Container layout recipes
VBox separation
$VBoxContainer.add_theme_constant_override("separation", 10)Responsive anchors
$MarginContainer.set_anchors_preset(Control.PRESET_FULL_RECT)
$MarginContainer.add_theme_constant_override("margin_left", 20)Size flags
button.size_flags_horizontal = Control.SIZE_EXPAND_FILL
button.size_flags_vertical = Control.SIZE_SHRINK_CENTERWeighted layouts: container_size_flags_pro.gd.
Split screen
See Expert Layout Patterns in SKILL.md — HSplitContainer + SubViewportContainer.stretch = true.
Virtual list
MANDATORY virtual_list.gd — do not paste one-off pool recyclers.