Problems with HTML and CSS, the icons dont get bigger

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
  font-family: 'poppins', sans-serif;
}

.topbar {
  position: fixed;
  background: #fff;
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.08);
  width: 100%;
  height: 60px;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 2fr 10fr 0.4fr 1fr;
  align-items: center;
  z-index: 1;
}

.logo h2 {
  color: #d34d4d;
}

.search {
  position: relative;
  width: 60%;
  justify-self: center;
}

.search input {
  width: 100%;
  height: 40px;
  padding: 0 40px;
  font-size: 16px;
  outline: none;
  border: none;
  border-radius: 10px;
  background: #f5f5f5;
}

.search>label {
  position: absolute;
  right: 15px;
  top: 50%;
  transform: translateY(-50%);
}

.user {
  position: relative;
  width: 50px;
  height: 50px;
}

.user img {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  object-fit: cover;
}


/* sidebar starts here */

.sidebar {
  position: fixed;
  top: 60px;
  width: 260px;
  height: calc(100% - 60px);
  background: #e26666;
  overflow-x: hidden;
}

.sidebar ul {
  margin-top: 20px;
}

.sidebar ul li {
  width: 100%;
  list-style: none;
}

.sidebar ul li a {
  width: 100%;
  text-decoration: none;
  color: rgb(255, 255, 255);
  height: 60px;
  display: flex;
  padding-left: 30px;
  justify-content: flex-start;
  align-items: center
}

.sidebar ul li a i {
  min-width: 60px;
  font-size: 24px;
  text-align: center;
  align-self: flex-start;
}

.sidebar ul li a svg {
  margin-right: 15px;
  width: 25px !important;
}


/* main section starts here*/

.main {
  position: absolute;
  top: 60px;
  width: calc(100% - 260px);
  left: 260px;
  min-height: calc(100vh - 60px);
  background: #f3f3f3;
}

.cards {
  width: 100%;
  padding: 35px 20px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-gap: 20px;
}

.cards .card {
  padding: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 7px 25px 0 rgb(0, 0, 0, 0.08);
}

.number {
  font-size: 35px;
  font-weight: 500;
  color: #e26666;
}

.card-name {
  color: #888;
  font-weight: 600;
}

.icon-box i {
  font-size: 45px;
  color: #e26666;
}

<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="style.css">
<script defer src="https://use.fontawesome.com/releases/v5.15.4/js/all.js" integrity="sha384-rOA1PnstxnOBLzCLMcre8ybwbTmemjzdNlILg8O7z1lUkLXozs4DHonlDtnE7fpc" crossorigin="anonymous"></script>
<title>Admin panel</title>
<div class="container">
  <div class="topbar">
    <div class="logo">
      <h2>Pomodone</h2>
    </div>
    <div class="search">
      <input type="text" id="search" placeholder="search here">
      <label for="search"><i class="fas fa-search"></i></label>
    </div>
    <i class="fas fa-bell"></i>
    <div class="user">
      <img src="img/user.png" alt="">
    </div>
  </div>
  <div class="sidebar">
    <ul>
      <li>
        <a href="#">
          <i class="fas fa-th-large"></i>
          <div>Dashboard</div>
        </a>
      </li>
      <li>
        <a href="#">
          <i class="fas fa-user-graduate"></i>
          <div>Students</div>
        </a>
      </li>
      <li>
        <a href="#">
          <i class="fas fa-chalkboard-teacher"></i>
          <div>Teachers</div>
        </a>
      </li>
      <li>
        <a href="#">
          <i class="fas fa-users"></i>
          <div>Employees</div>
        </a>
      </li>
      <li>
        <a href="#">
          <i class="fas fa-chart-bar"></i>
          <div>Analytics</div>
        </a>
      </li>
      <li>
        <a href="#">
          <i class="fas fa-hand-holding-usd"></i>
          <div>Earnings</div>
        </a>
      </li>
      <li>
        <a href="#">
          <i class="fas fa-cog"></i>
          <div>Settings</div>
        </a>
      </li>
      <li>
        <a href="#">
          <i class="fas fa-question"></i>
          <div>Help</div>
        </a>
      </li>
    </ul>
  </div>
  <div class="main">
    <div class="cards">
      <div class="card">
        <div class="card-content">
          <div class="number">1217</div>
          <div class="card-name">Students</div>
        </div>
        <div class="icon-box">
          <i class="fas fa-user-graduate"></i>
        </div>
      </div>
      <div class="card">
        <div class="card-content">
          <div class="number">42</div>
          <div class="card-name">Teachers</div>
        </div>
        <div class="icon-box">
          <i class="fas fa-chalkboard-teacher"></i>
        </div>
      </div>
      <div class="card">
        <div class="card-content">
          <div class="number">68</div>
          <div class="card-name">Employees</div>
        </div>
        <div class="icon-box">
          <i class="fas fa-users"></i>
        </div>
      </div>
      <div class="card">
        <div class="card-content">
          <div class="number">$4500</div>
          <div class="card-name">Earnings</div>
        </div>
        <div class="icon-box">
          <i class="fas fa-dollar-sign"></i>
        </div>
      </div>
    </div>
    <div class="charts"></div>
  </div>
</div>