:root{
  --bg:#0a0e17; --card:#111827; --card2:#1a2236; --text:#f0f2f5; --muted:#94a3b8;
  --line:rgba(255,255,255,.08); --line2:rgba(255,255,255,.12); --btn:#1a2236;
  --accent:#38bdf8; --accent2:#818cf8;
  --accent-glow:rgba(56,189,248,.12); --accent2-glow:rgba(129,140,248,.10);
  --ok:#34d399; --bad:#fb7185; --warn:#fbbf24;
  --radius:14px; --radius-sm:10px; --radius-pill:100px;
}

/* ─── Animations ──────────────────────────────────── */
@keyframes fadeUp{
  from{ opacity:0; transform:translateY(18px); }
  to{ opacity:1; transform:translateY(0); }
}
@keyframes shimmer{
  0%{ background-position:-200% 0; }
  100%{ background-position:200% 0; }
}
@keyframes glow-pulse{
  0%,100%{ opacity:.6; }
  50%{ opacity:1; }
}
@keyframes pop{
  0%{ transform:scale(.95); opacity:0; }
  60%{ transform:scale(1.02); }
  100%{ transform:scale(1); opacity:1; }
}
@keyframes correct-flash{
  0%{ box-shadow:0 0 0 0 rgba(52,211,153,.5); }
  50%{ box-shadow:0 0 28px 4px rgba(52,211,153,.18); }
  100%{ box-shadow:0 0 0 0 rgba(52,211,153,0); }
}
@keyframes wrong-shake{
  0%,100%{ transform:translateX(0); }
  20%{ transform:translateX(-5px); }
  40%{ transform:translateX(5px); }
  60%{ transform:translateX(-3px); }
  80%{ transform:translateX(3px); }
}

/* ─── Base ────────────────────────────────────────── */
body{
  margin:0; padding:24px;
  background:var(--bg);
  color:var(--text);
  font:16px/1.6 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  font-weight:400;
  min-height:100vh;
  overflow-x:hidden;
}

/* Ambient orbs — breathing glow */
body::before{
  content:''; position:fixed; top:-25%; left:-10%;
  width:65vw; height:65vh;
  background:radial-gradient(ellipse at center, rgba(56,189,248,.07) 0%, transparent 65%);
  pointer-events:none; z-index:0;
  animation:glow-pulse 8s ease-in-out infinite;
}
body::after{
  content:''; position:fixed; bottom:-20%; right:-5%;
  width:50vw; height:50vh;
  background:radial-gradient(ellipse at center, rgba(129,140,248,.06) 0%, transparent 65%);
  pointer-events:none; z-index:0;
  animation:glow-pulse 10s ease-in-out infinite 3s;
}

.wrap{ max-width:980px; margin:0 auto; position:relative; z-index:1; }

/* ─── Header ──────────────────────────────────────── */
header{
  display:flex; gap:12px; align-items:baseline;
  justify-content:space-between; margin-bottom:14px;
  animation:fadeUp .5s cubic-bezier(.16,1,.3,1) both;
}
h1{
  margin:0; font-size:22px; font-weight:700;
  letter-spacing:-.02em;
  color:#C7D6EB;
}
.hint{ color:var(--muted); font-size:13px; font-weight:400; }

/* ─── Card ────────────────────────────────────────── */
.card{
  position:relative;
  background:var(--card);
  border:1px solid var(--line2);
  border-radius:var(--radius);
  padding:22px 22px 16px;
  margin:14px 0;
  box-shadow:
    0 2px 8px rgba(0,0,0,.15),
    0 12px 36px rgba(0,0,0,.2);
  animation:fadeUp .55s cubic-bezier(.16,1,.3,1) both;
  transition:border-color .3s, box-shadow .3s, transform .3s;
}
/* Accent gradient line at top */
.card::before{
  content:''; position:absolute;
  top:0; left:24px; right:24px; height:1px;
  background:linear-gradient(90deg, transparent, rgba(56,189,248,.25), rgba(129,140,248,.2), transparent);
  border-radius:1px;
}
.card:hover{
  border-color:rgba(56,189,248,.15);
  box-shadow:
    0 2px 8px rgba(0,0,0,.15),
    0 16px 48px rgba(0,0,0,.25),
    0 0 40px rgba(56,189,248,.04);
  transform:translateY(-1px);
}

/* Stagger cards */
.card:nth-child(1){ animation-delay:.0s; }
.card:nth-child(2){ animation-delay:.06s; }
.card:nth-child(3){ animation-delay:.12s; }
.card:nth-child(4){ animation-delay:.18s; }
.card:nth-child(5){ animation-delay:.24s; }
.card:nth-child(n+6){ animation-delay:.3s; }

/* ─── Title row ───────────────────────────────────── */
.title{
  display:flex; gap:12px;
  align-items:flex-start;
  justify-content:space-between;
  margin-bottom:10px;
}
.title .qtext{
  margin:0; white-space:pre-wrap;
  flex:1 1 auto;
  font-weight:400; line-height:1.65;
  font-size:15.5px;
}
.pill{
  padding:6px 13px;
  border-radius:var(--radius-pill);
  border:1px solid var(--line2);
  background:rgba(255,255,255,.04);
  color:var(--muted);
  font-size:12px; font-weight:600;
  font-family:monospace;
  flex:0 0 auto;
  letter-spacing:.02em;
}

.qimg{
  width:100%; max-width:920px;
  display:block; margin:10px 0 14px;
  border-radius:var(--radius);
  border:1px solid var(--line2);
  background:rgba(255,255,255,.02);
  transition:transform .3s, box-shadow .3s;
}
.qimg:hover{
  transform:scale(1.005);
  box-shadow:0 12px 40px rgba(0,0,0,.3);
}

/* ─── Answer grid ─────────────────────────────────── */
.answers{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:10px; margin:12px 0 8px;
}
@media (max-width:720px){ .answers{ grid-template-columns:1fr; } }

button.option{
  position:relative;
  text-align:left;
  background:var(--btn);
  border:1px solid var(--line2);
  color:var(--text);
  padding:14px 16px;
  border-radius:var(--radius-sm);
  cursor:pointer;
  display:flex; gap:10px;
  align-items:flex-start;
  font-size:15px; font-weight:400;
  transition:all .2s cubic-bezier(.16,1,.3,1);
  overflow:hidden;
}
/* Shimmer sweep on hover */
button.option::after{
  content:''; position:absolute;
  top:0; left:0; right:0; bottom:0;
  background:linear-gradient(105deg, transparent 40%, rgba(56,189,248,.04) 50%, transparent 60%);
  background-size:200% 100%;
  opacity:0;
  transition:opacity .3s;
  pointer-events:none;
}
button.option:hover{
  border-color:rgba(56,189,248,.25);
  background:var(--card2);
  box-shadow:0 2px 10px rgba(0,0,0,.1);
}
button.option:hover::after{
  opacity:0;
}
button.option:active{ transform:translateY(1px); }
button.option.selected{
  outline:none;
  border-color:rgba(56,189,248,.5);
  background:rgba(56,189,248,.08);
  box-shadow:0 0 0 3px rgba(56,189,248,.1), 0 0 24px rgba(56,189,248,.05);
}

.badge{
  min-width:30px; height:30px;
  display:inline-grid; place-items:center;
  border-radius:var(--radius-sm);
  background:linear-gradient(135deg, rgba(56,189,248,.08), rgba(129,140,248,.08));
  border:1px solid rgba(255,255,255,.1);
  font-weight:700; font-size:13px;
  color:var(--accent);
  transition:all .2s;
}
button.option:hover .badge{
  background:linear-gradient(135deg, rgba(56,189,248,.15), rgba(129,140,248,.15));
  border-color:rgba(56,189,248,.25);
}

/* ─── Correction states ───────────────────────────── */
.answered button.option{ opacity:.92; }
.answered button.option.disabled{ pointer-events:none; opacity:.55; }

.option.correct{
  border-color:rgba(52,211,153,.6);
  background:rgba(52,211,153,.08);
  box-shadow:0 0 24px rgba(52,211,153,.08), inset 0 0 20px rgba(52,211,153,.03);
  animation:correct-flash .8s ease-out, pop .35s cubic-bezier(.16,1,.3,1);
}
.option.correct .badge{
  background:rgba(52,211,153,.15);
  border-color:rgba(52,211,153,.4);
  color:var(--ok);
}

.option.wrong{
  border-color:rgba(251,113,133,.55);
  background:rgba(251,113,133,.07);
  box-shadow:inset 0 0 16px rgba(251,113,133,.04);
  animation:wrong-shake .4s ease-out;
}
.option.wrong .badge{
  background:rgba(251,113,133,.12);
  border-color:rgba(251,113,133,.35);
  color:var(--bad);
}

.option.reveal{
  border-color:rgba(251,191,36,.45);
  box-shadow:0 0 0 2px rgba(251,191,36,.08) inset, 0 0 16px rgba(251,191,36,.05);
}
.option.reveal .badge{
  background:rgba(251,191,36,.12);
  border-color:rgba(251,191,36,.35);
  color:var(--warn);
}

/* ─── Meta / Controls ─────────────────────────────── */
.meta{
  margin-top:14px;
  display:flex; gap:10px; flex-wrap:wrap;
  align-items:center; justify-content:space-between;
  border-top:1px solid var(--line);
  padding-top:14px;
}
.controls{ display:flex; gap:8px; flex-wrap:wrap; }

.smallbtn{
  background:transparent;
  border:1px solid var(--line2);
  color:var(--muted);
  padding:8px 16px;
  border-radius:var(--radius-pill);
  cursor:pointer;
  font-size:13px; font-weight:500;
  
  transition:all .25s cubic-bezier(.16,1,.3,1);
  position:relative;
  overflow:hidden;
}
.smallbtn::before{
  content:''; position:absolute; inset:0;
  background:linear-gradient(135deg, var(--accent-glow), var(--accent2-glow));
  opacity:0; transition:opacity .25s;
}
.smallbtn:hover{
  border-color:rgba(56,189,248,.3);
  color:var(--text);
  transform:translateY(-1px);
  box-shadow:0 4px 12px rgba(0,0,0,.15);
}
.smallbtn:hover::before{ opacity:1; }
.smallbtn:active{ transform:translateY(0); }

/* ─── Result pills ────────────────────────────────── */
.result{
  font-size:14px; color:var(--muted);
  display:flex; gap:10px;
  align-items:center; flex-wrap:wrap;
}
.pill.ok{
  border-color:rgba(52,211,153,.4); color:#a7f3d0;
  background:linear-gradient(135deg, rgba(52,211,153,.1), rgba(52,211,153,.04));
  box-shadow:0 0 12px rgba(52,211,153,.06);
}
.pill.bad{
  border-color:rgba(251,113,133,.4); color:#fecdd3;
  background:linear-gradient(135deg, rgba(251,113,133,.1), rgba(251,113,133,.04));
  box-shadow:0 0 12px rgba(251,113,133,.06);
}
.pill.answer{
  border-color:rgba(251,191,36,.4); color:#fef3c7;
  background:linear-gradient(135deg, rgba(251,191,36,.1), rgba(251,191,36,.04));
  box-shadow:0 0 12px rgba(251,191,36,.06);
}

/* ─── Top bars ────────────────────────────────────── */
.topbar{
  display:flex; gap:10px; flex-wrap:wrap;
  align-items:center; justify-content:space-between;
  margin:10px 0 18px;
  animation:fadeUp .4s cubic-bezier(.16,1,.3,1) both;
}
.search{
  flex:1 1 420px;
  display:flex; gap:10px; align-items:center;
  border:1px solid var(--line2);
  background:var(--card);
  border-radius:var(--radius);
  padding:12px 16px;
  transition:all .25s;
  box-shadow:0 2px 8px rgba(0,0,0,.1);
}
.search:focus-within{
  border-color:rgba(56,189,248,.35);
  box-shadow:0 0 0 3px rgba(56,189,248,.08), 0 4px 16px rgba(0,0,0,.15);
}
.search input{
  width:100%; background:transparent;
  border:0; outline:none;
  color:var(--text);
  font-size:14px; 
  caret-color:var(--accent);
}
.search input::placeholder{ color:#334155; }
.count{
  color:var(--muted); font-size:13px; font-weight:500;
  font-family:monospace;
}

/* ─── Score pill ──────────────────────────────────── */
#scorePill.ok{
  border-color:rgba(52,211,153,.4); color:#a7f3d0;
  background:linear-gradient(135deg, rgba(52,211,153,.1), rgba(52,211,153,.04));
  box-shadow:0 0 12px rgba(52,211,153,.08);
}
#scorePill.bad{
  border-color:rgba(251,113,133,.4); color:#fecdd3;
  background:linear-gradient(135deg, rgba(251,113,133,.1), rgba(251,113,133,.04));
  box-shadow:0 0 12px rgba(251,113,133,.08);
}

/* ─── Nav ─────────────────────────────────────────── */
.nav{
  display:flex; gap:10px;
  justify-content:space-between;
  align-items:center;
  margin:18px 0 6px;
  animation:fadeUp .45s cubic-bezier(.16,1,.3,1) both .1s;
}
.nav a{
  color:var(--muted); text-decoration:none;
  border:1px solid var(--line2);
  padding:9px 18px;
  border-radius:var(--radius-pill);
  font-size:13px; font-weight:500;
  transition:all .25s cubic-bezier(.16,1,.3,1);
  position:relative; overflow:hidden;
}
.nav a::before{
  content:''; position:absolute; inset:0;
  background:linear-gradient(135deg, var(--accent-glow), var(--accent2-glow));
  opacity:0; transition:opacity .25s;
}
.nav a:hover{
  color:var(--text);
  border-color:rgba(56,189,248,.3);
  transform:translateY(-1px);
  box-shadow:0 4px 14px rgba(0,0,0,.2);
}
.nav a:hover::before{ opacity:1; }
.nav .center{
  color:var(--muted);
  font-size:13px;
  font-family:monospace;
}

/* ─── Home button ─────────────────────────────────── */
.homebtn{
  display:inline-flex; align-items:center;
  gap:8px; padding:12px 24px;
  border-radius:var(--radius-pill);
  background:linear-gradient(135deg, var(--card2), var(--card));
  border:1px solid var(--line2);
  color:var(--text); text-decoration:none;
  font-weight:600; font-size:14px;
  
  transition:all .3s cubic-bezier(.16,1,.3,1);
  box-shadow:0 4px 20px rgba(0,0,0,.25);
  position:relative; overflow:hidden;
}
/* Shimmer border on hover */
.homebtn::before{
  content:''; position:absolute; inset:-1px;
  border-radius:inherit;
  background:linear-gradient(135deg, rgba(56,189,248,.3), rgba(129,140,248,.3), rgba(56,189,248,.3));
  background-size:200% 200%;
  opacity:0; transition:opacity .3s;
  z-index:-1;
}
.homebtn:hover{
  transform:translateY(-2px);
  border-color:transparent;
  box-shadow:0 8px 32px rgba(0,0,0,.3), 0 0 30px rgba(56,189,248,.06);
}
.homebtn:hover::before{
  opacity:1;
  animation:shimmer 2s linear infinite;
}

/* ─── Responsive ──────────────────────────────────── */
@media (max-width:600px){
  body{ padding:16px; }
  .card{ padding:16px 16px 12px; }
  button.option{ padding:12px 12px; font-size:14px; }
  h1{ font-size:19px; }
}