:root{
  --bg:#f3f6f8;
  --surface:#ffffff;
  --surface-soft:#f8fafb;
  --ink:#14202b;
  --muted:#66737f;
  --line:#dce3e8;
  --teal:#087f8c;
  --teal-dark:#075d66;
  --green:#19734a;
  --green-bg:#e7f6ed;
  --red:#a43a3a;
  --red-bg:#fdecec;
  --shadow:0 14px 34px rgba(20,32,43,.07);
  --radius:20px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  line-height:1.55;
}
a{text-decoration:none;color:inherit}
button,input,select{font:inherit}
.topbar{
  position:sticky;
  top:0;
  z-index:50;
  background:rgba(255,255,255,.96);
  backdrop-filter:blur(16px);
  border-bottom:1px solid var(--line);
}
.topbar-inner{
  width:min(1220px,calc(100% - 36px));
  min-height:72px;
  margin:auto;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:24px;
}
.brand{font-weight:850;letter-spacing:-.025em;white-space:nowrap}
.brand span{
  margin-right:8px;
  padding:6px 9px;
  border-radius:8px;
  background:var(--ink);
  color:#fff;
  font-size:.75rem;
}
.topbar nav{display:flex;gap:5px;flex-wrap:wrap}
.topbar nav a{
  padding:9px 11px;
  border-radius:9px;
  color:var(--muted);
  font-size:.92rem;
  font-weight:650;
}
.topbar nav a:hover{background:#eef2f4;color:var(--ink)}
.shell{width:min(1220px,calc(100% - 36px));margin:auto}
.hero{
  margin:34px 0 22px;
  padding:42px;
  border-radius:26px;
  background:linear-gradient(135deg,#13222e,#2f4a5c);
  color:#fff;
  box-shadow:var(--shadow);
  display:flex;
  align-items:flex-end;
  justify-content:space-between;
  gap:32px;
}
.hero.compact{padding:34px}
.hero h1{
  margin:7px 0 10px;
  max-width:880px;
  font-size:clamp(2.15rem,4.8vw,4.25rem);
  line-height:1.04;
  letter-spacing:-.055em;
}
.hero p{max-width:760px;margin:0;opacity:.8;font-size:1.04rem}
.eyebrow{
  color:var(--muted);
  font-size:.74rem;
  font-weight:850;
  letter-spacing:.13em;
  text-transform:uppercase;
}
.hero .eyebrow{color:#bdd0d9}
.hero-stat{
  min-width:145px;
  padding:20px;
  border-radius:18px;
  background:rgba(255,255,255,.11);
  display:flex;
  flex-direction:column;
}
.hero-stat strong{font-size:3rem;line-height:1}
.hero-stat span{margin-top:7px;font-size:.82rem}
.track-grid,.module-grid,.subject-grid{
  display:grid;
  gap:18px;
}
.track-grid{grid-template-columns:repeat(3,1fr)}
.module-grid{grid-template-columns:repeat(3,1fr)}
.subject-grid{grid-template-columns:repeat(3,1fr);margin-bottom:34px}
.track-card,.module-card,.subject-card{
  position:relative;
  min-height:235px;
  padding:26px;
  border:1px solid var(--line);
  border-radius:var(--radius);
  background:var(--surface);
  box-shadow:var(--shadow);
  transition:transform .18s ease,border-color .18s ease;
}
.track-card:hover,.module-card:hover,.subject-card:hover{
  transform:translateY(-3px);
  border-color:#adc5c9;
}
.track-prelims{border-top:5px solid #2563eb}
.track-mains{border-top:5px solid #7c3aed}
.track-optional{border-top:5px solid var(--teal)}
.track-card h2,.module-card h2,.subject-card h2{
  margin:9px 0;
  font-size:1.55rem;
  letter-spacing:-.035em;
}
.track-card p,.module-card p,.subject-card p{color:var(--muted)}
.open-link{
  position:absolute;
  left:26px;
  bottom:22px;
  color:var(--teal-dark);
  font-weight:800;
}
.module-card.featured{background:linear-gradient(145deg,#fff,#eef8f8);border-color:#badfe1}
.module-index{font-size:.8rem;font-weight:850;color:var(--muted)}
.subject-count{
  display:inline-flex;
  min-width:52px;
  height:52px;
  align-items:center;
  justify-content:center;
  border-radius:14px;
  background:#e7f5f6;
  color:var(--teal-dark);
  font-weight:850;
}
.filter-panel{
  position:sticky;
  top:88px;
  z-index:20;
  margin:18px 0 24px;
  padding:22px;
  border:1px solid var(--line);
  border-radius:18px;
  background:rgba(255,255,255,.97);
  box-shadow:var(--shadow);
}
.filter-header{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:18px;
  margin-bottom:16px;
}
.filter-header h2{margin:3px 0 0;font-size:1.35rem}
.filter-grid{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:12px;
}
.filter-grid label{
  display:flex;
  flex-direction:column;
  gap:6px;
  color:var(--muted);
  font-size:.78rem;
  font-weight:750;
}
.filter-grid select,.filter-grid input{
  width:100%;
  min-height:45px;
  padding:10px 12px;
  border:1px solid var(--line);
  border-radius:10px;
  background:#fff;
  color:var(--ink);
}
.filter-status{margin-top:13px;color:var(--muted);font-size:.86rem}
.button-light{
  border:1px solid var(--line);
  border-radius:9px;
  padding:9px 12px;
  background:#eef2f4;
  color:var(--ink);
  cursor:pointer;
}
.question-list{display:grid;gap:18px}
.question-card{
  padding:28px;
  border:1px solid var(--line);
  border-radius:20px;
  background:var(--surface);
  box-shadow:var(--shadow);
}
.question-topline{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
}
.question-number{font-weight:850}
.question-tags{display:flex;gap:7px;flex-wrap:wrap}
.question-tags span{
  padding:4px 8px;
  border-radius:999px;
  background:#eef2f4;
  color:var(--muted);
  font-size:.75rem;
  font-weight:750;
}
.syllabus-path{
  margin:13px 0;
  color:var(--teal-dark);
  font-size:.84rem;
  font-weight:700;
}
.syllabus-path b{padding:0 5px;color:#94a2ac}
.question-card h2{
  margin:10px 0 20px;
  font-size:1.2rem;
  line-height:1.55;
  letter-spacing:-.015em;
}
.answer-options{display:grid;gap:10px}
.answer-option{
  width:100%;
  display:flex;
  align-items:flex-start;
  gap:12px;
  padding:14px;
  border:1px solid var(--line);
  border-radius:12px;
  background:var(--surface-soft);
  color:var(--ink);
  text-align:left;
  cursor:pointer;
  transition:border-color .15s,background .15s;
}
.answer-option:hover:not(:disabled){border-color:#9eb9bd;background:#f1f8f8}
.answer-option:disabled{cursor:default;opacity:1}
.option-letter{
  flex:0 0 30px;
  height:30px;
  display:grid;
  place-items:center;
  border-radius:50%;
  background:#e6ecef;
  font-weight:850;
}
.correct-answer{
  border-color:#70b28d!important;
  background:var(--green-bg)!important;
  color:#175e3d;
}
.correct-answer .option-letter{background:var(--green);color:#fff}
.wrong-answer{
  border-color:#d17e7e!important;
  background:var(--red-bg)!important;
  color:#812e2e;
}
.wrong-answer .option-letter{background:var(--red);color:#fff}
.question-actions{
  min-height:44px;
  margin-top:16px;
  display:flex;
  align-items:center;
  gap:10px;
  flex-wrap:wrap;
}
.answer-result{
  margin-right:auto;
  font-weight:850;
}
.result-correct{color:var(--green)}
.result-wrong{color:var(--red)}
.explanation-toggle,.mistake-link{
  border:0;
  border-radius:9px;
  padding:9px 12px;
  cursor:pointer;
}
.explanation-toggle{background:#e4f1f2;color:var(--teal-dark);font-weight:800}
.mistake-link{background:#eef1f3;color:var(--ink)}
.explanation-dropdown{
  margin-top:14px;
  padding:18px;
  border-left:4px solid var(--teal);
  border-radius:10px;
  background:#f0f6f7;
}
.explanation-dropdown p{margin-bottom:0;white-space:pre-line}
.correct-answer-line{color:var(--green)}
.empty-state{
  padding:38px;
  border:1px dashed #bfcbd2;
  border-radius:18px;
  background:#fff;
  color:var(--muted);
  text-align:center;
}
footer{
  margin-top:48px;
  padding:34px;
  border-top:1px solid var(--line);
  background:#fff;
  color:var(--muted);
  text-align:center;
  font-size:.85rem;
}
.muted{color:var(--muted)}
@media(max-width:900px){
  .topbar-inner{align-items:flex-start;flex-direction:column;padding:13px 0}
  .topbar nav{width:100%;overflow:auto;flex-wrap:nowrap}
  .hero{align-items:flex-start;flex-direction:column;padding:28px}
  .track-grid,.module-grid,.subject-grid{grid-template-columns:1fr}
  .filter-panel{position:static}
  .filter-grid{grid-template-columns:1fr}
  .question-card{padding:20px}
  .question-topline{align-items:flex-start;flex-direction:column}
}

.filter-panel{
  scroll-margin-top:96px;
}
.filter-panel.collapsed{
  padding:14px 18px;
}
.filter-panel.collapsed .filter-header{
  margin-bottom:0;
}
.filter-panel.collapsed .filter-title-group h2{
  display:none;
}
.filter-panel.collapsed .eyebrow{
  display:none;
}
.filter-title-group{
  min-width:0;
}
.filter-summary{
  display:block;
  margin-top:4px;
  color:var(--muted);
  font-size:.84rem;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
  max-width:760px;
}
.filter-header-actions{
  display:flex;
  gap:8px;
  flex-wrap:wrap;
}
.filter-body[hidden]{
  display:none!important;
}
.question-list{
  position:relative;
  z-index:1;
}
@media(max-width:900px){
  .filter-header{
    align-items:flex-start;
    flex-direction:column;
  }
  .filter-header-actions{
    width:100%;
  }
  .filter-header-actions button{
    flex:1;
  }
  .filter-summary{
    max-width:100%;
    white-space:normal;
  }
}

.filter-panel[hidden]{display:none!important}
.filter-panel{
  position:relative;
  top:auto;
  z-index:20;
  margin:18px 0 24px;
}
.filter-fab{
  position:fixed;
  right:24px;
  bottom:24px;
  z-index:60;
  width:52px;
  height:52px;
  border:0;
  border-radius:50%;
  background:var(--teal);
  color:#fff;
  box-shadow:0 12px 28px rgba(8,127,140,.28);
  cursor:pointer;
  display:grid;
  place-items:center;
}
.filter-fab:hover{background:var(--teal-dark)}
.filter-fab-icon{
  font-size:1.2rem;
  line-height:1;
}
.filter-fab-dot{
  position:absolute;
  top:5px;
  right:5px;
  width:10px;
  height:10px;
  border-radius:50%;
  background:#f59e0b;
  border:2px solid #fff;
}
.filters-open .filter-fab{
  opacity:.3;
  pointer-events:none;
}
@media(max-width:900px){
  .filter-fab{
    right:16px;
    bottom:16px;
    width:48px;
    height:48px;
  }
}