:root {
  --card: #fbfbfa;
  --card-2: #f7f6f3;
  --border: #eaeaea;
  --ink: #2f3437;
  --ink-strong: #111111;
  --muted: #787774;
  --accent-text: #956400;
  --accent-bg: #fbf3db;
  --mono: "Geist Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: "SF Pro Display", "Helvetica Neue", -apple-system, "Segoe UI", sans-serif;
  --serif: "Newsreader", "Playfair Display", Georgia, serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; }
body { background: #0a0e1c; color: var(--ink); font: 14px/1.6 var(--sans); }

#app, #app canvas { position: fixed; inset: 0; }

/* ---------- top bar ---------- */
#topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 16px 20px;
  pointer-events: none;
}
#topbar > * { pointer-events: auto; }

#brand {
  background: var(--card); border: 1px solid var(--border); border-radius: 10px;
  padding: 8px 16px 9px;
}
#brand h1 {
  font-family: var(--serif); font-size: 19px; font-weight: 500;
  letter-spacing: -0.02em; line-height: 1.1; color: var(--ink-strong);
}
#brand p { font-size: 11.5px; color: var(--muted); margin-top: 1px; }

#frameToggle {
  display: flex; gap: 4px; padding: 4px;
  background: var(--card); border: 1px solid var(--border); border-radius: 10px;
}
.frame-btn {
  border: 0; background: transparent; color: var(--muted); cursor: pointer;
  font: 500 13px var(--sans); padding: 8px 16px; border-radius: 6px;
  transition: background 0.2s, color 0.2s;
}
.frame-btn:hover { color: var(--ink-strong); }
.frame-btn.active { background: var(--ink-strong); color: #ffffff; }
.frame-btn:active { transform: scale(0.98); }

.chip {
  background: var(--card); border: 1px solid var(--border); color: var(--ink);
  border-radius: 10px; padding: 10px 18px; font: 500 13px var(--sans);
  cursor: pointer; min-width: 78px;
}
.chip:hover { background: var(--card-2); }
.chip:active { transform: scale(0.98); }

/* ---------- control panel ---------- */
#controls {
  position: fixed; top: 82px; left: 16px; width: 280px; z-index: 15;
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  max-height: calc(100dvh - 102px); overflow-y: auto;
  scrollbar-width: thin;
}
.block { padding: 18px 20px; }
.block + .block { border-top: 1px solid var(--border); }

.label {
  font: 500 10.5px var(--mono); letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--muted); margin-bottom: 10px;
  display: flex; justify-content: space-between; align-items: center;
}

#betaRow { display: flex; align-items: baseline; gap: 5px; }
#betaValue { font: 500 32px var(--mono); color: var(--ink-strong); letter-spacing: -0.02em; }
#betaRow .unit { font: italic 400 18px var(--serif); color: var(--muted); }

#speedSlider {
  width: 100%; appearance: none; height: 3px; border-radius: 2px;
  margin: 16px 0 12px; background: var(--border); outline: none;
}
#speedSlider::-webkit-slider-thumb {
  appearance: none; width: 16px; height: 16px; border-radius: 50%;
  background: var(--ink-strong); cursor: grab;
  border: 3px solid var(--card);
  box-shadow: 0 0 0 1px var(--border);
}
#speedSlider::-moz-range-thumb {
  width: 10px; height: 10px; border-radius: 50%; background: var(--ink-strong);
  border: 3px solid var(--card); cursor: grab;
}

#presets { display: flex; gap: 6px; }
#presets button {
  flex: 1; background: transparent; color: var(--muted);
  border: 1px solid var(--border); border-radius: 6px;
  font: 500 12px var(--mono); padding: 6px 0; cursor: pointer;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
#presets button:hover { color: var(--ink-strong); border-color: var(--ink-strong); }
#presets button:active { transform: scale(0.98); }

button:focus { outline: none; }
button:focus-visible { outline: 2px solid var(--ink-strong); outline-offset: 2px; }

#readouts { display: flex; flex-direction: column; gap: 8px; }
#readouts > div { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; }
#readouts dt { color: var(--muted); font-size: 12.5px; }
#readouts dd { font: 500 12.5px var(--mono); color: var(--ink); text-align: right; white-space: nowrap; }

.clockrow {
  display: grid; grid-template-columns: 1fr auto auto; gap: 10px;
  align-items: baseline; padding: 3px 0;
}
.who {
  font: 500 10.5px var(--mono); letter-spacing: 0.05em;
  text-transform: uppercase; color: var(--muted);
}
.tval { font: 500 16px var(--mono); color: var(--ink); }
.ticks { font: 400 11px var(--mono); color: var(--muted); }
.who.accent, .tval.accent {
  color: var(--accent-text);
}
.tval.accent {
  background: var(--accent-bg); border-radius: 4px; padding: 0 5px;
}

.mini {
  background: transparent; border: 1px solid var(--border); color: var(--muted);
  border-radius: 6px; font: 500 10px var(--mono); letter-spacing: 0.05em;
  text-transform: uppercase; padding: 3px 9px; cursor: pointer;
}
.mini:hover { color: var(--ink-strong); border-color: var(--ink-strong); }

#explain { font-size: 12.5px; color: var(--muted); line-height: 1.6; }
#explain b { color: var(--ink-strong); font-weight: 600; }

#keys {
  padding: 12px 20px 16px; font-size: 11px; color: var(--muted);
  display: flex; gap: 14px; align-items: center;
  border-top: 1px solid var(--border);
}
kbd {
  font: 500 10px var(--mono); background: var(--card-2);
  border: 1px solid var(--border); border-radius: 4px; padding: 1px 6px;
  margin-right: 4px; color: var(--ink);
}

@media (max-width: 720px) {
  #brand p { display: none; }
  #controls { width: calc(100vw - 32px); top: 130px; }
  #topbar { flex-wrap: wrap; }
}