* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: #000;
  color: #ff0;
  font-family: "Courier New", monospace;
  min-height: 100vh;
}

.app {
  max-width: 700px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

/* Header */
header {
  text-align: center;
  margin-bottom: 1rem;
}

header h1 {
  font-size: 1.6rem;
  letter-spacing: 0.05em;
  margin-bottom: 0.8rem;
}

.controls {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.6rem;
}

.scale-selector {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.scale-selector .label {
  margin-right: 0.3rem;
  font-size: 0.9rem;
}

.scale-btn {
  background: #000;
  color: #ff0;
  border: 2px solid #ff0;
  font-family: inherit;
  font-size: 1rem;
  width: 2.4rem;
  height: 2.4rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.scale-btn:hover {
  background: #ff0;
  color: #000;
}

.scale-btn.active {
  background: #ff0;
  color: #000;
  font-weight: bold;
}

.hint {
  font-size: 0.8rem;
  color: #888;
}

.hint kbd {
  background: #222;
  border: 1px solid #555;
  border-radius: 3px;
  padding: 0.1rem 0.4rem;
  font-family: inherit;
  color: #ff0;
}

/* Diagram */
.diagram-area {
  text-align: center;
}

.svg-container {
  border: 2px solid #ff0;
  border-radius: 4px;
  background: #111;
  max-width: 650px;
  margin: 0 auto;
}

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

.spawn-count {
  margin-top: 0.4rem;
  font-size: 0.85rem;
  color: #aaa;
}