:root {
  --course-red: #d92a2a;
  --course-blue: #4471eb;
  --course-dark: #1c1e21;
  --course-yellow: #fff59d;
  --course-text: #22252a;
  --course-muted: #667085;
  --course-border: #e2e5ea;
  --course-surface: #f6f7f9;
  --course-white: #fff;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--course-text);
  background: var(--course-white);
  font-family: "Roboto", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

a {
  color: var(--course-blue);
}

a:hover,
a:focus {
  color: #2f58c8;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 8px;
  left: 8px;
  padding: 8px 12px;
  color: var(--course-dark);
  background: var(--course-yellow);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.course-hero {
  color: var(--course-white);
  background: var(--course-dark);
}

.course-hero__inner,
.course-nav__inner,
.course-page,
.course-footer {
  width: min(100% - 40px, 980px);
  margin-right: auto;
  margin-left: auto;
}

.course-hero__inner {
  padding: 72px 0 64px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--course-red);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.course-hero .eyebrow {
  color: var(--course-yellow);
}

.course-home-link,
.course-home-link:hover,
.course-home-link:focus {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--course-yellow);
  text-decoration: none;
}

.course-home-link:hover,
.course-home-link:focus {
  opacity: 0.82;
}

.course-home-link__arrow {
  min-width: 30px;
  font-size: 32px;
  line-height: 1;
  transition: transform 0.15s ease;
}

.course-home-link:hover .course-home-link__arrow,
.course-home-link:focus .course-home-link__arrow {
  transform: translateX(-3px);
}

.course-hero h1 {
  max-width: 800px;
  margin: 0;
  color: var(--course-white);
  font-size: clamp(38px, 7vw, 64px);
  line-height: 1.05;
}

.course-hero__lead {
  max-width: 680px;
  margin: 22px 0 0;
  font-size: 22px;
}

.course-hero__languages {
  max-width: 760px;
  margin: 32px 0 0;
  color: #d7d9dd;
}

.course-page {
  padding: 56px 0 80px;
}

.course-page--home {
  padding-top: 32px;
}

.course-page h1,
.course-page h2,
.course-page h3,
.course-rendered-content h1,
.course-rendered-content h2,
.course-rendered-content h3,
.course-rendered-content h4 {
  color: var(--course-red);
  font-family: "Roboto", Arial, sans-serif;
  font-weight: 700;
}

.course-page h1,
.course-rendered-content h1 {
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1.1;
}

.course-page h2,
.course-rendered-content h2 {
  font-size: 30px;
  line-height: 1.2;
}

.course-page h3,
.course-rendered-content h3 {
  font-size: 23px;
}

.resource-section {
  width: 100%;
  margin: 0;
}

.resource-section + .resource-section {
  margin-top: 10px;
}

.resource-section summary {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
}

.resource-section summary::-webkit-details-marker {
  display: none;
}

.resource-section summary::after {
  margin-left: auto;
  color: var(--course-blue);
  content: "+";
  font-size: 24px;
  font-weight: 400;
  line-height: 1;
}

.resource-section[open] summary::after {
  content: "−";
}

.resource-section__title {
  color: var(--course-red);
  font-size: 30px;
  font-weight: 700;
  line-height: 1.2;
}

.resource-table-wrap {
  width: 100%;
  overflow-x: auto;
  padding-bottom: 14px;
}

.resource-table {
  display: table;
  width: 100%;
  min-width: 540px;
  table-layout: fixed;
  border-collapse: collapse;
  text-align: left;
}

.resource-table th {
  padding: 9px 12px;
  color: var(--course-muted);
  background: var(--course-surface);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.resource-table td {
  padding: 13px 12px;
  border-top: 1px solid var(--course-border);
  vertical-align: middle;
}

.resource-table tbody tr:hover td {
  background: var(--course-surface);
}

.resource-title {
  width: 65%;
}

.resource-link {
  color: var(--course-blue);
  font-weight: 700;
  text-decoration: none;
}

.resource-link:hover,
.resource-link:focus {
  text-decoration: underline;
}

.resource-file {
  color: var(--course-muted);
  font-family: Menlo, Monaco, Consolas, "Courier New", monospace;
  font-size: 12px;
}

.course-nav {
  position: sticky;
  z-index: 100;
  top: 0;
  color: var(--course-white);
  background: var(--course-dark);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.course-nav__inner {
  display: flex;
  min-height: 58px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.course-nav a {
  text-decoration: none;
}

.course-nav__brand,
.course-nav__brand:hover,
.course-nav__brand:focus {
  color: var(--course-yellow);
  font-weight: 700;
}

.course-nav__links {
  display: flex;
  align-items: center;
  gap: 18px;
}

.course-nav__links a {
  color: var(--course-white);
  font-size: 14px;
}

.course-nav__links a:hover,
.course-nav__links a:focus {
  color: var(--course-yellow);
}

.course-nav__source {
  padding-left: 18px;
  border-left: 1px solid rgba(255, 255, 255, 0.24);
}

.page-heading {
  margin-bottom: 32px;
}

.page-heading h1 {
  margin: 0;
}

.page-summary {
  margin-top: 14px;
  color: var(--course-muted);
}

.source-code,
.course-rendered-content pre {
  overflow-x: auto;
  padding: 18px;
  color: #f4f4f4;
  background: var(--course-dark);
  border: 0;
  border-radius: 6px;
  font-family: Menlo, Monaco, Consolas, "Courier New", monospace;
  font-size: 13px;
  line-height: 1.55;
  white-space: pre;
}

.source-code code,
.course-rendered-content pre code {
  padding: 0;
  color: inherit;
  background: transparent;
  font: inherit;
  white-space: inherit;
}

.course-rendered-content {
  width: min(100% - 40px, 980px);
  margin: 0 auto;
  padding: 34px 0 72px;
}

.course-rendered-content > .main-container,
.course-rendered-content .main-container {
  width: 100%;
  max-width: none;
  padding-right: 0;
  padding-left: 0;
}

.course-rendered-content table {
  width: 100%;
}

.course-rendered-content img {
  max-width: 100%;
  height: auto;
}

.course-footer {
  padding: 26px 0 54px;
  color: var(--course-muted);
  border-top: 1px solid var(--course-border);
  font-size: 14px;
}

.course-footer p {
  margin: 0;
}

.not-found {
  min-height: 70vh;
  padding-top: 15vh;
}

.not-found h1 {
  margin-bottom: 12px;
}

@media (max-width: 700px) {
  .course-hero__inner {
    padding: 52px 0 48px;
  }

  .course-hero__lead {
    font-size: 19px;
  }

  .resource-section summary {
    gap: 10px;
  }

  .resource-section__title {
    font-size: 24px;
  }

  .course-nav__inner {
    min-height: 64px;
    align-items: flex-start;
    flex-direction: column;
    gap: 3px;
    padding: 10px 0;
  }

  .course-nav__links {
    width: 100%;
    justify-content: space-between;
  }
}

@media print {
  .course-nav,
  .skip-link,
  .course-footer {
    display: none;
  }

  .course-rendered-content,
  .course-page {
    width: 100%;
    padding: 0;
  }
}