Поскольку flex допускает только одно направление, вам придется начать оборачивать свои элементы, чтобы выровнять их по своему желанию.
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
.main {
display: flex;
flex-direction: column;
}
#container {
display: flex;
width: 100%;
}
#container>div {
flex: 1;
display: flex;
flex-direction: column;
}
#container>div>h3 {
align-self: center;
}
#container>div>img {
max-width: 100%;
}
.btns {
display: flex;
}
.btns>button {
flex: 1;
}
<div class="main">
<div id="container">
<div>
<img src="https://i.pinimg.com/originals/fa/89/6c/fa896c405abec656a0c8516229fa55ad.jpg" />
<h3>Heading 1</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commod</p>
</div>
<div>
<img src="https://i.pinimg.com/originals/fa/89/6c/fa896c405abec656a0c8516229fa55ad.jpg" />
<h3>Heading 1</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ull</p>
</div>
<div>
<img src="https://i.pinimg.com/originals/fa/89/6c/fa896c405abec656a0c8516229fa55ad.jpg" />
<h3>Heading 1</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure</p>
</div>
</div>
<div class="btns">
<button>Text</button>
<button>Text again</button>
</div>
</div>
Использование CSS-сетки
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
ul {
display: grid;
grid-template-columns: 1fr 1fr 1fr;
}
ul>li>img {
max-width: 100%;
}
ul>li>h3 {
text-align: center;
}
.btnsContainer {
font-size: 0;
grid-column: 1/4
}
.btnsContainer>button {
width: 50%;
font-size: 16px;
}
<ul>
<li>
<img src="https://i.pinimg.com/originals/fa/89/6c/fa896c405abec656a0c8516229fa55ad.jpg" />
<h3>Heading 1</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commod</p>
</li>
<li>
<img src="https://i.pinimg.com/originals/fa/89/6c/fa896c405abec656a0c8516229fa55ad.jpg" />
<h3>Heading 1</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ull</p>
</li>
<li>
<img src="https://i.pinimg.com/originals/fa/89/6c/fa896c405abec656a0c8516229fa55ad.jpg" />
<h3>Heading 1</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure</p>
</li>
<li class="btnsContainer">
<button>Text</button>
<button>Text again</button>
</li>
</ul>