/* ==========================================================================
   KIẾN TRÚC GIAO DIỆN HIỆN ĐẠI (MODERN TECH EDITORIAL)
   NGUYENVIETNGOC.IO.VN — PERSONAL TECH HUB
   ========================================================================== */

:root {
  /* Color Palette - Dark Mode (Default) */
  --bg-primary: #070a12;
  --bg-surface: #0e1526;
  --bg-card: rgba(19, 29, 51, 0.75);
  --bg-card-hover: rgba(28, 43, 75, 0.85);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(34, 211, 238, 0.35);

  --accent-cyan: #22d3ee;
  --accent-cyan-dark: #0891b2;
  --accent-blue: #38bdf8;
  --accent-purple: #a855f7;
  --accent-emerald: #10b981;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --nav-bg: rgba(11, 15, 25, 0.85);
  --dock-bg: rgba(14, 21, 38, 0.92);

  /* Unified Button System - Dark */
  --btn-primary-bg: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
  --btn-primary-color: #ffffff;
  --btn-primary-shadow: 0 4px 16px rgba(6, 182, 212, 0.3);
  --btn-primary-shadow-hover: 0 6px 22px rgba(6, 182, 212, 0.45);

  --btn-secondary-bg: rgba(255, 255, 255, 0.05);
  --btn-secondary-border: rgba(255, 255, 255, 0.15);
  --btn-secondary-color: #f8fafc;
  --btn-secondary-hover-border: #22d3ee;
  --btn-secondary-hover-color: #22d3ee;
  --btn-secondary-hover-bg: rgba(34, 211, 238, 0.08);

  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px rgba(34, 211, 238, 0.18);
  --shadow-purple-glow: 0 0 25px rgba(168, 85, 247, 0.2);

  --transition-fast: 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Light Mode Variables */
[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-surface: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --border-color: #e2e8f0;
  --border-glow: rgba(8, 145, 178, 0.35);

  --accent-cyan: #0891b2;
  --accent-cyan-dark: #0e7490;
  --accent-blue: #0284c7;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;

  --nav-bg: rgba(255, 255, 255, 0.88);
  --dock-bg: rgba(255, 255, 255, 0.95);

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 25px -5px rgba(0, 0, 0, 0.08);
  --shadow-glow: 0 0 20px rgba(8, 145, 178, 0.14);

  /* Unified Button System - Light */
  --btn-primary-bg: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
  --btn-primary-color: #ffffff;
  --btn-primary-shadow: 0 4px 14px rgba(6, 182, 212, 0.25);
  --btn-primary-shadow-hover: 0 6px 20px rgba(6, 182, 212, 0.38);

  --btn-secondary-bg: #ffffff;
  --btn-secondary-border: #cbd5e1;
  --btn-secondary-color: #0f172a;
  --btn-secondary-hover-border: #0891b2;
  --btn-secondary-hover-color: #0891b2;
  --btn-secondary-hover-bg: rgba(8, 145, 178, 0.05);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Background Subtle Ambient Glows */
body::before, body::after {
  content: '';
  position: fixed;
  border-radius: 50%;
  filter: blur(140px);
  z-index: -1;
  pointer-events: none;
  opacity: 0.45;
}

body::before {
  top: -10%;
  right: -5%;
  width: 550px;
  height: 550px;
  background: radial-gradient(circle, rgba(34, 211, 238, 0.2), transparent 70%);
}

body::after {
  top: 40%;
  left: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(168, 85, 247, 0.15), transparent 70%);
}

a {
  color: inherit;
  text-decoration: none;
}

button, input, textarea {
  font-family: inherit;
  font-size: inherit;
}

img, svg {
  display: block;
  max-width: 100%;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
}

.gradient-text {
  background: linear-gradient(135deg, #ffffff 10%, #38bdf8 55%, #22d3ee 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="light"] .gradient-text {
  background: linear-gradient(135deg, #0f172a 15%, #0284c7 65%, #0891b2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-text-cyan {
  background: linear-gradient(135deg, #ffffff 20%, #22d3ee 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="light"] .gradient-text-cyan {
  background: linear-gradient(135deg, #0f172a 20%, #0891b2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Section Header Component */
.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.9rem;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-cyan);
  background: rgba(34, 211, 238, 0.08);
  border: 1px solid rgba(34, 211, 238, 0.25);
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}

[data-theme="light"] .section-tag {
  color: #0891b2;
  background: rgba(8, 145, 178, 0.08);
  border-color: rgba(8, 145, 178, 0.25);
}

.section-title {
  font-size: 2.25rem;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto;
}

/* --------------------------------------------------------------------------
   Header & Navbar (Sticky Glassmorphism)
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  background: var(--nav-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  z-index: 100;
  transition: all var(--transition-normal);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.brand-logo-img {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  display: block;
  object-fit: contain;
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.45);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.brand-logo:hover .brand-logo-img {
  transform: scale(1.08) rotate(3deg);
  box-shadow: 0 0 22px rgba(6, 182, 212, 0.7);
}

.logo-badge {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.4);
  background: transparent;
  overflow: hidden;
}

.logo-badge img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
}

.brand-sub {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-left: 4px;
  letter-spacing: 0.04em;
  display: inline-block;
  transition: color var(--transition-normal);
}

[data-theme="light"] .brand-sub {
  color: #0891b2;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  position: relative;
  padding: 0.4rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--accent-cyan);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent-cyan);
  border-radius: 2px;
  box-shadow: 0 0 8px var(--accent-cyan);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.action-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-primary);
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.action-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.lang-toggle-btn {
  padding: 0 0.85rem;
  height: 40px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lang-toggle-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.55rem 1.25rem;
  font-size: 0.88rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--btn-primary-bg);
  color: var(--btn-primary-color) !important;
  border: 1.5px solid transparent;
  cursor: pointer;
  box-shadow: var(--btn-primary-shadow);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--btn-primary-shadow-hover);
  filter: brightness(1.05);
  color: #ffffff !important;
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero-section {
  padding: 5.5rem 0 4.5rem;
  position: relative;
}

.hero-container {
  max-width: 960px;
  margin: 0 auto;
  text-align: center;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.95fr;
  align-items: center;
  gap: 3.5rem;
}

.hero-badge-wrap {
  display: flex;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.hero-headline {
  font-size: 3.25rem;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
}

.hero-title-prefix {
  font-weight: 500;
  color: var(--text-secondary);
  display: block;
  font-size: 1.35rem;
  margin-bottom: 0.35rem;
}

.hero-headline .sub-name {
  display: block;
  font-size: 1.85rem;
  color: var(--text-secondary);
  font-weight: 500;
  margin-bottom: 0.4rem;
}

.hero-tagline {
  max-width: 700px;
  margin: 0 auto 1.75rem;
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.hero-quote-box {
  position: relative;
  max-width: 650px;
  margin: 0 auto 2.25rem;
  text-align: center;
  padding: 1.1rem 1.4rem;
  border-radius: var(--radius-md);
  background: rgba(34, 211, 238, 0.04);
  border-left: 3px solid var(--accent-cyan);
}

[data-theme="light"] .hero-quote-box {
  background: #f1f5f9;
  border-left: 3px solid #0891b2;
}

.hero-quote-text {
  font-size: 0.95rem;
  font-style: italic;
  color: var(--text-primary);
  line-height: 1.55;
}

[data-theme="light"] .hero-quote-text {
  color: #334155;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.85rem;
  margin-bottom: 2.75rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.92rem;
  line-height: 1.4;
  border-radius: var(--radius-full);
  background: var(--btn-primary-bg);
  color: var(--btn-primary-color) !important;
  border: 1.5px solid transparent;
  cursor: pointer;
  box-shadow: var(--btn-primary-shadow);
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--btn-primary-shadow-hover);
  filter: brightness(1.06);
  color: #ffffff !important;
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.92rem;
  line-height: 1.4;
  border-radius: var(--radius-full);
  background: var(--btn-secondary-bg);
  color: var(--btn-secondary-color) !important;
  border: 1.5px solid var(--btn-secondary-border);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn-secondary:hover {
  border-color: var(--btn-secondary-hover-border);
  color: var(--btn-secondary-hover-color) !important;
  background: var(--btn-secondary-hover-bg);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:active {
  transform: translateY(0);
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: 2.25rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-value {
  font-size: 1.85rem;
  font-weight: 800;
  font-family: var(--font-heading);
  color: var(--accent-cyan);
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Hero Tech Graphic Showcase */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.tech-showcase-card {
  position: relative;
  width: 100%;
  max-width: 440px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(20px);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.tech-showcase-card:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
}

.avatar-badge-wrap {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-bottom: 1.75rem;
}

.avatar-photo {
  width: 76px;
  height: 76px;
  border-radius: 50%;
  padding: 3px;
  background: linear-gradient(135deg, #22d3ee, #a855f7);
  box-shadow: 0 0 20px rgba(34, 211, 238, 0.4);
}

.avatar-photo img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  background-color: var(--bg-surface);
}

.engineer-title {
  font-size: 1.2rem;
  font-weight: 700;
}

.engineer-status {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.8rem;
  color: var(--accent-emerald);
  font-family: var(--font-mono);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-emerald);
  box-shadow: 0 0 8px var(--accent-emerald);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

.code-terminal-box {
  background: rgba(0, 0, 0, 0.45);
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.05);
  padding: 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
}

[data-theme="light"] .code-terminal-box {
  background: #f1f5f9;
  border-color: rgba(0, 0, 0, 0.06);
}

.terminal-header {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 0.75rem;
}

.t-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.t-red { background: #ef4444; }
.t-yellow { background: #f59e0b; }
.t-green { background: #10b981; }

.t-keyword { color: #f43f5e; }
.t-prop { color: #38bdf8; }
.t-str { color: #34d399; }
.t-func { color: #fbbf24; }

/* --------------------------------------------------------------------------
   Section 1: Bento Grid Ecosystem Gateway
   -------------------------------------------------------------------------- */
.ecosystem-section {
  padding: 5rem 0;
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  max-width: 920px;
  margin: 0 auto;
  gap: 1.5rem;
}

.bento-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(16px);
  border-radius: var(--radius-lg);
  padding: 2.25rem 2rem;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
  overflow: hidden;
}

.bento-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--accent-cyan), transparent);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.bento-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
}

.bento-card:hover::before {
  opacity: 1;
}

.card-badge-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.card-pill {
  padding: 0.3rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 600;
  font-family: var(--font-mono);
  border-radius: var(--radius-full);
}

.pill-cyan {
  background: rgba(34, 211, 238, 0.12);
  color: var(--accent-cyan);
  border: 1px solid rgba(34, 211, 238, 0.25);
}

.pill-purple {
  background: rgba(6, 182, 212, 0.12);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.25);
}

[data-theme="light"] .pill-cyan,
[data-theme="light"] .pill-purple {
  background: rgba(8, 145, 178, 0.08);
  color: #0891b2;
  border-color: rgba(8, 145, 178, 0.25);
}

.pill-emerald {
  background: rgba(16, 185, 129, 0.12);
  color: var(--accent-emerald);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.card-icon-wrap {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.04);
  display: grid;
  place-items: center;
  font-size: 1.5rem;
  border: 1px solid var(--border-color);
}

.bento-card-title {
  font-size: 1.45rem;
  margin-bottom: 0.35rem;
}

.bento-card-sub {
  font-size: 0.85rem;
  color: var(--accent-cyan);
  font-weight: 600;
  margin-bottom: 1rem;
}

[data-theme="light"] .bento-card-sub {
  color: #0891b2;
}

.bento-card-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.75rem;
  flex-grow: 1;
}

.tech-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1.75rem;
}

.tech-tag {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.card-action-group {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.card-link-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.75rem 1.4rem;
  font-family: var(--font-body);
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  text-align: center;
  transition: all var(--transition-fast);
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
}

.btn-solid-cyan {
  background: var(--btn-primary-bg);
  color: var(--btn-primary-color) !important;
  border: 1.5px solid transparent;
  box-shadow: var(--btn-primary-shadow);
}

.btn-solid-cyan:hover {
  transform: translateY(-2px);
  box-shadow: var(--btn-primary-shadow-hover);
  filter: brightness(1.06);
  color: #ffffff !important;
}

.btn-outline-action {
  background: var(--btn-secondary-bg);
  border: 1.5px solid var(--btn-secondary-border);
  color: var(--btn-secondary-color) !important;
}

.btn-outline-action:hover {
  border-color: var(--btn-secondary-hover-border);
  color: var(--btn-secondary-hover-color) !important;
  background: var(--btn-secondary-hover-bg);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* --------------------------------------------------------------------------
   Dải Phân Cách Cyber Accent Stripe
   -------------------------------------------------------------------------- */
.cyber-stripe {
  height: 2px;
  background: linear-gradient(90deg, transparent 0%, #06b6d4 30%, #38bdf8 50%, #0891b2 70%, transparent 100%);
  box-shadow: 0 0 12px rgba(6, 182, 212, 0.35);
}

[data-theme="light"] .cyber-stripe {
  background: linear-gradient(90deg, transparent 0%, #0891b2 30%, #0284c7 50%, #06b6d4 70%, transparent 100%);
  box-shadow: none;
}

/* --------------------------------------------------------------------------
   Section 2: Tech Notes & Practical Docs (Học hỏi CuongMeAI)
   -------------------------------------------------------------------------- */
.notes-section {
  padding: 5.5rem 0 6rem;
  background: radial-gradient(circle at 50% 0%, rgba(34, 211, 238, 0.05), transparent 60%),
              linear-gradient(180deg, transparent, rgba(14, 21, 38, 0.45), transparent);
  position: relative;
}

/* 3 Criteria Cards: Cam kết chất lượng tài liệu thực chiến */
.criteria-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin: 2.5rem auto 3.5rem;
  max-width: 1040px;
}

.criteria-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(16px);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.35rem;
  display: flex;
  align-items: center;
  gap: 1.1rem;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.criteria-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-cyan), transparent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.criteria-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
}

.criteria-card:hover::after {
  opacity: 1;
}

.criteria-icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: rgba(34, 211, 238, 0.1);
  border: 1px solid rgba(34, 211, 238, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.35rem;
  box-shadow: 0 0 15px rgba(34, 211, 238, 0.15);
}

.criteria-text strong {
  display: block;
  font-size: 0.96rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.criteria-text span {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
  display: block;
}

/* Library Tools: Search Bar, Clear Button, Category Chips, Count */
.lib-tools {
  max-width: 900px;
  margin: 0 auto 1.75rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.15rem;
}

.lib-search {
  position: relative;
  width: 100%;
}

.lib-search svg {
  position: absolute;
  left: 1.35rem;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  color: var(--text-muted);
  pointer-events: none;
}

.lib-search input {
  width: 100%;
  padding: 1.05rem 3.25rem 1.05rem 3.5rem;
  background: var(--bg-surface);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-full);
  color: var(--text-primary);
  font-size: 1.02rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.lib-search input:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 25px rgba(34, 211, 238, 0.25);
}

.lib-clear {
  position: absolute;
  right: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255, 255, 255, 0.08);
  border: none;
  border-radius: 50%;
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lib-clear:hover {
  background: var(--accent-cyan);
  color: #0b0f19;
}

.lib-chips-wrapper {
  width: 100%;
  max-width: 100%;
  position: relative;
  display: flex;
  justify-content: center;
}

.lib-chips {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  gap: 0.65rem;
  overflow-x: auto;
  overflow-y: hidden;
  max-width: 100%;
  width: max-content;
  margin: 0 auto;
  padding: 0.35rem 0.65rem 0.85rem;
  -webkit-overflow-scrolling: touch;
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: rgba(6, 182, 212, 0.45) rgba(255, 255, 255, 0.06);
}

.lib-chips.is-dragging {
  cursor: grabbing;
  user-select: none;
  scroll-behavior: auto;
}

/* Thanh kéo ngang (Horizontal Scrollbar) tinh gọn & trực quan */
.lib-chips::-webkit-scrollbar {
  height: 6px;
}

.lib-chips::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-full);
}

[data-theme="light"] .lib-chips::-webkit-scrollbar-track {
  background: rgba(0, 0, 0, 0.06);
}

.lib-chips::-webkit-scrollbar-thumb {
  background: rgba(6, 182, 212, 0.4);
  border-radius: var(--radius-full);
  transition: background var(--transition-fast);
}

.lib-chips::-webkit-scrollbar-thumb:hover {
  background: var(--accent-cyan);
}

[data-theme="light"] .lib-chips::-webkit-scrollbar-thumb {
  background: rgba(8, 145, 178, 0.4);
}

[data-theme="light"] .lib-chips::-webkit-scrollbar-thumb:hover {
  background: #0891b2;
}

.lib-chip {
  flex-shrink: 0;
  white-space: nowrap;
  user-select: none;
  -webkit-user-select: none;
  padding: 0.5rem 1.15rem;
  font-size: 0.88rem;
  font-weight: 500;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.lib-chips.is-dragging .lib-chip {
  cursor: grabbing;
}

[data-theme="light"] .lib-chip {
  background: #ffffff;
  border-color: #e2e8f0;
  color: #475569;
}

.lib-chip span {
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  background: rgba(6, 182, 212, 0.12);
  color: var(--accent-cyan);
  padding: 1px 7px;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}

[data-theme="light"] .lib-chip span {
  background: rgba(8, 145, 178, 0.08);
  color: #0891b2;
}

.lib-chip:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

[data-theme="light"] .lib-chip:hover {
  border-color: #0891b2;
  color: #0891b2;
}

.lib-chip.is-on {
  background: var(--btn-primary-bg);
  color: #ffffff !important;
  font-weight: 600;
  border-color: transparent;
  box-shadow: var(--btn-primary-shadow);
}

.lib-chip.is-on span {
  background: rgba(255, 255, 255, 0.25);
  color: #ffffff !important;
}

.lib-count {
  font-size: 0.86rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* Grid hiển thị Cards chuẩn Thực Chiến: 3 thẻ 1 hàng trên màn hình lớn */
.plugins-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  width: 100%;
  align-items: stretch;
}

/* Nút Xem Thêm / Thu Gọn Cho Danh Sách Tài Liệu (9 Thẻ Ban Đầu) */
.loadmore-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-top: 2.5rem;
  width: 100%;
}

.btn-loadmore {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 2.25rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.btn-loadmore:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.btn-loadmore:active {
  transform: translateY(0);
}

@media (max-width: 640px) {
  .btn-loadmore {
    width: 100%;
    max-width: 320px;
  }
}

/* ==========================================================================
   THẺ BÀI VIẾT PROMPT & UI/UX CHUẨN (TINH GỌN 3 CỘT • VIẾT NGỌC TECH HUB)
   ========================================================================== */
.cuong-prompt-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(16px);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  position: relative;
  cursor: pointer;
  max-width: 100%;
  width: 100%;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1),
              box-shadow 0.3s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.25s ease;
  text-decoration: none;
}

.cuong-prompt-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--accent-cyan), transparent);
  opacity: 0;
  transition: opacity var(--transition-normal);
  z-index: 2;
}

.cuong-prompt-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow), 0 16px 36px -10px rgba(0, 0, 0, 0.4);
}

.cuong-prompt-card:hover::before {
  opacity: 1;
}

/* Phần trên: Nền Cyan Tech Gradient nhẹ */
.cpc-header {
  background: linear-gradient(180deg, rgba(6, 182, 212, 0.08) 0%, rgba(6, 182, 212, 0.02) 100%);
  padding: 1.2rem 1.25rem 1rem;
  border-bottom: 1px solid var(--border-color);
  position: relative;
}

[data-theme="light"] .cpc-header {
  background: linear-gradient(180deg, rgba(8, 145, 178, 0.08) 0%, rgba(240, 249, 255, 0.5) 100%);
  border-bottom-color: rgba(8, 145, 178, 0.12);
}

.cpc-icon-box {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: rgba(6, 182, 212, 0.12);
  border: 1px solid rgba(6, 182, 212, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cyan);
  margin-bottom: 0.85rem;
  box-shadow: 0 0 12px rgba(6, 182, 212, 0.12);
  transition: transform 0.25s ease, background 0.25s ease;
}

[data-theme="light"] .cpc-icon-box {
  background: rgba(8, 145, 178, 0.1);
  border-color: rgba(8, 145, 178, 0.25);
  color: #0891b2;
  box-shadow: 0 2px 8px rgba(8, 145, 178, 0.1);
}

.cuong-prompt-card:hover .cpc-icon-box {
  transform: scale(1.06) rotate(-2deg);
  background: rgba(6, 182, 212, 0.2);
}

.cpc-title {
  font-family: var(--font-heading);
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
  margin: 0 0 0.75rem 0;
  letter-spacing: -0.01em;
  transition: color 0.2s ease;
  min-height: 3rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.cuong-prompt-card:hover .cpc-title {
  color: var(--accent-cyan);
}

.cpc-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.cpc-steps {
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 0.82rem;
  font-family: var(--font-mono);
}

[data-theme="light"] .cpc-steps {
  color: #0891b2;
}

.cpc-example {
  color: var(--text-muted);
  font-size: 0.8rem;
}

.cpc-badge {
  border: 1px solid rgba(6, 182, 212, 0.3);
  background: rgba(6, 182, 212, 0.1);
  color: var(--accent-cyan);
  font-size: 0.65rem;
  font-weight: 700;
  font-family: var(--font-mono);
  letter-spacing: 0.5px;
  padding: 0.15rem 0.55rem;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  display: inline-block;
  line-height: 1.4;
}

[data-theme="light"] .cpc-badge {
  border-color: rgba(8, 145, 178, 0.3);
  background: rgba(8, 145, 178, 0.08);
  color: #0891b2;
}

/* Phần thân */
.cpc-body {
  padding: 1.1rem 1.25rem;
  background: transparent;
  border-bottom: 1px solid var(--border-color);
  flex: 1;
}

.cpc-desc {
  font-family: var(--font-body);
  font-size: 0.88rem;
  line-height: 1.55;
  color: var(--text-secondary);
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Phần chân: Link Xem hướng dẫn */
.cpc-footer {
  padding: 0.75rem 1.25rem 0.9rem;
  background: transparent;
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

.cpc-action {
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 0.84rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: transform 0.2s ease, color 0.2s ease;
}

[data-theme="light"] .cpc-action {
  color: #0891b2;
}

.cpc-action svg {
  width: 16px;
  height: 16px;
  transition: transform 0.2s ease;
}

.cuong-prompt-card:hover .cpc-action {
  transform: translateX(4px);
  color: var(--accent-blue);
}

[data-theme="light"] .cuong-prompt-card:hover .cpc-action {
  color: #0284c7;
}

/* Dark Theme specific overrides */
[data-theme="dark"] .cuong-prompt-card {
  background: var(--bg-card);
  border-color: var(--border-color);
}

[data-theme="dark"] .cuong-prompt-card:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow), 0 20px 45px -12px rgba(0, 0, 0, 0.7);
}

[data-theme="light"] .cuong-prompt-card {
  background: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
}

[data-theme="light"] .cuong-prompt-card:hover {
  border-color: #0891b2;
  box-shadow: 0 16px 36px -10px rgba(8, 145, 178, 0.18), 0 0 15px rgba(8, 145, 178, 0.08);
}


/* Card tài liệu chuyên nghiệp (Plugin Card) */
.plugin-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(16px);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1),
              box-shadow 0.3s cubic-bezier(0.22, 1, 0.36, 1),
              border-color 0.3s ease;
  cursor: pointer;
}

.plugin-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow);
  box-shadow: 0 20px 45px -12px rgba(0, 0, 0, 0.6), 0 0 25px rgba(34, 211, 238, 0.2);
}

[data-theme="light"] .plugin-card {
  background: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
}

[data-theme="light"] .plugin-card:hover {
  border-color: #0891b2;
  box-shadow: 0 16px 36px -10px rgba(8, 145, 178, 0.14), 0 0 15px rgba(8, 145, 178, 0.08);
}

/* Cover header với số watermark mờ sau nền */
.pc-cover {
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.5rem 1.6rem 1.1rem;
  background: rgba(255, 255, 255, 0.02);
  border-bottom: 1px solid var(--border-color);
}

[data-theme="light"] .pc-cover {
  background: #f8fafc;
  border-bottom-color: #e2e8f0;
}

.pc-cover-num {
  position: absolute;
  top: 6px;
  right: 14px;
  font-family: var(--font-heading);
  font-size: 50px;
  font-weight: 800;
  line-height: 1;
  color: var(--accent-cyan);
  opacity: 0.08;
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.plugin-card:hover .pc-cover-num {
  opacity: 0.18;
  transform: scale(1.05);
}

[data-theme="light"] .pc-cover-num {
  color: #0891b2;
  opacity: 0.07;
}

.pc-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(34, 211, 238, 0.1);
  border: 1px solid rgba(34, 211, 238, 0.25);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  flex-shrink: 0;
  transition: transform 0.25s ease, background 0.25s ease;
}

.plugin-card:hover .pc-icon {
  transform: scale(1.08);
  background: rgba(34, 211, 238, 0.2);
}

[data-theme="light"] .pc-icon {
  background: rgba(8, 145, 178, 0.08);
  border-color: rgba(8, 145, 178, 0.2);
  color: #0891b2;
}

.pc-cover-info {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  flex: 1;
  z-index: 1;
}

.pc-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: color var(--transition-fast);
}

.plugin-card:hover .pc-title {
  color: var(--accent-cyan);
}

[data-theme="light"] .plugin-card:hover .pc-title {
  color: #0891b2;
}

.pc-meta {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.pc-stars {
  font-size: 0.74rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--accent-cyan);
  background: rgba(34, 211, 238, 0.12);
  padding: 0.15rem 0.55rem;
  border-radius: var(--radius-full);
}

[data-theme="light"] .pc-stars {
  background: rgba(8, 145, 178, 0.08);
  color: #0891b2;
}

.pc-source {
  font-size: 0.74rem;
  color: var(--text-muted);
}

.pc-badge-install {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.18rem 0.55rem;
  border-radius: var(--radius-full);
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.25);
  color: var(--accent-cyan);
}

[data-theme="light"] .pc-badge-install {
  background: rgba(8, 145, 178, 0.08);
  border-color: rgba(8, 145, 178, 0.25);
  color: #0891b2;
}

/* Body thẻ */
.pc-body {
  padding: 1.25rem 1.6rem;
  flex: 1;
}

.pc-desc {
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--text-secondary);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Footer thẻ */
.pc-footer {
  padding: 1rem 1.6rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  gap: 0.75rem;
}

[data-theme="light"] .pc-footer {
  border-top-color: #e2e8f0;
}

.pc-install {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.pc-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-cyan);
  white-space: nowrap;
  transition: gap 0.2s ease, transform 0.2s ease;
}

[data-theme="light"] .pc-link {
  color: #0891b2;
}

[data-theme="light"] .pc-link:hover {
  color: #0e7490;
}

.pc-link svg {
  width: 14px;
  height: 14px;
  transition: transform 0.25s ease;
}

.plugin-card:hover .pc-link {
  gap: 8px;
}

.plugin-card:hover .pc-link svg {
  transform: translateX(4px);
}

@media (max-width: 900px) {
  .plugins-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.15rem;
  }
  .criteria-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .plugins-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
}


/* --------------------------------------------------------------------------
   Section 3: Skills Matrix (5 Columns)
   -------------------------------------------------------------------------- */
.skills-section {
  padding: 5rem 0;
}

.skills-matrix-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1.25rem;
}

.skill-col {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(14px);
  border-radius: var(--radius-md);
  padding: 1.5rem 1.25rem;
  transition: all var(--transition-fast);
}

.skill-col:hover {
  border-color: var(--border-glow);
  transform: translateY(-3px);
}

.skill-col-icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: rgba(34, 211, 238, 0.08);
  border: 1px solid rgba(34, 211, 238, 0.2);
  display: grid;
  place-items: center;
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.skill-col-title {
  font-size: 1.05rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.skill-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.skill-item {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.skill-item::before {
  content: '▸';
  color: var(--accent-cyan);
  font-size: 0.95rem;
  line-height: 1;
}

/* --------------------------------------------------------------------------
   Section 4: Experience & Education Timeline
   -------------------------------------------------------------------------- */
.timeline-section {
  padding: 5rem 0;
}

.timeline-wrap {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  padding-left: 2rem;
}

.timeline-wrap::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-cyan), var(--accent-purple), transparent);
}

.timeline-item {
  position: relative;
  margin-bottom: 2.75rem;
}

.timeline-dot {
  position: absolute;
  left: -2rem;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--bg-primary);
  border: 3px solid var(--accent-cyan);
  box-shadow: 0 0 10px var(--accent-cyan);
  transform: translateX(-6px);
}

.timeline-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(14px);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: all var(--transition-fast);
}

.timeline-card:hover {
  border-color: var(--border-glow);
  transform: translateX(4px);
}

.timeline-badge {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--accent-cyan);
  margin-bottom: 0.35rem;
  display: inline-block;
}

.timeline-role {
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
}

.timeline-org {
  font-size: 0.95rem;
  color: var(--text-muted);
  font-weight: 500;
  margin-bottom: 0.75rem;
}

.timeline-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --------------------------------------------------------------------------
   Section 5: Contact Box & Fast 1-Click
   -------------------------------------------------------------------------- */
.contact-section {
  padding: 5rem 0 6rem;
}

.contact-container {
  max-width: 800px;
  width: 100%;
  margin: 0 auto;
  box-sizing: border-box;
}

.contact-card-wrapper {
  background: linear-gradient(135deg, rgba(14, 21, 38, 0.9), rgba(19, 29, 51, 0.85));
  border: 1px solid var(--border-glow);
  box-shadow: var(--shadow-glow);
  border-radius: var(--radius-lg);
  padding: 2.75rem 2.25rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  width: 100%;
  max-width: 100%;
  box-sizing: border-box;
  overflow: hidden;
}

[data-theme="light"] .contact-card-wrapper {
  background: #ffffff;
  border-color: rgba(6, 182, 212, 0.25);
  box-shadow: var(--shadow-md);
}

.contact-info-col {
  margin: 0 auto;
  max-width: 650px;
  width: 100%;
  box-sizing: border-box;
}

.contact-info-col h3 {
  font-size: 2rem;
  line-height: 1.2;
  margin-bottom: 0.75rem;
}

.contact-info-col p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 1.75rem;
}

.quick-copy-group {
  display: flex;
  flex-direction: column;
  max-width: 480px;
  width: 100%;
  margin: 0 auto;
  gap: 0.75rem;
  box-sizing: border-box;
}

.copy-pill-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 100%;
  box-sizing: border-box;
  padding: 0.85rem 1.15rem;
  background: var(--bg-surface);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  min-height: 48px;
  overflow: hidden;
}

[data-theme="light"] .copy-pill-btn {
  background: #ffffff;
  border-color: #e2e8f0;
}

.copy-pill-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

[data-theme="light"] .copy-pill-btn:hover {
  border-color: #0891b2;
  color: #0891b2;
}

.copy-pill-text,
.copy-pill-btn span:first-child {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex: 1 1 auto;
  min-width: 0;
  text-align: left;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.copy-pill-text strong,
.copy-pill-btn span:first-child strong {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-weight: 700;
}

.copy-icon-tag {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.1);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(6, 182, 212, 0.25);
  flex-shrink: 0;
  margin-left: 0.5rem;
  white-space: nowrap;
}

[data-theme="light"] .copy-icon-tag {
  color: #0891b2;
  background: rgba(8, 145, 178, 0.08);
  border-color: rgba(8, 145, 178, 0.2);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-input, .form-textarea {
  width: 100%;
  padding: 0.85rem 1.1rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
}

.form-input:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 15px rgba(34, 211, 238, 0.2);
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.site-footer {
  padding: 2.5rem 0 3.5rem;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.footer-social-row {
  display: flex;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 1.25rem;
}

.social-link {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-secondary);
  display: grid;
  place-items: center;
  transition: all var(--transition-fast);
}

.social-link:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: translateY(-3px);
}

/* --------------------------------------------------------------------------
   Mobile Bottom Dock Bar (iOS/Android Native App Style)
   -------------------------------------------------------------------------- */
.mobile-bottom-dock {
  display: none;
  position: fixed;
  bottom: 1rem;
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - 2rem);
  max-width: 420px;
  background: var(--dock-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-glow);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
  border-radius: var(--radius-full);
  padding: 0.5rem 0.75rem;
  z-index: 99;
}

.dock-nav-list {
  display: flex;
  align-items: center;
  justify-content: space-around;
  list-style: none;
}

.dock-item-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  padding: 0.35rem 0.6rem;
  color: var(--text-secondary);
  font-size: 0.72rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.dock-icon {
  font-size: 1.15rem;
}

.dock-item-link.active, .dock-item-link:hover {
  color: var(--accent-cyan);
}

/* --------------------------------------------------------------------------
   Modal Components (Video & Tech Note Detail)
   -------------------------------------------------------------------------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(4, 7, 15, 0.85);
  backdrop-filter: blur(12px);
  z-index: 200;
  display: grid;
  place-items: center;
  padding: 1.5rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.modal-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-container {
  background: var(--bg-surface);
  border: 1px solid var(--border-glow);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.7);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 820px;
  max-height: 88vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: scale(0.95) translateY(20px);
  transition: transform var(--transition-normal);
}

.modal-overlay.open .modal-container {
  transform: scale(1) translateY(0);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.75rem;
  border-bottom: 1px solid var(--border-color);
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
}

.modal-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
  transition: color var(--transition-fast);
}

.modal-close-btn:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 1.75rem;
  overflow-y: auto;
  font-size: 0.95rem;
  line-height: 1.7;
}

.modal-body pre {
  background: #050811;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.1rem;
  overflow-x: auto;
  margin: 1rem 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

[data-theme="light"] .modal-body pre {
  background: #f1f5f9;
}

.modal-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.25rem 0;
  font-size: 0.88rem;
}

.modal-body th, .modal-body td {
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--border-color);
  text-align: left;
}

.modal-body th {
  background: rgba(34, 211, 238, 0.08);
  color: var(--accent-cyan);
}

.video-aspect-box {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 Aspect Ratio */
  background: #000;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.video-aspect-box iframe, .video-aspect-box video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
}

/* --------------------------------------------------------------------------
   Toast Notification
   -------------------------------------------------------------------------- */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(14, 21, 38, 0.95);
  border: 1px solid var(--accent-cyan);
  box-shadow: 0 8px 24px rgba(34, 211, 238, 0.25);
  backdrop-filter: blur(16px);
  color: #fff;
  padding: 0.85rem 1.35rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  transform: translateY(20px);
  opacity: 0;
  animation: slideToastIn 0.3s forwards;
}

@keyframes slideToastIn {
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

/* --------------------------------------------------------------------------
   Responsive Breakpoints & Mobile Optimization System
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .hero-visual {
    order: -1;
  }

  .skills-matrix-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .contact-card-wrapper {
    grid-template-columns: 1fr;
    gap: 2.5rem;
    padding: 2.5rem 1.75rem;
  }
}

/* ==========================================================================
   MOBILE & TABLET BREAKPOINT (max-width: 768px)
   Chuẩn công thái học smartphone: Trải nghiệm mượt mà, chạm ngón cái tiện lợi
   ========================================================================== */
@media (max-width: 768px) {
  /* Layout Container */
  .container {
    padding: 0 1rem;
  }

  /* Header & Navigation */
  .site-header {
    background: var(--nav-bg);
  }

  .navbar {
    height: 60px;
    padding: 0 0.25rem;
  }

  .logo-badge {
    width: 32px;
    height: 32px;
    font-size: 0.95rem;
    border-radius: 8px;
  }

  .brand-logo {
    font-size: 1.08rem;
    gap: 0.6rem;
  }

  .nav-menu, 
  .nav-actions .cta-button {
    display: none !important;
  }

  .nav-actions {
    gap: 0.45rem;
  }

  .theme-toggle,
  .lang-toggle {
    width: 38px;
    height: 38px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  /* Section Padding */
  .hero-section {
    padding: 2.25rem 0 1.75rem;
  }

  .ecosystem-section {
    padding: 2.5rem 0 2.25rem;
  }

  .notes-section {
    padding: 2.5rem 0 3rem;
  }

  .contact-section {
    padding: 2.5rem 0 3.5rem;
  }

  /* Section Headers */
  .section-header {
    margin-bottom: 1.5rem;
    text-align: center;
  }

  .section-tag {
    font-size: 0.72rem;
    padding: 0.3rem 0.75rem;
    margin-bottom: 0.65rem;
    letter-spacing: 0.05em;
  }

  .section-title {
    font-size: 1.85rem;
    line-height: 1.25;
    margin-bottom: 0.65rem;
  }

  .section-subtitle {
    font-size: 0.92rem;
    line-height: 1.55;
    padding: 0 0.25rem;
  }

  /* Hero Section Mobile */
  .hero-badge-wrap {
    margin-bottom: 1rem;
  }

  .hero-badge-wrap .section-tag {
    white-space: normal;
    text-align: center;
    line-height: 1.4;
    display: inline-block;
  }

  .hero-headline {
    font-size: clamp(2rem, 7vw, 2.5rem);
    line-height: 1.2;
    margin-bottom: 1rem;
  }

  .hero-title-prefix {
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
  }

  .hero-tagline {
    font-size: 0.98rem;
    line-height: 1.55;
    margin-bottom: 1.25rem;
    padding: 0 0.5rem;
  }

  .hero-quote-box {
    padding: 0.85rem 1rem;
    margin-bottom: 1.75rem;
  }

  .hero-quote-text {
    font-size: 0.88rem;
    line-height: 1.5;
  }

  .hero-cta-group {
    flex-direction: column;
    width: 100%;
    max-width: 360px;
    margin: 0 auto 1.5rem;
    gap: 0.75rem;
  }

  .hero-cta-group .btn-primary,
  .hero-cta-group .btn-secondary {
    width: 100%;
    min-height: 48px;
    font-size: 0.92rem;
    padding: 0.75rem 1.25rem;
    justify-content: center;
    text-align: center;
  }

  /* Bento Grid Mobile (1 Column) */
  .bento-grid {
    grid-template-columns: 1fr;
    gap: 1.15rem;
    max-width: 100%;
  }

  .bento-card {
    padding: 1.5rem 1.25rem;
    border-radius: var(--radius-md);
  }

  .card-badge-row {
    margin-bottom: 1rem;
  }

  .bento-card-title {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
  }

  .bento-card-sub {
    font-size: 0.82rem;
    margin-bottom: 0.65rem;
  }

  .bento-card-desc {
    font-size: 0.88rem;
    line-height: 1.55;
    margin-bottom: 1.25rem;
  }

  .card-action-group .btn-primary,
  .card-action-group .btn-secondary {
    width: 100%;
    min-height: 44px;
    justify-content: center;
  }

  /* Library & Filter Controls Mobile */
  .lib-search {
    margin-bottom: 1.15rem;
  }

  .lib-search input {
    font-size: 16px !important; /* Ngăn iOS Safari tự động zoom trang */
    padding: 0.85rem 2.6rem 0.85rem 2.85rem;
    border-radius: var(--radius-full);
  }

  .lib-search svg {
    left: 1rem;
    width: 18px;
    height: 18px;
  }

  .lib-clear {
    right: 0.85rem;
    width: 26px;
    height: 26px;
  }

  .lib-chips {
    gap: 0.45rem;
    padding-bottom: 0.65rem;
    margin-bottom: 0.85rem;
  }

  .lib-chip {
    padding: 0.4rem 0.85rem;
    font-size: 0.82rem;
    border-radius: var(--radius-full);
  }

  .plugins-grid {
    gap: 1.25rem;
  }

  /* Prompt Card Mobile */
  .cuong-prompt-card {
    max-width: 100%;
    width: 100%;
    border-radius: var(--radius-md);
  }

  .cpc-header {
    padding: 1.15rem 1rem 0.95rem;
  }

  .cpc-icon-box {
    width: 38px;
    height: 38px;
    border-radius: 8px;
    margin-bottom: 0.75rem;
  }

  .cpc-title {
    font-size: 1.08rem;
    line-height: 1.35;
    margin-bottom: 0.55rem;
    min-height: auto;
  }

  .cpc-meta {
    gap: 0.45rem;
    font-size: 0.8rem;
  }

  .cpc-badge {
    font-size: 0.65rem;
    padding: 0.15rem 0.5rem;
  }

  .cpc-body {
    padding: 1rem 1rem;
  }

  .cpc-desc {
    font-size: 0.86rem;
    line-height: 1.55;
    -webkit-line-clamp: 3;
  }

  .cpc-footer {
    padding: 0.75rem 1rem 0.85rem;
  }

  .cpc-action {
    font-size: 0.84rem;
  }

  /* Contact Section Mobile */
  .contact-container {
    max-width: 100%;
    width: 100%;
    box-sizing: border-box;
    padding: 0 0.85rem;
  }

  .contact-card-wrapper,
  .contact-container .contact-card-wrapper {
    padding: 1.65rem 1rem;
    border-radius: var(--radius-md);
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    overflow: hidden;
  }

  .contact-info-col {
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
  }

  .contact-info-col h3 {
    font-size: 1.55rem;
    margin-bottom: 0.6rem;
  }

  .contact-info-col p {
    font-size: 0.9rem;
    line-height: 1.55;
    margin-bottom: 1.35rem;
  }

  .quick-copy-group {
    gap: 0.65rem;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
  }

  .copy-pill-btn {
    padding: 0.75rem 0.85rem;
    min-height: 48px;
    border-radius: 12px;
    font-size: 0.84rem;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    overflow: hidden;
  }

  .copy-pill-text,
  .copy-pill-btn span:first-child {
    font-size: 0.84rem;
    flex: 1 1 auto;
    min-width: 0 !important;
    text-align: left;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .copy-icon-tag {
    padding: 0.2rem 0.55rem;
    font-size: 0.72rem;
    flex-shrink: 0;
    margin-left: 0.45rem;
  }

  /* Mobile Bottom Dock (Floating Bar) */
  .mobile-bottom-dock {
    display: block;
    position: fixed;
    bottom: max(0.85rem, env(safe-area-inset-bottom, 0.85rem));
    left: 50%;
    transform: translateX(-50%);
    width: calc(100% - 1.5rem);
    max-width: 400px;
    background: rgba(14, 21, 38, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-glow);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), 0 0 15px rgba(6, 182, 212, 0.15);
    border-radius: var(--radius-full);
    padding: 0.4rem 0.6rem;
    z-index: 999;
  }

  [data-theme="light"] .mobile-bottom-dock {
    background: rgba(255, 255, 255, 0.94);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08), 0 0 15px rgba(8, 145, 178, 0.12);
  }

  .dock-nav-list {
    display: flex;
    align-items: center;
    justify-content: space-around;
  }

  .dock-item-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.18rem;
    padding: 0.35rem 0.5rem;
    border-radius: 12px;
    color: var(--text-secondary);
    font-size: 0.7rem;
    font-weight: 600;
  }

  .dock-icon {
    font-size: 1.15rem;
  }

  .dock-item-link.active {
    color: var(--accent-cyan);
    background: rgba(6, 182, 212, 0.1);
  }

  [data-theme="light"] .dock-item-link.active {
    color: #0891b2;
    background: rgba(8, 145, 178, 0.08);
  }

  /* Footer & Toast Safe Margin */
  .site-footer {
    padding: 2.5rem 1rem max(5.75rem, calc(5rem + env(safe-area-inset-bottom, 0px)));
    text-align: center;
  }

  .toast-container {
    bottom: max(5.5rem, calc(4.75rem + env(safe-area-inset-bottom, 0px)));
    right: 1rem;
    left: 1rem;
  }

  /* ==========================================================================
     QUY CHUẨN TYPOGRAPHY 1-1 CHO MOBILE BÀI VIẾT TÀI LIỆU (MAX-WIDTH: 640PX)
     ========================================================================== */
  .article-wrap {
    padding: 1.5rem 1rem 0 !important;
    overflow-wrap: break-word;
    word-break: break-word;
  }

  /* 1. Breadcrumb & Hero */
  .doc-breadcrumb {
    font-size: 0.82rem !important;
    padding: 0.35rem 0.8rem !important;
    margin-bottom: 1.25rem !important;
  }

  .article-hero {
    padding: 1.25rem 0 1.5rem !important;
    margin-bottom: 1.75rem !important;
  }

  .article-title {
    font-size: clamp(1.55rem, 5.2vw, 1.95rem) !important;
    line-height: 1.28 !important;
    margin-bottom: 1rem !important;
    letter-spacing: -0.015em !important;
    word-break: break-word !important;
  }

  .article-lead {
    font-size: 0.98rem !important;
    line-height: 1.65 !important;
    margin-bottom: 1.35rem !important;
  }

  .article-meta-row {
    display: flex !important;
    flex-wrap: wrap !important;
    gap: 0.5rem 0.85rem !important;
    font-size: 0.82rem !important;
    margin-bottom: 1.5rem !important;
  }

  /* 2. Lưới thống kê 4 thẻ */
  .stats-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 0.75rem !important;
    margin: 1.25rem 0 1.75rem !important;
  }

  .stat-card {
    padding: 0.95rem 0.75rem !important;
  }

  .stat-val {
    font-size: 1.25rem !important;
    margin-bottom: 0.2rem !important;
  }

  .stat-desc {
    font-size: 0.76rem !important;
  }

  /* 3. Mục lục Dropdown */
  .article-toc {
    padding: 1rem 1.15rem !important;
    margin: 1.5rem 0 2rem !important;
  }

  .article-toc summary {
    font-size: 0.95rem !important;
  }

  .article-toc ul {
    font-size: 0.88rem !important;
    line-height: 1.7 !important;
    margin: 0.75rem 0 0 1rem !important;
  }

  /* 4. Nội dung bài viết (Headings & Body Text Chuẩn Tiếng Việt) */
  .article-content {
    font-size: 0.98rem !important;
    line-height: 1.75 !important;
    word-break: break-word !important;
    overflow-wrap: break-word !important;
  }

  .article-content h2 {
    font-size: 1.35rem !important;
    line-height: 1.35 !important;
    margin: 2.25rem 0 0.95rem !important;
    gap: 0.45rem !important;
    scroll-margin-top: 75px !important;
    word-break: break-word !important;
  }

  .article-content h3 {
    font-size: 1.15rem !important;
    line-height: 1.4 !important;
    margin: 1.65rem 0 0.75rem !important;
    scroll-margin-top: 75px !important;
    word-break: break-word !important;
  }

  .article-content p {
    margin-bottom: 1.15rem !important;
    font-size: 0.98rem !important;
    line-height: 1.75 !important;
  }

  .article-content ul,
  .article-content ol {
    margin: 0.75rem 0 1.25rem 1.15rem !important;
    font-size: 0.95rem !important;
    line-height: 1.7 !important;
  }

  .article-content li {
    margin-bottom: 0.4rem !important;
  }

  .callout-box {
    padding: 1rem 1.15rem !important;
    font-size: 0.92rem !important;
    line-height: 1.65 !important;
    margin: 1.5rem 0 !important;
  }

  /* 5. Khối Code & Bảng Biểu Tránh Vỡ Giao Diện */
  .code-container {
    margin: 1.25rem 0 1.5rem !important;
    border-radius: var(--radius-sm) !important;
  }

  .code-header {
    padding: 0.5rem 0.85rem !important;
    font-size: 0.76rem !important;
  }

  .btn-copy-code {
    font-size: 0.72rem !important;
    padding: 0.2rem 0.5rem !important;
  }

  pre code {
    padding: 1rem 0.85rem !important;
    font-size: 0.8rem !important;
    line-height: 1.55 !important;
    -webkit-overflow-scrolling: touch !important;
    white-space: pre !important;
    word-break: normal !important;
  }

  .table-container {
    margin: 1.5rem 0 !important;
    -webkit-overflow-scrolling: touch !important;
  }

  table {
    font-size: 0.82rem !important;
    min-width: 520px;
  }

  th, td {
    padding: 0.75rem 0.85rem !important;
  }

  /* 6. Hộp Demo Tương Tác */
  .interactive-demo-box {
    padding: 1.15rem 1rem !important;
    margin: 1.75rem 0 !important;
  }

  .demo-nav-tabs {
    gap: 0.35rem !important;
    margin-bottom: 1.15rem !important;
    overflow-x: auto !important;
    flex-wrap: nowrap !important;
    -webkit-overflow-scrolling: touch !important;
    padding-bottom: 0.5rem !important;
  }

  .demo-tab-btn {
    padding: 0.4rem 0.85rem !important;
    font-size: 0.82rem !important;
    flex-shrink: 0 !important;
    white-space: nowrap !important;
  }

  /* 7. Nút Quay Lại Cuối Bài Mobile */
  .article-bottom-nav {
    margin: 2.5rem 0 3rem !important;
    padding-top: 1.75rem !important;
    justify-content: center;
  }

  .article-bottom-nav .btn-secondary,
  .article-bottom-nav .btn-primary {
    width: 100% !important;
    min-height: 48px;
    padding: 0.75rem 1.5rem !important;
    font-size: 0.9rem !important;
    justify-content: center;
  }
}

/* ==========================================================================
   EXTRA SMALL SCREENS (max-width: 480px)
   ========================================================================== */
@media (max-width: 480px) {
  .hero-headline {
    font-size: clamp(1.85rem, 6.5vw, 2.2rem);
  }

  .hero-title-prefix {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.65rem;
  }

  .bento-card {
    padding: 1.25rem 1rem;
  }

  .bento-card-title {
    font-size: 1.18rem;
  }

  .cpc-header {
    padding: 1.15rem 1rem 0.95rem;
  }

  .cpc-body {
    padding: 1rem;
  }

  .cpc-title {
    font-size: 1.15rem;
  }

  .contact-card-wrapper,
  .contact-container .contact-card-wrapper {
    padding: 1.35rem 0.85rem;
  }

  .copy-pill-btn {
    padding: 0.7rem 0.75rem;
    font-size: 0.8rem;
  }

  .copy-pill-text,
  .copy-pill-btn span:first-child {
    font-size: 0.8rem;
    gap: 0.3rem;
  }

  .copy-icon-tag {
    padding: 0.18rem 0.45rem;
    font-size: 0.7rem;
    margin-left: 0.35rem;
  }
}

/* ==========================================================================
   TINY SCREENS (max-width: 380px)
   ========================================================================== */
@media (max-width: 380px) {
  .brand-sub {
    display: none;
  }

  .brand-logo span {
    font-size: 0.95rem;
  }

  .navbar {
    padding: 0 0.1rem;
  }

  .hero-quote-box {
    padding: 0.75rem 0.85rem;
  }

  .lib-chip {
    padding: 0.35rem 0.7rem;
    font-size: 0.78rem;
  }

  .contact-card-wrapper,
  .contact-container .contact-card-wrapper {
    padding: 1.25rem 0.65rem;
  }

  .copy-pill-btn {
    padding: 0.65rem 0.65rem;
  }

  .copy-pill-text,
  .copy-pill-btn span:first-child {
    font-size: 0.76rem;
    gap: 0.25rem;
  }

  .copy-icon-tag {
    padding: 0.15rem 0.4rem;
    font-size: 0.68rem;
    margin-left: 0.25rem;
  }
}

/* ==========================================================================
   CHUẨN NÚT ĐIỀU HƯỚNG BÀI VIẾT TÀI LIỆU (DOCUMENTATION NAVIGATION SYSTEM)
   ========================================================================== */

/* 1. Nút Breadcrumb Quay Lại Ở Đầu Bài */
.doc-breadcrumb {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 1.75rem;
  padding: 0.45rem 1rem;
  border-radius: var(--radius-full);
  background: rgba(6, 182, 212, 0.08);
  border: 1px solid rgba(6, 182, 212, 0.22);
  transition: all var(--transition-fast);
  text-decoration: none;
}

[data-theme="light"] .doc-breadcrumb {
  background: rgba(8, 145, 178, 0.08);
  border-color: rgba(8, 145, 178, 0.25);
  color: #0891b2;
}

.doc-breadcrumb:hover {
  background: rgba(6, 182, 212, 0.16);
  border-color: var(--accent-cyan);
  transform: translateX(-3px);
  color: var(--accent-cyan);
  box-shadow: 0 2px 12px rgba(6, 182, 212, 0.2);
}

[data-theme="light"] .doc-breadcrumb:hover {
  background: rgba(8, 145, 178, 0.14);
  border-color: #0891b2;
  color: #0891b2;
}

/* 2. Nút Quay Lại Duy Nhất Ở Cuối Bài */
.article-bottom-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 3.5rem 0 4rem;
  padding-top: 2.25rem;
  border-top: 1px solid var(--border-color);
  width: 100%;
}

.article-bottom-nav .btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 2rem;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.article-bottom-nav .btn-secondary:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.article-bottom-nav .btn-secondary:active {
  transform: translateY(0);
}

/* ==========================================================================
   HỆ THỐNG SONG NGỮ VIỆT - ANH BÀI VIẾT (BILINGUAL ARTICLE SYSTEM)
   Tự động hiển thị theo thiết lập ngôn ngữ toàn trang (localStorage: nvn_lang)
   Không chèn nút thủ công trong bài viết để tối ưu trải nghiệm đọc tinh gọn.
   ========================================================================== */

/* Ẩn/Hiện nội dung song ngữ theo thuộc tính data-doc-lang */
html[data-doc-lang="vi"] .lang-en,
[data-doc-lang="vi"] .lang-en {
  display: none !important;
}

html[data-doc-lang="en"] .lang-vi,
[data-doc-lang="en"] .lang-vi {
  display: none !important;
}