/* Dark-themed, iPhone-first styles */
:root{
  --bg:#0b0d10;
  --card:#0f1114;
  --muted:#9aa4b2;
  --accent:#6ee7b7;
  --danger:#ff6b6b;
  --glass: rgba(255,255,255,0.03);
  --radius:14px;
  --gap:14px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  color-scheme: dark;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  background:linear-gradient(180deg,var(--bg),#060708);
  margin:0;
  padding:env(safe-area-inset-top) 0 env(safe-area-inset-bottom);
  display:flex;
  align-items:stretch;
  justify-content:center;
  color:#e6eef6;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

#app{
  width:100%;
  max-width:430px; /* iPhone-width friendly */
  padding:calc(var(--gap) * 1.2);
}

/* Top bar */
.topbar{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  margin-bottom:10px;
}
.topbar h1{
  margin:0;
  font-size:18px;
  letter-spacing:0.2px;
}

/* Cards */
.card{
  background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border-radius:var(--radius);
  padding:16px;
  margin-bottom:12px;
  box-shadow: 0 6px 18px rgba(2,4,8,0.6);
}
.hidden{display:none}

/* Buttons */
button{
  font:inherit;
  border:0;
  padding:12px 14px;
  border-radius:12px;
  cursor:pointer;
  background:var(--glass);
  color:inherit;
  min-height:44px;
  display:inline-flex;
  align-items:center;
  justify-content:center;
}
button:active{transform:translateY(1px)}
.primary{background:linear-gradient(90deg, rgba(110,231,183,0.12), rgba(110,231,183,0.06));box-shadow:inset 0 -1px 0 rgba(255,255,255,0.02)}
.ghost{background:transparent;border:1px solid rgba(255,255,255,0.03)}
.icon-btn{padding:8px;border-radius:10px;font-size:18px;min-width:44px}

/* lists */
.list{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.topicBtn{width:100%;text-align:left;padding:14px;border-radius:12px;background:linear-gradient(180deg, rgba(255,255,255,0.01), transparent)}
.meta{font-size:12px;color:var(--muted);margin-top:6px}

/* Quiz player */
.playerHeader{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:8px}
.questionArea{padding:6px 0}
.progress{height:8px;background:rgba(255,255,255,0.03);border-radius:8px;overflow:hidden;margin-bottom:8px}
#progressFill{height:100%;width:0%;background:linear-gradient(90deg,var(--accent),#5ad9ff);border-radius:8px}
.questionArea h3{margin:8px 0 14px 0;font-size:16px}
.choices{display:grid;gap:10px}
.choiceBtn{padding:12px;border-radius:12px;text-align:left;background:rgba(255,255,255,0.02);min-height:54px}
.choiceBtn.selected{outline:2px solid rgba(110,231,183,0.18)}
.choiceBtn.correct{background:linear-gradient(90deg, rgba(110,231,183,0.08), transparent);border:1px solid rgba(102,255,180,0.12)}
.choiceBtn.wrong{background:linear-gradient(90deg, rgba(255,107,107,0.06), transparent);border:1px solid rgba(255,107,107,0.09)}

.foot{text-align:center;color:var(--muted);font-size:12px;margin-top:6px}

/* Accessibility and spacing for iPhone touch */
@media (hover:none) and (pointer:coarse) {
  button{min-height:54px;border-radius:14px}
  .topicBtn{padding:16px}
}

/* small screens adjustments */
@media (max-width:360px){
  #app{padding:12px}
  .topbar h1{font-size:16px}
}