:root{
  --bg:#f6f8f5; --panel:#ffffff; --ink:#1c2421; --muted:#5d6b63;
  --line:#dfe6e0; --accent:#3aa856; --accent-dark:#2c8344; --accent-soft:#e7f5ec;
  --block:#5fb56b; --block-edge:#3f8a4c; --placed:#c2ccc5; --placed-edge:#a9b4ad;
  --radius:12px; --shadow:0 1px 2px rgba(0,0,0,.05),0 4px 16px rgba(0,0,0,.05);
}
*{box-sizing:border-box}
html,body{margin:0}
body{background:var(--bg);color:var(--ink);
  font-family:'Inter',-apple-system,system-ui,'Segoe UI',Roboto,sans-serif;
  line-height:1.5;-webkit-text-size-adjust:100%}
.brandbar{display:flex;justify-content:space-between;align-items:center;gap:12px;
  background:var(--ink);padding:10px 16px}
.brandmark{display:inline-flex;align-items:center;gap:9px;color:#fff;text-decoration:none;
  font-family:'Space Grotesk',Inter,sans-serif;font-weight:700;font-size:17px;letter-spacing:-.01em}
.brandmark .wordmark span{color:#6ee29a}
.brandmark svg{border-radius:5px;flex-shrink:0}
.brandall{color:#bfe6cc;font-size:13px;font-weight:600;text-decoration:none;white-space:nowrap}
.brandall:hover{color:#fff}
.wrap{max-width:1040px;margin:0 auto;padding:18px 16px 60px}
header h1{font-family:'Space Grotesk',Inter,sans-serif;font-size:27px;font-weight:700;margin:0 0 4px;letter-spacing:-.02em}
header p{margin:0 0 18px;color:var(--muted);font-size:15px}
header .accent{color:var(--accent-dark)}
.layout{display:flex;gap:18px;align-items:flex-start;flex-wrap:wrap}
.panel{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.controls{flex:1 1 280px;min-width:260px;padding:16px}
.stage{flex:2 1 460px;min-width:300px;padding:16px;display:flex;flex-direction:column;gap:12px}
.grp{margin-bottom:16px}
.grp:last-child{margin-bottom:0}
.lbl{display:block;font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.05em;color:var(--muted);margin-bottom:7px}
.seg{display:flex;flex-wrap:wrap;gap:6px}
.seg button{flex:1 1 auto;padding:9px 10px;border:1px solid var(--line);background:#fff;border-radius:9px;
  font:inherit;font-size:14px;font-weight:600;color:var(--ink);cursor:pointer;transition:.12s}
.seg button:hover{border-color:var(--accent)}
.seg button.on{background:var(--accent);border-color:var(--accent);color:#fff}
.row{display:flex;gap:10px;align-items:center}
.row .field{flex:1}
input[type=number]{width:100%;padding:9px 10px;border:1px solid var(--line);border-radius:9px;font:inherit;font-size:15px}
input[type=range]{width:100%;accent-color:var(--accent)}
.hint{font-size:12.5px;color:var(--muted);margin-top:6px}
.sizecap{font-size:12px;color:var(--muted)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:9px 12px;border-radius:9px;
  border:1px solid var(--line);background:#fff;font:inherit;font-size:14px;font-weight:600;color:var(--ink);cursor:pointer}
.btn:hover{border-color:var(--accent)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#fff}
.btn.primary:hover{background:var(--accent-dark)}
.btn.primary2{background:var(--accent-soft);border-color:var(--accent);color:var(--accent-dark);font-weight:700}
.btn.primary2:hover{background:#d8efe0}
.btn.mini{padding:5px 10px;font-size:12.5px;margin-left:auto}
details.more{border-top:1px solid var(--line);margin-top:4px;padding-top:2px}
details.more summary{cursor:pointer;padding:9px 2px;font-size:13px;font-weight:700;color:var(--muted);
  list-style:none;display:flex;align-items:center;gap:7px;user-select:none}
details.more summary::-webkit-details-marker{display:none}
details.more summary::before{content:"";width:7px;height:7px;border-right:2px solid var(--muted);
  border-bottom:2px solid var(--muted);transform:rotate(-45deg);transition:transform .15s;flex-shrink:0}
details.more[open] summary::before{transform:rotate(45deg)}
details.more summary:hover{color:var(--accent-dark)}
details.more>.grp,details.more>.toolbar{margin-top:8px}
.toolbar{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.count{display:flex;gap:18px;flex-wrap:wrap;align-items:baseline}
.count .big{font-size:24px;font-weight:800}
.count .sub{font-size:13px;color:var(--muted)}
.layernav{display:flex;align-items:center;gap:10px}
.layernav .now{font-weight:700;min-width:96px;text-align:center}
.preview3d{background:var(--accent-soft);border:1px solid var(--line);border-radius:10px;
  padding:10px 10px 7px;text-align:center}
.preview3d canvas{display:block;margin:0 auto;max-width:100%}
.preview3d-cap{font-size:12px;color:var(--muted);margin-top:5px}
.canvas-host{position:relative;width:100%;overflow:auto;background:var(--accent-soft);
  border:1px solid var(--line);border-radius:10px;max-height:62vh}
canvas{display:block;image-rendering:pixelated;margin:0 auto}
.legend{display:flex;gap:16px;flex-wrap:wrap;font-size:12.5px;color:var(--muted)}
.legend span{display:inline-flex;align-items:center;gap:6px}
.sw{width:13px;height:13px;border-radius:3px;display:inline-block;border:1px solid}
.sw.block{background:var(--block);border-color:var(--block-edge)}
.sw.placed{background:var(--placed);border-color:var(--placed-edge)}
header .lead{font-size:16px;color:var(--ink);max-width:640px}
.presets{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin:14px 0 2px}
.presets-lbl{font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.05em;color:var(--muted)}
.presets button{padding:8px 13px;border:1px solid var(--line);background:#fff;border-radius:999px;
  font:inherit;font-size:14px;font-weight:600;color:var(--ink);cursor:pointer;transition:.12s;min-height:38px}
.presets button:hover{border-color:var(--accent);background:var(--accent-soft)}
.presets button:active{transform:scale(.97)}
.check{display:flex;align-items:center;gap:8px;font-size:14px;font-weight:600;margin-top:12px;cursor:pointer;min-height:24px}
.check input{width:18px;height:18px;accent-color:var(--accent);cursor:pointer}
.ways{display:flex;gap:12px;flex-wrap:wrap;margin:16px 0 4px}
.way{flex:1 1 280px;display:flex;gap:12px;align-items:flex-start;
  background:var(--accent-soft);border:1px solid var(--line);border-radius:12px;padding:13px 15px}
.way-ic{font-size:24px;line-height:1.1;flex-shrink:0}
.way strong{display:block;font-size:15px;margin-bottom:2px}
.way span{font-size:13.5px;color:var(--muted);line-height:1.4}
.way em{font-style:normal;font-weight:700;color:var(--accent-dark)}
#cmds small{font-weight:600;opacity:.85;font-size:12px}
.explain{margin-top:26px}
.explain h2{font-size:18px;font-weight:700;margin:0 0 10px}
.explain p{color:var(--muted);font-size:14.5px;margin:0 0 10px}
.explain .steps{margin:0 0 14px;padding-left:22px}
.explain .steps li{margin-bottom:8px;font-size:15px;line-height:1.45}
.explain .steps em{font-style:normal;font-weight:700;color:var(--accent-dark)}
.foot{margin-top:26px;font-size:12.5px;color:var(--muted)}
@media (max-width:760px){
  .controls,.stage{flex:1 1 100%}
  header h1{font-size:22px}
  .ways{flex-direction:column}
  .way{flex:0 0 auto}
}
.foot a{color:var(--accent-dark);font-weight:600}
@media print{
  .controls,.toolbar,.legend,.explain,.foot,header p,.preview3d,.presets,.brandbar,details.more{display:none}
  .canvas-host{overflow:visible;max-height:none;border:none;background:#fff}
  .stage{box-shadow:none;border:none}
}