:root {
  --bg: #fffdf8;
  --surface: #ffffff;
  --text: #2b2117;
  --muted: #7a6a58;
  --border: #e8ddce;
  --brand: #891918;
  --brand-dark: #701312;
  --brand-soft: #fdf4f3;
  --good: #1f7a3d;
  --bad: #b3261e;
  --sidebar-bg: #faf3e8;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(43, 33, 23, 0.08), 0 6px 20px rgba(43, 33, 23, 0.06);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
}

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  background: var(--brand);
  color: #fff;
  box-shadow: var(--shadow);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 60px;
}

.site-brand {
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.2px;
}

.site-nav a {
  color: #fff;
  text-decoration: none;
  padding: 6px 14px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 999px;
  font-size: 0.9rem;
  transition: background 0.15s ease;
}

.site-nav a:hover {
  background: rgba(255, 255, 255, 0.15);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 60px;
  padding: 20px 0;
  color: var(--muted);
  font-size: 0.9rem;
}

/* Home */
.home-hero {
  padding: 48px 20px 12px;
  max-width: 780px;
  margin: 0 auto;
  text-align: center;
}

.home-hero h1 {
  font-size: 2.1rem;
  margin: 0 0 10px;
  color: var(--brand-dark);
}

.home-hero .lead {
  font-size: 1.15rem;
  color: var(--muted);
  margin: 0;
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

.course-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  color: var(--text);
  text-decoration: none;
  overflow: hidden;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.course-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(43, 33, 23, 0.14);
}

.course-card-cover {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--sidebar-bg);
}

.course-card-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.course-card-body {
  padding: 18px 20px 20px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.course-card-body h2 {
  margin: 0 0 8px;
  font-size: 1.25rem;
  color: var(--brand-dark);
}

.course-card-body p {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 0.95rem;
}

.course-facts {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  font-size: 0.9rem;
  color: var(--muted);
}

.course-facts span {
  font-weight: 600;
  color: var(--text);
}

.course-card-cta {
  margin-top: auto;
  color: var(--brand);
  font-weight: 700;
}

/* Course layout */
.course-layout {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 32px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 32px 20px;
  align-items: start;
}

.course-sidebar {
  position: sticky;
  top: 16px;
  background: var(--sidebar-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.course-cover {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 16px;
}

.course-back {
  display: inline-block;
  margin-bottom: 14px;
  color: var(--brand);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
}

.course-back:hover {
  text-decoration: underline;
}

.course-sidebar-title {
  margin: 0 0 14px;
  font-size: 1.25rem;
  color: var(--brand-dark);
  line-height: 1.25;
}

.course-nav-title {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin: 18px 0 8px;
}

.course-nav ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

.course-nav li {
  border-bottom: 1px dashed var(--border);
}

.course-nav a {
  display: block;
  padding: 7px 4px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.9rem;
  line-height: 1.4;
}

.course-nav a:hover {
  color: var(--brand);
}

.course-nav li.current a {
  background: var(--brand);
  color: #fff;
  border-radius: 6px;
  padding: 7px 10px;
  margin: 2px 0;
}

.course-content {
  min-width: 0;
}

.breadcrumb {
  margin: 0 0 6px;
  color: var(--muted);
  font-size: 0.85rem;
}

.breadcrumb a {
  color: var(--brand);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.section-title {
  font-size: 2rem;
  color: var(--brand-dark);
  margin: 6px 0 18px;
  line-height: 1.2;
}

/* Section pager */
.section-pager {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 44px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.pager-link {
  flex: 1;
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  padding: 12px 16px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.pager-link:hover {
  border-color: var(--brand);
  box-shadow: var(--shadow);
}

.pager-link.next {
  text-align: right;
}

.pager-link.disabled {
  opacity: 0.45;
  pointer-events: none;
}

.pager-label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-bottom: 4px;
}

.pager-title {
  font-weight: 600;
  color: var(--brand-dark);
}

.course-content h2 {
  font-size: 1.6rem;
  color: var(--brand-dark);
  margin: 48px 0 10px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.course-content h2:first-child {
  border-top: 0;
  margin-top: 0;
}

.course-content h3 {
  color: var(--brand);
  margin: 28px 0 8px;
}

.course-content p {
  margin: 12px 0;
}

.course-content ul,
.course-content ol:not(.options, .questions) {
  padding-left: 22px;
}

.course-content a {
  color: var(--brand);
}

.course-content table {
  border-collapse: collapse;
  width: 100%;
  max-width: 480px;
  margin: 16px 0;
}

.course-content th,
.course-content td {
  border: 1px solid var(--border);
  padding: 8px 14px;
  text-align: left;
}

.course-content th {
  background: var(--sidebar-bg);
}

.course-content img {
  max-width: 100%;
  border-radius: 8px;
}

.img-15-width {
  width: 15%;
}

/* Video */
.video {
  position: relative;
  width: 100%;
  max-width: 720px;
  aspect-ratio: 16 / 9;
  background: #000;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  margin: 20px 0;
}

.video iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* Quizzes and exercises */
.quiz,
.exercise {
  border: 1px solid var(--border);
  border-left: 4px solid var(--brand);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px 22px;
  margin: 26px 0;
  box-shadow: var(--shadow);
}

.quiz-title,
.exercise-title {
  font-size: 1.1rem;
  margin: 0 0 10px;
  color: var(--brand-dark);
}

.questions {
  list-style: none;
  margin: 0;
  padding: 0;
}

.question {
  padding: 14px 0;
  border-top: 1px dashed var(--border);
}

.question:first-child {
  border-top: 0;
}

.question-text {
  font-weight: 600;
  margin: 0 0 8px;
}

.options {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 6px;
}

.options .option label {
  display: flex;
  gap: 10px;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  background: var(--bg);
  transition: border-color 0.12s ease, background 0.12s ease;
}

.options .option label:hover {
  border-color: var(--brand);
  background: var(--brand-soft);
}

.options .option input {
  accent-color: var(--brand);
  margin-top: 3px;
}

.options .option.is-correct label {
  border-color: var(--good);
  background: #eaf6ee;
  color: var(--good);
}

.options .option.is-wrong label {
  border-color: var(--bad);
  background: #fbe9e7;
  color: var(--bad);
}

.quiz-submit,
.exercise-submit {
  margin-top: 16px;
  background: var(--brand);
  color: #fff;
  border: 0;
  border-radius: 8px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease;
}

.quiz-submit:hover,
.exercise-submit:hover {
  background: var(--brand-dark);
}

.quiz-result,
.exercise-result {
  margin-top: 10px;
  font-weight: 600;
}

.quiz-result.good,
.exercise-result.good {
  color: var(--good);
}

.quiz-result.bad,
.exercise-result.bad {
  color: var(--bad);
}

.empty-state {
  text-align: center;
  color: var(--muted);
  margin-top: 60px;
}

/* Responsive */
@media (max-width: 880px) {
  .course-layout {
    grid-template-columns: 1fr;
  }

  .course-sidebar {
    position: static;
  }

  .course-nav ol {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 0 16px;
  }
}