/* Minimal, clean layout with collapsible sidebar */
* { box-sizing: border-box; }
html, body { height: 100%; }
body { margin: 0; font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, 'Helvetica Neue', Arial, 'Noto Sans', 'Liberation Sans', sans-serif; }

/* Toggle button */
.sidebar-toggle {
  position: fixed;
  top: 12px;
  left: 12px;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  background: #fff;
  cursor: pointer;
  z-index: 50;
  box-shadow: 0 2px 8px rgba(0,0,0,.05);
}
.sidebar-toggle:active { transform: translateY(1px); }

/* Backdrop for mobile */
.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.25);
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease;
  z-index: 40;
}

.layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: 100vh;
  transition: grid-template-columns .2s ease;
}
.sidebar {
  border-right: 1px solid #e5e7eb;
  padding: 1rem;
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  background: #fff;
  z-index: 41;
}
.sidebar h1 { margin: 0 0 .5rem 0; font-size: 1.25rem; }
.sidebar ul { list-style: none; padding: 0; margin: .5rem 0 0 0; overflow: auto; }
.sidebar li { margin: 0; }
.sidebar a { display: block; padding: .5rem .6rem; border-radius: .5rem; text-decoration: none; color: #111827; }
.sidebar a:hover { background: #f3f4f6; }
.sidebar a.active { background: #e5e7eb; font-weight: 600; }
.sidebar .foot { margin-top: auto; color: #6b7280; }

.content { position: relative; height: 100vh; }
#placeholder { padding: 2rem; }
#notesFrame { display: none; border: 0; width: 100%; height: 100%; }

/* Collapsed state (desktop) */
.layout.collapsed {
  grid-template-columns: 0 1fr;
}
.layout.collapsed .sidebar {
  overflow: hidden;
}

/* Mobile styles: sidebar becomes a drawer */
@media (max-width: 820px) {
  .layout { grid-template-columns: 1fr; }
  .layout.collapsed { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: min(80vw, 320px);
    height: 100vh;
    transform: translateX(-100%);
    transition: transform .2s ease;
  }
  /* When not collapsed, show the drawer and backdrop */
  .layout:not(.collapsed) .sidebar {
    transform: translateX(0);
  }
  .layout:not(.collapsed) ~ .backdrop,
  .layout:not(.collapsed) + .backdrop { /* fallback */
    opacity: 1;
    pointer-events: auto;
  }
  .content { height: auto; }
  #notesFrame { min-height: 65vh; }
}