:root {
  --bg: #07111f;
  --panel: rgba(8, 18, 34, 0.76);
  --panel-border: rgba(154, 184, 255, 0.22);
  --text: #eef4ff;
  --muted: #9db0cc;
  --accent: #6fd3ff;
  --accent-2: #ffd977;
  --danger: #ff8a8a;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  overflow: hidden;
  background:
    radial-gradient(circle at top, rgba(49, 93, 173, 0.18), transparent 28%),
    radial-gradient(circle at 20% 80%, rgba(10, 146, 170, 0.14), transparent 30%),
    linear-gradient(180deg, #09121f 0%, #040811 100%);
  color: var(--text);
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

#scene {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  display: block;
}

.hud {
  position: fixed;
  inset: 0;
  pointer-events: none;
  padding: 20px;
  display: grid;
  grid-template-columns: minmax(280px, 420px) 1fr;
  grid-template-rows: auto auto 1fr auto;
  gap: 14px;
}

.panel {
  pointer-events: auto;
  padding: 16px 18px;
  border: 1px solid var(--panel-border);
  background: var(--panel);
  backdrop-filter: blur(14px);
  border-radius: 18px;
  box-shadow: 0 18px 60px rgba(0, 0, 0, 0.28);
}

.title-panel {
  grid-column: 1;
  grid-row: 1;
}

.stats-panel {
  grid-column: 1;
  grid-row: 2;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 16px;
}

.source-panel {
  grid-column: 1;
  grid-row: 3;
  align-self: start;
}

.controls-panel {
  grid-column: 1;
  grid-row: 4;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 12px;
}

h1 {
  margin: 0;
  font-size: clamp(28px, 3vw, 42px);
  line-height: 1.05;
}

.lede,
.source-panel p {
  margin: 10px 0 0;
  color: var(--muted);
  line-height: 1.5;
}

.stat span {
  display: block;
  color: var(--muted);
  font-size: 12px;
  margin-bottom: 4px;
}

.stat strong {
  font-size: 15px;
  font-weight: 700;
}

button {
  appearance: none;
  border: 1px solid rgba(145, 189, 255, 0.32);
  background: linear-gradient(180deg, rgba(88, 149, 255, 0.24), rgba(19, 43, 78, 0.72));
  color: var(--text);
  border-radius: 999px;
  padding: 10px 14px;
  cursor: pointer;
  transition: transform 120ms ease, border-color 120ms ease, background 120ms ease;
}

button:hover {
  transform: translateY(-1px);
  border-color: rgba(186, 214, 255, 0.52);
}

#labels {
  position: fixed;
  inset: 0;
  pointer-events: none;
}

.target-label {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 6px;
  color: white;
  font-size: 13px;
  padding: 8px 11px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(4, 8, 15, 0.82);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.34);
  transform: translate(-50%, -50%);
  white-space: nowrap;
}

.earth-label .arrow {
  color: var(--accent);
}

.moon-label .arrow {
  color: var(--accent-2);
}

.ship-label .arrow {
  color: var(--danger);
}

@media (max-width: 900px) {
  .hud {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto auto;
    align-content: start;
  }

  .title-panel,
  .stats-panel,
  .source-panel,
  .controls-panel {
    grid-column: 1;
    grid-row: auto;
  }

  .stats-panel {
    grid-template-columns: 1fr;
  }
}