:root {
  --bg1: #05070d;
  --bg2: #0c1a2a;
  --panel: rgba(8, 18, 32, 0.8);
  --text: #eef3ff;
  --muted: #93a5bd;
  --accent: #7fd4ff;
  --line: rgba(180, 220, 255, 0.2);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  height: 100vh;
  overflow: hidden;
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 20% 20%, #1e2f4a 0%, transparent 35%),
    radial-gradient(circle at 80% 10%, #2f1a34 0%, transparent 30%),
    linear-gradient(180deg, var(--bg2), var(--bg1));
}

.app {
  display: grid;
  grid-template-columns: 300px 1fr;
  height: 100vh;
  overflow: hidden;
}

.panel {
  border-right: 1px solid var(--line);
  padding: 1.25rem;
  background: var(--panel);
  backdrop-filter: blur(6px);
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
}

h1 {
  margin: 0;
  font-size: 1.5rem;
}

p {
  margin-top: 0.3rem;
  margin-bottom: 1rem;
  color: var(--muted);
}

label {
  display: block;
  margin-top: 0.9rem;
  margin-bottom: 0.35rem;
  font-weight: 600;
}

input[type="range"] {
  width: 100%;
}

input[type="datetime-local"] {
  width: 100%;
  border: 1px solid var(--line);
  background: #0f1c2e;
  color: var(--text);
  padding: 0.5rem 0.55rem;
  border-radius: 8px;
}

select {
  width: 100%;
  border: 1px solid var(--line);
  background: #0f1c2e;
  color: var(--text);
  padding: 0.5rem 0.55rem;
  border-radius: 8px;
}

.value {
  margin-top: 0.2rem;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.datetime {
  font-size: 0.86rem;
  line-height: 1.3;
  color: #d8e9ff;
  min-height: 2.2em;
}

.time-range {
  display: flex;
  justify-content: space-between;
  margin-top: 0.15rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-variant-numeric: tabular-nums;
}

.jump-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.5rem;
  align-items: center;
}

.zoom-controls {
  display: grid;
  grid-template-columns: 1fr 72px 1fr;
  gap: 0.5rem;
  align-items: center;
}

.transport-controls {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.35rem;
  margin-top: 0.5rem;
}

.transport-controls button {
  min-height: 2.1rem;
  padding: 0.45rem 0.35rem;
  font-size: 0.74rem;
}

.zoom-readout {
  margin-top: 0;
  text-align: center;
}

.separation-readout {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.25rem 0.7rem;
  max-height: 132px;
  overflow: auto;
  padding: 0.55rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(10, 24, 40, 0.45);
  color: #d8e9ff;
  font-size: 0.78rem;
  font-variant-numeric: tabular-nums;
}

.separation-value {
  color: var(--accent);
  text-align: right;
}

.mass-controls {
  margin-top: 0.2rem;
  padding: 0.55rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: rgba(10, 24, 40, 0.55);
  max-height: 260px;
  overflow: auto;
}

.mass-controls-panel {
  grid-column: 1 / -1;
}

.mass-controls-label {
  margin-top: 0.35rem;
}

.mass-row + .mass-row {
  margin-top: 0.45rem;
}

.mass-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 0.35rem 0.6rem;
}

.mass-name {
  color: #cfe5ff;
  font-size: 0.8rem;
  font-weight: 600;
}

.mass-value {
  color: var(--accent);
  font-size: 0.78rem;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.mass-slider {
  grid-column: 1 / -1;
  width: 100%;
  margin: 0;
}

.buttons {
  margin-top: 1rem;
  display: grid;
  gap: 0.5rem;
  grid-template-columns: 1fr 1fr;
}

#pause {
  grid-column: 1 / -1;
}

#today {
  grid-column: 1 / -1;
}

#tychosEpoch {
  grid-column: 1 / -1;
}

#tychosPhysics {
  grid-column: 1 / -1;
}

#pioneer10Launch {
  grid-column: 1 / -1;
}

#voyager1Launch {
  grid-column: 1 / -1;
}

#halleySighting {
  grid-column: 1 / -1;
}

#scaleMode {
  grid-column: 1 / -1;
}

#recordedOverlay {
  grid-column: 1 / -1;
}

#spacecraftOverlay {
  grid-column: 1 / -1;
}

#originalTychosOverlay {
  grid-column: 1 / -1;
}

#tychosLabels {
  grid-column: 1 / -1;
}

#clearTrails {
  grid-column: 1 / -1;
}

#resetView {
  grid-column: 1 / -1;
}

button {
  border: 1px solid var(--line);
  background: #152339;
  color: var(--text);
  padding: 0.55rem 0.65rem;
  border-radius: 8px;
  cursor: pointer;
}

button:hover {
  background: #1a2e4a;
}

.stage {
  position: relative;
  min-height: 0;
  overflow: hidden;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  cursor: grab;
  touch-action: none;
  user-select: none;
}

.tooltip {
  position: absolute;
  left: 0;
  top: 0;
  z-index: 3;
  pointer-events: none;
  transform: translate(-50%, calc(-100% - 10px));
  background: rgba(5, 10, 20, 0.9);
  border: 1px solid rgba(140, 190, 255, 0.4);
  border-radius: 8px;
  padding: 0.45rem 0.55rem;
  color: #eaf2ff;
  font-size: 0.78rem;
  line-height: 1.25;
  white-space: nowrap;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.35);
}

@media (max-width: 900px) {
  .app {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(220px, 42vh) 1fr;
  }

  .panel {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .stage {
    min-height: 0;
  }
}