:root {
  --bg: #ffffff;
  --text: #111111;
  --link: #000000;
}

[data-theme="dark"] {
  --bg: #0f0f0f;
  --text: #f5f5f5;
  --link: #ffffff;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  margin-bottom: 3rem;
}

.nav-links {
  display: flex;
  justify-content: center;
  gap: 1rem;
}

.navbar a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
}

.navbar a.active {
  text-decoration: underline;
  text-underline-offset: 6px;
  font-weight: 600;
}

.home-link {
  text-decoration: none;
  font-size: 1.2rem;
}

#theme-toggle {
  background: transparent;
  border: none;
  color: var(--text);
  padding: 0.4rem 0.8rem;
  cursor: pointer;
  margin-top: 1rem;
}

#theme-toggle:hover {
  opacity: 0.75;
}

body {
  font-family: system-ui, sans-serif;
  max-width: 900px;
  margin: 0 auto;
  /* padding: 2rem; */
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  transition: background-color 0.3s ease, color 0.3s ease;
}

section {
  margin: 4rem 0;
}

main {
  flex: 1;
}

h1,
h2,
h3 {
  line-height: 1.2;
}

a {
  text-decoration: underline;
  color: var(--link);
}

#myBtn {
  display: none; /* Hidden by default */
  position: fixed; /* Fixed/sticky position */
  bottom: 20px; /* Place the button at the bottom of the page */
  right: 30px; /* Place the button 30px from the right */
  z-index: 99; /* Make sure it does not overlap */
  border: none; /* Remove borders */
  outline: none; /* Remove outline */
  background-color: var(--bg); /* Set a background color */
  color: var(--link); /* Text color */
  cursor: pointer; /* Add a mouse pointer on hover */
  padding: 10px; /* Some padding */
  border-radius: 10px; /* Rounded corners */
  font-size: 18px; /* Increase font size */
}

#myBtn:hover {
  background-color: #555; /* Add a dark-grey background on hover */
}

footer {
  margin: 6rem 0 2rem;
  font-size: 0.9rem;
  opacity: 0.7;
}