/* AIzalo.com / Zalo-Flow Community Portal — Pure High-Performance Modern CSS */
:root {
  --bg-main: #070a13;
  --bg-card: rgba(15, 23, 42, 0.75);
  --bg-card-hover: rgba(22, 35, 64, 0.85);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(0, 153, 255, 0.35);
  --primary: #0084ff;
  --primary-hover: #0070db;
  --primary-glow: rgba(0, 132, 255, 0.25);
  --cyan: #00d2ff;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --success: #10b981;
  --warning: #f59e0b;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  /* Z-Index Hierarchy Layering */
  --z-floating: 90;
  --z-navbar: 100;
  --z-backdrop: 200;
  --z-drawer: 201;
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  background: radial-gradient(circle at 50% 0%, #0f1d3a 0%, #070a13 55%, #05070d 100%);
  min-height: 100vh;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Navbar */
.navbar {
  position: sticky;
  top: 0;
  z-index: var(--z-navbar);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(7, 10, 19, 0.82);
  border-bottom: 1px solid var(--border-subtle);
  transition: all 0.3s ease;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: #fff;
  font-weight: 800;
  font-size: 1.35rem;
}

.brand-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

.brand-tag {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 6px;
  background: rgba(0, 132, 255, 0.15);
  color: var(--cyan);
  border: 1px solid rgba(0, 210, 255, 0.3);
  margin-left: 0.25rem;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Mobile Nav Toggle (Hamburger Button) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 38px;
  height: 38px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-subtle);
  border-radius: 9px;
  cursor: pointer;
  padding: 8px 7px;
  z-index: calc(var(--z-drawer) + 1);
  transition: all 0.25s ease;
}

.nav-toggle:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--border-accent);
}

.nav-toggle .bar {
  width: 100%;
  height: 2px;
  background-color: #fff;
  border-radius: 2px;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  transform-origin: center;
}

.nav-toggle.active .bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active .bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.nav-toggle.active .bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Drawer Backdrop */
.drawer-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.68);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: var(--z-backdrop);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.drawer-backdrop.active {
  opacity: 1;
  visibility: visible;
}

.mobile-only-action {
  display: none;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, #0084ff 0%, #0056d6 100%);
  color: #fff;
  box-shadow: 0 4px 18px var(--primary-glow);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #0094ff 0%, #0066f6 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(0, 132, 255, 0.4);
}

.btn-zalo {
  background: linear-gradient(135deg, #0068ff 0%, #004ecc 100%);
  color: #fff;
  border: 1px solid rgba(0, 210, 255, 0.35);
}

.btn-zalo:hover {
  background: linear-gradient(135deg, #0078ff 0%, #005ae6 100%);
  transform: translateY(-2px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 0.85rem 1.75rem;
  font-size: 1.05rem;
}

/* Hero Section */
.hero {
  padding: 4.5rem 0 3rem;
  text-align: center;
  position: relative;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  border-radius: 9999px;
  background: rgba(0, 132, 255, 0.1);
  border: 1px solid rgba(0, 210, 255, 0.3);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--cyan);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
  color: #fff;
}

.gradient-text {
  background: linear-gradient(135deg, #00d2ff 0%, #0084ff 50%, #9d4edd 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  max-width: 780px;
  margin: 0 auto 2rem;
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-muted);
  line-height: 1.65;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.cli-snippet {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 0.75rem 1.25rem;
  border-radius: 10px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: #38bdf8;
  cursor: pointer;
  transition: border-color 0.2s ease;
}

.cli-snippet:hover {
  border-color: var(--cyan);
}

.badges-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 1.25rem;
  padding: 1.25rem 0;
  color: var(--text-dim);
  font-size: 0.85rem;
}

.badge-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* SmartScreen Box */
.smartscreen-alert {
  max-width: 820px;
  margin: 1.5rem auto 3rem;
  background: rgba(2, 132, 199, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 14px;
  padding: 1.25rem 1.5rem;
  text-align: left;
}

.smartscreen-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: #38bdf8;
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.smartscreen-content {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.smartscreen-content code {
  font-family: var(--font-mono);
  background: rgba(0, 0, 0, 0.35);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  color: #f1f5f9;
}

/* GEO Quotable Box */
.geo-box {
  max-width: 820px;
  margin: 0 auto 4rem;
  background: rgba(15, 23, 42, 0.6);
  border-left: 4px solid var(--primary);
  border-radius: 0 12px 12px 0;
  padding: 1.25rem 1.75rem;
  text-align: left;
  font-size: 0.98rem;
  line-height: 1.7;
  color: var(--text-muted);
}

.geo-box strong {
  color: #fff;
}

/* Section Common */
.section {
  padding: 4.5rem 0;
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 3rem;
}

.section-tag {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--cyan);
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  line-height: 1.2;
  color: #fff;
  margin-bottom: 1rem;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Grid & Cards */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 2rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-accent);
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
  background: rgba(0, 132, 255, 0.12);
  border: 1px solid rgba(0, 210, 255, 0.25);
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
}

.card-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Comparison Table */
.table-wrapper {
  overflow-x: auto;
  margin: 2rem 0;
  border-radius: 14px;
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
}

.comp-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}

.comp-table th, .comp-table td {
  padding: 1.1rem 1.25rem;
  border-bottom: 1px solid var(--border-subtle);
}

.comp-table th {
  background: rgba(15, 23, 42, 0.95);
  font-weight: 700;
  color: #fff;
}

.comp-table tr:last-child td {
  border-bottom: none;
}

.comp-table .highlight-col {
  background: rgba(0, 132, 255, 0.08);
  font-weight: 600;
  color: #38bdf8;
}

/* Native Accordion FAQ */
.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item[open] {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
}

.faq-summary {
  padding: 1.25rem 1.5rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-summary::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--cyan);
  transition: transform 0.2s ease;
}

.faq-item[open] .faq-summary::after {
  transform: rotate(45deg);
}

.faq-content {
  padding: 0 1.5rem 1.25rem;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  border-top: 1px solid rgba(255, 255, 255, 0.04);
  margin-top: 0.25rem;
  padding-top: 0.75rem;
}

/* Blog Cards */
.blog-card {
  text-decoration: none;
  display: flex;
  flex-direction: column;
}

.blog-tag {
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  background: rgba(0, 132, 255, 0.15);
  color: #38bdf8;
  margin-bottom: 0.75rem;
}

.blog-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: auto;
  padding-top: 1rem;
}

/* Floating Badge */
.floating-badge {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: var(--z-floating);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: linear-gradient(135deg, #0084ff 0%, #0056d6 100%);
  color: #fff;
  padding: 0.75rem 1.25rem;
  border-radius: 9999px;
  font-size: 0.9rem;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 8px 24px rgba(0, 132, 255, 0.45);
  border: 1px solid rgba(255, 255, 255, 0.25);
  transition: all 0.25s ease;
  animation: float-pulse 3s infinite;
}

.floating-badge:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 12px 30px rgba(0, 132, 255, 0.6);
}

@keyframes float-pulse {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* Footer */
.footer {
  background: #04060b;
  border-top: 1px solid var(--border-subtle);
  padding: 4rem 0 2rem;
  margin-top: 5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-top: 0.75rem;
  max-width: 420px;
}

.footer-title {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s ease;
}

.footer-link:hover {
  color: var(--cyan);
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* Article Styling (For /blog/*) */
.article-container {
  max-width: 820px;
  margin: 3rem auto;
  padding: 0 1.25rem;
}

.article-header {
  margin-bottom: 2.5rem;
}

.article-breadcrumbs {
  display: flex;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 1rem;
}

.article-breadcrumbs a {
  color: var(--cyan);
  text-decoration: none;
}

.article-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  line-height: 1.2;
  color: #fff;
  margin-bottom: 1rem;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #cbd5e1;
}

.article-body h2 {
  font-size: 1.65rem;
  font-weight: 800;
  color: #fff;
  margin: 2.5rem 0 1rem;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 0.5rem;
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #e2e8f0;
  margin: 1.75rem 0 0.75rem;
}

.article-body p {
  margin-bottom: 1.25rem;
}

.article-body ul, .article-body ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.article-body strong {
  color: #fff;
}

.article-body blockquote {
  background: rgba(15, 23, 42, 0.7);
  border-left: 4px solid var(--primary);
  padding: 1rem 1.5rem;
  border-radius: 0 8px 8px 0;
  margin: 1.75rem 0;
  color: #94a3b8;
}

.article-body code {
  font-family: var(--font-mono);
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.1);
  padding: 0.15rem 0.4rem;
  border-radius: 5px;
  color: #38bdf8;
  font-size: 0.9em;
}

.article-body pre {
  background: #090e1a;
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 1.25rem;
  overflow-x: auto;
  margin: 1.5rem 0;
}

.article-body pre code {
  background: transparent;
  border: none;
  padding: 0;
  color: #f1f5f9;
}

/* GEO & AI Search Optimization Components */
.geo-answer-box {
  background: linear-gradient(135deg, rgba(0, 210, 255, 0.08) 0%, rgba(0, 132, 255, 0.04) 100%);
  border: 1px solid rgba(0, 210, 255, 0.35);
  border-left: 4px solid var(--cyan);
  border-radius: 12px;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0 2rem;
  box-shadow: 0 4px 20px rgba(0, 210, 255, 0.05);
}

.geo-answer-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--cyan);
  margin-bottom: 0.5rem;
}

.geo-answer-text {
  font-size: 1.05rem;
  line-height: 1.6;
  color: #f8fafc;
}

.geo-tldr-box {
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
}

.geo-tldr-title {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.geo-tldr-list {
  list-style: none !important;
  padding-left: 0 !important;
  margin-bottom: 0 !important;
}

.geo-tldr-list li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--text-muted);
}

.geo-tldr-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success);
  font-weight: bold;
}

.geo-table-wrapper {
  overflow-x: auto;
  margin: 1.75rem 0;
  border-radius: 12px;
  border: 1px solid var(--border-subtle);
  background: rgba(15, 23, 42, 0.6);
}

.geo-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}

.geo-table th {
  background: rgba(0, 132, 255, 0.12);
  color: #fff;
  padding: 0.85rem 1rem;
  font-weight: 700;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  white-space: nowrap;
}

.geo-table td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-muted);
  vertical-align: top;
}

.geo-table tr:last-child td {
  border-bottom: none;
}

.geo-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.geo-faq-section {
  margin-top: 2.5rem;
  border-top: 1px solid var(--border-subtle);
  padding-top: 2rem;
}

.geo-faq-item {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  margin-bottom: 0.75rem;
  transition: border-color 0.2s;
}

.geo-faq-item[open] {
  border-color: rgba(0, 210, 255, 0.4);
}

.geo-faq-summary {
  padding: 1rem 1.25rem;
  cursor: pointer;
  font-weight: 700;
  color: #f1f5f9;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.geo-faq-summary::-webkit-details-marker {
  display: none;
}

.geo-faq-summary::after {
  content: "+";
  font-size: 1.25rem;
  color: var(--cyan);
  transition: transform 0.2s;
}

.geo-faq-item[open] .geo-faq-summary::after {
  content: "−";
}

.geo-faq-answer {
  padding: 0 1.25rem 1.25rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Table Scroll Hint (Mobile) */
.table-scroll-hint {
  display: none;
}

/* ==========================================================================
   RESPONSIVE & MOBILE-FIRST OPTIMIZATIONS
   ========================================================================== */

/* Tablet & Mobile Navigation Drawer (Max-Width: 900px) */
@media (max-width: 900px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 0;
    right: -300px;
    width: min(300px, 85vw);
    height: 100vh;
    height: 100dvh;
    background: rgba(9, 14, 26, 0.98);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    flex-direction: column;
    align-items: stretch;
    padding: 5rem 1.5rem max(1.5rem, env(safe-area-inset-bottom));
    gap: 0.6rem;
    z-index: var(--z-drawer);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -10px 0 35px rgba(0, 0, 0, 0.75);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
    border-left: 1px solid var(--border-subtle);
  }

  .nav-menu.active {
    transform: translateX(-300px);
  }

  .nav-link {
    display: block;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-main);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: background-color 0.2s ease, color 0.2s ease;
  }

  .nav-link:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--cyan);
  }

  .mobile-only-action {
    display: block;
    margin-top: 0.5rem;
  }

  .mobile-only-action .btn {
    width: 100%;
    justify-content: center;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

/* Smartphone Portrait Viewport (Max-Width: 640px) */
@media (max-width: 640px) {
  /* 1. Header gọn gàng & cân đối */
  .nav-container {
    height: 3.6rem;
  }

  .brand {
    font-size: 1.15rem;
    gap: 0.5rem;
  }

  .brand-icon {
    width: 28px;
    height: 28px;
  }

  .brand-tag {
    font-size: 0.65rem;
    padding: 0.1rem 0.4rem;
  }

  .nav-actions {
    gap: 0.5rem;
  }

  .nav-actions .btn {
    padding: 0.4rem 0.75rem;
    font-size: 0.8rem;
    border-radius: 8px;
  }

  .nav-actions .btn-zalo {
    display: none; /* Ẩn bớt trên header mobile để chống đè logo, đã có trong Drawer và Hero */
  }

  /* 2. Hero Section & Typography chuẩn 2-3 dòng */
  .hero {
    padding: 2.5rem 0 2rem;
  }

  .hero-pill {
    font-size: 0.75rem;
    padding: 0.3rem 0.75rem;
    line-height: 1.4;
    white-space: normal;
    max-width: 95%;
    margin-bottom: 1.25rem;
  }

  .hero-title {
    font-size: 1.75rem !important;
    line-height: 1.25;
    margin-bottom: 1rem;
    letter-spacing: -0.01em;
  }

  .hero-desc {
    font-size: 0.95rem;
    line-height: 1.6;
    padding: 0 0.5rem;
    margin-bottom: 1.5rem;
  }

  /* 3. CTA Buttons Full-Width dễ thao tác một tay */
  .hero-cta-group {
    flex-direction: column;
    width: 100%;
    gap: 0.75rem;
    margin-bottom: 2rem;
  }

  .hero-cta-group .btn,
  .hero-cta-group .cli-snippet {
    width: 100%;
    max-width: 340px;
    justify-content: center;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
  }

  /* 4. Badges bar dạng Chip hiện đại */
  .badges-bar {
    gap: 0.5rem;
    padding: 0.75rem 0;
  }

  .badges-bar .badge-item:nth-child(even) {
    display: none; /* Ẩn dấu chấm • trên mobile */
  }

  .badge-item {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 0.35rem 0.65rem;
    border-radius: 6px;
    font-size: 0.78rem;
  }

  /* 5. Cảnh Báo SmartScreen & Định Nghĩa GEO */
  .smartscreen-alert {
    padding: 1rem 1.15rem;
    margin: 1rem auto 2.5rem;
    border-radius: 12px;
  }

  .smartscreen-header {
    font-size: 0.92rem;
  }

  .smartscreen-content {
    font-size: 0.85rem;
  }

  .geo-box {
    padding: 1rem 1.15rem;
    font-size: 0.92rem;
    margin: 0 auto 2.5rem;
    border-radius: 0 10px 10px 0;
  }

  /* 6. Sections & Cards (Zero Horizontal Scroll) */
  .section {
    padding: 2.75rem 0;
  }

  .section-header {
    margin-bottom: 2rem;
  }

  .section-title {
    font-size: 1.55rem;
  }

  .grid-3, .grid-2 {
    grid-template-columns: 1fr !important;
    gap: 1.25rem;
  }

  .card {
    padding: 1.25rem;
    border-radius: 14px;
  }

  /* 7. Bảng So Sánh */
  .table-scroll-hint {
    display: block;
    font-size: 0.82rem;
    color: var(--cyan);
    text-align: center;
    margin-bottom: 0.75rem;
  }

  .comp-table th, .comp-table td {
    padding: 0.75rem 0.85rem;
    font-size: 0.88rem;
  }

  /* 8. Floating Badge thu gọn & Safe Area */
  .floating-badge {
    bottom: max(1rem, env(safe-area-inset-bottom));
    right: 1rem;
    padding: 0.5rem 0.85rem;
    font-size: 0.8rem;
  }

  /* 9. Footer thu gọn */
  .footer {
    padding: 2.5rem 0 1.5rem;
    margin-top: 3rem;
  }
}