:root{
  --bg:#f8f8f8;
  --ink:#1a1a1a;
  --muted:#6b7280;
  --muted2:#374151;
  --card:#fff;
  --stroke:#e5e7eb;
  --shadow:0 4px 12px rgba(0,0,0,.06);
  --accent:#2563eb;
  --accent-hover:#1d4ed8;
  --r:8px;
  --good:#059669;
  --bad:#dc2626;
  --hint:#eff6ff;
}

*{box-sizing:border-box}

html{
  -webkit-text-size-adjust:100%;
}

body{
  margin:0;
  font-family:'DM Sans',-apple-system,BlinkMacSystemFont,sans-serif;
  background:var(--bg);
  color:var(--ink);
  padding-bottom:env(safe-area-inset-bottom, 0);
}

/* Touch: remove tap highlight, use outline for focus */
.btn,.lever input{
  -webkit-tap-highlight-color:transparent;
}
.btn:focus-visible,.lever input:focus-visible{
  outline:2px solid var(--accent);
  outline-offset:2px;
}

.wrap{
  max-width:1040px;
  margin:0 auto;
  padding:14px;
  display:grid;
  gap:10px;
}

header{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  padding:10px 12px;
  border:1px solid var(--stroke);
  border-radius:var(--r);
  background:var(--card);
  box-shadow:var(--shadow);
}

header .left{display:flex; align-items:center; gap:10px}
header h1{font-size:15px; margin:0; font-weight:600}
header .btns{display:flex; gap:8px; flex-wrap:wrap; justify-content:flex-end; align-items:center}

.btn{
  appearance:none;
  border:1px solid var(--stroke);
  background:var(--card);
  color:var(--ink);
  padding:9px 12px;
  border-radius:6px;
  font-weight:600;
  font-family:'DM Sans',sans-serif;
  cursor:pointer;
  box-shadow:var(--shadow);
  transition:border-color .2s ease, color .2s ease;
}
.btn:hover{border-color:var(--accent); color:var(--accent)}

.card{
  border:1px solid var(--stroke);
  border-radius:var(--r);
  background:var(--card);
  box-shadow:var(--shadow);
  overflow:hidden;
}

.infoInner{padding:10px 12px}
.infoTitle{font-weight:600; margin-bottom:6px}
.infoText{font-size:12px; color:var(--muted2); line-height:1.5}

.stage{padding:10px}

canvas{
  width:100%;
  height:660px;
  display:block;
  border-radius:8px;
  background:var(--bg);
  border:1px solid var(--stroke)
}

.levers{
  display:flex;
  gap:10px;
  flex-wrap:wrap;
  padding:10px 12px;
  border-top:1px solid var(--stroke);
  background:var(--card);
  align-items:stretch;
}

.lever{
  flex:1 1 260px;
  min-width:260px;
  padding:12px;
  border-radius:8px;
  border:1px solid var(--stroke);
  background:var(--card)
}
.lever.hidden{display:none}
.lever .top{display:flex; justify-content:space-between; align-items:center; gap:10px}
.lever .name{font-size:13px; font-weight:600}
.lever .val{font-size:12px; color:var(--muted); font-family:'JetBrains Mono',monospace; font-weight:500}
.lever input{width:100%; margin-top:10px}
.lever .hint{margin-top:8px; font-size:12px; color:var(--muted); line-height:1.25}

/* Modal */
.overlay{
  position:fixed; inset:0;
  display:none;
  align-items:center;
  justify-content:center;
  padding:18px;
  background:rgba(0,0,0,.4);
  z-index:50;
}

.modal{
  width:min(720px, 100%);
  border-radius:8px;
  border:1px solid var(--stroke);
  background:var(--card);
  box-shadow:0 20px 60px rgba(0,0,0,.15);
  overflow:hidden;
}

.modal .head{
  display:flex;
  justify-content:space-between;
  align-items:flex-start;
  gap:10px;
  padding:16px 16px 0 16px
}

.modal .head .tag{
  font-size:11px;
  color:var(--muted);
  font-weight:600;
  font-family:'JetBrains Mono',monospace;
  text-transform:uppercase;
  letter-spacing:.08em;
  border:1px solid var(--stroke);
  background:var(--hint);
  padding:6px 10px;
  border-radius:6px
}

.modal h3{margin:10px 16px 0 16px; font-size:18px; font-weight:600}

.modal .body{padding:12px 16px 0 16px; display:grid; gap:10px}

.box{
  border:1px solid var(--stroke);
  border-radius:8px;
  background:var(--bg);
  padding:12px
}

.box p{
  margin:0;
  font-size:13px;
  color:var(--muted2);
  line-height:1.5;
  white-space:pre-line
}

.nerdLine{
  font-size:12px;
  color:var(--muted);
  margin-top:8px
}

.modal .foot{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:10px;
  padding:14px 16px 16px 16px
}

.toast{
  position:fixed;
  left:50%;
  transform:translateX(-50%);
  bottom:18px;
  padding:10px 12px;
  border-radius:6px;
  border:1px solid var(--stroke);
  background:var(--card);
  color:var(--ink);
  font-weight:600;
  display:none;
  z-index:60;
  box-shadow:var(--shadow)
}

/* Tablet */
@media (max-width: 900px){
  canvas{height:600px}
  .lever{min-width:unset; flex:1 1 100%}
}

/* Mobile */
@media (max-width: 640px){
  .wrap{
    padding:10px;
    gap:8px;
  }

  header{
    flex-direction:column;
    align-items:stretch;
    gap:12px;
    padding:12px;
  }
  header .left{
    gap:8px;
  }
  header h1{font-size:14px}
  header .btns{
    display:grid;
    grid-template-columns:repeat(4, 1fr);
    gap:8px;
  }
  header .btns .btn{
    min-height:44px;
    padding:10px 8px;
    font-size:13px;
  }
  /* Speed button can span or shrink */
  header .btns #btnSpeed{grid-column:span 2}

  .stage{padding:8px}
  canvas{
    height:min(420px, 60vh);
    min-height:300px;
  }
  .levers{
    padding:10px 8px;
    gap:8px;
  }
  .lever{
    min-width:unset;
    flex:1 1 100%;
    padding:12px 10px;
  }
  .lever .name{font-size:12px}
  .lever .val{font-size:11px}
  .lever input{
    margin-top:8px;
    min-height:28px;
    touch-action:none;
  }
  .lever .hint{font-size:11px}

  /* Modal: fit small screens and scroll */
  .overlay{
    padding:12px;
    align-items:flex-start;
    padding-top:max(12px, env(safe-area-inset-top));
  }
  .modal{
    max-height:min(85vh, 90dvh);
    overflow-y:auto;
    -webkit-overflow-scrolling:touch;
  }
  .modal .head{padding:12px 12px 0 12px}
  .modal .head .tag{font-size:10px; padding:5px 8px}
  .modal h3{margin:8px 12px 0 12px; font-size:16px}
  .modal .body{padding:10px 12px 0 12px}
  .box{padding:10px}
  .box p{font-size:12px}
  .modal .foot{
    padding:12px;
    padding-bottom:max(12px, env(safe-area-inset-bottom));
    flex-wrap:wrap;
    gap:8px;
  }
  .modal .foot .btn{
    min-height:44px;
    flex:1 1 auto;
  }

  .toast{
    bottom:max(18px, env(safe-area-inset-bottom));
    left:12px;
    right:12px;
    transform:translateX(0);
    width:auto;
    max-width:100%;
  }
}

/* Extra narrow (e.g. iPhone SE, small phones) */
@media (max-width: 480px){
  .wrap{padding:8px; gap:6px}
  header{padding:10px}
  header h1{font-size:13px}
  header .btns .btn{font-size:12px; padding:8px 6px}
  .stage{padding:6px}
  canvas{
    height:min(380px, 55vh);
    min-height:280px;
  }
}

/* Touch: larger hit areas and no hover reliance */
@media (hover: none){
  .btn:focus-visible,
  .btn:hover{
    border-color:var(--accent);
    color:var(--accent);
  }
  .lever input{
    min-height:32px;
  }
}

.modalExtra{
  margin-top:10px;
  padding-top:10px;
  border-top:1px dashed var(--stroke);
}

.modalExtra .rooflineWrap{
  display:grid;
  gap:10px;
}

.modalExtra .rooflineCaption{
  font-size:12px;
  color:var(--muted);
  line-height:1.35;
}

.modalExtra a{
  color:var(--accent);
  font-weight:600;
  text-decoration:underline;
}

.modalExtra a:hover{
  color:var(--accent-hover);
}