/* ═══════════════════════════════════════════════════════════════
   sm-layout.css — SenseMake.uk Shared Framework (optional)
   Sidebar + main canvas layout with collapsible sidebar
   
   Usage:
   <div class="sm-app-canvas">
     <div class="sm-layout">
       <div class="sm-sidebar" id="controls">...</div>
       <div class="sm-main" id="canvas">...</div>
     </div>
   </div>

   SM.layout.init() injects the collapse toggle as the first child of
   .sm-layout (sibling of .sm-sidebar) so it is not clipped when the
   sidebar is width:0 / overflow:hidden.

   The sidebar collapses to an icon strip on narrow screens or
   when the user clicks the collapse toggle.
   ═══════════════════════════════════════════════════════════════ */

/* ── Layout container ──────────────────────────────────────────── */
.sm-layout {
  position: relative;
  display: grid;
  grid-template-columns: var(--sm-sidebar-width, 260px) 1fr;
  height: 100%;
  gap: 1px;
  background: var(--sm-border);
}

/* ── Sidebar ───────────────────────────────────────────────────── */
.sm-sidebar {
  background: var(--sm-surface);
  padding: 14px 14px 60px;
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: relative;
  transition: width 0.25s ease, padding 0.25s ease;
}

.sm-sidebar-heading {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--sm-text-muted);
  margin: 0;
  user-select: none;
}

/* ── Collapse toggle button (sibling of sidebar, not inside it — avoids clipping) ─ */
.sm-sidebar-toggle {
  position: absolute;
  z-index: 50;
  top: 14px;
  left: calc(var(--sm-sidebar-width, 260px) - 36px);
  width: 26px;
  height: 26px;
  border: 1.5px solid var(--sm-border);
  border-radius: 6px;
  background: var(--sm-surface);
  color: var(--sm-text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  transition: background var(--sm-transition-fast), color var(--sm-transition-fast), transform 0.25s ease;
}
.sm-sidebar-toggle:hover {
  background: var(--sm-surface-raised);
  color: var(--sm-text);
}
.sm-sidebar-toggle svg {
  width: 14px;
  height: 14px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform 0.25s ease;
}

/* Rotated arrow when collapsed */
.sm-layout.collapsed .sm-sidebar-toggle svg {
  transform: rotate(180deg);
}

/* ── Collapsed state ───────────────────────────────────────────── */
.sm-layout.collapsed {
  grid-template-columns: 0px 1fr;
}
/* Do not set opacity on .sm-sidebar: it hides the collapse toggle (a child).
   Fade content only; width/overflow already hides controls. */
.sm-layout.collapsed .sm-sidebar {
  width: 0;
  padding: 0;
  overflow: hidden;
  pointer-events: none;
}
.sm-layout.collapsed .sm-sidebar > * {
  opacity: 0;
  transition: opacity 0.15s ease;
}

/* When collapsed, move toggle outside the sidebar into the main area */
.sm-layout.collapsed .sm-sidebar-toggle {
  position: fixed;
  top: calc(var(--sm-top-offset) + 8px);
  left: 8px;
  right: auto;
  opacity: 0.7;
  pointer-events: auto;
  z-index: 100;
}
.sm-layout.collapsed .sm-sidebar-toggle:hover {
  opacity: 1;
}

/* ── Main canvas area ──────────────────────────────────────────── */
.sm-main {
  background: var(--sm-canvas-bg);
  overflow: hidden;
  position: relative;
}

/* ── Responsive: stack on narrow screens ────────────────────────── */
@media (max-width: 640px) {
  .sm-layout {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }

  .sm-sidebar {
    max-height: 40vh;
    padding: 12px 14px 14px;
    gap: 10px;
  }

  .sm-sidebar-toggle {
    left: auto;
    right: 14px;
    top: 12px;
  }

  /* On mobile, collapse toggle hides the sidebar entirely */
  .sm-layout.collapsed {
    grid-template-columns: 1fr;
    grid-template-rows: 0px 1fr;
  }
  .sm-layout.collapsed .sm-sidebar {
    height: 0;
    max-height: 0;
  }
}

/* ── Custom sidebar widths ─────────────────────────────────────── */
.sm-layout.sm-sidebar-narrow  { --sm-sidebar-width: 200px; }
.sm-layout.sm-sidebar-wide    { --sm-sidebar-width: 320px; }