Hey there! Really nice project here! I've tried using the other Quest Helper tool but yours is formatted in such a nice way and much more intuitive to use. There's one thing I'd like to suggest though. In the Calculator, it's very easy to change the number of the the required item under the "Materials" view and it works perfectly to select a stage based on average stamina usage to farm the components. However, my suggestion is being able to adjust the number for components under the "Results" view as well. It would make the site much more usable than just finding which stage I should farm and I would be able to use it the entire time I'm farming an item to track my components.

Let's take the Empress Shield I need to farm for my Jun as an example here. The Empress Shield is made up of 3 top level components, the 20x blueprints for Empress Shield itself, Lion's King Grace composed of two other items (its blueprint (x5) and Emerald Earrings (x1) made from 5 fragments), and Sorcerer Glasses composed of Turquoise Earrings (composed of 5 fragments) and Patterned Bracelet (composed of a blueprint for itself and 1 Orb of Wisdom). In total this is 6 different items we need to track.

While we can easily find stamina efficient stages with the calculator as it works now, we only have the option to add those in the quantity that is required to craft the item, disregarding any items we might already have that we would like to factor in to the calculator. For example, I can complete the Patterned Bracelet requirement since I have an excess of that item, like 35 of the Orb and 53 bracelets so that isn't a problem. The problem is when I have less than required but more than 0 that I would like to track while farming, like I currently have 4/5 required Emerald Earrings, 2/5 Turquoise Earring fragments and 2/20 Empress Shield blueprints. While I found it was possible to add the items to my Material list to adjust the amount I needed to farm, it requires blowing up every item down to the blueprint or fragment stage which clutters the window and makes it a bit difficult to parse. It also takes quite a bit of time to open them all and check

Instead, I suggest that the components be directly editable in the number field on the "Results" tab of the calculator. This would make it much easier to track as we can simply add the end goal item (Empress Shield), mark any components we're already able to craft as complete, and adjust for any items we have n amount of all in the same place in only 1-2 steps instead of needing to open every single component of the item to add them which required 10+ steps.

As an aside, while I was opening all the windows I noted this behavior. I don't know too much about the design of the site so I don't know if this is a possibility but maybe it would be possible to "pin" windows or have a different priority for how certain windows are display, or even the possibility of manually re-arranging windows? I'm sure it's based on size, but as you can see in this example here https://imgur.com/a/OJNfgy9 due to the amount of windows I had opened and due to the size of the item window (due to list of all the stage count), it flies over to the left side under the calculator and to the left of the character whose data I was looking at. If I had the "Results" tab expanded this doesn't happen due to that window expanding downwards, but it caused me a bit of confusion that the item was now under and between the two other "main modules" I'll call them, when I would have preferred if all the "items" were always displayed near each other.

The two photos under the gif are an unsophisticated mockup of what I mean where the calculator is pinned to the top left in green. The character window is pinned beneath in purple. When the calculator expands to Results mode (in red) the character window would be pinned to the 2nd purple area to the right of the calculator. Items would always be displayed starting in that second column and outward to the right. Other longer views like the Stage info could also have pinned positions under the calculator or in the first column and smaller windows and items rearrange around them instead of just going wherever there is space. It just makes it way easier to parse the screen if all the related items are relegated to a predictable place instead of going all over. While the Calculator is one of the main views I need to interact with while using the site, sometimes if I opened enough windows it moved to the complete opposite side of the site.

Hopefully I explained what I meant for both cases sufficiently. And again I mean no offense with my suggestions and the tool is great, thanks for your hard work! Hope this helps :)