* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #ffffff;
  color: #202122;
  font-family: Georgia, "Times New Roman", Times, serif;
  line-height: 1.65;
  font-size: 17px;
}

a {
  color: #0645ad;
  text-decoration: none;
}

a:hover,
a:focus {
  text-decoration: underline;
}

.page {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}

.layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 26px;
}

.toc {
  position: sticky;
  top: 16px;
  align-self: start;
  max-height: calc(100vh - 32px);
  overflow: auto;
  border: 1px solid #c8ccd1;
  background: #f8f9fa;
  padding: 12px;
}

.toc h2 {
  margin: 0 0 10px;
  font-size: 15px;
  font-family: Arial, Helvetica, sans-serif;
  border-bottom: 1px solid #c8ccd1;
  padding-bottom: 6px;
}

.toc ol {
  margin: 0;
  padding-left: 22px;
}

.toc li {
  margin: 7px 0;
  font-size: 14px;
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.4;
}

.toc a.active {
  font-weight: 700;
  color: #202122;
}

.article {
  min-width: 0;
}

h1 {
  margin: 2px 0 8px;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 39px;
  font-weight: 400;
  line-height: 1.2;
}

.last-updated {
  margin: 0 0 18px;
  color: #54595d;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 13px;
}

h2 {
  margin: 34px 0 10px;
  padding-bottom: 5px;
  border-bottom: 1px solid #a2a9b1;
  font-family: Arial, Helvetica, sans-serif;
  font-weight: 400;
  font-size: 31px;
}

h3 {
  margin: 24px 0 8px;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 24px;
  font-weight: 600;
}

p {
  margin: 0 0 16px;
}

ul {
  margin: 0 0 16px;
  padding-left: 22px;
}

li {
  margin: 6px 0;
}

.intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 18px;
  margin-bottom: 8px;
}

.lead {
  border: 1px solid #c8ccd1;
  background: #f8f9fa;
  padding: 16px;
  font-size: 20px;
  line-height: 1.6;
}

.infobox {
  border: 1px solid #a2a9b1;
  background: #f8f9fa;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 14px;
}

.infobox h3 {
  margin: 0;
  text-align: center;
  padding: 10px;
  font-size: 18px;
  background: #dce8f6;
  border-bottom: 1px solid #a2a9b1;
}

.infobox table {
  width: 100%;
  border-collapse: collapse;
}

.infobox th,
.infobox td {
  border-top: 1px solid #c8ccd1;
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

.infobox th {
  width: 42%;
  font-weight: 700;
}

.key-points {
  border-left: 3px solid #a2a9b1;
  padding: 0 0 0 14px;
  margin: 0 0 20px;
}

.faq-block dt {
  font-weight: 700;
  font-family: Arial, Helvetica, sans-serif;
  margin: 20px 0 6px;
}

.faq-block dd {
  margin: 0 0 14px;
}

.article-footer {
  margin-top: 50px;
  border-top: 1px solid #c8ccd1;
  padding-top: 14px;
  font-size: 14px;
  color: #54595d;
  font-family: Arial, Helvetica, sans-serif;
}

@media (max-width: 1080px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
    max-height: none;
  }

  .intro-grid {
    grid-template-columns: 1fr;
  }
}