/* ─────────────────────────────────────────────────────────────────── */
/* DOCUMENTATION STANDARDS CSS                                         */
/* Reading time, difficulty levels, TOC, collapsible sections         */
/* ─────────────────────────────────────────────────────────────────── */

/* ─── Metadata Display ─────────────────────────────────────────────── */
.doc-metadata {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  align-items: center;
  padding: 1.5rem;
  background: rgba(99, 102, 241, 0.05);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: 12px;
  margin-bottom: 2rem;
  font-size: 0.95rem;
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--muted);
}

.meta-label {
  font-weight: 600;
  color: var(--text);
}

.meta-value {
  color: var(--accent);
}

/* ─── Difficulty Badges ────────────────────────────────────────────── */
.difficulty-badge {
  display: inline-block;
  padding: 0.4rem 1rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  white-space: nowrap;
}

.difficulty-beginner {
  background: rgba(59, 130, 246, 0.2);
  color: #60A5FA;
  border: 1px solid rgba(59, 130, 246, 0.4);
}

.difficulty-intermediate {
  background: rgba(139, 92, 246, 0.2);
  color: #A78BFA;
  border: 1px solid rgba(139, 92, 246, 0.4);
}

.difficulty-advanced {
  background: rgba(245, 158, 11, 0.2);
  color: #FBBF24;
  border: 1px solid rgba(245, 158, 11, 0.4);
}

.difficulty-expert {
  background: rgba(239, 68, 68, 0.2);
  color: #F87171;
  border: 1px solid rgba(239, 68, 68, 0.4);
}

/* ─── Reading Time ────────────────────────────────────────────────── */
.reading-time {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: 8px;
  color: #6EE7B7;
  font-size: 0.9rem;
  font-weight: 500;
}

.reading-time::before {
  content: '⏱';
}

/* ─── Prerequisites ────────────────────────────────────────────────── */
.prerequisites {
  padding: 1.5rem;
  background: rgba(245, 158, 11, 0.05);
  border-left: 4px solid #FBBF24;
  border-radius: 8px;
  margin-bottom: 2rem;
}

.prerequisites h4 {
  font-family: var(--fd, 'Space Grotesk', sans-serif);
  color: #FBBF24;
  margin-bottom: 1rem;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.prerequisites ul {
  list-style: none;
  padding-left: 0;
}

.prerequisites li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--sub);
}

.prerequisites li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: #FBBF24;
  font-weight: 700;
}

/* ─── Table of Contents ────────────────────────────────────────────── */
.doc-toc {
  position: sticky;
  top: 80px;
  padding: 1.5rem;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-bottom: 2rem;
  max-height: 80vh;
  overflow-y: auto;
}

.doc-toc-title {
  font-weight: 700;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.doc-toc-title::before {
  content: '≡';
  font-size: 1.2rem;
}

.doc-toc-list {
  list-style: none;
  padding: 0;
}

.doc-toc-item {
  padding: 0.4rem 0;
}

.doc-toc-link {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  transition: all 0.2s;
  display: block;
}

.doc-toc-link:hover {
  background: rgba(99, 102, 241, 0.1);
  color: var(--accent);
}

.doc-toc-link.active {
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent);
  font-weight: 600;
  padding-left: 1rem;
}

.doc-toc-item.level-1 { padding-left: 0; }
.doc-toc-item.level-2 { padding-left: 1rem; }
.doc-toc-item.level-3 { padding-left: 2rem; }

/* ─── Reading Progress ────────────────────────────────────────────── */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: transparent;
  z-index: 999;
  pointer-events: none;
}

.reading-progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), #A78BFA);
  width: 0%;
  transition: width 0.2s ease;
}

/* ─── Collapsible Sections ────────────────────────────────────────── */
.collapsible-section {
  margin: 1.5rem 0;
}

.collapsible-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem;
  background: rgba(99, 102, 241, 0.08);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.2s;
  user-select: none;
}

.collapsible-header:hover {
  background: rgba(99, 102, 241, 0.12);
  border-color: rgba(99, 102, 241, 0.4);
}

.collapsible-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 4px;
  background: rgba(99, 102, 241, 0.2);
  color: var(--accent);
  font-size: 1.2rem;
  line-height: 1;
  transition: transform 0.3s;
  flex-shrink: 0;
}

.collapsible-header.expanded .collapsible-toggle {
  transform: rotate(180deg);
}

.collapsible-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  padding-left: 1rem;
}

.collapsible-header.expanded + .collapsible-content {
  max-height: 2000px;
  padding: 1rem 0 1rem 1rem;
}

.collapsible-content > * {
  opacity: 0;
  animation: slideIn 0.3s ease 0.1s forwards;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ─── Code Blocks & Copy Button ────────────────────────────────────── */
.code-block-wrapper {
  position: relative;
  margin: 1.5rem 0;
}

code, pre {
  font-family: 'Courier New', monospace;
}

pre {
  background: #0F1419;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.copy-code-button {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  padding: 0.4rem 0.75rem;
  background: rgba(99, 102, 241, 0.2);
  border: 1px solid rgba(99, 102, 241, 0.4);
  color: var(--accent);
  border-radius: 6px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
  z-index: 10;
}

.copy-code-button:hover {
  background: rgba(99, 102, 241, 0.3);
  border-color: rgba(99, 102, 241, 0.6);
}

.copy-code-button.copied {
  background: rgba(16, 185, 129, 0.2);
  border-color: rgba(16, 185, 129, 0.4);
  color: #6EE7B7;
}

.copy-code-button.copied::after {
  content: '✓ Copied!';
}

/* ─── Article Version Info ────────────────────────────────────────── */
.article-version {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  padding: 1rem 1.5rem;
  background: rgba(255, 255, 255, 0.03);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin: 2rem 0;
  font-size: 0.9rem;
  color: var(--muted);
}

.version-item {
  display: flex;
  gap: 0.5rem;
}

.version-item strong {
  color: var(--text);
}

/* ─── Callout Boxes ────────────────────────────────────────────────── */
.callout {
  padding: 1.5rem;
  border-left: 4px solid;
  border-radius: 8px;
  margin: 1.5rem 0;
}

.callout-note {
  background: rgba(59, 130, 246, 0.08);
  border-color: #60A5FA;
  color: var(--text);
}

.callout-warning {
  background: rgba(245, 158, 11, 0.08);
  border-color: #FBBF24;
  color: var(--text);
}

.callout-tip {
  background: rgba(16, 185, 129, 0.08);
  border-color: #6EE7B7;
  color: var(--text);
}

.callout-danger {
  background: rgba(239, 68, 68, 0.08);
  border-color: #F87171;
  color: var(--text);
}

.callout strong {
  display: block;
  margin-bottom: 0.5rem;
  font-family: var(--fd, 'Space Grotesk', sans-serif);
  text-transform: uppercase;
  font-size: 0.85rem;
  letter-spacing: 0.05em;
}

/* ─── Print Styles ────────────────────────────────────────────────── */
@media print {
  nav, footer, .doc-toc, .reading-progress, .copy-code-button {
    display: none;
  }

  body {
    color: #000;
    background: #fff;
  }

  .article-content {
    max-width: 100%;
  }

  h1, h2, h3, h4, h5, h6 {
    page-break-after: avoid;
  }

  p {
    page-break-inside: avoid;
  }

  pre {
    background: #f5f5f5;
    color: #000;
    border: 1px solid #ddd;
  }

  a {
    color: #0366d6;
    text-decoration: underline;
  }

  .doc-metadata {
    background: #f5f5f5;
    color: #000;
    border: 1px solid #ddd;
  }
}

/* ─── Responsive ────────────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .doc-toc {
    position: relative;
    top: 0;
    max-height: none;
    margin-bottom: 2rem;
  }
}

@media (max-width: 768px) {
  .doc-metadata {
    flex-direction: column;
    gap: 1rem;
    align-items: flex-start;
  }

  .copy-code-button {
    top: 0.5rem;
    right: 0.5rem;
    padding: 0.3rem 0.6rem;
    font-size: 0.75rem;
  }

  pre {
    padding: 1rem;
    font-size: 0.85rem;
  }
}

/* ─── Reduced Motion ────────────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}