#import "@preview/hydra:0.6.0": hydra

#let project(title: "", subtitle: "", authors: (), logo: none, body) = {

  // Set the document's basic properties.
  set document(author: authors, title: title)
  set text(lang: "de")
  set heading(numbering: "1.1")

  set align(center)

  // Title page.
  v(1fr)
  
  // Logo
  if logo != none {
    image(logo, width: 50%)
  }
  v(3em)

  // Title
  text(2em, weight: 700, title)

  linebreak()
  v(0.1em)

  // Subtitle
  text(2em, weight: 400, subtitle)
  
  v(1em)

  // Author
  grid(
    ..authors,
  )

  v(1fr)
  pagebreak()

  set align(left)

  set page(numbering: "I", number-align: center)

  // Table of contents
  outline(depth: 3)
  pagebreak()

  let show-header(ctx, candidates) = {
    candidates.body
    v(-0.8em)
    line(length: 100%, stroke: 0.5pt)
  }

  set page(header: context {
    hydra(1, skip-starting: false, display: show-header)
  })

  set page(numbering: "1")
  counter(page).update(1)

  // Main body
  set par(justify: true)

  body
}