#import "@preview/chic-hdr:0.5.0": *
#import "@preview/theorion:0.4.1": *
#import cosmos.fancy: *

#let notes(
  class : "",
  lecture: "",
  number: none,
  date: none,
  body
) = {

  show: chic.with(
    chic-footer(
      left-side: date,
      right-side: chic-page-number()
    ),
    chic-header(
      left-side: class,
      right-side: [Lecture #number : #lecture]),
    chic-separator(1pt)
  )

  show heading: set text(fill: black)
  show heading.where(level: 1): set heading(numbering: none)
  set heading(numbering: (first, ..nums) => numbering("1", ..nums))
  show heading.where(level: 2): set align(center)
  show heading.where(level: 2): set text(size: 18pt, font: "New Computer Modern")

  show heading: it => {
    if it.level == 2 {
      block[
        #smallcaps[Chapter. ]
        #counter(heading).display(it.numbering)
        #smallcaps[#it.body]
      ]
    } else {
      block[#it.body]
    }
  }

  show: show-theorion

  set-primary-body-color(red.lighten(80%))
  set-primary-border-color(red.darken(50%))

  set-secondary-border-color(green.darken(50%))
  set-secondary-body-color(green.lighten(80%))
  set-secondary-symbol[#sym.suit.diamond.filled]

  [= Lecture #number: #lecture]

  outline(title: none, target: figure.where(kind: "theorem"))

  outline(title: none, target: figure.where(kind: "definition"))

  line(length: 100%, stroke: 1pt)

  body
}