*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  color-scheme: dark;
  --bg: #06140a;
  --panel: rgba(12, 29, 17, 0.9);
  --accent: #7cb342;
  --text: #e4f5e8;
  --muted: rgba(228, 245, 232, 0.6);
  --border: rgba(124, 179, 66, 0.35);
  font-family: "JetBrains Mono", "Fira Code", "Source Code Pro", monospace;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at top, #0d3018 0%, var(--bg) 60%);
  color: var(--text);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2rem;
}

.app-shell {
  width: min(1200px, 100%);
  display: grid;
  gap: 1.5rem;
  grid-template-columns: 2fr minmax(220px, 1fr);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: 0 25px 45px rgba(0, 0, 0, 0.35);
  padding: 2rem;
}

.app-header {
  grid-column: 1 / span 2;
}

.app-header h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.8rem, 2.4vw, 2.4rem);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.app-header p {
  margin: 0;
  color: var(--muted);
  max-width: 60ch;
}

.canvas-panel {
  position: relative;
  background: rgba(5, 14, 9, 0.85);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  aspect-ratio: 4 / 3;
}

canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.legend {
  align-self: start;
  background: rgba(6, 20, 10, 0.6);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.legend h2 {
  margin: 0;
  font-size: 1rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}

.legend ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.4rem;
}

.legend li {
  color: var(--text);
}

.legend .hint {
  margin: 0;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.4;
}

@media (max-width: 960px) {
  body {
    padding: 1.25rem;
  }

  .app-shell {
    grid-template-columns: 1fr;
    padding: 1.5rem;
  }

  .app-header {
    grid-column: auto;
  }

  .canvas-panel {
    aspect-ratio: 1;
  }
}