/* ─── LESSON PAGE STYLES ─── */

/* Prevent any horizontal scroll globally on lesson pages */
html, body {
  overflow-x: hidden;
  max-width: 100%;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--muted);
  letter-spacing: 0.06em;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s;
}

.breadcrumb a:hover { color: var(--ink); }
.breadcrumb span { color: var(--border); }
.crumb-current { color: var(--ink); }

.lesson-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
  border-top: 1px solid var(--border);
  flex: 1;
  align-items: start;
  min-width: 0;
  overflow: hidden;
}

.lesson-nav {
  border-right: 1px solid var(--border);
  padding: 28px 24px 28px 0;
  position: sticky;
  top: 24px;
}

.lesson-nav-toggle {
  display: none;
  width: 100%;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: none;
  border: 1px solid var(--border);
  color: var(--ink);
  padding: 12px 16px;
  cursor: pointer;
  text-align: left;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0;
}

.lesson-nav-toggle-icon {
  font-size: 0.9rem;
  transition: transform 0.2s;
}

.lesson-nav-title {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 1.2rem;
  letter-spacing: 0.04em;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.lesson-nav-group {
  margin-bottom: 24px;
}

.lesson-nav-group-label {
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 6px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.lesson-nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  color: var(--muted);
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  transition: color 0.12s, padding-left 0.1s;
}

.lesson-nav-item:last-child { border-bottom: none; }

.lesson-nav-item:not(.locked):hover {
  color: var(--ink);
  padding-left: 5px;
}

.lesson-nav-item.current {
  color: var(--ink);
  font-weight: 600;
}

.lesson-nav-item.locked {
  opacity: 0.38;
  cursor: default;
  pointer-events: none;
}

.lni-num {
  font-size: 0.62rem;
  color: var(--border);
  min-width: 18px;
  flex-shrink: 0;
}

.lni-name { flex: 1; line-height: 1.4; }

.lni-check {
  font-size: 0.65rem;
  flex-shrink: 0;
}

.lni-check.done { color: #2a7a3b; }

.lesson-nav-progress {
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.progress-bar-track {
  width: 100%;
  height: 3px;
  background: var(--border);
  margin-bottom: 8px;
}

.progress-bar-fill {
  height: 100%;
  background: var(--accent);
}

.progress-label {
  font-size: 0.68rem;
  color: var(--muted);
  letter-spacing: 0.06em;
}

.lesson-content {
  padding: 36px 0 56px 48px;
  max-width: 740px;
  min-width: 0;
  overflow-x: hidden;
}

.lesson-header {
  margin-bottom: 36px;
}

.lesson-eyebrow {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.lesson-num-badge {
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 4px 10px;
}

.lesson-time {
  font-size: 0.7rem;
  color: var(--muted);
  letter-spacing: 0.08em;
}

.lesson-header h1 {
  font-family: 'Bebas Neue', sans-serif;
  font-size: clamp(2.8rem, 5vw, 4.2rem);
  line-height: 0.95;
  letter-spacing: 0.02em;
  margin-bottom: 18px;
}

.lesson-header h1 em {
  font-style: normal;
  color: var(--accent);
}

.lesson-intro {
  font-size: 1rem;
  color: var(--muted);
  line-height: 1.9;
  letter-spacing: 0.01em;
}

.lesson-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0 0 44px;
}

.lesson-section {
  margin-bottom: 48px;
}

.lesson-section h2 {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 1.9rem;
  letter-spacing: 0.03em;
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.lesson-section p {
  font-size: 0.95rem;
  color: var(--ink);
  line-height: 1.95;
  letter-spacing: 0.01em;
  margin-bottom: 18px;
}

.lesson-section p:last-child { margin-bottom: 0; }

.lesson-section strong {
  color: var(--ink);
  font-weight: 600;
}

.lesson-section code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.85rem;
  background: #e6e3dc;
  padding: 2px 6px;
  border-radius: 2px;
}

.code-block {
  background: #1a1a1a;
  margin: 22px 0 26px;
  overflow-x: auto;
  max-width: 100%;
  box-sizing: border-box;
}

.code-block-label {
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #666;
  padding: 10px 18px 8px;
  border-bottom: 1px solid #2a2a2a;
}

.code-block pre {
  padding: 22px 20px;
  margin: 0;
  overflow-x: auto;
  max-width: 100%;
  box-sizing: border-box;
}

.code-block code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.88rem;
  line-height: 1.9;
  background: none;
  padding: 0;
  color: #d4d0c8;
  white-space: pre;
  display: block;
}

.c-tag     { color: #e06c75; }
.c-attr    { color: #d19a66; }
.c-str     { color: #98c379; }
.c-comment { color: #5c6370; font-style: italic; }

.lesson-callout {
  border-left: 3px solid var(--accent);
  padding: 18px 22px;
  background: #ece9e2;
  margin: 0 0 44px;
}

.callout-label {
  font-size: 0.65rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}

.lesson-callout p {
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--ink);
  margin: 0;
}

.lesson-callout code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.84rem;
  background: #dedad2;
  padding: 2px 6px;
}

.anatomy-table {
  border-top: 1px solid var(--border);
  border-left: 1px solid var(--border);
  margin-top: 22px;
  overflow-x: auto;
  max-width: 100%;
  box-sizing: border-box;
}

.anatomy-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.anatomy-tag,
.anatomy-desc {
  padding: 14px 18px;
  font-size: 0.84rem;
  line-height: 1.6;
  letter-spacing: 0.01em;
}

.anatomy-tag {
  border-right: 1px solid var(--border);
  background: #ece9e2;
}

.anatomy-tag code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.82rem;
  color: var(--accent);
  background: none;
  padding: 0;
}

.anatomy-desc { color: var(--muted); }

.knowledge-check {
  border: 1px solid var(--border);
  padding: 28px;
  margin: 44px 0;
}

.kc-label {
  font-size: 0.67rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 14px;
}

.kc-question {
  font-size: 0.95rem;
  color: var(--ink);
  line-height: 1.65;
  letter-spacing: 0.01em;
  margin-bottom: 22px;
  font-weight: 600;
}

.kc-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.kc-option {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.84rem;
  letter-spacing: 0.02em;
  background: none;
  border: 1px solid var(--border);
  color: var(--ink);
  padding: 13px 18px;
  text-align: left;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
  display: flex;
  gap: 14px;
  align-items: center;
}

.kc-option span {
  color: var(--muted);
  font-size: 0.74rem;
  min-width: 16px;
  flex-shrink: 0;
}

.kc-option:not(:disabled):hover {
  background: #e8e5de;
  border-color: var(--ink);
}

.kc-option:disabled { cursor: default; }

.kc-option.correct {
  border-color: #2a7a3b;
  background: #eaf5ec;
  color: #2a7a3b;
}

.kc-option.wrong {
  border-color: var(--accent);
  background: #faeae5;
  color: var(--accent);
}

.kc-feedback {
  font-size: 0.78rem;
  line-height: 1.65;
  letter-spacing: 0.02em;
  margin-top: 18px;
  min-height: 1rem;
}

.kc-feedback.correct { color: #2a7a3b; }
.kc-feedback.wrong   { color: var(--accent); }

.lesson-footer-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-top: 1px solid var(--border);
  margin-top: 12px;
}

.lfn-prev,
.lfn-next {
  padding: 22px 0;
  text-decoration: none;
  color: inherit;
  transition: background 0.12s;
}

.lfn-prev {
  border-right: 1px solid var(--border);
  padding-right: 24px;
}

.lfn-next {
  padding-left: 24px;
  text-align: right;
}

.lfn-prev:not(.disabled):hover,
.lfn-next:hover { background: #e8e5de; }

.lfn-prev.disabled { opacity: 0.35; cursor: default; pointer-events: none; }

.lfn-label {
  font-size: 0.67rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 7px;
}

.lfn-title {
  font-size: 0.9rem;
  color: var(--ink);
  letter-spacing: 0.02em;
}

.lfn-next .lfn-title { color: var(--accent); }

/* ─── TABLET (max 900px) ─── */
@media (max-width: 900px) {
  .lesson-layout {
    grid-template-columns: 1fr;
  }

  .lesson-nav {
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 0;
    position: static;
  }

  .lesson-nav-toggle {
    display: flex;
  }

  .lesson-nav-body {
    display: none;
    padding: 20px 0;
    border-top: 1px solid var(--border);
  }

  .lesson-nav-body.open {
    display: block;
  }

  .lesson-nav-title {
    display: none;
  }

  .lesson-content {
    padding: 32px 0 44px;
  }
}

/* ─── MOBILE (max 600px) ─── */
@media (max-width: 600px) {
  .breadcrumb {
    font-size: 0.68rem;
    gap: 7px;
    margin-bottom: 28px;
  }

  .lesson-header h1 {
    font-size: clamp(2.4rem, 11vw, 3.4rem);
  }

  .lesson-intro {
    font-size: 0.92rem;
  }

  .lesson-section h2 {
    font-size: 1.6rem;
  }

  .lesson-section p {
    font-size: 0.9rem;
    line-height: 1.85;
  }

  .lesson-section code {
    font-size: 0.8rem;
  }

  .code-block code {
    font-size: 0.8rem;
    line-height: 1.75;
    white-space: pre-wrap;
    word-break: break-all;
  }

  .code-block pre {
    padding: 16px 14px;
  }

  .lesson-callout p {
    font-size: 0.86rem;
  }

  .anatomy-row {
    grid-template-columns: 1fr;
  }

  .anatomy-tag {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .anatomy-tag,
  .anatomy-desc {
    font-size: 0.8rem;
  }

  .knowledge-check {
    padding: 20px 16px;
  }

  .kc-question {
    font-size: 0.88rem;
  }

  .kc-option {
    font-size: 0.8rem;
    padding: 12px 14px;
  }

  .kc-feedback {
    font-size: 0.75rem;
  }

  .lesson-footer-nav {
    grid-template-columns: 1fr;
  }

  .lfn-prev {
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding-right: 0;
  }

  .lfn-next {
    padding-left: 0;
    text-align: left;
  }

  .lfn-title {
    font-size: 0.84rem;
  }
}

/* ─── SMALL MOBILE (max 380px) ─── */
@media (max-width: 380px) {
  .lesson-header h1 {
    font-size: clamp(2rem, 12vw, 2.8rem);
  }

  .lesson-section p {
    font-size: 0.86rem;
  }

  .code-block code {
    font-size: 0.74rem;
    white-space: pre-wrap;
    word-break: break-all;
  }
}