:root {
  --bg: #0f1220;
  --panel: #1a1f35;
  --panel2: #222845;
  --accent: #7c8cff;
  --accent2: #4fd1c5;
  --good: #34d399;
  --bad: #f87171;
  --warn: #fbbf24;
  --text: #e8ebf7;
  --muted: #9aa3c7;
  --radius: 14px;
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; min-height: 100%; }
#app { max-width: 680px; margin: 0 auto; padding: 16px 14px 90px; }
h1 { font-size: 1.45rem; margin: 8px 0 4px; }
h2 { font-size: 1.15rem; margin: 18px 0 8px; }
p, li { line-height: 1.55; }
.muted { color: var(--muted); font-size: .92rem; }
a { color: var(--accent); }

.card {
  background: var(--panel); border-radius: var(--radius);
  padding: 16px; margin: 10px 0; border: 1px solid #2c3355;
}
.card.hl { border-color: var(--accent); }

.btn {
  display: inline-block; background: var(--panel2); color: var(--text);
  border: 1px solid #343c66; border-radius: 10px;
  padding: 10px 16px; font-size: 1rem; cursor: pointer; margin: 4px 6px 4px 0;
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }
.btn.good { background: var(--good); border-color: var(--good); color: #04241a; font-weight: 600; }
.btn.bad { background: var(--bad); border-color: var(--bad); color: #2b0505; font-weight: 600; }
.btn.ghost { background: transparent; }
.btn:active { transform: scale(.98); }
.btn.wide { width: 100%; }

.opt {
  display: block; width: 100%; text-align: left;
  background: var(--panel2); color: var(--text);
  border: 1px solid #343c66; border-radius: 12px;
  padding: 13px 14px; font-size: 1rem; margin: 8px 0; cursor: pointer;
}
.opt.correct { border-color: var(--good); background: rgba(52,211,153,.15); }
.opt.wrong { border-color: var(--bad); background: rgba(248,113,113,.15); }
.opt:disabled { cursor: default; opacity: .92; }

.row { display: flex; align-items: center; justify-content: space-between; gap: 8px; flex-wrap: wrap; }
.tag { display: inline-block; background: var(--panel2); border: 1px solid #343c66; color: var(--muted);
  border-radius: 999px; padding: 3px 10px; font-size: .78rem; margin: 2px 4px 2px 0; }
.tag.done { color: var(--good); border-color: var(--good); }

.bar { height: 8px; background: var(--panel2); border-radius: 6px; overflow: hidden; margin: 6px 0; }
.bar > div { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent2)); border-radius: 6px; transition: width .3s; }

/* Leitner box pills */
.boxes { display: flex; gap: 4px; }
.boxes span { width: 16px; height: 8px; border-radius: 4px; background: #2c3355; }
.boxes span.on { background: var(--accent2); }

.statgrid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; margin: 12px 0; }
.stat { background: var(--panel); border: 1px solid #2c3355; border-radius: 12px; padding: 10px; text-align: center; }
.stat b { font-size: 1.3rem; display: block; }
.stat small { color: var(--muted); }

details, .hintbox, .explain { background: var(--panel2); border-radius: 10px; padding: 10px 12px; margin: 10px 0; }
.hintbox { border: 1px dashed #4a558f; }
.explain { border-left: 3px solid var(--accent2); }
details summary { cursor: pointer; color: var(--accent2); font-weight: 600; }

.back { background: none; border: none; color: var(--accent); font-size: 1rem; cursor: pointer; padding: 6px 0; }
footer { color: var(--muted); font-size: .8rem; text-align: center; margin-top: 40px; }
.prognum { font-weight: 700; color: var(--accent2); }

/* notes markdown */
.md h1 { font-size: 1.3rem; }
.md h2 { border-bottom: 1px solid #2c3355; padding-bottom: 4px; }
.md h3 { font-size: 1.02rem; color: var(--accent2); }
.md code { background: #2c3355; padding: 1px 5px; border-radius: 5px; font-size: .9em; }
.md pre { background: #2c3355; padding: 10px; border-radius: 8px; overflow-x: auto; }
.md table { border-collapse: collapse; margin: 8px 0; display: block; overflow-x: auto; max-width: 100%; font-size: .9rem; }
.md { overflow-wrap: break-word; }
.md td, .md th { min-width: 110px; overflow-wrap: normal; word-break: normal; vertical-align: top; }
.md br + br { display: none; }
.md th, .md td { border: 1px solid #343c66; padding: 6px 10px; }
.MathJaxSnip, .math { font-family: ui-monospace, Menlo, monospace; background: #2c3355; border-radius: 5px; padding: 1px 5px; }

.modal { position: fixed; inset: 0; background: rgba(0,0,0,.55); display: flex; align-items: center; justify-content: center; z-index: 50; }
.modal > div { background: var(--panel); border: 1px solid #343c66; border-radius: var(--radius); padding: 20px; max-width: 480px; margin: 16px; max-height: 85vh; overflow: auto; }
textarea#importta { width: 100%; height: 120px; background: var(--bg); color: var(--text); border: 1px solid #343c66; border-radius: 8px; padding: 8px; }