/* === ARTICLE STYLES === */
/* Used by all pillar and sub-pages (Pattern A/B/C/D) */

/* === BREADCRUMB === */
.art-breadcrumb {
  padding: 20px 0 0;
  font-size: 13px;
  color: #6b7280;
}
.art-breadcrumb a { color: #6b7280; }
.art-breadcrumb a:hover { color: #f97316; }
.art-breadcrumb .sep { margin: 0 8px; color: #9ca3af; }

/* === ARTICLE WRAP === */
.art-wrap {
  max-width: 820px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

/* === ARTICLE HEADER === */
.art-header { margin-bottom: 40px; }
.art-header h1 {
  font-size: 38px;
  font-weight: 900;
  line-height: 1.2;
  color: #111827;
  margin-bottom: 16px;
}
.art-meta {
  font-size: 14px;
  color: #6b7280;
}
.art-meta span { margin-right: 16px; }

/* === ARTICLE INTRO === */
.art-intro {
  font-size: 18px;
  line-height: 1.8;
  color: #374151;
  padding: 24px 0;
  border-bottom: 1px solid #e5e7eb;
  margin-bottom: 32px;
}

/* === TABLE OF CONTENTS (Pattern A pillar pages) === */
.art-toc {
  background: #f8fafc;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 24px 28px;
  margin-bottom: 40px;
}
.art-toc h2 {
  font-size: 16px;
  font-weight: 700;
  color: #6b7280;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 12px;
}
.art-toc ol {
  list-style: decimal;
  padding-left: 20px;
}
.art-toc li {
  padding: 6px 0;
  font-size: 15px;
}
.art-toc a { color: #1d4ed8; }
.art-toc a:hover { color: #f97316; }

/* === CONTENT BODY === */
.art-body h2 {
  font-size: 28px;
  font-weight: 800;
  color: #111827;
  margin: 48px 0 16px;
  padding-top: 16px;
}
.art-body h3 {
  font-size: 22px;
  font-weight: 700;
  color: #1f2937;
  margin: 32px 0 12px;
}
.art-body h4 {
  font-size: 18px;
  font-weight: 700;
  color: #374151;
  margin: 24px 0 10px;
}
.art-body p {
  font-size: 16px;
  line-height: 1.8;
  color: #374151;
  margin-bottom: 18px;
}
.art-body ul, .art-body ol {
  margin: 16px 0 24px;
  padding-left: 24px;
}
.art-body li {
  font-size: 16px;
  line-height: 1.7;
  color: #374151;
  margin-bottom: 8px;
}
.art-body strong { color: #111827; font-weight: 700; }
.art-body blockquote {
  border-left: 3px solid #f97316;
  padding: 16px 24px;
  margin: 24px 0;
  background: #fff7ed;
  border-radius: 0 8px 8px 0;
  color: #6b7280;
  font-style: italic;
}
.art-body code {
  background: #f3f4f6;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 14px;
  color: #dc2626;
  font-family: "JetBrains Mono", "Fira Code", monospace;
}
.art-body pre {
  background: #0a1628;
  border: 1px solid #1e293b;
  border-radius: 12px;
  padding: 20px 24px;
  overflow-x: auto;
  margin: 24px 0;
}
.art-body pre code {
  background: none;
  padding: 0;
  font-size: 14px;
  color: #e2e8f0;
}
.art-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 15px;
}
.art-body th {
  background: #f8fafc;
  color: #111827;
  font-weight: 700;
  text-align: left;
  padding: 12px 16px;
  border-bottom: 2px solid #e5e7eb;
}
.art-body td {
  padding: 12px 16px;
  border-bottom: 1px solid #e5e7eb;
  color: #374151;
}
.art-body tr:hover td { background: #f9fafb; }
.art-body img {
  border-radius: 12px;
  margin: 24px 0;
}
.art-body a { color: #1d4ed8; text-decoration: underline; text-decoration-color: rgba(29,78,216,0.3); }
.art-body a:hover { color: #f97316; text-decoration-color: rgba(249,115,22,0.3); }

/* === HOW-TO STEPS (Pattern C) === */
.art-steps { counter-reset: step-counter; margin: 32px 0; }
.art-step {
  counter-increment: step-counter;
  position: relative;
  padding: 24px 24px 24px 72px;
  margin-bottom: 16px;
  background: #f8fafc;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
}
.art-step::before {
  content: counter(step-counter);
  position: absolute;
  left: 20px;
  top: 24px;
  width: 36px;
  height: 36px;
  background: #fff7ed;
  border: 2px solid #fed7aa;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 800;
  color: #f97316;
}
.art-step h3 {
  font-size: 18px;
  font-weight: 700;
  color: #111827;
  margin: 0 0 8px;
}
.art-step p {
  font-size: 15px;
  line-height: 1.7;
  color: #6b7280;
  margin: 0;
}

/* === Q&A SECTION (Pattern D) === */
.art-qa { margin: 32px 0; }
.art-qa-item {
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  margin-bottom: 16px;
  overflow: hidden;
}
.art-qa-question {
  padding: 20px 24px;
  background: #f8fafc;
  font-size: 17px;
  font-weight: 700;
  color: #111827;
}
.art-qa-answer {
  padding: 20px 24px;
  font-size: 15px;
  line-height: 1.7;
  color: #6b7280;
}

/* === PILLAR GRID (Pattern A sub-page listing) === */
.art-pillar-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin: 32px 0; }
.art-pillar-link {
  display: block;
  padding: 16px 20px;
  background: #ffffff;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  color: #374151;
  font-size: 15px;
  font-weight: 600;
  transition: border-color 0.15s, color 0.15s, box-shadow 0.15s;
  text-decoration: none;
}
.art-pillar-link:hover {
  border-color: #f97316;
  color: #f97316;
  box-shadow: 0 4px 12px rgba(249,115,22,0.08);
}

/* === RELATED ARTICLES === */
.art-related {
  margin-top: 60px;
  padding-top: 40px;
  border-top: 1px solid #e5e7eb;
}
.art-related h2 {
  font-size: 22px;
  font-weight: 800;
  color: #111827;
  margin-bottom: 20px;
}
.art-related-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.art-related-item {
  display: block;
  padding: 16px 20px;
  background: #f8fafc;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  text-decoration: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.art-related-item:hover { border-color: #f97316; box-shadow: 0 4px 12px rgba(249,115,22,0.08); }
.art-related-item h3 { font-size: 15px; font-weight: 600; color: #111827; margin-bottom: 4px; }
.art-related-item p { font-size: 13px; color: #6b7280; margin: 0; }

/* === FORMULA/EQUATION BLOCKS === */
.art-formula {
  background: #f8fafc;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 20px 24px;
  margin: 24px 0;
  text-align: center;
  font-size: 18px;
  font-family: "JetBrains Mono", "Fira Code", monospace;
  color: #0a1628;
  letter-spacing: 0.5px;
}

/* === KEY TAKEAWAY BOX === */
.art-takeaway {
  background: #fff7ed;
  border: 1px solid #fed7aa;
  border-radius: 12px;
  padding: 20px 24px;
  margin: 32px 0;
}
.art-takeaway-title {
  font-size: 14px;
  font-weight: 700;
  color: #f97316;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}
.art-takeaway p { font-size: 15px; line-height: 1.7; color: #374151; margin: 0; }

/* === RESPONSIVE === */
@media (max-width: 768px) {
  .art-wrap { padding: 24px 16px 60px; }
  .art-header h1 { font-size: 28px; }
  .art-intro { font-size: 16px; }
  .art-body h2 { font-size: 24px; }
  .art-body h3 { font-size: 19px; }
  .art-pillar-grid { grid-template-columns: 1fr; }
  .art-related-grid { grid-template-columns: 1fr; }
  .art-step { padding-left: 60px; }
  .art-step::before { left: 14px; width: 32px; height: 32px; font-size: 14px; }
}

@media (max-width: 480px) {
  .art-header h1 { font-size: 24px; }
  .art-body h2 { font-size: 22px; }
}