:root {
  --brand: #0b6e69;
  --brand-dark: #075a56;
  --accent: #f2b134;
  --bg: #f7faf9;
  --card: #ffffff;
  --text: #18302e;
  --muted: #6f817f;
  --good: #168a62;
  --bad: #c9484a;
  --line: #dce7e5;
  --shadow: 0 12px 30px rgba(11, 110, 105, 0.10);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, ui-rounded, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: linear-gradient(180deg, #edf8f6 0%, #f8fbfa 50%, #eef5f4 100%);
  color: var(--text);
  min-height: 100vh;
}
button, input, select { font: inherit; }
button { cursor: pointer; }
#app { min-height: 100vh; }
.shell {
  width: min(100%, 460px);
  min-height: 100vh;
  margin: 0 auto;
  background: var(--bg);
  position: relative;
  box-shadow: 0 0 50px rgba(0,0,0,.08);
  overflow-x: hidden;
}
.splash {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 28px;
  background: radial-gradient(circle at 20% 20%, #d7f2ec, transparent 38%), linear-gradient(145deg, #0b6e69, #0a5f70);
  color: white;
  text-align: center;
}
.logo-bird {
  width: 110px; height: 110px; border-radius: 32px;
  background: rgba(255,255,255,.16);
  display: grid; place-items: center;
  font-size: 58px; margin: 0 auto 18px;
  border: 2px solid rgba(255,255,255,.26);
}
.splash h1 { font-size: 42px; margin: 0 0 8px; letter-spacing: -.04em; }
.splash p { color: #d9f4ef; font-size: 17px; line-height: 1.55; }
.primary, .secondary, .ghost, .choice {
  border: 0; border-radius: 16px; padding: 15px 18px; font-weight: 800;
}
.primary { background: var(--accent); color: #372600; box-shadow: 0 6px 0 #c58a17; }
.primary:active { transform: translateY(3px); box-shadow: 0 3px 0 #c58a17; }
.secondary { background: var(--brand); color: white; }
.ghost { background: #e9f4f2; color: var(--brand-dark); }
.full { width: 100%; }
.welcome-actions { display: grid; gap: 13px; margin-top: 26px; }
.screen { padding: 22px 20px 105px; }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 18px; }
.brandmark { display: flex; gap: 10px; align-items: center; }
.brandmark .mini { width: 42px; height: 42px; border-radius: 14px; background: var(--brand); color: white; display: grid; place-items: center; font-size: 22px; }
.brandmark strong { display: block; font-size: 18px; }
.brandmark small { color: var(--muted); }
.stats { display: flex; gap: 8px; }
.stat { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 7px 9px; font-weight: 800; font-size: 13px; }
h1,h2,h3 { letter-spacing: -.025em; }
h2 { margin: 0 0 8px; }
.sub { color: var(--muted); line-height: 1.5; margin-top: 0; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 22px; padding: 18px; box-shadow: var(--shadow); margin-bottom: 16px; }
.progress-wrap { margin-top: 14px; }
.progress { height: 12px; border-radius: 999px; background: #dfece9; overflow: hidden; }
.progress > span { display: block; height: 100%; background: linear-gradient(90deg, var(--brand), #2ca58d); border-radius: inherit; }
.path { display: flex; flex-direction: column; align-items: center; gap: 10px; padding: 15px 0; }
.path-line { width: 5px; height: 30px; border-radius: 99px; background: #c8ddda; }
.lesson-node {
  width: 82px; height: 82px; border-radius: 50%; border: 0; font-size: 30px; display: grid; place-items: center;
  box-shadow: 0 7px 0 #075a56; background: var(--brand); color: white; position: relative;
}
.lesson-node.done { background: #168a62; box-shadow: 0 7px 0 #0e6346; }
.lesson-node.locked { background: #c9d2d1; box-shadow: 0 7px 0 #9ca9a7; color: #6c7e7c; }
.lesson-label { text-align: center; font-weight: 800; margin-top: 4px; }
.lesson-label small { display:block; color: var(--muted); font-weight: 600; margin-top: 3px; }
.bottom-nav {
  position: fixed; bottom: 0; left: 50%; transform: translateX(-50%);
  width: min(100%, 460px); height: 80px; background: rgba(255,255,255,.96); backdrop-filter: blur(14px);
  border-top: 1px solid var(--line); display: grid; grid-template-columns: repeat(5,1fr); padding: 9px 6px calc(9px + env(safe-area-inset-bottom)); z-index: 20;
}
.nav-btn { border: 0; background: transparent; color: #70817f; font-size: 11px; font-weight: 800; border-radius: 14px; }
.nav-btn .ico { display:block; font-size: 21px; margin-bottom: 2px; }
.nav-btn.active { color: var(--brand); background: #e9f4f2; }
.option-grid { display: grid; gap: 12px; }
.choice { text-align: left; background: white; border: 2px solid var(--line); color: var(--text); }
.choice:hover { border-color: var(--brand); }
.choice.correct { border-color: var(--good); background: #eaf8f2; }
.choice.wrong { border-color: var(--bad); background: #fff0f0; }
.question { font-size: 25px; margin: 16px 0 18px; }
.prompt-box { background: #edf7f5; border-radius: 18px; padding: 16px; font-size: 18px; line-height: 1.5; margin-bottom: 18px; border: 1px solid #d2e8e4; }
.lesson-head { display: flex; align-items:center; gap: 12px; }
.close { width: 40px; height: 40px; border-radius: 14px; border: 0; background: #e7efee; }
.lesson-progress { flex: 1; }
.feedback { border-radius: 18px; padding: 15px; margin-top: 16px; font-weight: 700; }
.feedback.good { background: #e7f7f0; color: #0f6b4b; }
.feedback.bad { background: #fff0f0; color: #9b3235; }
.big-score { font-size: 50px; font-weight: 900; color: var(--brand); margin: 8px 0; }
.metric { display:flex; justify-content:space-between; margin: 12px 0 7px; font-weight:700; }
.practice-grid { display:grid; grid-template-columns:1fr 1fr; gap:12px; }
.practice-card { border:1px solid var(--line); background:white; border-radius:20px; padding:18px; min-height:125px; box-shadow: var(--shadow); }
.practice-card span { font-size:30px; display:block; margin-bottom:10px; }
.ai-orb { width: 118px; height:118px; border-radius:50%; display:grid; place-items:center; margin:22px auto; background:linear-gradient(145deg,#0b6e69,#168a8a); color:white; font-size:48px; box-shadow:0 18px 40px rgba(11,110,105,.25); }
.transcript { min-height: 112px; padding: 16px; border-radius:18px; background:#f1f7f6; border:1px dashed #b8cfcb; line-height:1.6; }
.pills { display:flex; gap:8px; overflow:auto; padding-bottom:5px; }
.pill { flex:0 0 auto; border:1px solid var(--line); background:white; border-radius:999px; padding:9px 12px; font-weight:700; }
.pill.active { background:var(--brand); color:white; border-color:var(--brand); }
.rank-row { display:grid; grid-template-columns:42px 1fr auto; align-items:center; gap:10px; padding:13px 0; border-bottom:1px solid var(--line); }
.avatar { width:40px; height:40px; display:grid; place-items:center; border-radius:14px; background:#e7f4f2; font-weight:900; }
.rank-row.me { background:#eef8f6; margin:0 -12px; padding:13px 12px; border-radius:16px; }
.profile-hero { text-align:center; }
.profile-avatar { width:92px;height:92px;border-radius:30px;background:var(--brand);color:white;display:grid;place-items:center;font-size:36px;margin:0 auto 12px; }
.row { display:flex; justify-content:space-between; gap:12px; align-items:center; }
.input { width:100%; padding:15px; border-radius:15px; border:1px solid var(--line); background:white; margin-bottom:12px; }
.segment { display:grid; gap:10px; margin:18px 0; }
.segment button { text-align:left; border:2px solid var(--line); background:white; padding:14px; border-radius:16px; font-weight:750; }
.segment button.selected { border-color:var(--brand); background:#e9f4f2; }
.tiny { font-size:12px; color:var(--muted); }
.center { text-align:center; }
.confetti { font-size:48px; }
@media (min-width: 700px) {
  body { padding: 26px 0; }
  .shell { min-height: calc(100vh - 52px); border-radius: 30px; overflow:hidden; }
  .bottom-nav { bottom: 26px; border-radius: 0 0 30px 30px; }
}