font-size: 17px; }
.grand-test-card-mini p { margin: 0; color: var(--text-muted); font-size: 13px; flex: 1; }
.grand-test-card-mini button { align-self: flex-start; }
.gt-badge {
  display: inline-block; align-self: flex-start;
  font-size: 11px; font-weight: 700; letter-spacing: .5px;
  text-transform: uppercase;
  background: rgba(91,140,255,.25);
  color: var(--text);
  padding: 3px 8px; border-radius: 999px;
}
.gt-badge.fixed { background: rgba(168,85,247,.25); }
.gt-stats { display: flex; gap: 8px; font-size: 11px; color: var(--text-muted); margin-top: 4px; }

/* ======== Section titles ======== */
.section-title { font-size: 20px; margin: 28px 0 6px; }
.section-sub { color: var(--text-muted); margin: 0 0 16px; font-size: 14px; }

/* ======== Subject grid ======== */
.subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 14px;
}
.subject-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  cursor: pointer;
  transition: transform .15s, border-color .15s, background .15s;
  display: flex; flex-direction: column; gap: 10px;
}
.subject-card:hover { transform: translateY(-2px); border-color: var(--accent); }
.subject-card .sc-icon {
  width: 36px; height: 36px; border-radius: 8px;
  display: grid; place-items: center; font-size: 18px;
  background: var(--bg-elev);
}
.subject-card .sc-name { font-weight: 600; font-size: 16px; }
.subject-card .sc-meta { color: var(--text-muted); font-size: 12px; }
.subject-card .sc-stats { display: flex; gap: 12px; margin-top: auto; padding-top: 8px; border-top: 1px dashed var(--border); }
.subject-card .sc-stat { font-size: 12px; }
.subject-card .sc-stat strong { display: block; color: var(--text); font-size: 14px; }

/* ======== Buttons ======== */
.btn-primary, .btn-ghost, .btn-danger {
  font-size: 14px; font-weight: 600; padding: 10px 16px;
  border-radius: 8px; border: 0; cursor: pointer;
  transition: background .15s, transform .05s;
}
.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-strong); }
.btn-ghost { background: var(--bg-card); color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--bg-elev); }
.btn-ghost.danger { color: var(--bad); border-color: rgba(248,113,113,.4); }
.btn-danger { background: var(--bad); color: white; }
.btn-danger:hover { background: #ef4444; }
button:active { transform: translateY(1px); }

/* ======== Footer ======== */
.footer {
  text-align: center; padding: 18px;
  color: var(--text-muted); font-size: 12px;
  border-top: 1px solid var(--border);
}

/* ======== Modal ======== */
.modal {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.6);
  display: grid; place-items: center;
  z-index: 50;
  backdrop-filter: blur(4px);
}
.modal.hidden { display: none; }
.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
  width: min(92vw, 460px);
  box-shadow: var(--shadow);
}
.modal-card h2 { margin: 0 0 6px; }
.modal-card label { display: block; font-size: 13px; color: var(--text-muted); margin: 14px 0 6px; }
.modal-card select, .modal-card input, .modal-card textarea {
  width: 100%; padding: 10px 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px; color: var(--text);
  font-size: 14px;
}
.modal-actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 20px; }

/* ======== Exam (test view) ======== */
.exam-topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 24px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 5;
}
.exam-title { font-weight: 700; }
.exam-stats { display: flex; align-items: center; gap: 20px; }
.stat { display: flex; flex-direction: column; align-items: flex-end; }
.stat-label { font-size: 11px; color: var(--text-muted); text-transform: uppercase; letter-spacing: .5px; }
.stat-value { font-weight: 700; font-size: 14px; }
.stat.timer .stat-value { color: var(--warn); font-variant-numeric: tabular-nums; }
.stat.timer.danger .stat-value { color: var(--bad); animation: pulse 1s infinite; }
@keyframes pulse { 50% { opacity: .55; } }

.exam-main {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 20px;
  padding: 20px 24px;
  max-width: 1280px; margin: 0 auto; width: 100%;
  flex: 1;
}
@media (max-width: 900px) {
  .exam-main { grid-template-columns: 1fr; }
  .exam-palette { order: -1; }
}

.exam-question {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
}
.qmeta { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.qmeta-num { background: var(--bg-elev); padding: 4px 10px; border-radius: 6px; font-weight: 700; font-size: 13px; }
.qmeta-topic { color: var(--text-muted); font-size: 13px; }
.qstem { font-size: 16px; line-height: 1.65; margin-bottom: 18px; white-space: pre-wrap; }
.qoptions { display: flex; flex-direction: column; gap: 10px; }
.qopt {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  cursor: pointer;
  display: flex; gap: 12px; align-items: flex-start;
  transition: border-color .15s, background .15s;
}
.qopt:hover { border-color: var(--accent); }
.qopt.selected { border-color: var(--accent); background: rgba(91,140,255,.12); }
.qopt .opt-letter {
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--bg-elev);
  display: grid; place-items: center; font-weight: 700; font-size: 13px;
  flex-shrink: 0;
}
.qopt.selected .opt-letter { background: var(--accent); color: white; }
.qopt .opt-text { flex: 1; }

.exam-controls { display: flex; gap: 8px; margin-top: 22px; align-items: center; flex-wrap: wrap; }
.exam-controls .spacer { flex: 1; }

/* ======== Palette ======== */
.exam-palette {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  align-self: start;
  position: sticky; top: 80px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}
.exam-palette h3 { margin: 0 0 10px; font-size: 14px; }
.palette-legend { display: flex; flex-direction: column; gap: 4px; font-size: 11px; color: var(--text-muted); margin-bottom: 12px; }
.palette-legend .dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; margin-right: 6px; vertical-align: middle; }
.palette-legend .dot.answered { background: var(--good); }
.palette-legend .dot.marked { background: #a855f7; }
.palette-legend .dot.answered-marked { background: linear-gradient(135deg, var(--good) 50%, #a855f7 50%); }
.palette-legend .dot.unanswered { background: var(--bad); }
.palette-legend .dot.not-visited { background: var(--bg-elev); border: 1px solid var(--border); }

.palette-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}
.pal-cell {
  aspect-ratio: 1;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 12px; font-weight: 600;
  display: grid; place-items: center;
  cursor: pointer;
  color: var(--text);
}
.pal-cell:hover { border-color: var(--accent); }
.pal-cell.current { outline: 2px solid var(--accent); outline-offset: 1px; }
.pal-cell.answered { background: var(--good); color: #052e1c; border-color: transparent; }
.pal-cell.unanswered { background: var(--bad); color: white; border-color: transparent; }
.pal-cell.marked { background: #a855f7; color: white; border-color: transparent; }
.pal-cell.answered-marked { background: linear-gradient(135deg, var(--good) 50%, #a855f7 50%); color: white; border-color: transparent; }

/* ======== Results ======== */
.result-summary {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 20px; align-items: stretch;
  margin-bottom: 12px;
}
@media (max-width: 720px) { .result-summary { grid-template-columns: 1fr; } }

.score-card {
  background: linear-gradient(135deg, rgba(91,140,255,.18), rgba(138,91,255,.14));
  border: 1px solid rgba(91,140,255,.35);
  border-radius: 14px;
  padding: 24px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.score-big { font-size: 36px; font-weight: 800; }
.score-pct { font-size: 18px; color: var(--text-muted); margin-top: 4px; }
.score-grade { font-size: 14px; font-weight: 600; margin-top: 12px; padding: 4px 12px; border-radius: 999px; background: var(--bg-elev); }

.kpi-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
@media (max-width: 540px) { .kpi-grid { grid-template-columns: repeat(2, 1fr); } }
.kpi {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}
.kpi-label { font-size: 12px; color: var(--text-muted); text-transform: uppercase; letter-spacing: .5px; }
.kpi-value { font-size: 22px; font-weight: 700; margin-top: 4px; }
.kpi-value.good { color: var(--good); }
.kpi-value.bad { color: var(--bad); }

/* Topic breakdown */
.topic-breakdown {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  margin-bottom: 12px;
}
.topic-row {
  display: grid;
  grid-template-columns: 200px 1fr 80px 70px;
  gap: 12px;
  align-items: center;
  padding: 10px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
}
@media (max-width: 700px) { .topic-row { grid-template-columns: 1fr; gap: 6px; } }
.topic-bar {
  background: var(--bg);
  height: 10px; border-radius: 6px;
  overflow: hidden;
  position: relative;
}
.topic-bar .fill { height: 100%; background: var(--good); }
.topic-bar .fill.low { background: var(--bad); }
.topic-bar .fill.mid { background: var(--warn); }
.topic-name { font-weight: 600; font-size: 14px; }
.topic-stats { font-size: 13px; color: var(--text-muted); text-align: right; }
.topic-acc { font-weight: 700; text-align: right; }

/* Insights */
.insights {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px;
  margin-bottom: 12px;
}
.insights ul { margin: 6px 0; padding-left: 22px; }
.insights li { margin: 4px 0; }

/* Review */
.review-toolbar {
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px;
  margin-top: 28px; margin-bottom: 12px;
}
.filter-chips { display: flex; gap: 6px; flex-wrap: wrap; }
.chip {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 6px 12px; border-radius: 999px;
  font-size: 13px; cursor: pointer;
}
.chip.active, .chip:hover { color: var(--text); border-color: var(--accent); }

.review-list { display: flex; flex-direction: column; gap: 12px; }
.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
}
.review-card.correct { border-left: 4px solid var(--good); }
.review-card.wrong { border-left: 4px solid var(--bad); }
.review-card.skipped { border-left: 4px solid var(--text-muted); }
.review-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 8px; gap: 12px; }
.review-num { font-weight: 700; }
.review-tag { font-size: 12px; padding: 2px 8px; border-radius: 999px; background: var(--bg-elev); color: var(--text-muted); }
.review-tag.correct { background: rgba(52,211,153,.15); color: var(--good); }
.review-tag.wrong { background: rgba(248,113,113,.15); color: var(--bad); }
.review-q { white-space: pre-wrap; margin-bottom: 10px; }
.review-opts { display: flex; flex-direction: column; gap: 6px; margin-bottom: 10px; }
.review-opt {
  padding: 8px 12px; border-radius: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  font-size: 14px;
}
.review-opt.correct-ans { border-color: var(--good); background: rgba(52,211,153,.08); }
.review-opt.user-wrong { border-color: var(--bad); background: rgba(248,113,113,.08); }
.review-explain {
  background: var(--bg);
  border-left: 3px solid var(--accent);
  padding: 10px 14px;
  border-radius: 0 8px 8px 0;
  font-size: 14px;
  color: var(--text);
}

/* Progress */
.progress-summary {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px; margin-top: 8px;
}
@media (max-width: 700px) { .progress-summary { grid-template-columns: repeat(2, 1fr); } }
.progress-list { display: flex; flex-direction: column; gap: 8px; }
.progress-row {
  display: grid;
  grid-template-columns: 1fr 80px 100px 100px;
  gap: 12px; align-items: center;
  padding: 12px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
}
@media (max-width: 700px) { .progress-row { grid-template-columns: 1fr 1fr; gap: 6px; } }

.attempt-list { display: flex; flex-direction: column; gap: 6px; margin-top: 6px; }
.attempt-row {
  display: grid;
  grid-template-columns: 1fr 80px 100px 100px;
  gap: 12px;
  padding: 10px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
}
@media (max-width: 700px) { .attempt-row { grid-template-columns: 1fr 1fr; } }

.actions-row { display: flex; gap: 8px;