* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, sans-serif;
  background: #101317;
  color: #d3d8de;
  font-size: 14px;
}
#topbar {
  display: flex; gap: 8px; align-items: center;
  padding: 10px 14px;
  background: #171b21;
  border-bottom: 1px solid #232a32;
}
#topbar strong { font-size: 15px; letter-spacing: 0.2px; }
#topbar .spacer { flex: 1; }
#topbar label { color: #8b929c; font-size: 13px; }

main { display: grid; grid-template-columns: 340px 1fr; gap: 14px; padding: 14px; }

#stack { background: #171b21; padding: 14px; border-radius: 10px; border: 1px solid #232a32; height: fit-content; }
#stack h2 { margin: 0 0 12px; font-size: 13px; text-transform: uppercase; letter-spacing: 1px; color: #8b929c; }

.element-row { border: 1px solid #2a323b; border-radius: 8px; padding: 10px; margin-bottom: 10px; background: #1c2129; }
.element-row header { display: flex; align-items: center; gap: 8px; cursor: grab; }
.element-row header span { flex: 1; font-weight: 600; }
.element-row .params { margin-top: 8px; display: grid; grid-template-columns: auto 1fr; gap: 6px 10px; align-items: center; }
.element-row .params label { color: #8b929c; font-size: 13px; }
.element-row.invalid { border-color: #d1566b; box-shadow: 0 0 0 1px rgba(209, 86, 107, 0.25); }
.err { color: #f2889b; font-size: 12px; margin-top: 6px; }

#lengthCtl { margin-top: 12px; padding-top: 12px; border-top: 1px solid #232a32; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
#lengthNote { flex-basis: 100%; color: #8b929c; font-size: 12px; }
#tapCount { flex-basis: 100%; margin-top: 4px; font-weight: 600; color: #5b9dff; }
#minPhaseLabel { flex-basis: 100%; margin-top: 6px; color: #d3d8de; font-size: 13px; }
#minPhaseNote { flex-basis: 100%; color: #e0b34a; font-size: 12px; }
#addType, #addBtn { margin-top: 4px; }

#plots { display: flex; flex-direction: column; gap: 12px; }
#plotControls { display: flex; align-items: center; gap: 8px; }
#plotControls label { color: #8b929c; font-size: 13px; }
input.bad { border-color: #d1566b; }
canvas {
  display: block;
  background: #151a1f;
  border: 1px solid #232a32;
  border-radius: 10px;
  width: 100%;
  height: 210px;
}

button, select, input {
  background: #232a32; color: #d3d8de;
  border: 1px solid #333c46; border-radius: 6px;
  padding: 5px 9px; font-size: 13px;
}
input:focus, select:focus { outline: none; border-color: #5b9dff; }
button { cursor: pointer; }
button:hover { background: #2c343e; }
#exportBtn { background: #2f5fb0; border-color: #3f6fc0; }
#exportBtn:hover { background: #3968bd; }

dialog { background: #171b21; color: #d3d8de; border: 1px solid #2a323b; border-radius: 12px; padding: 16px; min-width: 480px; }
dialog::backdrop { background: rgba(0, 0, 0, 0.55); }
dialog select { margin-bottom: 10px; }
dialog button { margin-right: 8px; margin-top: 10px; }
textarea { width: 100%; height: 260px; background: #101317; color: #d3d8de; border: 1px solid #2a323b; border-radius: 8px; font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 12px; padding: 8px; }