* {
  text-decoration: none;
}

*:hover { text-decoration: none; color:#ff7b00; }
*:focus { text-decoration: none; color:#ff7b00; }
*:active { text-decoration: none; color:#ff7b00; }

a:hover { text-decoration: none; color:#ff7b00; }
a:focus { text-decoration: none; color:#ff7b00; }
a:active { text-decoration: none; color:#ff7b00; }

a:visited { 
  text-decoration: none;
  color: #ff7b00; 
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 20px;
  background-color: #000f25;
  color: #ff7b00;
}

button {
  align-items: center;
  background-image: linear-gradient(to left, #000f25, #333);
  border: none;
  color: #ff7b00;
  font-size: larger;
  padding: 15px 32px;
  text-align: center;
  font-weight: 600;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  border-radius: 5%;
  min-width: 20%;
}

button:hover { text-decoration: none; color:#ff7b00; }
button:focus { text-decoration: none; color:#ff7b00; }
button:active { text-decoration: none; color:#ff7b00;}
.button:hover { text-decoration: none; color:#ff7b00; }
.button:focus { text-decoration: none; color:#ff7b00; }
.button:active { text-decoration: none; color:#ff7b00; }

header {
  background-image: linear-gradient(to right, #333, #000f25);
  padding: 10px;
  display: flex;
  justify-content: space-around;
}

.logo {
  font-family: 'Pacifico', cursive;
  font-size: 24px;
  color: #ff7b00;
}

.menu-toggle {
  display: none;
}

nav {
  display: flex;
  align-items: center;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
}

nav ul li {
  margin-left: 15px;
}

nav ul li a {
  color: #ff7b00;
  text-decoration: none;
  font-family: 'Pacifico', cursive;
}

li {
  min-width: max-content;
  background-image: linear-gradient(to left, #333, #000f25);
  border-radius: 10%;
  padding-left: 2%;
}

main {
  margin-top: 20px;
  margin-bottom: 20px;
}

.row {
  display: flex;
  margin-bottom: 20px;
}

.row > div {
  flex: 1;
  padding: 10px;
  background-color: #000f25;
  border-radius: 6px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  text-align: center;
}

footer {
  background-color: #333;
  padding: 10px;
  text-align: center;
  font-size: 14px;
  color: #ff7b00;
}

/* styles */


/* Mobile devices */
@media only screen and (max-width: 767px) {

  header {
    padding: 5px;
  }

  .logo {
    font-size: 20px;
  }

  nav {
    flex-direction: column; /* Change flex direction to column */
    align-items: flex-start; /* Adjust alignment for vertical layout */
  }

  nav ul {
    flex-direction: column; /* Change flex direction to column */
  }

  nav ul li {
    margin-left: 0; /* Remove margin-left to stack items vertically */
    margin-bottom: 10px; /* Add margin-bottom for spacing */
  }

  main {
    margin-top: 10px;
    margin-bottom: 10px;
  }

  .row {
    flex-direction: column;
    margin-bottom: 10px;
  }

  .row > div {
    margin-bottom: 10px;
  }

  footer {
    font-size: 12px;
  }
}

/* Computer devices */
@media only screen and (min-width: 768px) {
  nav {
    flex-direction: row; /* Change flex direction to row */
    align-items: center; /* Adjust alignment for horizontal layout */
  }

  nav ul {
    flex-direction: row; /* Change flex direction to row */
  }

  nav ul li {
    margin-left: 15px; /* Add back the margin-left for horizontal layout */
    margin-bottom: 0; /* Remove margin-bottom */
  }

  /* Rest of the styles for computer devices */
  header {
    padding: 15px;
  }

  .logo {
    font-size: 22px;
  }

  .row > div {
    padding: 20px;
  }

  footer {
    padding: 20px;
  }
}

With these changes, the navigation items should appear vertically on phone-sized screens and horizontally on computer-sized screens.