* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  font: 15px/1.4 "Segoe UI", system-ui, sans-serif;
  color: #1c2430;
  background: #e7e2d8;
}
#app { display: flex; height: 100%; min-height: 0; }
#panel {
  width: 380px;
  flex: none;
  overflow: auto;
  background: #f6f3ec;
  border-right: 1px solid #d5cfc3;
  padding: 16px 16px 32px;
}
.intro h1 { font-size: 22px; margin: 0 0 6px; letter-spacing: 0.02em; }
.intro p { margin: 0 0 12px; color: #3d4754; }
.intro a { color: #1f4b6e; }
input:disabled { opacity: 0.55; }
#status {
  margin: 0 0 12px;
  padding: 8px 10px;
  background: #fde8e2;
  color: #7a2618;
  border: 1px solid #e3b2a6;
  border-radius: 6px;
}
#status[hidden] { display: none; }
.card {
  background: #fff;
  border: 1px solid #e0dacf;
  border-radius: 8px;
  padding: 12px;
  margin: 0 0 12px;
}
.card h2 { font-size: 16px; margin: 0 0 8px; }
.row { margin: 0 0 8px; }
.row[hidden] { display: none; }
.row span.lbl, .choice legend, .vec legend {
  display: block;
  font-size: 12px;
  font-weight: 650;
  color: #3d4754;
  margin-bottom: 3px;
}
.slider {
  display: grid;
  grid-template-columns: 1fr 76px;
  gap: 8px;
  align-items: center;
}
input[type="range"] { width: 100%; }
input[type="number"], select {
  width: 100%;
  font: inherit;
  padding: 4px 6px;
  border: 1px solid #cfc8bb;
  border-radius: 4px;
  background: #fff;
}
.choice { border: 0; margin: 0 0 8px; padding: 0; }
.choice label { display: block; margin: 2px 0; font-weight: 500; }
.vec { border: 0; margin: 0 0 8px; padding: 0; }
.axes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
}
.axes label { font-size: 11px; color: #5c6774; display: block; }
.note { margin: 0 0 8px; font-size: 12px; color: #5c6774; }
.end-readout { margin: 8px 0 0; font-size: 12px; color: #1f4b6e; }
#stage { flex: 1; min-width: 0; display: flex; flex-direction: column; background: #f4f7fb; }
#view { flex: 1; min-height: 0; position: relative; touch-action: none; }
#view canvas { display: block; width: 100%; height: 100%; }
#bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 12px;
  background: #fff;
  border-top: 1px solid #d5cfc3;
}
#hint { margin: 0; color: #3d4754; font-size: 13px; }
#fit {
  font: inherit;
  padding: 6px 12px;
  border-radius: 6px;
  border: 1px solid #1f4b6e;
  background: #1f4b6e;
  color: #fff;
  cursor: pointer;
}
#fit:hover { background: #163852; }
@media (max-width: 800px) {
  #app { flex-direction: column; }
  #panel { width: auto; max-height: 46%; }
  #stage { min-height: 50%; }
}