Why my margin does not work?

<div class="headerContainer">
  <img src="https://i.imgur.com/kF6nml7.png" />
  <div class="nav-list">
    <button class="menu-btn currentPage" active>ABC</button>
    <button class="menu-btn">DEFG</button>
    <button class="menu-btn">HIJ</button>
  </div>
</div>

body,
html {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 0;
  padding: 0;
  width: 100%;
}

.headerContainer {
  background-color: yellow;
  width: 100%;
  padding: 20px 0px;
  display: flex;
  flex-wrap: wrap;
  flex-direction: row;
  margin: 0px 20px;
}

.headerContainer img {
  height: 54px;
  margin-right: auto;
}

.nav-list {
  display: flex;
  flex-direction: row;
  align-items: center;
}
.menu-btn {
  height: fit-content;
  padding: 4px 8px;
  font-size: 16px;
  color: var(--grey-text);
  background-color: transparent;
  border: none;
  cursor: pointer;
  transition-duration: 0.3s;
  border-radius: 4px;
  display: block;
}

.menu-btn:hover,
.currentPage {
  background-color: var(--main-green-0);
  color: var(--white);
}


:root {
  /* color theme */
  --white: hsl(0, 0%, 100%);
  --main-green-0: hsl(80, 60%, 50%);
  --grey-text: hsl(0, 0%, 38%);
}