/* Learn R lesson styling — uses site-wide CSS variables for dark mode */

/* Course landing page lesson cards */
.lesson-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.lesson-card {
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 1.25rem;
  background: var(--card-bg);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
  display: flex;
  flex-direction: column;
  box-shadow: 0 2px 8px var(--card-shadow);
}

.lesson-card:hover {
  box-shadow: 0 6px 18px var(--card-shadow);
  transform: translateY(-2px);
}

.lesson-card .lesson-number {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted-text);
  margin-bottom: 0.25rem;
}

.lesson-card h3 {
  margin: 0 0 0.5rem 0;
  font-size: 1.15rem;
}

.lesson-card h3 a {
  color: var(--link-color);
  text-decoration: none;
}

.lesson-card h3 a:hover {
  text-decoration: underline;
}

.lesson-card p {
  font-size: 0.95rem;
  color: var(--text-color);
  flex-grow: 1;
  margin-bottom: 0.5rem;
}

.lesson-card .lesson-time {
  font-size: 0.85rem;
  color: var(--muted-text);
  margin-top: auto;
}

/* Callout boxes */
.callout {
  border-left: 4px solid var(--card-border);
  padding: 0.75rem 1rem;
  margin: 1rem 0;
  background: var(--well-bg);
  border-radius: 0 4px 4px 0;
}

.callout-title {
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.callout-tip {
  border-left-color: #28a745;
}

.callout-tip .callout-title { color: #28a745; }

.callout-note {
  border-left-color: var(--link-color);
}

.callout-note .callout-title { color: var(--link-color); }

.callout-warning {
  border-left-color: #f0ad4e;
}

.callout-warning .callout-title { color: #d18a1a; }

[data-theme="dark"] .callout-warning .callout-title { color: #f0ad4e; }

/* Exercise blocks */
.exercise {
  border: 1px solid var(--card-border);
  border-left: 4px solid var(--link-color);
  background: var(--card-bg);
  padding: 1rem 1.25rem;
  margin: 1.25rem 0;
  border-radius: 0 6px 6px 0;
}

.exercise-title {
  font-weight: 600;
  color: var(--link-color);
  margin-bottom: 0.5rem;
}

.exercise details {
  margin-top: 0.75rem;
}

.exercise details > summary {
  cursor: pointer;
  color: var(--link-color);
  font-weight: 500;
  user-select: none;
  padding: 0.25rem 0;
}

.exercise details > summary:hover {
  text-decoration: underline;
}

.exercise details[open] > summary {
  margin-bottom: 0.5rem;
}

/* Prev/next lesson navigation */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin: 2.5rem 0 1.5rem 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--card-border);
}

.lesson-nav > p {
  display: flex;
  width: 100%;
  gap: 1rem;
  margin: 0;
}

.lesson-nav a {
  flex: 1;
  max-width: 48%;
  padding: 0.85rem 1rem;
  border: 1px solid var(--card-border);
  border-radius: 6px;
  text-decoration: none !important;
  color: var(--text-color) !important;
  background: var(--card-bg);
  transition: background 0.15s ease, border-color 0.15s ease;
}

.lesson-nav a:hover {
  border-color: var(--link-color);
}

.lesson-nav .lesson-nav-label {
  display: block;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted-text);
  margin-bottom: 0.15rem;
}

.lesson-nav .lesson-nav-title {
  font-weight: 500;
}

.lesson-nav .nav-prev {
  text-align: left;
}

.lesson-nav .nav-next {
  text-align: right;
  margin-left: auto;
}

.lesson-nav .nav-placeholder {
  visibility: hidden;
}

/* Course mini-progress at top of each lesson */
.course-progress {
  font-size: 0.9rem;
  color: var(--muted-text);
  margin: 0.5rem 0 1.5rem 0;
  padding: 0.6rem 0.9rem;
  background: var(--well-bg);
  border-radius: 4px;
  border-left: 3px solid var(--link-color);
}

.course-progress a {
  color: var(--link-color);
  text-decoration: none;
}

.course-progress a:hover {
  text-decoration: underline;
}

/* Inline keyboard / file path styling */
kbd {
  display: inline-block;
  padding: 1px 6px;
  font-size: 0.85em;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  background: var(--code-bg);
  color: var(--text-color);
  border: 1px solid var(--card-border);
  border-bottom-width: 2px;
  border-radius: 3px;
}