How Do I remove the small white space between my navbar and the next section? How do I remove the sm-CodePudding

I'm coding this website as the last project of the HTMl course on freecodecamp, and I'm running into two errors I don't know how to fix. On the one hand, a small white line stays between my navbar and my first section. On the other hand, I use a hover selector to make the background of my nav bar links gray, but a small darker line stays at the bottom.

Here is what the white line looks like:

To fix the first white line, I've tried removing paddings and margins (which removed some of the whitespaces on the edges, but not the one that's left, between the two sections. I also changed all the CSS backgrounds to blue to find out which section was filling in the space, and it only turned blue when I changed body's background, which already has margins and padding set to 0.

Here is what the little black line looks like: As you can see, there is a little black line below the grey background!

For this one I tried understanding what exact space the different tags in my navbar take (li, ul, a...) to no avail, I don't really understand how these tags decide to take up space, or not within the navbar. I couldn't find any of the tags that took that extra black line space.

Here is the HTML:

<!DOCTYPE html>
<html lang='en'>
  <head>
    <meta charset='UTF-8'>
    <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
    <title>Double Team Cooking</title>
    <link rel='stylesheet' href='styles.css'>
  </head>
  <body>
    <section id="welcome">
      <nav id='navbar'>
        <ul>
          <li><a href="#whodis">Who Am I?</a></li>
          <li><a href="#Projectos">My Projects</a></li>
          <li><a href="#hola">Contact</a></li>
        </ul>
      </nav>
    </section>
      
      
    <section id='Who-Am-I'>
      <h2 id='whodis'>Who Am I?</h2>
      <p> Hey, I'm Pedro.</p>
      <p> A man, a cook, a student, a coder, a business developer, a problem solver.</p>
    </section>

    <section id='Projects'>
      <h2 id='Projectos' >My Projects</h2>
      <p>So, what am I working on?</p>
      <div id="electriccar"></div>
      <div id="website"></div>
      <div id="TWR"></div>
    </section>

    <section id="Contact">
      <h2 id="hola">Contact Me</h2>
      <p>You'd like to reach out? Of course! Feel free to reach out to me through these mediums!</p>
    </section>
    
  </body>
</html>

And here is the CSS:

*,
*::after,
*::before {
  box-sizing: border-box;
}

body {
  width: 100%;
  padding: 0px;
  margin: 0px;
}



nav {
  display: flex;
  flex-direction: row;
  justify-content: center;
  width: 100%;
  height: 40px;
  background-color: rgb(24,24,24);
}

nav ul {
  display: flex;
  justify-content: space-evenly;
  list-style-type: none;
  padding-left: 0px;
  width: 100%;
  height: 100%;
  margin: 0px;
  align-items: center;
  
}

nav li {
  display: inline-block;
  
  
}

li a {
  text-decoration: none;
  color: white;
  padding: 10px;
  
}

li a:hover {
  background-color: rgb(64,64,64);

}

#Who-Am-I {
  height: 100%;
  background-color: rgba(0,30,0,0.8);
}

Thanks a lot for the help!

CodePudding user response：

Try

* {
  padding: 0;
  margin: 0;
}