/* ═══════════════════════════════════════════
   LAYOUT — Topbar, App, Main
═══════════════════════════════════════════ */

/* ── Topbar ── */
#topbar {
  height: var(--topbar-h);
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  padding: 0 var(--sp-4);
  gap: var(--sp-3);
  flex-shrink: 0;
  z-index: 200;
  position: relative;
  backdrop-filter: blur(12px);
}

.logo {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.5px;
  user-select: none;
  flex-shrink: 0;
}
.logo-text {
  background: linear-gradient(135deg, #a5b4fc 0%, #818cf8 50%, #6366f1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.logo-accent {
  color: var(--accent-cyan);
  -webkit-text-fill-color: var(--accent-cyan);
}

.topbar-meta {
  display: flex;
  gap: var(--sp-2);
  align-items: center;
}

.topbar-actions {
  margin-left: auto;
  display: flex;
  gap: var(--sp-1);
  align-items: center;
}

/* ── App Layout ── */
#app {
  display: flex;
  flex: 1;
  overflow: hidden;
  position: relative;
}

/* ── Main ── */
#main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-width: 0;
  background: var(--bg-base);
}

/* ── Algo Header ── */
#algo-header {
  height: 56px;
  padding: 0 var(--sp-6);
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
  background: var(--bg-panel);
}

.algo-title-group { flex: 1; min-width: 0; }

#algo-title {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.3px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

#algo-subtitle {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 1px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.complexity-badges {
  display: flex;
  gap: var(--sp-2);
  flex-shrink: 0;
}

.cmplx-badge {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  padding: 3px 9px;
  border-radius: var(--r-sm);
  border: 1px solid;
  white-space: nowrap;
}
.cmplx-time  { color: #a78bfa; border-color: rgba(167,139,250,0.35); background: rgba(167,139,250,0.08); }
.cmplx-space { color: #67e8f9; border-color: rgba(103,232,249,0.3);  background: rgba(103,232,249,0.06); }
.cmplx-best  { color: #6ee7b7; border-color: rgba(110,231,183,0.3);  background: rgba(110,231,183,0.06); }

/* ── Canvas Area ── */
#canvas-area {
  flex: 1;
  position: relative;
  overflow: hidden;
  background: var(--bg-base);
}

#canvas-area::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 15% 50%, rgba(99,102,241,0.06) 0%, transparent 55%),
    radial-gradient(ellipse at 85% 50%, rgba(34,211,238,0.04) 0%, transparent 55%);
  pointer-events: none;
  z-index: 0;
}

#main-canvas {
  display: block;
  width: 100%;
  height: 100%;
  position: relative;
  z-index: 1;
}

#canvas-overlay {
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
}

.canvas-hint {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 12px;
  color: var(--text-muted);
  background: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  border-radius: var(--r-full);
  padding: 5px 14px;
  pointer-events: none;
  z-index: 3;
  white-space: nowrap;
  transition: opacity 0.3s;
}
.canvas-hint.hidden { opacity: 0; }

/* ── Canvas Overlay Controls ── */
.canvas-toolbar {
  position: absolute;
  top: 12px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: var(--sp-2);
  background: var(--bg-panel);
  border: 1px solid var(--border-default);
  border-radius: var(--r-lg);
  padding: var(--sp-2);
  pointer-events: all;
  z-index: 4;
  box-shadow: var(--shadow-md);
}

.canvas-tool-btn {
  padding: 5px 12px;
  border-radius: var(--r-sm);
  border: 1px solid transparent;
  background: none;
  color: var(--text-secondary);
  font-size: 11px;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--t-fast) var(--ease);
  white-space: nowrap;
}
.canvas-tool-btn:hover { background: var(--bg-hover); color: var(--text-primary); }
.canvas-tool-btn.active {
  background: var(--accent-purple-dim);
  color: var(--text-accent);
  border-color: var(--border-accent);
}

/* ── Status Bar ── */
#status-bar {
  height: var(--statusbar-h);
  background: var(--bg-panel);
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-4);
  flex-shrink: 0;
  z-index: 10;
}

.status-left  { display: flex; align-items: center; gap: var(--sp-2); }
.status-right { font-family: var(--font-mono); font-size: 10px; color: var(--text-muted); }

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--text-muted);
  flex-shrink: 0;
  transition: background var(--t-base);
}
.status-dot.ready   { background: var(--text-muted); }
.status-dot.running { background: var(--accent-amber); animation: pulse-dot 1s infinite; }
.status-dot.paused  { background: var(--accent-amber); }
.status-dot.done    { background: var(--accent-emerald); }

#status-text { font-size: 12px; color: var(--text-secondary); }

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

/* ── Compare Overlay ── */
#compare-overlay {
  position: fixed;
  inset: var(--topbar-h) 0 var(--statusbar-h) 0;
  background: var(--bg-base);
  z-index: 500;
  display: flex;
  flex-direction: column;
}
#compare-canvases {
  flex: 1;
  display: flex;
  overflow: hidden;
}
.compare-pane {
  flex: 1;
  position: relative;
  display: flex;
  flex-direction: column;
}
.compare-pane canvas { flex: 1; display: block; width: 100%; }
.compare-label {
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-panel);
  border-top: 1px solid var(--border-subtle);
  text-align: center;
}
.compare-divider {
  width: 1px;
  background: var(--border-default);
  flex-shrink: 0;
}