:root {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  color: #1f2937;
  background-color: #f9fafb;
}

body {
  max-width: 720px;
  margin: 2rem auto;
  padding: 1.5rem;
  background-color: #ffffff;
  border-radius: 12px;
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.1);
  line-height: 1.6;
}

h1,
h2,
h3,
h4 {
  color: #0f172a;
}

h1 {
  margin-top: 0;
}

section,
article,
nav,
ul {
  margin-bottom: 1.5rem;
}

ul {
  padding-left: 1.25rem;
}

a {
  color: #2563eb;
}

a:hover,
a:focus {
  color: #1d4ed8;
}

nav a {
  margin-right: 0.75rem;
}

footer {
  border-top: 1px solid #e2e8f0;
  padding-top: 1rem;
}