CODE ADDICT Simply Recipes Tutorial - CSS navbar button error

Hi, I’m brand new at this and I’m following along Code Addicts Build a Recipes Website Tutorial ( HTML & CSS Project Tutorial - Build a Recipes Website - YouTube ) but I’ve made an error somewhere which is preventing my navbar displaying in a column. Please can someone tell me where I’ve messed up? I’ve looked at the final file and I can’t see what I’ve missed.

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

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500;600&family=Montserrat&display=swap');
html {
  font-size: 100%;
} /*16px*/

:root {
  /* colors */
  --primary-100: #e2e0ff;
  --primary-200: #c1beff;
  --primary-300: #a29dff;
  --primary-400: #837dff;
  --primary-500: #645cff;
  --primary-600: #504acc;
  --primary-700: #3c3799;
  --primary-800: #282566;
  --primary-900: #141233;

  /* grey */
  --grey-50: #f8fafc;
  --grey-100: #f1f5f9;
  --grey-200: #e2e8f0;
  --grey-300: #cbd5e1;
  --grey-400: #94a3b8;
  --grey-500: #64748b;
  --grey-600: #475569;
  --grey-700: #334155;
  --grey-800: #1e293b;
  --grey-900: #0f172a;
  /* rest of the colors */
  --black: #222;
  --white: #fff;
  --red-light: #f8d7da;
  --red-dark: #842029;
  --green-light: #d1e7dd;
  --green-dark: #0f5132;

  /* fonts  */
  --headingFont: 'Roboto', sans-serif;
  --bodyFont: 'Nunito', sans-serif;
  --smallText: 0.7em;
  /* rest of the vars */
  --backgroundColor: var(--grey-50);
  --textColor: var(--grey-900);
  --borderRadius: 0.25rem;
  --letterSpacing: 1px;
  --transition: 0.3s ease-in-out all;
  --max-width: 1120px;
  --fixed-width: 600px;

  /* box shadow*/
  --shadow-1: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-2: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-3: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-4: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
    0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
  background: var(--backgroundColor);
  font-family: var(--bodyFont);
  font-weight: 400;
  line-height: 1.75;
  color: var(--textColor);
}

p {
  margin-top: 0;
  margin-bottom: 1.5rem;
  max-width: 40em;
}

h1,
h2,
h3,
h4,
h5 {
  margin: 0;
  margin-bottom: 1.38rem;
  font-family: var(--headingFont);
  font-weight: 400;
  line-height: 1.3;
  text-transform: capitalize;
  letter-spacing: var(--letterSpacing);
}

h1 {
  margin-top: 0;
  font-size: 3.052rem;
}

h2 {
  font-size: 2.441rem;
}

h3 {
  font-size: 1.953rem;
}

h4 {
  font-size: 1.563rem;
}

h5 {
  font-size: 1.25rem;
}

small,
.text-small {
  font-size: var(--smallText);
}

a {
  text-decoration: none;
}
ul {
  list-style-type: none;
  padding: 0;
}

.img {
  width: 100%;
  display: block;
  object-fit: cover;
}
/* buttons */

.btn {
  cursor: pointer;
  color: var(--white);
  background: var(--primary-500);
  border: transparent;
  border-radius: var(--borderRadius);
  letter-spacing: var(--letterSpacing);
  padding: 0.375rem 0.75rem;
  box-shadow: var(--shadow-1);
  transition: var(--transtion);
  text-transform: capitalize;
  display: inline-block;
}
.btn:hover {
  background: var(--primary-700);
  box-shadow: var(--shadow-3);
}
.btn-hipster {
  color: var(--primary-500);
  background: var(--primary-200);
}
.btn-hipster:hover {
  color: var(--primary-200);
  background: var(--primary-700);
}
.btn-block {
  width: 100%;
}

/* alerts */
.alert {
  padding: 0.375rem 0.75rem;
  margin-bottom: 1rem;
  border-color: transparent;
  border-radius: var(--borderRadius);
}

.alert-danger {
  color: var(--red-dark);
  background: var(--red-light);
}
.alert-success {
  color: var(--green-dark);
  background: var(--green-light);
}
/* form */

.form {
  width: 90vw;
  max-width: var(--fixed-width);
  background: var(--white);
  border-radius: var(--borderRadius);
  box-shadow: var(--shadow-2);
  padding: 2rem 2.5rem;
  margin: 3rem auto;
}
.form-label {
  display: block;
  font-size: var(--smallText);
  margin-bottom: 0.5rem;
  text-transform: capitalize;
  letter-spacing: var(--letterSpacing);
}
.form-input,
.form-textarea {
  width: 100%;
  padding: 0.375rem 0.75rem;
  border-radius: var(--borderRadius);
  background: var(--backgroundColor);
  border: 1px solid var(--grey-200);
}

.form-row {
  margin-bottom: 1rem;
}

.form-textarea {
  height: 7rem;
}
::placeholder {
  font-family: inherit;
  color: var(--grey-400);
}
.form-alert {
  color: var(--red-dark);
  letter-spacing: var(--letterSpacing);
  text-transform: capitalize;
}
/* alert */

@keyframes spinner {
  to {
    transform: rotate(360deg);
  }
}

.loading {
  width: 6rem;
  height: 6rem;
  border: 5px solid var(--grey-400);
  border-radius: 50%;
  border-top-color: var(--primary-500);
  animation: spinner 0.6s linear infinite;
}
.loading {
  margin: 0 auto;
}
/* title */

.title {
  text-align: center;
}

.title-underline {
  background: var(--primary-500);
  width: 7rem;
  height: 0.25rem;
  margin: 0 auto;
  margin-top: -1rem;
}

/*
=============== 
Navbar
===============
*/
.navbar{
display: flex;
justify-content: center;
align-items: center;
background: black;
}
.nav-center{
  width: 90vw;
  max-width: var(--max-width);
  background: gray;
}

.nav-header{
  height: 6rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-header img{
  width: 200px;
}

.nav-logo{
  display: flex;
  align-items: flex-end;
}

.nav-btn{
  padding: 0.15rem 0.75rem;
}

.nav-btn i{
  font-size: 1.25rem;
}

.nav-links {
  display: flex;
  flex-direction: column;
  /* todo */
}

.nav-link {
  display: block;
  text-align: center;
  font-size: 1.25rem;
  text-transform: capitalize;
  color: var(--grey-900);
  letter-spacing: var(--letterSpacing);
  padding: 1rem;
  border-top: 1px solid var(--grey-500);
  transition: var(--transition);
}

.nav-link:hover{
  color: var(--primary-500);
}

.contact-link a{
  padding: 0.15rem 1rem;
}
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Simply Recipes || Starter</title>
    <!-- favicon -->
    <link rel="shortcut icon" href="./assets/favicon.ico" type="image/x-icon" />
    <!-- normalize -->
    <link rel="stylesheet" href="./css/normalize.css" />
    <!-- font-awesome -->
    <link
      rel="stylesheet"
      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css"
    />
    <!-- main css -->
    <link rel="stylesheet" href="./css/main.css" />
  </head>
  <body>
   <!-- nav-->
<nav class="navbar">
  <div class="nav-center">
   <!--HEADER-->
    <div class="nav-header">
      <a href="index.html" class="nav-logo">
        <img src="./assets/logo.svg" alt="simply recipes"/>
      </a>
      <button type="button" class="btn nav-btn">
        <i class="fas fa-align-justify"></i>
      </button>
    </div>
  <!--LINKS-->
    <div class="nav-links">
    <a href="index.html" class="nav-link">Home</a>
    <a href="about.html" class="nav-link">About</a>
    <a href="tags.html" class="nav-link">Tags</a>
    <a href="recipes.html" class="nav-link">Recipes</a>
    <div class="nav-link contact-link">
      <a href="contact.html" class="btn">Contact</a>
    </div>
  </div>
</div>
</nav>
   <!--end of nav-->
  
  </body>
</html>

You don’t have any way of linking to this in codepen but codepen provides a way to use normalize as the base.

Click cog icon in codepen’s CSS editor and in the “CSS Base” section select the “Normalize” radio button. (it defaults to “Neither”)
Save & Close and…