Slate Core

• New: quick action buttons on the inventory. Three small buttons at the top left corner of the inventory and of the creative inventory set the time of day (day, noon, night), the game mode (Survival and Creative) and the weather (clear and rain) with one click, and each shows where the world is at. They send the game's own commands, so the server needs nothing, and only players who may use those commands (operators) see them (suggested by Starcage).
• The buttons can be switched off: Slate settings, Inventory, "Quick action buttons" (quickActions in core.json).
• New: smooth corners. "Smooth corners" under Slate settings, Look (with Slate Config: Options > Interface > Look) draws the rounded corners of panels, cards, buttons, popups, menus, tooltips and toasts, their outlines and shadows, as smooth arcs at the screen's full resolution instead of pixel steps; every shape keeps its size. Off by default: the pixel look stays the default (suggested by Iammaliikk).
• New: a pointer in Slate's look. "Pointer" under Slate settings, Look: System (the default), Slate (the arrow in Slate's light colour with a dark outline and a hard shadow) or Accent; it grows with the GUI scale (suggested by Iammaliikk).
• The layout editor's pencil button can be moved to another corner of the screen or hidden: "Pencil button" under Slate settings, Development (also Options > Interface > Development and the Developer page). F7 opens the editor with or without the button (suggested by Iammaliikk).
• A menu's background picture and the layout editor's image elements can be GIF, JPEG, BMP or TIFF as well as PNG; an animated GIF plays at the times the file gives its frames. Memory stays bounded: a very large GIF is kept smaller, and files over 64 MB are not read (suggested by Iammaliikk).
• Fixed: when a popup's choice left a world or closed the screen while the mouse button was still held, the next click on any screen was swallowed (the Core side of the "first click after leaving a world" fix).

Every Slate module needs the Core of its own version: update all of them together.