/* Reset & Base Article */
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  color: #1e293b;
  background-color: #f1f5f9;
  line-height: 1.6;
}
a { color: #0284c7; text-decoration: none; }

/* 1. Sticky Nav */
nav.sticky-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #0369a1;
  color: #ffffff;
  padding: 12px 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.12);
}
.nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1280px;
  margin: 0 auto;
  flex-wrap: wrap;
  gap: 12px;
}
.brand-logo { font-size: 20px; font-weight: 700; color: #bae6fd; }
ul.nav-menu {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 16px;
  flex-wrap: wrap;
}
ul.nav-menu li a {
  color: #ffffff;
  font-weight: 600;
  font-size: 13.5px;
  padding: 5px 10px;
  border-radius: 4px;
}
ul.nav-menu li a:hover { background: #075985; }

/* 2. Main Layout Flexbox */
main.article-page-main {
  padding: 24px;
  max-width: 1280px;
  margin: 0 auto;
  min-height: 900px;
}
.article-two-cols {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 24px;
  flex-wrap: wrap;
}
.col-article-body {
  flex: 3.5 1 660px;
}

/* Relative / Absolute pairs */
.article-header-card {
  position: relative;
  background: #ffffff;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  padding: 32px 24px 20px;
  margin-bottom: 20px;
}
.abs-badge {
  position: absolute;
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
}
.editor-badge {
  top: 14px;
  left: 14px;
  background: #0284c7;
  color: #ffffff;
}
.read-time-pill {
  top: 14px;
  right: 14px;
  background: #e2e8f0;
  color: #334155;
}
.article-header-card h2 { margin: 12px 0 8px; font-size: 24px; color: #0f172a; line-height: 1.3; }
.article-lead { font-size: 15px; color: #475569; margin: 0 0 16px; }
.author-bar { font-size: 13px; color: #64748b; }
.verified-tick {
  display: inline-block;
  background: #e0f2fe;
  color: #0369a1;
  padding: 2px 8px;
  border-radius: 999px;
  font-weight: 700;
  margin-left: 8px;
}

/* 3. Khối hover giải nghĩa thuật ngữ */
.term-hover-interactive {
  position: relative;
  margin-bottom: 20px;
}
.hover-term-trigger {
  display: inline-block;
  background: #f0f9ff;
  color: #0369a1;
  border: 1px dashed #0284c7;
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 600;
  cursor: help;
}
.hover-term-flyout {
  display: none;
  position: absolute;
  top: 110%;
  left: 0;
  z-index: 50;
  background: #0f172a;
  color: #f8fafc;
  padding: 16px;
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.25);
  width: 340px;
}
.term-hover-interactive:hover .hover-term-flyout {
  display: block;
}
.hover-term-flyout h4 { margin: 0 0 6px; font-size: 13px; color: #38bdf8; }
.hover-term-flyout p { margin: 0; font-size: 12px; color: #cbd5e1; }

/* 4. 6 Thẻ Flexbox kích thước không đều */
.sections-flex-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
  align-items: stretch;
  gap: 16px;
}
.section-card {
  background: #ffffff;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  padding: 16px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}
.section-card.b1 { flex: 2.7 1 330px; }
.section-card.b2 { flex: 1 1 160px; }
.section-card.b3 { flex: 1.4 1 200px; align-self: flex-start; }
.section-card.b4 { flex: 2 1 250px; }
.section-card.b5 { flex: 1.1 1 170px; }
.section-card.b6.highlight-conclusion {
  flex: 2.5 1 310px;
  order: -1;
  background: #f0f9ff;
  border-color: #7dd3fc;
}
.sec-label {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: #e2e8f0;
  color: #475569;
  margin-bottom: 6px;
}
.highlight-label { background: #bae6fd; color: #0369a1; }
.section-card h3 { margin: 0 0 6px; font-size: 15px; color: #0f172a; }
.section-card p { margin: 0; font-size: 13px; color: #475569; }

/* Display none */
.draft-footnote-hidden { display: none; }

/* 5. Cột mục lục Sticky & Iframe */
aside.col-sticky-toc {
  flex: 1 1 280px;
  position: sticky;
  top: 70px;
  align-self: flex-start;
  background: #ffffff;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  padding: 18px;
}
aside.col-sticky-toc h3 { margin: 0 0 10px; font-size: 15px; color: #0369a1; }
.toc-list { margin: 0 0 16px; padding-left: 18px; font-size: 13px; color: #475569; }
.toc-list li { margin-bottom: 6px; }
aside.col-sticky-toc h4 { margin: 0 0 6px; font-size: 14px; color: #0f172a; }
aside.col-sticky-toc p { margin: 0 0 10px; font-size: 12.5px; color: #64748b; }
.embedded-podcast {
  width: 100%;
  height: 180px;
  border: none;
  border-radius: 6px;
}

/* 6. Footer */
footer.article-footer {
  background: #0c4a6e;
  color: #e0f2fe;
  padding: 28px 24px;
  margin-top: 40px;
}
.footer-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 20px;
  max-width: 1280px;
  margin: 0 auto;
}
.footer-col { flex: 1 1 220px; }
.footer-col h4 { margin: 0 0 10px; font-size: 15px; color: #ffffff; }
.footer-col p { margin: 0; font-size: 13px; color: #bae6fd; }
.footer-col ul { list-style: none; margin: 0; padding: 0; font-size: 13px; }
.footer-col ul li { margin-bottom: 6px; color: #bae6fd; }