Как прижать элементы к краям родителя вертикально на flex-box

.projects-wrapper{ 
     min-width: 250px; 
     max-width: 250px; 
     min-height: 250px; 
     display: flex; 
     justify-content: space-between; 
     align-items: center; 
     flex-wrap: wrap; 
     background: grey;     
     align-content: space-between; 
} 
.project-item{ 
    min-width: 100px; 
    min-height: 50px; 
    background: red; 
}

<div class="colum projects-wrapper"> 
    <div class="project-item" style="background-image: url(css/img/projects/h_f_students_of_kpi.png)"></div> 
    <div class="project-item" style="background-image: url(css/img/projects/h_clubs_nagoruny.png)"></div> 
    <div class="project-item" style="background-image: url(css/img/projects/r_complex_campus.png)"></div> 
    <div class="project-item" style="background-image: url(css/img/projects/h_f_students_of_kpi2.png)"></div> 
</div>

.projects-wrapper { 
  min-height: 100vh; 
  display: grid; 
  grid-template-columns: repeat(2, 1fr); 
  grid-template-rows: repeat(2, 1fr); 
  grid-gap: 15px; 
  background: grey; 
} 
 
.project-item { 
  min-width: 100px; 
  min-height: 50px; 
  background: red; 
} 
 
.project-item--1, 
.project-item--2 { 
  align-self: start; 
} 
 
.project-item--3, 
.project-item--4 { 
  align-self: end; 
}

<div class="colum projects-wrapper"> 
  <div class="project-item project-item--1" style="background-image: url(css/img/projects/h_f_students_of_kpi.png)"></div> 
  <div class="project-item project-item--2" style="background-image: url(css/img/projects/h_clubs_nagoruny.png)"></div> 
  <div class="project-item project-item--3" style="background-image: url(css/img/projects/r_complex_campus.png)"></div> 
  <div class="project-item project-item--4" style="background-image: url(css/img/projects/h_f_students_of_kpi2.png)"></div> 
</div>