* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #0f172a;
  font-family: system-ui, -apple-system, sans-serif;
  color: #f8fafc;
}

#app {
  text-align: center;
  padding: 16px;
}

h1 {
  margin: 0 0 8px;
  letter-spacing: 2px;
}

#hud {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin: 0 auto 12px;
  max-width: 400px;
  font-size: 14px;
}

#board {
  border: 2px solid #334155;
  border-radius: 6px;
  background: #111827;
  max-width: 100%;
}

#controls {
  margin-top: 14px;
  user-select: none;
}

#controls .row {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin: 6px 0;
}

#controls button {
  min-width: 56px;
  padding: 10px 14px;
  font-size: 18px;
  border: none;
  border-radius: 8px;
  background: #1e293b;
  color: #f8fafc;
  cursor: pointer;
  transition: background 0.15s;
}

#controls button:hover {
  background: #334155;
}

#controls button:active {
  background: #475569;
}

.hint {
  color: #94a3b8;
  font-size: 13px;
}