* {
  padding: 0;
  margin: 0;
}
:root {
  --bg-color: white;
  --text-color: black;
  --border-color: black;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #121212;
    --text-color: #f5f5f5;
    --border-color: white;
  }
}

body {
  font-family: "Roboto", sans-serif;
  font-optical-sizing: auto;
  font-style: normal;
  font-variation-settings: "wdth" 100;
  margin: 0;
  padding: 0 20px;
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: sans-serif;
  transition: background 0.3s, color 0.3s;
}

header,
main,
footer {
  margin-bottom: 40px;
}

a {
  text-decoration: none;
  color: var(--text-color);
}

a:hover {
  text-decoration: underline;
}

.courses-list li::before {
  content: "- ";
}

.contact-form {
  border: 2px solid var(--border-color);
  padding: 20px;
  border-radius: 10px;
}

form {
  border-color: var(--border-color);
}

form input,
form textarea {
  border: 1px solid var(--border-color);
  padding: 10px;
  border-radius: 4px;
  font-family: inherit;
  font-size: inherit;
  color: black;
}



.about-me-section div:first-child {
  padding-bottom: 20px;
}

.education-section {
  padding-bottom: 20px;
}

h2 {
  color: var(--text-color);
  padding-bottom: 10px;
}

@media (max-width: 600px) {
  nav {
    flex-direction: column;
    gap: 0;
  }

  nav div {
    gap: 0;
    padding-left: 0;
  }

  /* Make sections stack vertically on small screens, but let
     their children stretch full-width instead of centering them. */
  section {
    flex-direction: column;
    align-items: stretch;
  }

  .reviews-section div {
    flex-direction: column;
    align-items: center;
  }
}