.b,
.text-b {
  font-weight: 600;
}

h1 {
  font-size: 2.5em; /* 40px at default browser settings */
  font-weight: bold;
  color: #333;
  margin-bottom: 0.5em;
  line-height: 1.2;
}

h2 {
  font-size: 2em; /* 32px */
  font-weight: 600;
  color: #444;
  margin-bottom: 0.4em;
  line-height: 1.3;
}

h3 {
  font-size: 1.75em; /* 28px */
  font-weight: 500;
  color: #555;
  margin-bottom: 0.3em;
  line-height: 1.4;
}

h4 {
  font-size: 1.5em; /* 24px */
  font-weight: 400;
  color: #666;
  margin-bottom: 0.2em;
  line-height: 1.5;
}

h5 {
  font-size: 1.25em; /* 20px */
  font-weight: 400;
  color: #777;
  margin-bottom: 0.2em;
  line-height: 1.6;
}