:root {
    --bg: #16181d;
    --panel: #1e2129;
    --line: #2c303a;
    --text: #e7e9ee;
    --muted: #8a8f9c;
    --accent: #5ec8b8;
    --guide: #3a4048;
    --good: #5ec8b8;
    --bad: #e0665c;
}
* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0; height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  overflow: hidden;
}
#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
  gap: 12px;
}
header h1 {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin: 0;
  color: var(--text);
}
.controls {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
}
.field {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
}
.segmented {
  display: flex;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}
.segmented button {
  background: transparent;
  border: none;
  color: var(--muted);
  padding: 7px 14px;
  font-size: 13px;
  cursor: pointer;
  transition: background .15s, color .15s;
}
.segmented button.active {
  background: var(--accent);
  color: #0e1116;
  font-weight: 600;
}
input[type="range"] {
  accent-color: var(--accent);
  width: 110px;
}
button.primary {
  background: var(--accent);
  color: #0e1116;
  border: none;
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
button.primary:hover { filter: brightness(1.08); }
.stats {
  font-size: 13px;
  color: var(--muted);
  display: flex;
  gap: 16px;
}
.stats b { color: var(--text); }
#canvasWrap {
  position: relative;
  flex: 1;
  overflow: hidden;
}
canvas {
  position: absolute;
  top: 0; left: 0;
  touch-action: none;
}