:root {
  --font-family: "Segoe UI", Arial, sans-serif;
  --line-height: 1.6;
  --background-color: #35424a;
  --header-color: #ffffff;
  --article-border-color: #35424a;
  --article-background: #f9f9f9;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-family);
  line-height: var(--line-height);
  margin: 0;
  padding: 0;
  background-color: var(--background-color);
  scroll-behavior: smooth;
}

.id-card {
  width: 324px;
  height: auto;
  margin: 0 auto;
  display: block;
}

header {
  color: var(--header-color);
  background: var(--background-color);
  padding: 10px 0;
  text-align: center;
  position: sticky;
  top: 0;
}

nav a {
  color: var(--header-color);
  text-decoration: none;
  padding: 10px 15px;
}

section {
  width: 50%;
  margin: 20px auto;
  padding: 20px;
  background: var(--header-color);
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

main {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background-color: #f4f4f4;
  min-height: 100dvh;
  overflow: auto;
}

h1 {
  text-align: center;
}

h1,
h2 {
  color: var(--header-background);
}

article {
  margin-bottom: 20px;
  padding: 15px;
  border-left: 5px solid var(--article-border-color);
  background: var(--article-background);
}

footer {
  text-align: center;
  padding: 10px 0;
  background: var(--background-color);
  color: var(--header-color);
  position: sticky;
  bottom: 0;
}

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

@media (max-width: 767px) {
  section {
    width: 90%;
  }

  .id-card {
    width: 100%;
    height: auto;
    margin: 0 auto;
    display: block;
  }
}