:root {
  --bg: #f4f5f7;
  --panel: #ffffff;
  --border: #dde1e6;
  --text: #1f2430;
  --text-muted: #6b7280;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --secondary: #10b981;
  --secondary-hover: #059669;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

header {
  padding: 24px 32px 8px;
}

header h1 {
  margin: 0 0 4px;
  font-size: 1.6rem;
}

.subtitle {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

main {
  display: grid;
  grid-template-columns: 340px 1fr;
  grid-template-rows: auto auto;
  gap: 20px;
  padding: 20px 32px 40px;
}

.controls {
  grid-row: 1 / 3;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.panel h2 {
  margin-top: 0;
  font-size: 1.05rem;
}

.field-group {
  margin-bottom: 22px;
}

.field-group h3 {
  margin: 0 0 10px;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.field-row {
  display: flex;
  gap: 12px;
  margin-bottom: 12px;
}

.field-row label {
  flex: 1;
  display: flex;
  flex-direction: column;
  font-size: 0.85rem;
  color: var(--text);
  gap: 6px;
}

input[type="number"] {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.95rem;
  width: 100%;
}

input[type="number"]:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
}

.hint {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.4;
  margin: 6px 0 0;
}

.actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 12px 16px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  color: white;
  transition: background 0.15s ease;
}

.btn-primary {
  background: var(--accent);
}
.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  background: var(--secondary);
}
.btn-secondary:hover {
  background: var(--secondary-hover);
}

.stats {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin: 0;
  white-space: pre-line;
}

.svg-wrap {
  width: 100%;
  overflow: auto;
  background: repeating-conic-gradient(#f0f1f3 0% 25%, #ffffff 0% 50%) 50% / 20px 20px;
  border: 1px solid var(--border);
  border-radius: 6px;
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.svg-wrap svg {
  max-width: 100%;
  height: auto;
  display: block;
}

.wall-hit {
  stroke: transparent;
  cursor: pointer;
}
.wall-hit:hover {
  stroke: rgba(37, 99, 235, 0.35);
}

select {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.9rem;
  width: 100%;
  background: white;
}

input[type="text"] {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.95rem;
  width: 100%;
}

@media (max-width: 900px) {
  main {
    grid-template-columns: 1fr;
  }
  .controls {
    grid-row: auto;
  }
}