/* Общие стили */
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f7f9fc;
  color: #333;
  line-height: 1.6;
  margin: 0;
  padding: 20px;
}

main {
  max-width: 800px;
  margin: 40px auto;
  background: white;
  padding: 40px;
  border-radius: 14px;
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.1);
}

/* Заголовки */
h1 {
  font-size: 2.8em;
  color: #2c3e50;
  text-align: center;
  margin-bottom: 8px;
  font-weight: 600;
}

h2 {
  font-size: 1.5em;
  color: #7f8c8d;
  text-align: center;
  margin-top: 0;
  margin-bottom: 30px;
  font-weight: 400;
}

h3 {
  color: #3498db;
  border-bottom: 2px solid #ecf0f1;
  padding-bottom: 10px;
  margin-top: 30px;
  font-weight: 500;
}

/* Секции */
section {
  margin-bottom: 28px;
}

section p {
  margin-bottom: 12px;
  font-size: 1em;
  color: #555;
}

/* Список */
ul {
  list-style-type: none;
  padding-left: 0;
}

ul li {
  margin-bottom: 10px;
  position: relative;
  padding-left: 24px;
  font-size: 1em;
  color: #444;
}

ul li::before {
  content: "•";
  color: #3498db;
  font-size: 1.4em;
  position: absolute;
  left: 8px;
  top: -2px;
  font-weight: bold;
}

/* Адаптивность */
@media (max-width: 600px) {
  main {
    padding: 24px;
    margin: 20px;
  }
  h1 {
    font-size: 2.3em;
  }
  h2 {
    font-size: 1.3em;
  }
  section {
    margin-bottom: 24px;
  }
}