:root {
  --green: #0b6b3a; --green-2: #0e8a4b; --yellow: #ffd23f; --red: #d62839; --blue: #2f6fde; --orange: #f08a24;
  --bg: #f3f5f2; --card: #fff; --ink: #18211c; --muted: #5e6b63; --line: #dfe5e0;
  --ok: #18864b; --bad: #c62f3c; --radius: 16px;
  --shadow: 0 1px 2px rgb(0 0 0 / .06), 0 4px 14px rgb(0 0 0 / .05);
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1512; --card: #18211c; --ink: #e8efe9; --muted: #9aa8a0; --line: #2a362f; --ok: #3ccf7f; --bad: #ff6b76; --shadow: none; }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 17px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Noto Sans Arabic", sans-serif;
  padding-bottom: calc(72px + env(safe-area-inset-bottom));
}
a { color: var(--green-2); }
@media (prefers-color-scheme: dark) { a { color: #5fd69a; } }
main { max-width: 680px; margin: 0 auto; padding: 12px 14px 24px; outline: none; }
h1, h2, h3 { line-height: 1.25; margin: 0 0 .4em; }
h1 { font-size: 1.45rem; } h2 { font-size: 1.15rem; } h3 { font-size: 1.05rem; }
.loading { text-align: center; color: var(--muted); padding: 4em 0; }
.muted { color: var(--muted); } .small { font-size: .88rem; } .center { text-align: center; }
.okc { color: var(--ok); font-weight: 600; } .badc { color: var(--bad); font-weight: 600; }

/* top + tab bars */
.topbar {
  position: sticky; top: 0; z-index: 5; display: flex; align-items: center; justify-content: space-between;
  padding: calc(8px + env(safe-area-inset-top)) 14px 8px; background: var(--card); border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 8px; text-decoration: none; color: var(--ink); font-weight: 700; }
.brand-mark { width: 28px; height: 28px; }
.brand-state { font-weight: 500; color: var(--muted); font-size: .9rem; }
.topstats { display: flex; gap: 6px; }
.pill { background: var(--bg); border: 1px solid var(--line); border-radius: 99px; padding: 2px 10px; font-size: .85rem; white-space: nowrap; }
.tabbar {
  position: fixed; bottom: 0; left: 0; right: 0; z-index: 5; display: flex; justify-content: center;
  background: var(--card); border-top: 1px solid var(--line); padding-bottom: env(safe-area-inset-bottom);
}
.tabbar a { flex: 1; max-width: 120px; display: flex; flex-direction: column; align-items: center; padding: 7px 0 6px; text-decoration: none; color: var(--muted); font-size: 1.25rem; }
.tabbar a small { font-size: .7rem; margin-top: 1px; }
.tabbar a.on { color: var(--green-2); }
.tabbar a.on small { font-weight: 700; }

/* cards & buttons */
.card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); border: 1px solid var(--line); padding: 16px; margin: 0 0 12px; display: block; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px; border: 1px solid var(--line); background: var(--card);
  color: var(--ink); font: inherit; font-weight: 600; padding: 10px 16px; border-radius: 12px; cursor: pointer; text-decoration: none; min-height: 44px;
}
.btn.big { padding: 13px 20px; font-size: 1.05rem; }
.btn.primary { background: var(--green); border-color: var(--green); color: #fff; }
.btn.primary:hover { background: var(--green-2); }
.btn.danger { color: var(--bad); border-color: var(--bad); }
.btn:disabled { opacity: .55; cursor: default; }
.badge { background: var(--yellow); color: #222; border-radius: 99px; padding: 1px 8px; font-size: .8rem; }
.row { display: flex; justify-content: space-between; align-items: center; gap: 8px; flex-wrap: wrap; }
.row.gap { justify-content: center; gap: 10px; margin-top: 12px; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }
.grid2 .card { margin: 0; }
.section { margin: 20px 4px 10px; }
.pagetitle { text-align: center; margin-top: 8px; }
.back { display: inline-block; margin: 4px 0 8px; text-decoration: none; }
.fineprint { font-size: .78rem; color: var(--muted); text-align: center; margin: 16px 8px; }

/* home */
.hero { display: flex; gap: 18px; align-items: center; }
.hero-text { flex: 1; }
.hero-text p { margin: 0 0 12px; color: var(--muted); }
.ring {
  --size: 118px; flex: none; width: var(--size); height: var(--size); border-radius: 50%; display: grid; place-items: center;
  background: conic-gradient(var(--green-2) calc(var(--p) * 360deg), var(--line) 0);
}
.ring > div { width: calc(var(--size) - 22px); height: calc(var(--size) - 22px); border-radius: 50%; background: var(--card); display: grid; place-content: center; text-align: center; }
.ring b { font-size: 1.6rem; line-height: 1; } .ring small { color: var(--muted); font-size: .72rem; }
@media (max-width: 460px) { .hero { flex-direction: column; text-align: center; } }
.bar { height: 10px; background: var(--line); border-radius: 99px; overflow: hidden; margin: 8px 0; }
.bar i { display: block; height: 100%; background: linear-gradient(90deg, var(--green), var(--yellow)); border-radius: 99px; transition: width .4s; }
.tile { text-decoration: none; color: var(--ink); display: flex; flex-direction: column; gap: 2px; }
.tile:hover { border-color: var(--green-2); }
.tile-icon { font-size: 1.7rem; }
.tile small { color: var(--muted); }
.install { width: 100%; font: inherit; font-weight: 600; cursor: pointer; color: var(--ink); text-align: center; }
.how ul { padding-inline-start: 1.2em; margin: 0; } .how li { margin-bottom: .45em; }

/* questions */
.progress { height: 6px; background: var(--line); border-radius: 99px; overflow: hidden; margin: 4px 0 12px; }
.progress i { display: block; height: 100%; background: var(--green-2); transition: width .3s; }
.qmeta { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 10px; }
.chip { font-size: .75rem; font-weight: 600; background: color-mix(in srgb, var(--green-2) 14%, transparent); color: var(--green-2); padding: 2px 10px; border-radius: 99px; }
.chip.alt { background: color-mix(in srgb, var(--orange) 18%, transparent); color: var(--orange); }
.qtext { font-size: 1.15rem; font-weight: 650; }
.qcard.scenario .qtext { font-weight: 500; }
img.sign { display: block; margin: 4px auto 14px; width: 160px; height: 160px; object-fit: contain; }
img.sign.small { width: 90px; height: 90px; margin: 0 0 8px; }
img.sign.tiny { width: 44px; height: 44px; margin: 0; flex: none; display: inline-block; }
.choices { display: grid; gap: 9px; margin-top: 12px; }
.choices.tf { grid-template-columns: 1fr 1fr; }
.choice {
  display: flex; gap: 12px; align-items: center; text-align: start; width: 100%; font: inherit; color: var(--ink);
  background: var(--bg); border: 2px solid var(--line); border-radius: 12px; padding: 12px 14px; cursor: pointer; min-height: 52px;
}
.choices.tf .choice { justify-content: center; font-weight: 700; }
.choice:hover:not(:disabled) { border-color: var(--green-2); }
.choice .key { flex: none; width: 26px; height: 26px; border-radius: 7px; display: grid; place-items: center; background: var(--card); border: 1px solid var(--line); font-size: .8rem; font-weight: 700; }
.choice.picked { border-color: var(--blue); background: color-mix(in srgb, var(--blue) 10%, var(--bg)); }
.choice.right { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 14%, var(--bg)); }
.choice.wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, var(--bg)); }
.choice:disabled { cursor: default; }
.numform { display: flex; align-items: center; gap: 10px; margin-top: 14px; }
.numin { font: inherit; font-size: 1.4rem; width: 9ch; padding: 8px 12px; border-radius: 12px; border: 2px solid var(--line); background: var(--bg); color: var(--ink); text-align: center; }
.numin:focus { outline: none; border-color: var(--blue); }
.numin.right { border-color: var(--ok); } .numin.wrong { border-color: var(--bad); }
.unit { color: var(--muted); font-weight: 600; }
.commit { display: flex; gap: 10px; margin-top: 14px; }
.commit .btn { flex: 1; min-height: 50px; }
.commit .sure { background: var(--green); border-color: var(--green); color: #fff; }
.commit .guess { background: color-mix(in srgb, var(--yellow) 30%, var(--card)); border-color: var(--yellow); }

/* feedback */
.feedback { border-width: 2px; animation: pop .25s ease-out; }
.feedback.good { border-color: var(--ok); } .feedback.meh { border-color: var(--yellow); }
.feedback.bad { border-color: var(--bad); }
.feedback.surprise { border-color: var(--orange); background: color-mix(in srgb, var(--orange) 8%, var(--card)); }
.feedback h3 { display: flex; justify-content: space-between; gap: 8px; }
.xp { color: var(--green-2); font-size: .9rem; white-space: nowrap; }
.answer { margin: 0 0 8px; }
.explain .fact { font-weight: 600; margin: 0 0 6px; }
.explain .why { margin: 0 0 6px; } .explain .hook { margin: 0 0 6px; background: color-mix(in srgb, var(--yellow) 22%, transparent); padding: 6px 10px; border-radius: 10px; }
.explain .src { font-size: .85rem; }
.feedback .btn { width: 100%; margin-top: 12px; }
@keyframes pop { from { transform: scale(.97); opacity: .4; } to { transform: none; opacity: 1; } }

/* done / exam */
.big-emoji { font-size: 2.8rem; }
.stats3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 14px 0; }
.stats3 b { display: block; font-size: 1.5rem; } .stats3 small { color: var(--muted); }
.score { font-size: 2.4rem; font-weight: 800; margin: 0; }
.passed { border: 2px solid var(--ok); }
.review p { margin: 4px 0; }

/* sprint */
.sprintbar { display: flex; align-items: center; gap: 12px; margin: 4px 0 12px; font-weight: 600; }
.timer { flex: 1; height: 12px; background: var(--line); border-radius: 99px; overflow: hidden; }
.timer i { display: block; height: 100%; background: linear-gradient(90deg, var(--red), var(--orange), var(--yellow)); }
.combo { color: var(--orange); }
.signrow { display: flex; gap: 12px; align-items: center; }
.signrow img { width: 60px; height: 60px; object-fit: contain; flex: none; }
.signrow p { margin: 2px 0 0; }

/* topics */
.topicgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; }
.topic { margin: 0; text-decoration: none; color: var(--ink); text-align: center; display: flex; flex-direction: column; align-items: center; gap: 6px; }
.topic small { color: var(--muted); }
.tring { width: 64px; height: 64px; border-radius: 50%; display: grid; place-items: center; background: conic-gradient(var(--green-2) calc(var(--p) * 360deg), var(--line) 0); }
.tring span { width: 50px; height: 50px; border-radius: 50%; background: var(--card); display: grid; place-items: center; font-size: .8rem; font-weight: 700; }
.factrow { padding: 12px 14px; margin-bottom: 8px; }
.factrow summary { display: flex; gap: 10px; align-items: center; cursor: pointer; list-style: none; }
.factrow summary::-webkit-details-marker { display: none; }
.factrow .explain { margin-top: 10px; }
.dot { flex: none; width: 11px; height: 11px; border-radius: 50%; display: inline-block; background: var(--line); }
.dot.weak { background: var(--bad); } .dot.learning { background: var(--yellow); } .dot.mastered { background: var(--ok); }
.legend { text-align: center; } .legend .dot { margin: 0 4px 0 10px; vertical-align: -1px; }

/* more */
.field { display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.field select { font: inherit; padding: 8px 10px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg); color: var(--ink); }
.badges { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.bdg { text-align: center; opacity: .3; filter: grayscale(1); }
.bdg.on { opacity: 1; filter: none; }
.bdg span { font-size: 1.8rem; display: block; } .bdg small { font-size: .7rem; line-height: 1.2; display: block; }

/* confetti */
.confetti { position: fixed; inset: 0; pointer-events: none; overflow: hidden; z-index: 50; }
.confetti i { position: absolute; top: -12px; width: 9px; height: 14px; border-radius: 2px; animation: fall 2.4s ease-in forwards; }
@keyframes fall { to { transform: translateY(105vh) rotate(720deg); } }
@media (prefers-reduced-motion: reduce) { .confetti, .feedback { animation: none; } .confetti { display: none; } }

/* language picker */
.langbtn { font: inherit; font-size: .85rem; color: var(--ink); cursor: pointer; font-weight: 700; border-color: var(--green-2); }
.langdlg { border: none; border-radius: var(--radius); padding: 20px; width: min(420px, 92vw); background: var(--card); color: var(--ink); box-shadow: 0 20px 60px rgb(0 0 0 / .35); }
.langdlg::backdrop { background: rgb(0 0 0 / .45); }
.langdlg h2 { font-size: 1rem; text-align: center; color: var(--muted); }
.langdlg [data-close] { display: block; margin: 14px auto 0; }
.langlist { display: grid; gap: 10px; }
.langlist.row4 { grid-template-columns: repeat(3, 1fr); }
.langopt {
  font: inherit; font-size: 1.15rem; font-weight: 600; padding: 12px; min-height: 52px; border-radius: 12px; cursor: pointer;
  background: var(--bg); color: var(--ink); border: 2px solid var(--line);
}
.langopt:hover { border-color: var(--green-2); }
.langopt.on { border-color: var(--green-2); background: color-mix(in srgb, var(--green-2) 14%, var(--bg)); }
.langstrip p { margin: 0 0 10px; text-align: center; color: var(--muted); font-size: .9rem; }
.langstrip .langopt { font-size: 1rem; padding: 10px 6px; }
@media (max-width: 420px) { .brand-state { display: none; } .topstats { gap: 4px; } .pill { padding: 2px 8px; } }