:root {
  color-scheme: dark;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #101722;
  color: #e9f2fa;
}

* { box-sizing: border-box; }

html, body, .app { width: 100%; height: 100%; margin: 0; }

.app { position: relative; overflow: hidden; }
.viewport { width: 100%; height: 100%; }
.viewport canvas { display: block; width: 100%; height: 100%; }

.panel {
  position: absolute;
  top: 18px;
  right: 18px;
  width: min(320px, calc(100vw - 36px));
  max-height: calc(100vh - 36px);
  overflow: auto;
  padding: 22px;
  border: 1px solid #40566b;
  border-radius: 16px;
  background: rgb(20 32 47 / 94%);
  box-shadow: 0 14px 42px rgb(0 0 0 / 28%);
}

.eyebrow { margin: 0 0 8px; color: #78c8ef; font-size: 11px; font-weight: 700; letter-spacing: .12em; }
h1 { margin: 0; font-size: 24px; }
.intro, .note { color: #adbfcd; font-size: 14px; line-height: 1.55; }
.intro { margin: 9px 0 20px; }
.note { margin: 20px 0 0; padding-top: 14px; border-top: 1px solid #40566b; }
.control { margin: 0 0 17px; }
.control label { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 7px; font-size: 14px; }
output { color: #78c8ef; font-variant-numeric: tabular-nums; }
input[type="range"] { width: 100%; accent-color: #4bb7e5; cursor: pointer; }
.checkbox { display: flex; align-items: center; gap: 9px; font-size: 14px; cursor: pointer; }
.checkbox input { accent-color: #4bb7e5; }

@media (max-width: 600px) {
  .panel { top: 10px; right: 10px; width: min(285px, calc(100vw - 20px)); padding: 16px; }
  h1 { font-size: 21px; }
}