* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  overflow: hidden; background: #0d1117;
  font-family: system-ui, -apple-system, sans-serif;
  display: flex; height: 100vh;
}

/* ── Sidebar ────────────────────────────────── */
#sidebar {
  width: 252px; min-width: 252px;
  background: #161b22; border-right: 1px solid #30363d;
  display: flex; flex-direction: column; height: 100vh;
  z-index: 10; overflow: hidden;
  transition: width 0.22s ease, min-width 0.22s ease;
}
#sidebar.collapsed { width: 0; min-width: 0; }

/* Sidebar collapse toggle — floats on canvas left edge */
#sidebar-toggle {
  position: absolute; left: 0; top: 50%;
  transform: translateY(-50%);
  z-index: 20; width: 18px; height: 48px;
  background: rgba(22,27,34,0.92);
  border: 1px solid #30363d; border-left: none;
  border-radius: 0 5px 5px 0;
  color: #484f58; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 9px; padding: 0;
  transition: color 0.12s, background 0.12s, opacity 0.12s;
}
#sidebar-toggle:hover { color: #8b949e; background: rgba(33,38,45,0.97); }
.toggle-arrow { display: inline-block; transition: transform 0.22s ease; }
.sec-hdr {
  padding: 12px 14px 7px;
  font-size: 10px; font-weight: 700; letter-spacing: 0.10em;
  color: #6e7681; text-transform: uppercase; flex-shrink: 0;
  border-bottom: 1px solid #21262d;
}

#lib-search-wrap {
  padding: 7px 7px 6px; flex-shrink: 0;
}
#lib-search {
  width: 100%; background: #0d1117; border: 1px solid #30363d;
  border-radius: 6px; padding: 6px 9px; font-size: 11px; color: #c9d1d9;
  outline: none; font-family: inherit;
  transition: border-color 0.12s;
}
#lib-search::placeholder { color: #484f58; }
#lib-search:focus { border-color: #388bfd; }

/* Scrollable library panel */
#lib-panel {
  flex: 1; min-height: 0; overflow-y: auto; padding: 2px 0 4px;
}
#lib-panel::-webkit-scrollbar { width: 4px; }
#lib-panel::-webkit-scrollbar-track { background: transparent; }
#lib-panel::-webkit-scrollbar-thumb { background: #30363d; border-radius: 2px; }

/* Category groups */
.lib-cat { border-top: 1px solid #21262d; }
.lib-cat:first-child { border-top: none; }
.lib-cat-hdr {
  display: flex; align-items: center; gap: 5px;
  padding: 6px 9px 6px 10px; cursor: pointer; user-select: none;
  font-size: 10px; font-weight: 700; letter-spacing: 0.07em;
  color: #b0bec5; text-transform: uppercase;
  transition: color 0.12s, background 0.12s;
}
.lib-cat-hdr:hover { color: #e6edf3; background: rgba(255,255,255,0.04); }
.lib-cat-arrow {
  font-size: 8px; color: #6e7681; flex-shrink: 0;
  transition: transform 0.18s; display: inline-block;
}
.lib-cat.collapsed .lib-cat-arrow { transform: rotate(-90deg); }
.lib-cat-name { flex: 1; }
.lib-cat-count {
  font-size: 9px; font-weight: 700; color: #6e7681;
  background: #21262d; border: 1px solid #30363d;
  border-radius: 8px; padding: 0px 5px; flex-shrink: 0;
}
.lib-cat-body { overflow: hidden; }
.lib-cat.collapsed .lib-cat-body { display: none; }

/* 3-column grid inside categories */
.lib-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 4px; padding: 2px 6px 8px;
}

/* Card in grid mode — vertical layout */
.lib-grid .part-card {
  flex-direction: column; align-items: center;
  padding: 7px 3px 6px; gap: 4px; text-align: center;
}
.lib-grid .part-icon { width: 30px; height: 30px; }

/* Shared card styles */
.part-card {
  background: #1c2128; border: 1px solid #30363d; border-radius: 7px;
  cursor: grab; user-select: none;
  display: flex; align-items: center; gap: 9px;
  transition: background 0.12s, border-color 0.12s;
}
.part-card:hover   { background: #21262d; border-color: #58a6ff; transform: translateY(-1px); box-shadow: 0 3px 8px rgba(0,0,0,0.35); }
.part-card:active  { cursor: grabbing; transform: none; box-shadow: none; }
.part-card.dragging { opacity: 0.38; }
.part-card.soon    { opacity: 0.28; cursor: not-allowed; pointer-events: none; }
.part-icon {
  width: 36px; height: 36px; border-radius: 5px; flex-shrink: 0;
  background: #0d1117; border: 1px solid #21262d;
  display: flex; align-items: center; justify-content: center;
}
.part-name { font-size: 10px; font-weight: 700; color: #e6edf3; line-height: 1.3; }
.part-desc { font-size: 10px; color: #6e7681; margin-top: 1px; line-height: 1.4; }

/* No-results message */
#lib-no-results {
  display: none; padding: 20px 14px;
  font-size: 11px; color: #484f58; text-align: center;
}

/* ── Sidebar tabs ──────────────────────────────── */
#sidebar-tabs {
  display: flex; flex-shrink: 0;
  border-bottom: 1px solid #21262d;
}
.sb-tab {
  flex: 1; background: transparent; border: none;
  border-bottom: 2px solid transparent;
  color: #6e7681; font-size: 11px; font-weight: 600;
  padding: 8px 4px; cursor: pointer;
  transition: color 0.12s, border-color 0.12s;
  font-family: inherit;
}
.sb-tab:hover { color: #c9d1d9; }
.sb-tab.active { color: #e6edf3; border-bottom-color: #58a6ff; }
#placed-badge {
  font-size: 9px; font-weight: 700; color: #484f58;
  background: #21262d; border: 1px solid #30363d;
  border-radius: 8px; padding: 0px 5px; display: inline-block;
}
.sb-tab.active #placed-badge { color: #79c0ff; border-color: #1a3a5c; background: #0d1e2e; }

/* ── Tab panel containers ───────────────────────── */
.sb-panel { display: none; flex: 1; flex-direction: column; min-height: 0; overflow: hidden; }
.sb-panel.active { display: flex; }

/* ── Library tools bar ──────────────────────────── */
#lib-tools {
  display: flex; align-items: center; gap: 4px;
  padding: 5px 8px 5px 10px; flex-shrink: 0;
  border-bottom: 1px solid #21262d;
}
.lib-tools-label {
  flex: 1; font-size: 10px; font-weight: 700;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: #8b949e;
}
.lib-tools-actions { display: flex; gap: 3px; }
.lib-tools-actions button {
  background: #21262d; border: 1px solid #30363d;
  color: #8b949e; border-radius: 4px;
  width: 22px; height: 22px; font-size: 10px;
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  line-height: 1; padding: 0; font-family: inherit;
  transition: background 0.12s, color 0.12s;
}
.lib-tools-actions button:hover { background: #2d333b; color: #e6edf3; border-color: #8b949e; }

/* ── Placed panel ───────────────────────────────── */
#placed-panel-wrap { background: #161b22; }
#placed-list {
  padding: 5px 6px 6px; display: flex; flex-direction: column;
  gap: 3px; overflow-y: auto; flex: 1;
}
#placed-list::-webkit-scrollbar { width: 4px; }
#placed-list::-webkit-scrollbar-track { background: transparent; }
#placed-list::-webkit-scrollbar-thumb { background: #30363d; border-radius: 2px; }
#placed-empty {
  padding: 20px 12px; font-size: 11px; color: #484f58;
  text-align: center; line-height: 1.6;
}
.placed-item {
  background: #1c2128; border: 1px solid #30363d; border-radius: 6px;
  padding: 7px 9px; cursor: pointer; user-select: none;
  display: flex; align-items: center; gap: 7px;
  transition: background 0.12s, border-color 0.12s;
}
.placed-item:hover { background: #21262d; border-color: #484f58; }
.placed-item.selected { border-color: #58a6ff; background: #122030; }
.pi-name[contenteditable="true"] {
  outline: none; border-bottom: 1px solid #388bfd;
  cursor: text; border-radius: 2px; padding: 0 2px;
  background: rgba(56,139,253,0.08);
}
.pi-num {
  font-size: 9px; font-weight: 700; padding: 1px 4px; border-radius: 3px;
  background: #21262d; color: #6e7681; flex-shrink: 0;
}
.placed-item.selected .pi-num { background: #1a3a5c; color: #79c0ff; }
.pi-name { font-size: 11px; color: #c9d1d9; }
.placed-item.selected .pi-name { color: #e6edf3; }

/* ── Canvas ──────────────────────────────────── */
#canvas-wrap { flex: 1; position: relative; height: 100vh; overflow: hidden; }
#canvas-wrap canvas { display: block; }

#drop-overlay {
  pointer-events: none; display: none;
  position: absolute; inset: 0; z-index: 5;
  border: 2px dashed #58a6ff; background: rgba(88,166,255,0.05);
  align-items: center; justify-content: center;
}
#drop-overlay.active { display: flex; }
#drop-overlay span {
  color: #58a6ff; font-size: 16px; font-weight: 600;
  background: rgba(13,17,23,0.9); padding: 10px 24px; border-radius: 9px;
}
#empty-hint {
  position: absolute; inset: 0; pointer-events: none;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 10px;
}
#empty-hint .arrow { font-size: 34px; color: #21262d; animation: float 2.2s ease-in-out infinite; }
#empty-hint .text  { font-size: 13px; color: #3d444d; }
@keyframes float { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-6px)} }

/* Controls panel */
#controls {
  display: none; position: absolute; top: 14px; right: 14px;
  z-index: 10; flex-direction: column; gap: 6px;
}
#controls.visible { display: flex; }
#sel-label {
  background: rgba(22,27,34,0.93); border: 1px solid #30363d; border-radius: 7px;
  padding: 6px 12px; color: #6e7681; font-size: 11px; text-align: center;
}
#sel-label.active { color: #58a6ff; border-color: #1a3a5c; background: rgba(18,32,48,0.95); }
.btn {
  color: #e6edf3; border-radius: 7px; padding: 7px 14px;
  font-size: 12px; font-weight: 600; cursor: pointer; border: 1px solid;
  transition: background 0.14s, opacity 0.14s; min-width: 130px; text-align: center;
}
.btn:disabled { opacity: 0.30; cursor: not-allowed; }
#add-btn  { background: #238636; border-color: #3fb950; }
#add-btn:hover:not(:disabled) { background: #2ea043; }
#divL-btn { background: #6d28d9; border-color: #a78bfa; }
#divL-btn:hover:not(:disabled) { background: #7c3aed; }
#divR-btn { background: #1d4ed8; border-color: #60a5fa; }
#divR-btn:hover:not(:disabled) { background: #2563eb; }
#str-btn  { background: #065f46; border-color: #34d399; }
#str-btn:hover:not(:disabled)  { background: #047857; }
#divert-group { display: flex; flex-direction: column; gap: 5px; }
#edit-group, #save-group { display: flex; flex-direction: column; gap: 5px; }
#undo-btn, #redo-btn { background: #1c2128; border-color: #484f58; }
#undo-btn:hover:not(:disabled), #redo-btn:hover:not(:disabled) { background: #21262d; border-color: #8b949e; }
#del-btn  { background: #6e1212; border-color: #f85149; }
#del-btn:hover:not(:disabled)  { background: #8b1a1a; }
#stats {
  background: rgba(22,27,34,0.90); border: 1px solid #30363d; border-radius: 7px;
  padding: 6px 12px; color: #6e7681; font-size: 10px; line-height: 2.0;
  font-variant-numeric: tabular-nums; font-family: ui-monospace, monospace;
}
#stats b { color: #79c0ff; font-weight: 700; }
#hint {
  position: absolute; bottom: 11px; left: 50%; transform: translateX(-50%);
  color: #3d444d; font-size: 11px; pointer-events: none; white-space: nowrap;
}

/* Sim speed group */
.grp-label {
  font-size: 9px; font-weight: 700; color: #6e7681;
  text-transform: uppercase; letter-spacing: 0.08em;
}
#speed-group { display: flex; flex-direction: column; gap: 4px; }
#speed-btns { display: flex; gap: 4px; }
.spd-btn {
  flex: 1; background: #1c2128; border: 1px solid #30363d;
  color: #8b949e; border-radius: 6px; padding: 5px 0;
  font-size: 11px; font-weight: 700; cursor: pointer;
  transition: background 0.12s, border-color 0.12s, color 0.12s;
}
.spd-btn:hover { background: #21262d; border-color: #8b949e; color: #e6edf3; }
.spd-btn.active { background: #0d419d; border-color: #388bfd; color: #ffffff; }

/* Swivel exit selector */
#exit-group { display: flex; flex-direction: column; gap: 4px; }
#exit-btns  { display: flex; gap: 4px; }

/* Belt speed group */
#belt-speed-group { display: flex; flex-direction: column; gap: 4px; }
#belt-speed-row {
  display: flex; align-items: center; gap: 6px;
  background: rgba(22,27,34,0.90); border: 1px solid #30363d;
  border-radius: 7px; padding: 5px 10px;
}
#belt-speed { flex: 1; accent-color: #388bfd; cursor: pointer; }
#belt-speed-val { font-size: 10px; color: #79c0ff; flex-shrink: 0; min-width: 52px; text-align: right; }

/* Tote size group */
#tote-size-group { display: flex; flex-direction: column; gap: 4px; }
#tote-size-btns  { display: flex; gap: 4px; }

/* Zone length group */
#zone-len-group { display: flex; flex-direction: column; gap: 4px; }
#zone-len-btns  { display: flex; gap: 3px; flex-wrap: wrap; }
#zone-len-btns .spd-btn { font-size: 10px; padding: 5px 0; }

/* Zone PE sensors */
#zone-sensors-group { flex-direction: column; gap: 5px; }
#zone-sensors-list  { display: flex; flex-direction: column; gap: 4px; }
.zone-sensor-row {
  display: flex; align-items: center; gap: 6px;
}
.zone-sensor-lbl {
  font-size: 10px; font-weight: 700; color: #6e7681;
  background: #21262d; border-radius: 3px; padding: 2px 5px;
  flex-shrink: 0; min-width: 22px; text-align: center;
}
.zone-pe-btn {
  flex: 1; font-size: 10px; padding: 5px 8px;
  background: #1c2128; border-color: #484f58;
  min-width: unset;
}
.zone-pe-btn:hover { background: #21262d; border-color: #8b949e; }

/* Auto-spawn group */
#spawn-outer { display: flex; flex-direction: column; gap: 5px; }
#spawn-toggle { background: #1c2128; border-color: #484f58; }
#spawn-toggle:hover { background: #21262d; border-color: #8b949e; }
#spawn-toggle.spawning { background: #5a1d1d; border-color: #f85149; }
#spawn-rate-row {
  display: flex; align-items: center; gap: 6px;
  background: rgba(22,27,34,0.90); border: 1px solid #30363d;
  border-radius: 7px; padding: 5px 10px;
}
.rate-label { font-size: 10px; color: #6e7681; flex-shrink: 0; }
#spawn-rate { flex: 1; accent-color: #388bfd; cursor: pointer; }
#spawn-rate-val { font-size: 10px; color: #79c0ff; flex-shrink: 0; min-width: 44px; text-align: right; }

/* ── Multi-page layout ───────────────────────────────── */
body.builder-layout, body.sim-layout {
  flex-direction: column;
}
.builder-main {
  flex: 1; display: flex; overflow: hidden; min-height: 0;
}
/* Override 100vh heights set on sidebar/canvas — in builder/sim layouts
   these live inside .builder-main whose height is already correct */
body.builder-layout #sidebar,
body.builder-layout #canvas-wrap,
body.sim-layout #sidebar,
body.sim-layout #canvas-wrap {
  height: 100%;
}

/* ── App header (builder + simulation) ──────────────── */
#app-header {
  height: 44px; min-height: 44px; flex-shrink: 0;
  background: #161b22; border-bottom: 1px solid #30363d;
  display: flex; align-items: center; padding: 0 14px; gap: 10px; z-index: 20;
}
.app-logo {
  font-size: 14px; font-weight: 800; color: #58a6ff;
  text-decoration: none; letter-spacing: 0.05em;
}
.app-logo span { color: #6e7681; font-weight: 600; }
#project-name-text {
  font-size: 13px; color: #e6edf3; font-weight: 500;
  background: transparent; border: none; outline: none;
  cursor: text; min-width: 120px; max-width: 280px;
  border-bottom: 1px solid transparent; padding: 1px 2px;
  font-family: inherit;
}
#project-name-text:not([readonly]):focus { border-bottom-color: #388bfd; }
#project-name-text[readonly] { cursor: default; color: #8b949e; }
#unsaved-dot {
  font-size: 14px; color: #e3b341; display: none; line-height: 1;
}
.hdr-spacer { flex: 1; }
.hdr-btn {
  background: #21262d; border: 1px solid #30363d; color: #e6edf3;
  border-radius: 6px; padding: 5px 13px; font-size: 12px; font-weight: 600;
  cursor: pointer; transition: background 0.12s, border-color 0.12s; white-space: nowrap;
}
.hdr-btn:hover { background: #2d333b; border-color: #8b949e; }
.hdr-btn-sim  { background: #238636; border-color: #3fb950; }
.hdr-btn-sim:hover  { background: #2ea043; }
.hdr-btn-stop { background: #6e1212; border-color: #f85149; }
.hdr-btn-stop:hover { background: #8b1a1a; }
.hdr-btn-save { background: #0d2d4a; border-color: #388bfd; }
.hdr-btn-save:hover { background: #1158a7; }
.hdr-btn-load { background: #0d2d1e; border-color: #3fb950; cursor: pointer; }
.hdr-btn-load:hover { background: #1a4731; }
.hdr-btn-logout { background: #1c2128; border-color: #30363d; }
.hdr-btn-logout:hover { background: #6e1212; border-color: #f85149; color: #f85149; }
#sim-clock {
  font-size: 12px; font-weight: 700; color: #79c0ff;
  font-variant-numeric: tabular-nums; letter-spacing: 0.05em;
  background: rgba(22,27,34,0.90); border: 1px solid #30363d;
  border-radius: 5px; padding: 3px 9px;
}
#sim-status {
  font-size: 11px; font-weight: 600; color: #3fb950;
}

/* ── Settings / generic modal ───────────────────────── */
.modal-overlay {
  display: none; position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,0.72); align-items: center; justify-content: center;
}
.modal-overlay.open { display: flex; }
.modal-box {
  background: #161b22; border: 1px solid #30363d; border-radius: 12px;
  min-width: 320px; max-width: 440px; width: 100%;
  box-shadow: 0 24px 48px rgba(0,0,0,0.65);
}
.modal-hdr {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 18px 10px; border-bottom: 1px solid #21262d;
}
.modal-hdr-title { font-size: 13px; font-weight: 700; color: #e6edf3; }
.modal-close-btn {
  background: none; border: none; color: #6e7681; cursor: pointer;
  font-size: 16px; padding: 2px 7px; border-radius: 4px; line-height: 1;
}
.modal-close-btn:hover { color: #e6edf3; background: #21262d; }
.modal-body { padding: 14px 18px; display: flex; flex-direction: column; gap: 14px; }
.modal-footer {
  padding: 10px 18px 14px; border-top: 1px solid #21262d;
  display: flex; justify-content: flex-end;
}
.modal-apply-btn {
  background: #238636; border: 1px solid #3fb950; color: #fff;
  border-radius: 6px; padding: 7px 20px; font-size: 12px; font-weight: 600;
  cursor: pointer; transition: background 0.12s;
}
.modal-apply-btn:hover { background: #2ea043; }

/* ── Sim-only controls ───────────────────────────────── */
#sim-controls-group { display: flex; flex-direction: column; gap: 5px; }
#pause-sim-btn  { background: #0d2d4a; border-color: #388bfd; }
#pause-sim-btn:hover:not(:disabled)  { background: #1158a7; }
#resume-sim-btn { background: #238636; border-color: #3fb950; }
#resume-sim-btn:hover:not(:disabled) { background: #2ea043; }

/* ── Home page ──────────────────────────────────────── */
body.home-layout {
  align-items: center; justify-content: center; flex-direction: column;
  gap: 0; background: #0d1117;
}
#home-wrap {
  display: flex; flex-direction: column; align-items: center; gap: 0;
  text-align: center;
}
.home-logo {
  font-size: 48px; font-weight: 900; color: #58a6ff;
  letter-spacing: 0.04em; line-height: 1;
}
.home-logo span { color: #30363d; }
.home-sub {
  font-size: 15px; font-weight: 500; color: #8b949e;
  margin-top: 10px; margin-bottom: 40px;
  letter-spacing: 0.02em;
}
.home-btns { display: flex; flex-direction: column; gap: 10px; width: 260px; }
.home-btn {
  padding: 13px 0; font-size: 14px; font-weight: 700;
  border-radius: 8px; cursor: pointer; border: 1px solid;
  transition: background 0.14s; text-align: center; display: block;
  color: #e6edf3; text-decoration: none;
}
.home-btn-primary { background: #238636; border-color: #3fb950; }
.home-btn-primary:hover { background: #2ea043; }
.home-btn-secondary { background: #1c2128; border-color: #30363d; }
.home-btn-secondary:hover { background: #21262d; border-color: #8b949e; }