/* =============================
   BIẾN MÀU & FONT CHUNG / GLOBAL COLORS & FONT
   ============================= */
.section-post-template {
  --bg: #f9fafb;
  --panel: #ffffff;       
  --muted: #475569;       
  --text: #111827;        
  --accent: #0284c7;      
  --accent-2: #313d5d;
  --ok: #16a34a;          
  --warn: #d97706;        
  --danger: #dc2626;      
  --chip: #e2e8f0;        
  --card: #ffffff;        
  --shadow: 0 6px 18px rgba(0,0,0,.08);
  --round: 14px;

  font: 16px/1.6 system-ui, -apple-system, Segoe UI, Roboto, Inter, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  scroll-behavior: smooth;
  margin: 0;
}

/* =============================
   LAYOUT CHUNG / GENERAL LAYOUT
   ============================= */
.section-post-template .layout {
  display: flex;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
  gap: 20px;
}

/* =============================
   THANH MỤC LỤC (TOC) / TABLE OF CONTENTS (TOC)
   ============================= */
.section-post-template nav.toc {
  flex: 0 0 250px;
  align-self: flex-start;
  position: sticky;
  top: 20px;
  background: var(--panel);
  border: 1px solid #cbd5e1;
  border-radius: var(--round);
  padding: 18px 26px;
  height: max-content;
  box-shadow: var(--shadow);
}

.section-post-template nav.toc h3 {
  margin: 0 0 10px;
  font-size: 16px;
  text-transform: uppercase;
  text-align: center;
  color: var(--accent-2);
}

.section-post-template nav.toc ul {
  margin: 0;
  padding-left: 10px;
  list-style: none;
}

.section-post-template nav.toc li {
  margin: 10px 0;
}

.section-post-template nav.toc a {
  color: var(--accent-2);
  text-decoration: none;
  display: block;
  padding: 4px 6px;
  border-radius: 6px;
  transition: all .2s ease;
}

.section-post-template nav.toc a:hover {
  background: rgba(49,61,93,0.08);
  transform: translateX(4px);
}

.section-post-template nav.toc a.active {
  background: rgba(49,61,93,0.12);
  font-weight: 600;
}

/* =============================
   PHẦN NỘI DUNG CHÍNH / MAIN CONTENT AREA
   ============================= */
.section-post-template main.content {
  flex: 1;
}

/* =============================
   CẤU TRÚC SECTION & ANIMATION / SECTION STRUCTURE & ANIMATION
   ============================= */
.section-post-template section {
  background: var(--panel);
  border: 1px solid #cbd5e1;
  border-radius: var(--round);
  padding: 20px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
  opacity: 0; 
  transform: translateY(20px);
  transition: opacity .6s ease, transform .6s ease, background .4s ease;
  position: relative;
}

.section-post-template section.visible {
  opacity: 1;
  transform: translateY(0);
}

.section-post-template section h2 {
  margin-top: 0;
  font-size: 28px;
  color: var(--accent-2);
  position: relative;
  display: inline-block;
  transition: color .3s ease;
}

.section-post-template section.active {
  background: #f1f5f9;
}

.section-post-template section.active::before {
  content: "";
  position: absolute;
  top: 0; 
  left: 0;
  width: 6px; 
  height: 100%;
  background: var(--accent-2);
  transform: scaleY(0);
  transform-origin: top;
  animation: markerSlide .4s forwards;
  border-top-left-radius: var(--round);
  border-bottom-left-radius: var(--round);
}

@keyframes markerSlide {
  to { transform: scaleY(1); }
}

.section-post-template section.active h2 { 
  color: var(--accent); 
}

.section-post-template section h2::after {
  content: "";
  position: absolute;
  bottom: -4px; 
  left: 0;
  width: 0; 
  height: 3px;
  background: var(--accent-2);
  transition: width .4s ease;
}

.section-post-template section h2:hover::after { 
  width: 100%; 
}

/* =============================
   HỘP GHI CHÚ (CALLOUT) / CALLOUT BOX
   ============================= */
.section-post-template .callout {
  border-left: 4px solid var(--accent);
  background: #f0f9ff;
  padding: 12px 14px 12px 40px;
  border-radius: 8px;
  margin: 14px 0;
  position: relative;
}

/* =============================
   THẺ NỘI DUNG (CARD) / CONTENT CARD
   ============================= */
.section-post-template .card {
  background: var(--card);
  border: 1px solid #cbd5e1;
  border-radius: var(--round);
  padding: 16px;
  margin: 14px 0;
  box-shadow: var(--shadow);
  transition: all .25s ease;
}

.section-post-template .card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 20px rgba(0,0,0,.15);
}

/* =============================
   PHẦN TÀI LIỆU THAM KHẢO / REFERENCES SECTION
   ============================= */
.section-post-template #refs h2 {
  text-align: center;
  font-size: 22px;
  color: var(--accent-2);
}

/* =============================
   ẢNH & FIGURE / IMAGES & FIGURE
   ============================= */
.section-post-template figure { 
  text-align: center; 
  margin: 16px 0; 
}

.section-post-template .img-wrap {
  width: 100%; 
  overflow: hidden; 
  border-radius: 12px; 
  border: 1px solid #e5e7eb;
}

.section-post-template .img {
  width: 100%; 
  display: block; 
  margin: auto; 
  height: auto;
}

.section-post-template figcaption {
  font-size: 13px; 
  color: #6b7280; 
  margin-top: 8px; 
  text-align: center;
}