:root { font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif; }
body { margin: 0; background: #f6f7f8; color: #111; }
.header {
  display: flex; gap: 16px; justify-content: space-between; align-items: flex-end;
  padding: 16px 18px; background: white; border-bottom: 1px solid #e5e7eb;
}
h1 { margin: 0; font-size: 18px; }
.meta { font-size: 12px; color: #555; margin-top: 4px; }
.controls { display: flex; gap: 10px; align-items: end; flex-wrap: wrap; }
label { display: grid; gap: 4px; font-size: 12px; color: #333; }
select, button {
  padding: 8px 10px; border: 1px solid #d1d5db; border-radius: 8px; background: white;
}
input[type="range"] { accent-color: #111; }
.difficultyRange {
  display: flex;
  align-items: center;
  gap: 6px;
}
.difficultyRange input[type="range"] {
  width: 90px;
}
button { cursor: pointer; font-weight: 600; }
button.secondary { font-weight: 500; background: #f3f4f6; }
.container { padding: 18px; max-width: 920px; margin: 0 auto; }
.card {
  background: white; border: 1px solid #e5e7eb; border-radius: 14px;
  padding: 16px; box-shadow: 0 1px 8px rgba(0,0,0,.05);
}
.hidden { display: none; }
.empty { padding: 40px 12px; color: #444; text-align: center; }
.tabs { display: inline-flex; gap: 6px; margin-bottom: 10px; }
.tab {
  padding: 6px 10px; border-radius: 999px; border: 1px solid #d1d5db;
  background: #f3f4f6; font-size: 12px;
}
.tab.active { background: #111; color: white; border-color: #111; }
h2 { margin: 0; font-size: 28px; }
.sub { margin-top: 6px; font-size: 13px; color: #555; }
.section { margin-top: 18px; }
.section h3 { margin: 0 0 8px 0; font-size: 14px; }
.prompt { padding: 10px 12px; border: 1px dashed #d1d5db; border-radius: 10px; background: #fafafa; }
.code { background: #0b1020; color: #dbeafe; padding: 12px; border-radius: 10px; overflow: auto; }
li { margin: 6px 0; }
.trivia-q { font-weight: 600; }
.answer { margin-top: 6px; }
.choices { margin-top: 6px; font-size: 13px; color: #444; }
.revealBtn { margin-left: 8px; padding: 3px 8px; font-size: 12px; border-radius: 999px; }
a { color: #2563eb; text-decoration: none; }
a:hover { text-decoration: underline; }