Size of divs in HTML

Question

I want to reduce the size of these divs so that every row contain 3 cards at most. As I change the measurements in the CSS, it gets smaller and smaller. PS I'm not allowed to use Bootstrap! I tried using different measurements and also the grid feature but it was of no help.

This is the screenshot of the divs on my website

.locations .box-container {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  grid-template-rows: auto;
}

.locations .box-container .box {
  overflow: hidden;
  box-shadow: 0 1rem 2rem rgba(0, 0, 0, 0.1);
  border: 1rem solid #fff;
  border-radius: 0.5rem;
  flex: 1 1 30rem;
  height: 25rem;
  position: relative;
}

.locations .box-container .box img {
  height: 100%;
  width: 100%;
  object-fit: cover;
}

.locations .box-container .box .card-body {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  text-align: center;
  background: rgba(0, 0, 0, 0.7);
  padding: 2rem;
  padding-top: 5rem;
}

.locations .box-container .box .card-body .card-btn {
  display: inline-block;
  margin-top: 1rem;
  background: orange;
  color: #fff;
  padding: 0.8rem 3rem;
  border: 0.2rem solid orange;
  cursor: pointer;
  font-size: 1.7rem;
}

.locations .box-container .box .card-body .card-btn:hover {
  border: 2px solid orange;
  color: orange;
  background: transparent;
  transition: 0.4s ease;
}

.locations .box-container .box .card-body .card-btn:focus {
  outline: none;
}

.locations .box-container .box .card-body h5 {
  font-size: 2.5rem;
  color: orange;
}

.locations .box-container .box .card-body p {
  font-size: 1.5rem;
  color: #eee;
  padding: 0.5rem 0;
}

<section class="locations">
  <h1>Locations</h1>
  <p>"Adventure is out there."</p>
  <br>
  <div class="box-container">
    <div class="box">
      <div class="card">
        <img src="./murree.jpg" alt="Murree, Pakistan">
        <div class="card-body">
          <h5>Murree</h5>
          <p>Some quick example text to build on the card title and make up the bulk of the card's content.</p>
          <a href="#" class="card-btn">View</a>
        </div>
      </div>
    </div>
  </div>
</section>

Answer 1

I simplified your HTML and CSS a bit, but this solution should work. This will give you 3 cards per row, and will fill the rows below it. I removed some of your styling for brevity, so you'll need to add that back, but this should give you the structure you need.

.locations .box-container
{
  display: flex;
  flex-wrap: wrap;
}

.locations .box-container .box
{
  overflow: hidden;
  box-shadow: 0 1rem 2rem rgba(0, 0, 0, 0.1);
  border: 1rem solid #fff;
  border-radius: 0.5rem;
  height: 25rem;  
  flex: 1 0 25%;
  margin: 0.5rem;
  box-sizing: border-box;
}       

.locations .box-container .box .card
{  
  height: 100%;
  width: 100%;
  text-align: center;
  background: rgba(0, 0, 0, 0.7);
  padding: 2rem;  
}
        
.locations .box-container .card h5
{
  font-size: 2.5rem;
  color: orange;
}

.locations .box-container .card p
{
  font-size: 1.5rem;
  color: #eee;
  padding: 0.5rem 0;
}

.locations .box-container .card a
{
  display: inline-block;
  margin-top: 1rem;
  background: orange;
  color: #fff;
  padding: 0.8rem 3rem;
  border: 0.2rem solid orange;
  cursor: pointer;
  font-size: 1.7rem;
}

<section class="locations">
  <div class="box-container">
  <div class="box">
    <div class="card">
      <h5>Title</h5>
      <p>Card content.</p>
      <a href="#">View</a>
    </div>
  </div>
  <div class="box">
    <div class="card">
      <h5>Title</h5>
      <p>Card content.</p>
      <a href="#">View</a>
    </div>
  </div>
  <div class="box">
    <div class="card">
      <h5>Title</h5>
      <p>Card content.</p>
      <a href="#">View</a>
    </div>
  </div>
    <div class="box">
    <div class="card">
      <h5>Title</h5>
      <p>Card content.</p>
      <a href="#">View</a>
    </div>
  </div>
    <div class="box">
    <div class="card">
      <h5>Title</h5>
      <p>Card content.</p>
      <a href="#">View</a>
    </div>
  </div>
  </div>
</section>