:root {
  --bg: #0f1320; --panel: #181d2e; --panel2: #20263a; --border: #2a3147;
  --text: #eef1f7; --muted: #9aa3bd; --accent: #3fd07a; --accent-ink: #06210f;
  --accent2: #6aa7ff; --warn: #f5b945; --danger: #f8736b; --purple: #b89cff;
  --gradeD: #f5b945;
  --radius: 16px; --maxw: 640px;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
[data-theme="light"] {
  --bg: #f7f9fc; --panel: #ffffff; --panel2: #eef2f8; --border: #e1e7f0;
  --text: #161b29; --muted: #5c6580; --accent: #18a558; --accent-ink: #ffffff; --accent2: #2b6fe0;
  --danger: #e0483f; --purple: #6f4bd8;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { background: var(--bg); color: var(--text); font-family: var(--sans); line-height: 1.55; -webkit-font-smoothing: antialiased; }
button { font-family: inherit; }
a { color: var(--accent2); }

/* App bar */
.appbar { position: sticky; top: 0; z-index: 30; display: flex; align-items: center; gap: 12px;
  padding: 12px 18px; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.brand { display: flex; align-items: center; gap: 9px; font-weight: 800; font-size: 17px; color: var(--text); text-decoration: none; }
.brand-mark { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 9px; background: var(--accent); color: var(--accent-ink); font-weight: 900; font-size: 13px; }
.appbar-progress { flex: 1; max-width: 260px; height: 8px; border-radius: 99px; background: var(--panel2); overflow: hidden; margin: 0 4px; }
.appbar-progress > span { display: block; height: 100%; background: var(--accent); width: 0%; transition: width .4s; }
.ref-link { margin-left: auto; font-size: 13.5px; color: var(--muted); text-decoration: none; white-space: nowrap; }
.ref-link:hover { color: var(--text); }
.icon-btn { background: none; border: 1px solid var(--border); color: var(--text); width: 38px; height: 36px; border-radius: 10px; cursor: pointer; font-size: 16px; }

.app { max-width: 980px; margin: 0 auto; padding: 26px 18px 90px; }
.loading { color: var(--muted); padding: 40px 0; text-align: center; }

/* Home hero */
.hero { text-align: center; padding: 18px 0 8px; }
.hero h1 { font-size: 34px; line-height: 1.12; margin: 8px 0; }
.hero p { color: var(--muted); font-size: 17px; max-width: 540px; margin: 0 auto 18px; }
.btn { display: inline-flex; align-items: center; gap: 8px; background: var(--accent); color: var(--accent-ink); border: none;
  padding: 13px 22px; border-radius: 999px; font-weight: 700; font-size: 16px; cursor: pointer; text-decoration: none; }
.btn:hover { filter: brightness(1.06); text-decoration: none; }
.btn.ghost { background: var(--panel); color: var(--text); border: 1px solid var(--border); }
.btn.big { font-size: 17px; padding: 15px 26px; }
.btn[disabled] { opacity: .5; cursor: default; }

/* Module grid */
.modules { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; margin-top: 26px; }
.mod-card { display: flex; gap: 14px; align-items: center; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 18px; color: var(--text); text-decoration: none; transition: .14s; }
.mod-card:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.mod-emoji { font-size: 30px; width: 52px; height: 52px; display: grid; place-items: center; background: var(--panel2); border-radius: 14px; flex: none; }
.mod-card h3 { margin: 0 0 3px; font-size: 17px; }
.mod-card p { margin: 0; color: var(--muted); font-size: 13.5px; }
.mod-card .mod-meta { margin-top: 7px; font-size: 12px; color: var(--muted); }
.ring { --p: 0; width: 46px; height: 46px; flex: none; border-radius: 50%; display: grid; place-items: center;
  background: conic-gradient(var(--accent) calc(var(--p) * 1%), var(--panel2) 0); }
.ring > i { width: 36px; height: 36px; border-radius: 50%; background: var(--panel); display: grid; place-items: center; font-style: normal; font-size: 11px; font-weight: 700; color: var(--muted); }
.ring.done { --p: 100; }
.ring.done > i { color: var(--accent); }

/* Module detail */
.mod-head { display: flex; align-items: center; gap: 16px; margin-bottom: 6px; }
.mod-head .mod-emoji { width: 60px; height: 60px; font-size: 34px; }
.mod-head h1 { margin: 0; font-size: 26px; }
.mod-head p { margin: 4px 0 0; color: var(--muted); }
.lesson-list { margin-top: 20px; max-width: var(--maxw); }
.lesson-row { display: flex; align-items: center; gap: 14px; padding: 14px 16px; background: var(--panel); border: 1px solid var(--border);
  border-radius: 14px; margin-bottom: 10px; color: var(--text); text-decoration: none; }
.lesson-row:hover { border-color: var(--accent2); text-decoration: none; }
.lesson-row .lnum { width: 34px; height: 34px; flex: none; border-radius: 50%; display: grid; place-items: center; background: var(--panel2); font-weight: 700; font-size: 14px; }
.lesson-row.done .lnum { background: var(--accent); color: var(--accent-ink); }
.lesson-row h4 { margin: 0; font-size: 15.5px; }
.lesson-row small { color: var(--muted); }

/* Lesson player */
.player { max-width: var(--maxw); margin: 0 auto; }
.lp-top { display: flex; align-items: center; gap: 12px; margin-bottom: 22px; }
.lp-top a.x { color: var(--muted); text-decoration: none; font-size: 22px; line-height: 1; }
.lp-bar { flex: 1; height: 9px; border-radius: 99px; background: var(--panel2); overflow: hidden; }
.lp-bar > span { display: block; height: 100%; background: var(--accent); transition: width .3s; }
.screen { animation: fade .25s ease; min-height: 50vh; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
.screen .emoji-big { font-size: 56px; text-align: center; margin: 6px 0 10px; }
.screen h2 { font-size: 25px; line-height: 1.2; margin: 0 0 14px; }
.screen .body { font-size: 17.5px; color: var(--text); }
.screen .body p { margin: 0 0 14px; }
.screen .body strong { color: var(--text); }
.screen .hint { color: var(--muted); font-size: 14px; text-align: center; margin-top: 6px; }

/* Cards / callouts inside screens */
.viz-card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; margin: 8px 0 4px; }
.payoff-svg, .gauge-svg { width: 100%; height: auto; display: block; cursor: crosshair; touch-action: pan-y; }
.payoff-readout { text-align: center; color: var(--muted); font-size: 15px; margin-top: 8px; }
.gauge-caption { text-align: center; color: var(--muted); font-size: 13.5px; margin-top: 2px; }
.callout { background: var(--panel); border: 1px solid var(--border); border-left: 4px solid var(--accent2); border-radius: 12px; padding: 14px 16px; margin: 6px 0; font-size: 16px; }
.callout.eg { border-left-color: var(--warn); }

/* Quiz */
.quiz h2 { margin-bottom: 16px; }
.choices { display: grid; gap: 10px; }
.choice { text-align: left; background: var(--panel); border: 1.5px solid var(--border); color: var(--text); border-radius: 13px; padding: 14px 16px; font-size: 16px; cursor: pointer; transition: .12s; }
.choice:hover { border-color: var(--accent2); }
.choice.correct { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 14%, transparent); }
.choice.wrong { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 12%, transparent); }
.choice[disabled] { cursor: default; }
.explain { margin-top: 14px; padding: 13px 16px; border-radius: 12px; font-size: 15.5px; background: var(--panel2); display: none; }
.explain.show { display: block; }
.explain.ok { border: 1px solid var(--accent); }
.explain.no { border: 1px solid var(--danger); }

/* Takeaway */
.takeaways { list-style: none; padding: 0; margin: 10px 0 18px; }
.takeaways li { display: flex; gap: 10px; align-items: flex-start; background: var(--panel); border: 1px solid var(--border); border-radius: 12px; padding: 12px 15px; margin-bottom: 9px; font-size: 16px; }
.takeaways li::before { content: "✓"; color: var(--accent); font-weight: 800; }
.deeper { display: inline-flex; align-items: center; gap: 7px; font-size: 14px; color: var(--muted); text-decoration: none; border: 1px dashed var(--border); padding: 8px 14px; border-radius: 99px; }
.deeper:hover { color: var(--text); border-color: var(--accent2); }

/* Lesson nav */
.lp-nav { display: flex; gap: 12px; margin-top: 28px; }
.lp-nav .btn { flex: 1; justify-content: center; }
.complete-card { text-align: center; padding: 24px 0; }
.complete-card .big { font-size: 50px; }

/* Footer note */
.note { color: var(--muted); font-size: 12.5px; text-align: center; margin-top: 40px; }

@media (max-width: 560px) {
  .app { padding: 18px 14px 80px; }
  .hero h1 { font-size: 28px; }
  .screen h2 { font-size: 22px; }
  .screen .body { font-size: 16.5px; }
}

/* --- production a11y + risk gate --- */
.visually-hidden{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.skip-link{position:absolute;left:8px;top:-48px;z-index:100;background:var(--accent,#3fd07a);color:#06210f;padding:8px 14px;border-radius:8px;text-decoration:none;font-weight:700;transition:top .15s}
.skip-link:focus{top:8px}
a:focus-visible,button:focus-visible,input:focus-visible,.choice:focus-visible,.mod-card:focus-visible,.lesson-row:focus-visible,.sec-h:focus-visible{outline:3px solid var(--accent2,#6aa7ff);outline-offset:2px;border-radius:4px}
@media (prefers-reduced-motion: reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
#riskGate{position:fixed;inset:0;z-index:1000;background:rgba(0,0,0,.72);display:grid;place-items:center;padding:20px}
#riskGate .rg-box{background:var(--panel,#181d2e);border:1px solid var(--border,#2a3147);border-radius:16px;max-width:520px;padding:24px;font-family:inherit}
#riskGate h2{margin:0 0 10px;font-size:20px;color:var(--text,#eef1f7)}
#riskGate p{color:var(--muted,#9aa3bd);font-size:15px;line-height:1.55}
#riskGate .rg-warn{color:#f5b945;font-weight:700}
#riskGate b{color:var(--text,#eef1f7)}
#riskGate a{color:var(--accent2,#6aa7ff)}
#riskGate button{margin-top:16px;background:var(--accent,#3fd07a);color:#06210f;border:none;border-radius:999px;padding:13px 22px;font-weight:700;font-size:15px;cursor:pointer;width:100%}
.app-footer{margin-top:auto;padding:18px;text-align:center;color:var(--muted,#9aa3bd);font-size:12.5px;border-top:1px solid var(--border,#2a3147)}
.app-footer a{color:var(--muted,#9aa3bd)}