Center logo in html

I have an logo in the header of the page and I want to make in centered. This is my html:

body {
  width: 90%;
  margin: 0 auto;
}
header {
  margin-top: 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid #b5b5b5;
}
.logo {
  width: 250px;
  height: 150px;
  text-align: center;
}

<body>
  <header>
    <div class="row">
      <div class="logo-row">
        <img src="resources/img/logo.png" alt="logo" class="logo">
      </div>
    </div>
  </header>

Solution

You need to add a width to the logo-row class and use margin: 0 auto.

body {
    width: 90%;
    margin: 0 auto;
}

header {
    margin-top: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #b5b5b5;
}

.logo-row {
    width: 250px;
    margin: 0 auto;
}

.logo {
    width: 100%;
    height: 150px;
    text-align: center;
}

<body>
  <header>
    <div class="row">
      <div class="logo-row">
        <img src="resources/img/logo.png" alt="logo" class="logo">
      </div>
    </div>
  </header>