/* ── Reset & base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:          #0f0f19;
  --bg2:         #14141f;
  --bg3:         #1a1a2e;
  --border:      #2a2a42;
  --text:        #c8c8dc;
  --text-dim:    #6a6a88;
  --gold:        #ffdc32;
  --cyan:        #50c8c8;
  --green:       #50c878;
  --red:         #ff6b6b;
  --accent:      #7070ff;
  --radius:      8px;
}

html, body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, sans-serif;
  font-size: 14px;
  min-height: 100vh;
}

/* ── Header ── */
header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 24px;
  border-bottom: 1px solid var(--border);
  background: var(--bg2);
}

header h1 {
  font-size: 20px;
  font-weight: 700;
  color: var(--gold);
  letter-spacing: 0.04em;
}

.subtitle {
  color: var(--text-dim);
  font-size: 13px;
  flex: 1;
}

.badge {
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 99px;
  font-weight: 600;
}
.badge.connected    { background: #1a3a1a; color: var(--green); border: 1px solid var(--green); }
.badge.disconnected { background: #3a1a1a; color: var(--red);   border: 1px solid var(--red); }

/* ── Main layout ── */
main {
  display: flex;
  gap: 16px;
  padding: 16px 24px;
  align-items: flex-start;
}

/* ── Arena section ── */
.arena-section {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex-shrink: 0;
}

.canvas-wrapper {
  position: relative;
  line-height: 0;
}

#arena {
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  inset: 0;
  background: rgba(10, 10, 20, 0.6);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  transition: opacity 0.3s;
}
.overlay.hidden { opacity: 0; }

.overlay-text {
  font-size: 22px;
  font-weight: 600;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* ── HUD bar ── */
.hud {
  display: flex;
  gap: 6px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 14px;
}

.hud-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
}

.hud-label {
  font-size: 10px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.hud-val {
  font-size: 16px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}

/* ── Controls sidebar ── */
.controls {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  width: 220px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.btn-primary {
  width: 100%;
  padding: 10px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
}
.btn-primary:hover:not(:disabled) { background: #8888ff; }
.btn-primary:active:not(:disabled) { transform: scale(0.97); }
.btn-primary:disabled { background: var(--bg3); color: var(--text-dim); cursor: not-allowed; }
.btn-primary.running { background: #7a2020; }
.btn-primary.running:hover:not(:disabled) { background: #a03030; }

.divider {
  height: 1px;
  background: var(--border);
}

.param-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.param-label {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: var(--text);
}

.param-val {
  color: var(--gold);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  cursor: pointer;
}

.param-hint {
  font-size: 11px;
  color: var(--text-dim);
}

.change-note {
  font-size: 11px;
  color: var(--text-dim);
  font-style: italic;
}

/* ── Legend ── */
.legend {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-dim);
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  flex-shrink: 0;
}
.dot.alpha  { background: #ffff64; border: 2px solid #ffd700; }
.dot.normal { background: #50c878; border: 2px solid #fff; }

.block.obs {
  width: 14px;
  height: 10px;
  border-radius: 2px;
  background: #3c3c50;
  border: 1px solid #50506e;
  flex-shrink: 0;
}

/* ── Fitness graph ── */
.graph-section {
  padding: 0 24px 24px;
}

.graph-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.graph-title {
  font-size: 13px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.graph-legend {
  display: flex;
  gap: 16px;
  font-size: 12px;
}
.gl-item.gold { color: var(--gold); }
.gl-item.cyan { color: var(--cyan); }

#graph {
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 100%;
  height: auto;
}

/* ── Responsive ── */
@media (max-width: 1100px) {
  main { flex-direction: column; align-items: stretch; }
  .controls { width: 100%; flex-direction: row; flex-wrap: wrap; gap: 12px; }
  .controls .btn-primary { width: auto; min-width: 120px; }
  .controls .divider { display: none; }
}