/* ==========================================================================
   HÀ NỘI ĐƯA "BÌNH DÂN HỌC VỤ SỐ" ĐẾN TỪNG NGƯỜI DÂN
   Longform Báo Chí Kinh Tế – Chính Luận Cao Cấp
   Thiết kế: Đỏ đô thị, Xanh công nghệ, Trắng tinh bản báo
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;0,6..72,600;0,6..72,700;1,6..72,400;1,6..72,600&family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Space+Grotesk:wght@500;700&display=swap');

/* --- Design Tokens --- */
:root {
  /* Color Palette */
  --c-red-urban: #B91C1C;         /* Đỏ đô thị Hà Nội - trang trọng, lắng đọng */
  --c-red-deep: #991B1B;
  --c-red-soft: #FEF2F2;
  --c-red-border: #FCA5A5;

  --c-blue-tech: #0369A1;        /* Xanh công nghệ - tri thức số, hiện đại */
  --c-blue-cobalt: #1D4ED8;
  --c-blue-cyan: #0284C7;
  --c-blue-deep: #0F172A;
  --c-blue-soft: #F0F9FF;
  --c-blue-border: #BAE6FD;

  --c-bg-page: #FAF8F5;          /* Màu giấy báo in cao cấp (warm paper) */
  --c-bg-card: #FFFFFF;
  --c-bg-subtle: #F1F5F9;

  --c-text-primary: #1E293B;     /* Mực in than chì sắc nét, êm mắt */
  --c-text-secondary: #475569;
  --c-text-muted: #64748B;
  --c-text-light: #94A3B8;

  --c-border: #E2E8F0;
  --c-border-strong: #CBD5E1;

  /* Typography Scales */
  --font-serif: 'Newsreader', Georgia, 'Times New Roman', serif;
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Space Grotesk', monospace;

  --text-base-size: 1.1875rem;   /* 19px: Cỡ chữ đọc longform hoàn hảo */
  --line-height-body: 1.82;

  /* Spacing */
  --col-text: 740px;             /* Bề rộng cột chữ chuẩn tỷ lệ vàng báo chí */
  --col-breakout: 1040px;        /* Độ rộng cho ảnh và infographic minh họa */
  --col-wide: 1200px;

  /* Transitions */
  --transition-smooth: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Dark mode subtle support */
[data-theme="dark"] {
  --c-bg-page: #0B0F19;
  --c-bg-card: #131A29;
  --c-bg-subtle: #1E293B;
  --c-text-primary: #F1F5F9;
  --c-text-secondary: #CBD5E1;
  --c-text-muted: #94A3B8;
  --c-border: #243046;
  --c-border-strong: #334155;
  --c-red-soft: #2D1418;
  --c-blue-soft: #08233C;
}

/* Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background-color: var(--c-bg-page);
  color: var(--c-text-primary);
  line-height: var(--line-height-body);
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

/* --- Reading Progress Bar --- */
#reading-progress-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3.5px;
  background: rgba(226, 232, 240, 0.4);
  z-index: 1000;
}

#reading-progress-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--c-red-urban) 0%, var(--c-blue-cyan) 60%, var(--c-blue-cobalt) 100%);
  transition: width 0.1s linear;
}

/* --- Top Editorial Header Bar --- */
.editorial-topbar {
  border-bottom: 1px solid var(--c-border);
  background: rgba(250, 248, 245, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 900;
  font-size: 0.8125rem;
}

[data-theme="dark"] .editorial-topbar {
  background: rgba(11, 15, 25, 0.92);
}

.topbar-inner {
  max-width: var(--col-wide);
  margin: 0 auto;
  padding: 10px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.topbar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-badge {
  background-color: var(--c-red-urban);
  color: #FFFFFF;
  font-size: 0.6875rem;
  font-weight: 700;
  padding: 3px 8px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: 2px;
}

.brand-title {
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--c-text-primary);
  letter-spacing: 0.02em;
}

.topbar-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  color: var(--c-text-muted);
}

.reading-time {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.reading-time svg {
  width: 14px;
  height: 14px;
  stroke: currentColor;
}

.font-resizer {
  display: flex;
  align-items: center;
  gap: 6px;
  border-left: 1px solid var(--c-border);
  padding-left: 16px;
}

.btn-icon {
  background: transparent;
  border: 1px solid var(--c-border);
  color: var(--c-text-secondary);
  border-radius: 4px;
  padding: 3px 8px;
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.btn-icon:hover {
  background: var(--c-bg-card);
  color: var(--c-red-urban);
  border-color: var(--c-red-urban);
}

/* --- Hero & Article Header --- */
.article-header {
  max-width: var(--col-breakout);
  margin: 0 auto;
  padding: 60px 24px 36px 24px;
  position: relative;
}

.kicker-wrapper {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.kicker-bar {
  width: 32px;
  height: 2px;
  background-color: var(--c-red-urban);
}

.kicker-tag {
  color: var(--c-red-urban);
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.kicker-divider {
  color: var(--c-border-strong);
}

.kicker-date {
  font-size: 0.8125rem;
  color: var(--c-text-muted);
  font-weight: 500;
}

/* Article Main Headline */
.article-headline {
  font-family: var(--font-serif);
  font-size: clamp(2.35rem, 5.5vw, 3.85rem);
  font-weight: 700;
  line-height: 1.18;
  color: var(--c-text-primary);
  letter-spacing: -0.025em;
  margin-bottom: 32px;
}

/* Lead & Sapo Box */
.lead-section {
  border-left: 3px solid var(--c-red-urban);
  padding: 4px 0 4px 28px;
  margin-bottom: 36px;
}

.article-sapo {
  font-family: var(--font-serif);
  font-size: clamp(1.25rem, 2.2vw, 1.48rem);
  font-weight: 500;
  line-height: 1.62;
  color: var(--c-text-primary);
  margin-bottom: 20px;
}

.article-intro {
  font-family: var(--font-sans);
  font-size: 1.125rem;
  line-height: 1.78;
  color: var(--c-text-secondary);
  font-weight: 400;
}

/* Author byline */
.byline-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
  padding: 16px 0;
  margin-top: 28px;
  font-size: 0.875rem;
}

.byline-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author-indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-red-urban);
}

.author-label {
  color: var(--c-text-muted);
  font-weight: 500;
}

.author-name {
  font-weight: 700;
  color: var(--c-text-primary);
  letter-spacing: 0.01em;
}

.byline-scope {
  color: var(--c-blue-tech);
  font-weight: 600;
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* --- Section Navigation Bar --- */
.quick-nav {
  max-width: var(--col-text);
  margin: 32px auto 48px auto;
  padding: 16px 20px;
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: 6px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02);
}

.quick-nav-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-text-muted);
  margin-bottom: 10px;
}

.quick-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.quick-nav-item a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
  color: var(--c-text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.quick-nav-num {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--c-blue-cyan);
}

.quick-nav-item a:hover {
  color: var(--c-red-urban);
  transform: translateX(4px);
}

/* --- Article Main Content Stream --- */
.article-stream {
  width: 100%;
}

.article-section {
  padding: 40px 0 20px 0;
  position: relative;
}

.article-section:not(:last-of-type)::after {
  content: "";
  display: block;
  width: 60px;
  height: 2px;
  background-color: var(--c-border-strong);
  margin: 56px auto 20px auto;
}

/* Section Header */
.section-header-wrap {
  max-width: var(--col-text);
  margin: 0 auto 32px auto;
  padding: 0 24px;
}

.section-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--c-red-urban);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.85rem, 3.8vw, 2.5rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--c-text-primary);
  letter-spacing: -0.02em;
}

/* Reading Prose Column */
.prose-column {
  max-width: var(--col-text);
  margin: 0 auto;
  padding: 0 24px;
  font-size: var(--text-base-size);
  line-height: var(--line-height-body);
  color: var(--c-text-primary);
}

.prose-column p {
  margin-bottom: 1.85em;
  font-weight: 400;
  text-align: justify;
  text-justify: inter-word;
}

/* Drop Cap on initial section paragraph */
.has-dropcap::first-letter {
  font-family: var(--font-serif);
  float: left;
  font-size: 4.65rem;
  line-height: 0.82;
  padding-top: 6px;
  padding-right: 14px;
  padding-bottom: 4px;
  color: var(--c-red-urban);
  font-weight: 700;
}

/* Highlight Quote in text */
.editorial-pullquote {
  border-top: 2px solid var(--c-blue-cyan);
  border-bottom: 1px solid var(--c-border);
  padding: 24px 16px;
  margin: 40px 0;
  background: var(--c-bg-card);
  border-radius: 4px;
}

.pullquote-text {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-style: italic;
  line-height: 1.55;
  color: var(--c-blue-deep);
  margin-bottom: 12px;
}

[data-theme="dark"] .pullquote-text {
  color: #E2E8F0;
}

.pullquote-attribution {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--c-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* --- Visual Media Breakout (16:9 Illustrations & Infographics) --- */
.media-breakout {
  max-width: var(--col-breakout);
  margin: 48px auto;
  padding: 0 24px;
}

.visual-container {
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 10px 30px -10px rgba(15, 23, 42, 0.07);
  transition: var(--transition-smooth);
}

.visual-container:hover {
  box-shadow: 0 16px 36px -10px rgba(15, 23, 42, 0.12);
  border-color: var(--c-border-strong);
}

.visual-figure {
  width: 100%;
  position: relative;
  background-color: #FFFFFF;
}

.visual-image {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.visual-caption-bar {
  padding: 18px 24px;
  background: var(--c-bg-card);
  border-top: 1px solid var(--c-border);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.caption-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-blue-tech);
}

.caption-text {
  font-size: 0.9375rem;
  line-height: 1.58;
  color: var(--c-text-secondary);
}

/* --- Editorial Data Callout Cards (Rich Data Companions) --- */
.data-dashboard-strip {
  max-width: var(--col-text);
  margin: 36px auto 44px auto;
  padding: 0 24px;
}

.data-grid-2x2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.data-stat-card {
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-top: 3px solid var(--c-blue-tech);
  border-radius: 4px;
  padding: 20px;
  position: relative;
  transition: var(--transition-smooth);
}

.data-stat-card.accent-red {
  border-top-color: var(--c-red-urban);
}

.data-stat-card:hover {
  transform: translateY(-2px);
  border-color: var(--c-border-strong);
}

.stat-metric {
  font-family: var(--font-mono);
  font-size: 2.15rem;
  font-weight: 700;
  line-height: 1;
  color: var(--c-blue-deep);
  margin-bottom: 8px;
}

[data-theme="dark"] .stat-metric {
  color: #FFFFFF;
}

.stat-metric.red-val {
  color: var(--c-red-urban);
}

.stat-label {
  font-size: 0.875rem;
  line-height: 1.45;
  color: var(--c-text-muted);
  font-weight: 500;
}

/* Section 3 Horizon Targets Matrix */
.target-matrix-wrapper {
  max-width: var(--col-text);
  margin: 36px auto 44px auto;
  padding: 0 24px;
}

.target-matrix {
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: 6px;
  overflow: hidden;
}

.target-matrix-header {
  background: var(--c-bg-subtle);
  padding: 14px 20px;
  border-bottom: 1px solid var(--c-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.matrix-title {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-text-primary);
}

.matrix-scope {
  font-size: 0.75rem;
  color: var(--c-text-muted);
}

.target-matrix-body {
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.target-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 12px;
  border-bottom: 1px dashed var(--c-border);
}

.target-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.target-desc {
  font-size: 0.9375rem;
  color: var(--c-text-secondary);
  line-height: 1.45;
}

.target-pill {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.875rem;
  padding: 4px 10px;
  border-radius: 4px;
  background: var(--c-blue-soft);
  color: var(--c-blue-tech);
  border: 1px solid var(--c-blue-border);
}

.target-pill.red-pill {
  background: var(--c-red-soft);
  color: var(--c-red-urban);
  border-color: var(--c-red-border);
}

/* --- Article Conclusion & Author Signoff --- */
.article-signoff {
  max-width: var(--col-text);
  margin: 48px auto 80px auto;
  padding: 0 24px;
}

.signoff-box {
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-left: 4px solid var(--c-red-urban);
  padding: 24px 28px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.signoff-author-line {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.signoff-author-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-text-muted);
}

.signoff-author-name {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--c-text-primary);
}

.signoff-city-stamp {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--c-blue-tech);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 6px 14px;
  background: var(--c-bg-subtle);
  border-radius: 4px;
}

/* --- Footer --- */
.editorial-footer {
  border-top: 1px solid var(--c-border);
  background: var(--c-bg-subtle);
  padding: 48px 24px;
  font-size: 0.875rem;
  color: var(--c-text-muted);
}

.footer-inner {
  max-width: var(--col-wide);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.footer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  border-bottom: 1px solid var(--c-border);
  padding-bottom: 20px;
}

.footer-brand {
  font-weight: 700;
  color: var(--c-text-primary);
  letter-spacing: 0.02em;
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a {
  color: var(--c-text-secondary);
  text-decoration: none;
  transition: var(--transition-smooth);
}

.footer-links a:hover {
  color: var(--c-red-urban);
}

.footer-bottom {
  font-size: 0.8125rem;
  line-height: 1.6;
}

/* --- Floating Utilities --- */
.floating-back-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 44px;
  height: 44px;
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--c-text-primary);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: var(--transition-smooth);
  z-index: 800;
}

.floating-back-top.show {
  opacity: 1;
  pointer-events: auto;
}

.floating-back-top:hover {
  background: var(--c-red-urban);
  color: #FFFFFF;
  border-color: var(--c-red-urban);
  transform: translateY(-3px);
}

/* --- Responsive Media Queries --- */
@media (max-width: 860px) {
  .editorial-topbar {
    padding: 0;
  }
  
  .topbar-meta .reading-time {
    display: none;
  }

  .article-header {
    padding: 40px 20px 24px 20px;
  }

  .lead-section {
    padding-left: 18px;
  }

  .media-breakout {
    padding: 0 16px;
    margin: 32px auto;
  }

  .data-grid-2x2 {
    grid-template-columns: 1fr;
  }

  .byline-wrapper {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .signoff-box {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .prose-column p {
    text-align: left;
  }
}

@media print {
  #reading-progress-container,
  .editorial-topbar,
  .quick-nav,
  .floating-back-top,
  .btn-icon {
    display: none !important;
  }

  body {
    background: #FFFFFF !important;
    color: #000000 !important;
  }

  .prose-column {
    font-size: 11pt;
    line-height: 1.5;
  }
}