/* GENERATED by build-lessons.js: base styles from cpluspluscoding/cpp-arcade.html + arcade-extra.css */
  :root{
    --bg:#0c0f2b;
    --bg2:#0a0c22;
    --panel:#161a42;
    --panel-2:#1d2255;
    --inset:#0d1030;
    --line:rgba(255,255,255,.08);
    --line-strong:rgba(255,255,255,.16);
    --ink:#eceeffe6;
    --ink-dim:#a7abd6;
    --ink-faint:#6f74a3;
    --amber:#ffb454;
    --amber-deep:#f59a2e;
    --peri:#8ea2ff;
    --cyan:#5cc9e6;
    --good:#57d99a;
    --bad:#ff6f6f;
    --font-ui:"Space Grotesk",system-ui,sans-serif;
    --font-mono:"JetBrains Mono",ui-monospace,monospace;
    box-sizing:border-box;
    padding-top:env(safe-area-inset-top,0px);
    padding-bottom:env(safe-area-inset-bottom,0px);
  }
  *,*::before,*::after{box-sizing:border-box}
  html{scroll-padding-top:env(safe-area-inset-top,0px);height:100%}
  body{
    margin:0;min-height:100%;
    font-family:var(--font-ui);
    color:var(--ink);
    background:
      radial-gradient(1200px 700px at 15% -10%, #1a1f52 0%, transparent 55%),
      radial-gradient(1000px 600px at 100% 0%, #17244d 0%, transparent 50%),
      var(--bg);
    line-height:1.5;
    -webkit-font-smoothing:antialiased;
  }
  .wrap{max-width:1180px;margin:0 auto;padding:22px clamp(14px,3vw,30px) 60px}

  /* ---------- header ---------- */
  header.top{display:flex;flex-wrap:wrap;align-items:flex-end;gap:16px 26px;margin-bottom:20px}
  .brand{display:flex;align-items:baseline;gap:12px;flex:1 1 auto;min-width:220px}
  .logo-mark{
    font-family:var(--font-mono);font-weight:700;font-size:clamp(26px,5vw,40px);
    color:var(--amber);letter-spacing:-1px;line-height:1;
    text-shadow:0 0 22px rgba(255,180,84,.35);
  }
  .brand h1{font-size:clamp(22px,4.4vw,34px);font-weight:700;letter-spacing:-.5px;margin:0;line-height:1}
  .brand p{margin:4px 0 0;color:var(--ink-dim);font-size:14px;font-weight:400}
  .progress{display:flex;flex-direction:column;align-items:flex-end;gap:8px}
  .pips{display:flex;gap:8px}
  .pip{
    width:30px;height:30px;border-radius:9px;display:grid;place-items:center;
    font-family:var(--font-mono);font-size:13px;font-weight:700;
    background:var(--panel);border:1px solid var(--line);color:var(--ink-faint);
    cursor:not-allowed;transition:transform .12s ease,background .2s,color .2s,border-color .2s;
  }
  .pip.done{background:linear-gradient(180deg,var(--amber),var(--amber-deep));color:#3a2400;border-color:transparent;box-shadow:0 4px 14px rgba(245,154,46,.3)}
  .pip.unlocked{cursor:pointer;color:var(--ink)}
  .pip.unlocked:hover{transform:translateY(-2px);border-color:var(--line-strong)}
  .pip.current{border-color:var(--amber);color:var(--amber);box-shadow:0 0 0 3px rgba(255,180,84,.14)}
  .progress .count{font-size:12px;color:var(--ink-faint);font-family:var(--font-mono)}

  /* ---------- layout ---------- */
  .board{display:grid;grid-template-columns:minmax(0,0.9fr) minmax(0,1.1fr);gap:20px;align-items:start}
  @media (max-width:860px){.board{grid-template-columns:1fr}}

  .panel{background:var(--panel);border:1px solid var(--line);border-radius:18px}
  .kicker{font-family:var(--font-mono);font-size:12px;color:var(--amber);letter-spacing:.5px}

  /* ---------- briefing ---------- */
  .briefing{padding:22px 22px 24px;position:sticky;top:14px}
  @media (max-width:860px){.briefing{position:static}}
  .lvl-head{display:flex;align-items:center;gap:10px;margin-bottom:2px}
  .lvl-tag{font-family:var(--font-mono);font-size:12px;color:var(--ink-faint)}
  .briefing h2{margin:6px 0 14px;font-size:23px;font-weight:700;letter-spacing:-.4px;line-height:1.15}
  .lesson p{margin:0 0 12px;color:var(--ink-dim);font-size:15px}
  .lesson p strong{color:var(--ink);font-weight:600}
  .lesson code.inl{font-family:var(--font-mono);font-size:.9em;background:rgba(142,162,255,.13);color:#c6d0ff;padding:1px 6px;border-radius:6px}
  pre.snippet{
    font-family:var(--font-mono);font-size:13px;line-height:1.55;
    background:var(--inset);border:1px solid var(--line);border-left:3px solid var(--peri);
    border-radius:10px;padding:12px 14px;margin:0 0 14px;overflow-x:auto;color:#d7dcff;
  }
  pre.snippet .cmt{color:#6f74a3;font-style:italic}
  .snippet-label{font-family:var(--font-mono);font-size:11px;color:var(--ink-faint);margin:-6px 0 6px}

  .goal{
    margin-top:18px;background:linear-gradient(180deg,rgba(255,180,84,.10),rgba(255,180,84,.03));
    border:1px solid rgba(255,180,84,.28);border-radius:12px;padding:14px 16px;
  }
  .goal .kicker{display:block;margin-bottom:6px}
  .goal p{margin:0;color:var(--ink);font-size:15px}
  .goal .target-fmt{font-family:var(--font-mono);font-size:13px;white-space:pre;display:block;margin-top:10px;color:#ffd79a;background:rgba(0,0,0,.25);padding:10px 12px;border-radius:8px;overflow-x:auto}

  .hints{margin-top:16px}
  .hint-btn{
    font-family:var(--font-ui);font-size:13px;font-weight:500;cursor:pointer;
    background:transparent;color:var(--peri);border:1px dashed rgba(142,162,255,.4);
    border-radius:9px;padding:7px 12px;
  }
  .hint-btn:hover{background:rgba(142,162,255,.08)}
  .hint-btn:disabled{opacity:.4;cursor:default}
  .hint{margin-top:10px;font-size:14px;color:var(--ink-dim);background:rgba(142,162,255,.06);border-left:2px solid var(--peri);padding:8px 12px;border-radius:0 8px 8px 0}

  /* ---------- workbench ---------- */
  .workbench{display:flex;flex-direction:column;gap:16px}
  .editor-shell{background:var(--panel);border:1px solid var(--line);border-radius:18px;overflow:hidden}
  .editor-bar{display:flex;align-items:center;gap:10px;padding:11px 14px;border-bottom:1px solid var(--line);background:var(--panel-2)}
  .dot{width:11px;height:11px;border-radius:50%}
  .dots{display:flex;gap:7px;margin-right:4px}
  .fname{font-family:var(--font-mono);font-size:12.5px;color:var(--ink-dim)}
  .editor-body{display:flex;background:var(--inset);max-height:none}
  .gutter{
    font-family:var(--font-mono);font-size:13.5px;line-height:1.6;
    padding:14px 8px 14px 14px;text-align:right;color:var(--ink-faint);
    user-select:none;background:rgba(0,0,0,.18);min-width:40px;white-space:pre;overflow:hidden;
  }
  textarea#code{
    flex:1;border:0;outline:0;resize:vertical;min-height:250px;
    font-family:var(--font-mono);font-size:13.5px;line-height:1.6;
    padding:14px 16px;background:transparent;color:#e7ebff;
    caret-color:var(--amber);tab-size:4;white-space:pre;overflow-wrap:normal;
  }
  textarea#code::selection{background:rgba(255,180,84,.28)}

  .tools{display:flex;align-items:center;gap:12px;padding:12px 14px;border-top:1px solid var(--line)}
  .btn-run{
    font-family:var(--font-ui);font-weight:600;font-size:15px;color:#3a2400;cursor:pointer;
    background:linear-gradient(180deg,var(--amber),var(--amber-deep));border:0;border-radius:11px;
    padding:11px 22px;display:inline-flex;align-items:center;gap:9px;
    box-shadow:0 5px 16px rgba(245,154,46,.32);transition:transform .1s ease,filter .15s,opacity .2s;
  }
  .btn-run:hover:not(:disabled){filter:brightness(1.06)}
  .btn-run:active:not(:disabled){transform:translateY(1px)}
  .btn-run:disabled{opacity:.5;cursor:progress;box-shadow:none}
  .btn-run .tri{width:0;height:0;border-left:11px solid #3a2400;border-top:7px solid transparent;border-bottom:7px solid transparent}
  .btn-ghost{
    font-family:var(--font-ui);font-weight:500;font-size:14px;color:var(--ink-dim);cursor:pointer;
    background:transparent;border:1px solid var(--line-strong);border-radius:10px;padding:10px 16px;
  }
  .btn-ghost:hover{color:var(--ink);border-color:var(--ink-faint)}
  .runhint{margin-left:auto;font-family:var(--font-mono);font-size:11.5px;color:var(--ink-faint)}
  @media (max-width:520px){.runhint{display:none}}

  /* ---------- stage ---------- */
  .stage{padding:16px 18px 20px}
  .stage-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:12px}
  .stage-head .kicker{color:var(--cyan)}
  .status{font-family:var(--font-mono);font-size:12px;padding:4px 10px;border-radius:20px;border:1px solid var(--line)}
  .status.idle{color:var(--ink-faint)}
  .status.run{color:var(--amber);border-color:rgba(255,180,84,.4)}
  .status.ok{color:var(--good);border-color:rgba(87,217,154,.45);background:rgba(87,217,154,.08)}
  .status.err{color:var(--bad);border-color:rgba(255,111,111,.45);background:rgba(255,111,111,.08)}

  pre.out{
    font-family:var(--font-mono);font-size:13.5px;line-height:1.6;color:#dfe4ff;
    background:var(--inset);border:1px solid var(--line);border-radius:11px;
    padding:14px 16px;margin:0;min-height:74px;white-space:pre-wrap;word-break:break-word;
  }
  pre.out.empty{color:var(--ink-faint);font-style:italic}
  .err-box{
    font-family:var(--font-mono);font-size:13px;line-height:1.55;color:#ffc9c9;
    background:rgba(255,111,111,.07);border:1px solid rgba(255,111,111,.32);border-left:3px solid var(--bad);
    border-radius:0 10px 10px 0;padding:12px 14px;margin:0;white-space:pre-wrap;
  }
  .feedback{margin-top:12px;font-size:14px;color:var(--ink-dim)}
  .feedback b{color:var(--ink)}

  /* test runner table */
  table.tests{width:100%;border-collapse:collapse;font-family:var(--font-mono);font-size:12.5px;margin-top:2px}
  table.tests th{text-align:left;color:var(--ink-faint);font-weight:500;padding:6px 10px;border-bottom:1px solid var(--line)}
  table.tests td{padding:7px 10px;border-bottom:1px solid var(--line);color:var(--ink-dim)}
  table.tests tr:last-child td{border-bottom:0}
  td.verdict.pass{color:var(--good)}
  td.verdict.fail{color:var(--bad)}
  td .mine{color:#e7ebff}

  /* physics canvas */
  .canvas-wrap{background:var(--inset);border:1px solid var(--line);border-radius:12px;overflow:hidden}
  canvas#field{display:block;max-width:100%;height:auto;margin:0 auto}
  .launch-read{font-family:var(--font-mono);font-size:12px;color:var(--ink-faint);margin-top:10px}
  .launch-read span{color:var(--cyan)}

  /* win banner */
  .win{
    margin-top:14px;display:none;align-items:center;gap:14px;flex-wrap:wrap;
    background:linear-gradient(180deg,rgba(87,217,154,.12),rgba(87,217,154,.04));
    border:1px solid rgba(87,217,154,.4);border-radius:12px;padding:14px 16px;
  }
  .win.show{display:flex}
  .win .stamp{font-family:var(--font-mono);font-weight:700;color:var(--good);font-size:15px}
  .win p{margin:0;font-size:14px;color:var(--ink-dim);flex:1 1 200px}
  .btn-next{
    font-family:var(--font-ui);font-weight:600;font-size:14px;color:#052015;cursor:pointer;
    background:linear-gradient(180deg,var(--good),#3fbd82);border:0;border-radius:10px;padding:10px 18px;
    display:inline-flex;align-items:center;gap:8px;
  }
  .btn-next:hover{filter:brightness(1.05)}

  /* confetti */
  .spark{position:absolute;width:8px;height:8px;border-radius:2px;pointer-events:none;will-change:transform,opacity}

  /* finale */
  .finale{display:none;text-align:center;padding:40px 24px}
  .finale.show{display:block}
  .finale h2{font-size:30px;margin:0 0 10px;letter-spacing:-.5px}
  .finale p{color:var(--ink-dim);max-width:520px;margin:0 auto 8px}
  .finale .recap{font-family:var(--font-mono);font-size:13px;color:var(--cyan);margin:18px 0 22px}

  .loadbar{font-family:var(--font-mono);font-size:12px;color:var(--ink-faint);display:inline-flex;align-items:center;gap:8px}
  .spin{width:12px;height:12px;border-radius:50%;border:2px solid rgba(255,180,84,.3);border-top-color:var(--amber);animation:sp .7s linear infinite}
  @keyframes sp{to{transform:rotate(360deg)}}

  @media (prefers-reduced-motion:reduce){
    *{animation-duration:.001ms!important;transition-duration:.001ms!important}
  }

/* ======================= combined-site layout (arcade-extra.css) ======================= */
/* Layout and sidebar for the combined C++ Arcade site.
   Appended to the original page styles by build-lessons.js. */

:root{ --side-w:300px; }

.app{display:flex;min-height:100vh;align-items:stretch}

/* ---------- side panel ---------- */
.side{
  flex:0 0 0;width:0;overflow:hidden;
  background:var(--bg2);border-right:1px solid transparent;
  position:sticky;top:0;height:100vh;
  transition:flex-basis .22s ease,width .22s ease,border-color .22s;
}
.app.side-open .side{flex-basis:var(--side-w);width:var(--side-w);border-right-color:var(--line)}
.side-inner{width:var(--side-w);height:100%;display:flex;flex-direction:column}

.side-head{display:flex;align-items:center;gap:10px;padding:16px 14px 10px 18px}
.side-head .side-title{font-family:var(--font-mono);font-size:12px;letter-spacing:.6px;color:var(--amber);text-transform:uppercase;flex:1}
.side-close{
  background:transparent;border:1px solid var(--line);color:var(--ink-dim);border-radius:8px;
  width:30px;height:30px;cursor:pointer;font-size:15px;line-height:1;display:grid;place-items:center;
}
.side-close:hover{color:var(--ink);border-color:var(--line-strong)}

.side-prog{padding:0 18px 12px}
.bar{height:6px;background:var(--panel);border:1px solid var(--line);border-radius:5px;overflow:hidden}
.bar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--amber),var(--good));transition:width .3s ease}
.side-count{font-family:var(--font-mono);font-size:11.5px;color:var(--ink-faint);margin-top:7px;display:flex;justify-content:space-between}

.lessons{flex:1;overflow-y:auto;padding:0 10px 24px;scrollbar-width:thin;scrollbar-color:var(--panel-2) transparent}
.part{margin-top:6px}
.part-head{
  width:100%;display:flex;align-items:center;gap:8px;background:transparent;border:0;cursor:pointer;
  color:var(--ink);font-family:var(--font-ui);font-weight:600;font-size:13.5px;padding:12px 8px 6px;text-align:left;
}
.part-head:hover{color:var(--amber)}
.part-head .chev{display:inline-block;font-size:10px;color:var(--ink-faint);transition:transform .15s;width:12px}
.part.folded .part-head .chev{transform:rotate(-90deg)}
.part-head .pnum{font-family:var(--font-mono);font-size:11px;color:var(--ink-faint);letter-spacing:.4px}
.part-head .pcount{margin-left:auto;font-family:var(--font-mono);font-size:11px;color:var(--ink-faint)}
.part.complete .part-head .pcount{color:var(--good)}
.part ol{list-style:none;margin:0;padding:0 0 4px}
.part.folded ol{display:none}

.li{
  display:flex;align-items:center;gap:10px;width:100%;padding:8px 10px;border-radius:9px;
  background:transparent;border:0;cursor:pointer;text-align:left;
  color:var(--ink-dim);font-family:var(--font-ui);font-size:14px;line-height:1.3;
}
.li:hover{background:rgba(255,255,255,.04);color:var(--ink)}
.li .n{font-family:var(--font-mono);font-size:11.5px;color:var(--ink-faint);flex:0 0 34px}
.li .t{flex:1;min-width:0}
.li .m{font-family:var(--font-mono);font-size:12px;flex:0 0 16px;text-align:center;color:var(--ink-faint)}
.li.done .m{color:var(--good)}
.li.current{background:rgba(255,180,84,.10);color:var(--ink);box-shadow:inset 0 0 0 1px rgba(255,180,84,.28)}
.li.current .n{color:var(--amber)}
.li.locked{opacity:.45;cursor:not-allowed}
.li.locked:hover{background:transparent;color:var(--ink-dim)}

.side-foot{padding:10px 18px 16px;border-top:1px solid var(--line);display:flex;gap:8px;align-items:center}
.side-foot .btn-ghost{font-size:12.5px;padding:7px 11px}
.side-foot .tip{font-family:var(--font-mono);font-size:11px;color:var(--ink-faint);margin-left:auto}

.backdrop{display:none}

/* ---------- no inline styles (strict Content-Security-Policy) ---------- */
.dot-r{background:#ff6f6f}
.dot-y{background:#ffb454}
.dot-g{background:#57d99a}
#goalFmt,#finP3{display:none}
.hint .hint-n{color:var(--peri)}

/* ---------- main column ---------- */
.main{flex:1 1 auto;min-width:0}
.side-btn{
  background:var(--panel);border:1px solid var(--line);color:var(--ink-dim);border-radius:10px;
  width:40px;height:40px;cursor:pointer;display:grid;place-items:center;align-self:center;
  font-size:18px;line-height:1;flex:0 0 auto;
}
.side-btn:hover{color:var(--ink);border-color:var(--line-strong)}
header.top{align-items:center}
.brand{align-items:center}
.brand .part-label{font-family:var(--font-mono);font-size:11.5px;color:var(--ink-faint);letter-spacing:.5px;display:block;margin-bottom:2px}

.finale .finale-actions{margin-top:24px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.finale p.p3{color:var(--amber)}

/* ---------- narrow screens: the panel becomes a drawer ---------- */
@media (max-width:900px){
  .side{
    position:fixed;left:0;top:0;bottom:0;z-index:60;height:auto;
    flex:none;width:var(--side-w);border-right:1px solid var(--line);
    transform:translateX(-100%);
    transition:transform .22s ease;box-shadow:0 0 40px rgba(0,0,0,.5);
  }
  .app.side-open .side{transform:none;width:var(--side-w)}
  .backdrop{position:fixed;inset:0;background:rgba(5,7,24,.55);z-index:55}
  .app.side-open .backdrop{display:block}
}