:root {
  --ground: #000000;       /* page and 3D scene background, also the fog color */
  --plane: #0a0a0a;        /* 3D ground plane */
  --grid-major: #222;      /* 500 m grid lines */
  --grid-minor: #161616;   /* 100 m grid lines */
  --panel: rgba(20, 20, 20, 0.92);
  --panel-edge: #333;
  --text: #ddd;
  --muted: #888;
  --faint: #555;
  --work: #dc143c;
  --easy: #444;
  --pace-slow: #551100;
  --pace-mid: #cc3300;
  --pace-fast: #ffee55;
  --focus: #dc143c;
  --display: "Space Mono", Consolas, "Courier New", monospace;
  --ui: "Space Mono", Consolas, "Courier New", monospace;
}
html, body { margin: 0; height: 100%; }
body {
  background: var(--ground); color: var(--text); font-family: var(--ui); font-size: 12px;
  overflow: hidden; -webkit-font-smoothing: antialiased;
}
#scene { position: fixed; inset: 0; display: block; }
#scene canvas { display: block; }
.panel {
  position: fixed; background: var(--panel); border: 1px solid var(--panel-edge);
  border-radius: 6px; backdrop-filter: blur(6px); pointer-events: auto;
}
#session { top: 16px; left: 16px; padding: 14px 18px 12px; min-width: 250px; }
#session h1 {
  margin: 0; font-family: var(--display); font-weight: 700; font-size: 22px; line-height: 1.1;
  letter-spacing: -0.01em; text-wrap: balance;
}
#session .sub { margin: 6px 0 14px; color: var(--muted); font-size: 11px; }
.stats { display: grid; grid-template-columns: repeat(3, auto); gap: 10px 22px; }
.stat .k { color: var(--muted); font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.08em; }
.stat .v {
  font-family: var(--display); font-weight: 700; font-size: 20px; line-height: 1.05;
  font-variant-numeric: tabular-nums; margin-top: 2px;
}
.stat .v small { font-size: 11px; color: var(--muted); font-family: var(--ui); margin-left: 3px; font-weight: 500; }
#phase {
  display: inline-flex; align-items: center; gap: 7px; margin-top: 12px; padding: 3px 10px 3px 7px;
  border-radius: 999px; font-size: 11.5px; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase;
  background: #2a2a2a; color: var(--text);
}
#phase::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--muted); }
#phase.work { background: rgba(220, 20, 60, 0.18); }
#phase.work::before { background: var(--work); }

#reps { top: 16px; right: 16px; padding: 12px 14px; width: 232px; }
#reps h2, #legend h2 {
  margin: 0 0 8px; font-size: 10.5px; color: var(--muted); font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.08em;
}
#reps table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
#reps td { padding: 4px 0; border-top: 1px solid var(--panel-edge); font-size: 12.5px; }
#reps tr:first-child td { border-top: 0; }
#reps td:first-child { font-weight: 600; }
#reps td:first-child::before {
  content: ""; display: inline-block; width: 8px; height: 8px; border-radius: 2px;
  background: var(--work); margin-right: 7px; vertical-align: 1px;
}
#reps td.n { text-align: right; color: var(--muted); }
#reps td.n b { color: var(--text); font-weight: 600; }
#reps tr { cursor: pointer; }
#reps tr:hover td { color: var(--pace-fast); }

#legend { right: 16px; top: 158px; padding: 12px 14px; width: 232px; }
#legend .note { margin: 0 0 10px; color: var(--muted); font-size: 11.5px; line-height: 1.4; }
.ramp { height: 8px; border-radius: 4px; background: linear-gradient(90deg, var(--pace-slow), var(--pace-mid), var(--pace-fast)); }
.ramp-l { display: flex; justify-content: space-between; color: var(--muted); font-size: 11px; margin-top: 4px; font-variant-numeric: tabular-nums; }
.sw { display: flex; gap: 14px; margin-top: 10px; font-size: 11.5px; color: var(--muted); }
.sw span::before { content: ""; display: inline-block; width: 10px; height: 10px; border-radius: 2px; margin-right: 6px; vertical-align: -1px; opacity: 0.8; }
.sw .w::before { background: var(--work); }
.sw .e::before { background: #666; }

#bar {
  left: 16px; right: 16px; bottom: 16px; padding: 10px 14px;
  display: grid; grid-template-columns: auto auto 1fr auto auto auto; gap: 14px; align-items: center;
}
button, select {
  font: inherit; font-weight: 600; color: var(--text); background: #222; border: 1px solid var(--panel-edge);
  border-radius: 4px; padding: 6px 12px; cursor: pointer;
}
button:hover, select:hover { border-color: var(--faint); }
button:focus-visible, select:focus-visible, input:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
button.on { background: var(--work); border-color: var(--work); color: #fff; }
#play { width: 74px; }
.clock { font-family: var(--display); font-size: 20px; font-weight: 700; font-variant-numeric: tabular-nums; min-width: 64px; line-height: 1; }
.clock small { font-family: var(--ui); font-size: 11px; color: var(--muted); font-weight: 500; }
#time { width: 100%; }
input[type=range] { accent-color: var(--work); height: 24px; margin: 0; }
label.ctl { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 11.5px; white-space: nowrap; }
label.ctl input[type=range] { width: 90px; }
label.ctl output { color: var(--text); font-variant-numeric: tabular-nums; min-width: 28px; }
.seg { display: inline-flex; border: 1px solid var(--panel-edge); border-radius: 4px; overflow: hidden; }
.seg button { border: 0; border-radius: 0; padding: 6px 10px; }
.seg button + button { border-left: 1px solid var(--panel-edge); }

#tip {
  position: fixed; pointer-events: none; display: none; padding: 6px 9px; border-radius: 4px;
  background: var(--panel); border: 1px solid var(--panel-edge); font-size: 11.5px; line-height: 1.5;
  font-variant-numeric: tabular-nums; transform: translate(12px, -50%);
}
#tip b { font-family: var(--display); font-size: 14px; font-weight: 700; }
#hint { position: fixed; left: 50%; bottom: 74px; transform: translateX(-50%); color: var(--faint); font-size: 11px; pointer-events: none; }

@media (max-width: 860px) {
  #legend, #reps { display: none; }
  #bar { grid-template-columns: auto auto 1fr; }
  #bar .hide-sm { display: none; }
}
@media (prefers-reduced-motion: reduce) { .panel { backdrop-filter: none; } }