:root {
  --bg: #07070f;
  --bg-panel: #0c0d1bcc;
  --line: #23243f;
  --line-soft: #1a1b30;
  --text: #e4e6f7;
  --text-dim: #9a9dc4;
  --text-faint: #5c5f85;
  --accent: #8fd6ff;
  --accent-2: #b79cff;
  --hz-glow: #6ee7b7;
  --font-display: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --font-mono: "IBM Plex Mono", "SF Mono", "Cascadia Code", Consolas, monospace;
  --font-ui: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0; height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  overflow: hidden;
}

body {
  background-image:
    radial-gradient(1px 1px at 12% 18%, #ffffff55, transparent),
    radial-gradient(1px 1px at 78% 42%, #ffffff44, transparent),
    radial-gradient(1.5px 1.5px at 34% 68%, #ffffff33, transparent),
    radial-gradient(1px 1px at 91% 82%, #ffffff40, transparent),
    radial-gradient(1px 1px at 55% 12%, #ffffff33, transparent),
    radial-gradient(1.5px 1.5px at 22% 88%, #ffffff2e, transparent);
  background-repeat: no-repeat;
}

.stage {
  display: flex;
  height: 100vh;
  width: 100vw;
}

.viz-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* ---------- Top bar ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 16px 22px 10px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 9px;
  flex-shrink: 0;
}

.brand-mark {
  font-size: 15px;
  color: var(--accent);
  opacity: 0.85;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 15.5px;
  letter-spacing: 0.22em;
  color: var(--text);
  font-style: italic;
}

.system-picker {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.sys-tab {
  background: none;
  border: 1px solid var(--line);
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.03em;
  padding: 6px 11px;
  border-radius: 3px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}

.sys-tab:hover { border-color: var(--accent); color: var(--text); }

.sys-tab.active {
  border-color: var(--accent);
  color: var(--bg);
  background: var(--accent);
  font-weight: 600;
}

/* ---------- System intro ---------- */

.system-intro {
  padding: 2px 24px 10px;
  max-width: 900px;
}

.system-intro h1 {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 500;
  font-size: 22px;
  margin: 0 0 3px;
  color: var(--text);
}

.system-intro .sys-meta {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  margin: 0 0 6px;
}

.system-intro p.desc {
  font-size: 13px;
  line-height: 1.55;
  color: var(--text-dim);
  margin: 0;
}

/* ---------- Orbit stage ---------- */

.orbit-stage {
  flex: 1;
  position: relative;
  min-height: 0;
  margin: 4px 10px 0;
}

#orbit-svg { display: block; width: 100%; height: 100%; }

.stage-caption {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-faint);
  letter-spacing: 0.05em;
  pointer-events: none;
  text-align: center;
}

/* Orbit path lines */
.orbit-path {
  fill: none;
  stroke-width: 1;
  opacity: 0.55;
}

.orbit-path.selected {
  stroke-width: 2;
  opacity: 0.95;
}

.orbit-hit {
  fill: none;
  stroke: transparent;
  stroke-width: 14;
  cursor: pointer;
}

.planet-dot {
  cursor: pointer;
  stroke: #05060c;
  stroke-width: 1;
}

.planet-dot.selected {
  stroke: var(--accent);
  stroke-width: 2;
}

.planet-label {
  font-family: var(--font-mono);
  font-size: 10px;
  fill: var(--text-dim);
  text-anchor: middle;
  pointer-events: none;
}

.planet-label.selected { fill: var(--accent); font-weight: 600; }

.trail-path {
  fill: none;
  stroke: var(--accent);
  stroke-width: 1;
  opacity: 0.35;
}

/* ---------- Controls bar ---------- */

.controls-bar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 22px 16px;
  flex-wrap: wrap;
}

.ctl-btn {
  width: 30px; height: 30px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: #10112699;
  color: var(--text);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: border-color 0.15s;
}

.ctl-btn:hover { border-color: var(--accent); }

.speed-group { display: flex; gap: 3px; }

.speed-btn {
  background: none;
  border: 1px solid var(--line-soft);
  color: var(--text-faint);
  font-family: var(--font-mono);
  font-size: 10.5px;
  padding: 5px 9px;
  border-radius: 3px;
  cursor: pointer;
}

.speed-btn:hover { color: var(--text-dim); }

.speed-btn.active {
  border-color: var(--accent-2);
  color: var(--accent-2);
}

.hz-toggle {
  display: flex; align-items: center; gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-dim);
  cursor: pointer;
  user-select: none;
}

.hz-toggle input { accent-color: var(--hz-glow); }

.scale-note {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-faint);
}

/* ---------- Info panel ---------- */

.info-panel {
  width: 340px;
  flex-shrink: 0;
  border-left: 1px solid var(--line);
  background: var(--bg-panel);
  backdrop-filter: blur(6px);
  overflow-y: auto;
  padding: 24px 20px 40px;
  position: relative;
}

.info-close-btn {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: #10112699;
  color: var(--text-dim);
  font-size: 18px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

.info-close-btn:hover {
  border-color: var(--accent);
  color: var(--text);
}

.info-empty {
  color: var(--text-faint);
  font-size: 13px;
  padding-top: 40vh;
  text-align: center;
}

.planet-name {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 21px;
  margin: 0 0 3px;
  padding-right: 34px;
}

.official-name {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--accent-2);
  letter-spacing: 0.03em;
  margin: 0 0 12px;
}

.planet-kind-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  padding: 3px 8px;
  border-radius: 2px;
  border: 1px solid var(--accent);
  color: var(--accent);
  margin-bottom: 14px;
}

.planet-kind-badge.hz-badge {
  border-color: var(--hz-glow);
  color: var(--hz-glow);
}

.info-section { margin-top: 18px; padding-top: 12px; border-top: 1px dashed var(--line-soft); }
.info-section:first-of-type { margin-top: 0; border-top: none; padding-top: 0; }
.info-section h3 {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.09em;
  color: var(--text-faint);
  text-transform: uppercase;
  margin: 0 0 8px;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  font-size: 12.5px;
  padding: 4px 0;
  border-bottom: 1px dashed var(--line-soft);
}

.stat-row .k { color: var(--text-dim); white-space: nowrap; }
.stat-row .v { font-family: var(--font-mono); color: var(--text); text-align: right; }

.hz-note {
  font-size: 12px;
  line-height: 1.55;
  color: var(--text-dim);
  margin: 0;
}

.hz-note.in-zone { color: var(--hz-glow); }

@media (max-width: 860px) {
  .stage { flex-direction: column; height: auto; overflow-y: auto; }
  .info-panel { width: 100%; border-left: none; border-top: 1px solid var(--line); }
  .orbit-stage { height: 55vh; }
}