night/day mode: optional, can be turned it on and off by toggling the option in the customisation panel. it is activated by clicking the moon icon on the bottom right corner.

tabs: all are optional, and can be toggled on and off.

sidebar buttons: if you don't have asks enabled, the ask button will not appear. all 3 custom links are optional, and will not appear if no link is provided in the customisation panel.

search bar (with entries): optional, and so are the tag suggestions. you can have up to five; if you know a bit about coding, you can add more by making some tweaks.

custom title: while there is no official limit, i would not recommend making it too long, especially while using a big title font size. optional.

custom description: you can add basic html to it. optional.

custom sidebar image: max width is 300px, but you can upload smaller images without problem. if no sidebar image is provided, the code will default to the user icon.

tags on click: tags are hidden until the tag button is clicked.

scroll to top: what it says on the tin. optional.

tracking tag highlight: optional. you can add your tracking tag (or anything else) and, when the box is hovered, additional text will appear (for example, what media you will and will not reblog). if the box is clicked, the user is redirected to browse the tag on Tumblr in general (and not on the blog).

featured posts: optional. 3 featured posts at once. they are defined by the last 3 posts tagged with a certain tag (of your choice). they don't have to necessarily be original posts, or image posts/gifsets. all types of posts can be featured in the featured posts box.

mobile friendly: it has its own version for smaller screens like mini desktop screens, cellphone and tablets.

highly customisable: everything can either be tweaked or turned it off, all without any coding required (everything can be done in the customisation panel). the only obligatory elements are the sidebar, the ask button icon (if ask is enabled), the posts container, pagination and credits (that i ask for you not to remove).

a reminder: the Tumblr customisation panel is buggy, so you might have to toggle on and off some elements you want/do not want to make it work. i also recommend you "reset" your custom theme before installing this one (ie, select the default Tumblr theme), so no preferences of your previous theme are inherited by this code. it's not a necessary step, but it helps when customising.