body {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  grid-template-rows: var(--topbar-h) 1fr;
  grid-template-areas:
    "sidebar topbar"
    "sidebar main";
  height: 100vh;
}

.sidebar {
  grid-area: sidebar;
  background: var(--bg-2);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
  transition: margin-left var(--t-mid);
}
body.sidebar-collapsed .sidebar { margin-left: calc(-1 * var(--sidebar-w)); }
body.sidebar-collapsed { grid-template-columns: 0 1fr; }

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  font-weight: 600;
}
.brand .logo { color: var(--accent); font-size: 18px; }
.brand-name { letter-spacing: .2px; }

.vtabs {
  display: flex;
  flex-direction: column;
  padding: 8px;
  gap: 2px;
  border-bottom: 1px solid var(--line);
}
.vtabs button {
  background: transparent;
  border: 1px solid transparent;
  color: var(--fg-2);
  text-align: left;
  padding: 7px 10px;
  border-radius: var(--r-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
}
.vtabs button:hover { background: var(--bg-3); color: var(--fg); }
.vtabs button.active {
  background: var(--accent-soft);
  border-color: rgba(124,156,255,.25);
  color: var(--fg);
}
.vtabs .icn { width: 18px; text-align: center; }

.palette {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  align-content: start;
}
.palette-item {
  background: var(--bg-3);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  padding: 8px 10px;
  cursor: pointer;
  font-size: 13px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: border-color var(--t-fast), transform var(--t-fast);
}
.palette-item:hover { border-color: var(--accent); transform: translateY(-1px); }
.palette-item .pi-name { font-weight: 500; }
.palette-item .pi-meta { color: var(--fg-3); font-size: 11px; }

.sidebar-foot {
  border-top: 1px solid var(--line);
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 12px;
}
.link { color: var(--fg-2); }
.link:hover { color: var(--accent); text-decoration: none; }

.topbar {
  grid-area: topbar;
  background: var(--bg-2);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 14px;
}
.bp-switch {
  display: flex;
  background: var(--bg-3);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  padding: 2px;
}
.bp {
  background: transparent;
  border: none;
  color: var(--fg-2);
  padding: 4px 12px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 13px;
}
.bp:hover { color: var(--fg); }
.bp.active { background: var(--accent-2); color: white; }

.topbar-spacer { flex: 1; }
.topbar-actions { display: flex; align-items: center; gap: 8px; }
.hint {
  color: var(--fg-3);
  font-size: 12px;
  background: var(--bg-3);
  border: 1px solid var(--line);
  padding: 3px 8px;
  border-radius: 4px;
}

.main {
  grid-area: main;
  overflow: hidden;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 14px;
  background:
    radial-gradient(1200px 600px at 60% -10%, rgba(124,156,255,.06), transparent 60%),
    var(--bg);
}

.grid-frame {
  position: relative;
  width: 100%;
  height: 100%;
  max-width: var(--frame-max, 100%);
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-soft);
  overflow: auto;
  transition: max-width var(--t-mid);
}

.empty-hint {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  color: var(--fg-3);
  pointer-events: none;
}
.empty-hint.hidden { display: none; }

@media (max-width: 800px) {
  body { grid-template-columns: 0 1fr; }
  .sidebar { position: fixed; inset: var(--topbar-h) 0 0 0; width: var(--sidebar-w); z-index: 50; }
  body:not(.sidebar-open) .sidebar { transform: translateX(-100%); }
  body.sidebar-open .sidebar { transform: translateX(0); }
}