.wf-stack{
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.wf-row{
  flex: 1;
  min-height: 0;
  background: rgba(0,0,0,.12);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 10px;
  overflow: hidden;
}

/* Pane should be a column: title on top, canvas fills the rest */
.msim-pane{                 /* use the real class name of your pane wrapper */
  display: flex;
  flex-direction: column;
  min-height: 0;            /* critical in nested flex layouts */
}

.pane-title{
  flex: 0 0 auto;
  padding: 6px 10px;
  font-weight: 800;
  font-size: 12px;
  opacity: 0.85;
}

.wf-fill{
  flex: 1 1 auto;
  min-height: 0;            /* critical */
}
.wf-canvas{
  width: 100%;
  height: 100%;
  display: block;
}

/* 4 stacked panes fill remaining screen */
.msim-screen-stack{
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.msim-pane{
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,.08);
  background: rgba(0,0,0,.12);
}

/* title shouldn't eat space */
.pane-title{
  flex: 0 0 auto;
  padding: 6px 10px;
  font-weight: 800;
  font-size: 12px;
  opacity: .85;
}

/* canvas must fill */
.wf-canvas{
  flex: 1 1 auto;
  min-height: 0;
  width: 100%;
  height: 100%;
  display: block;
}