/* ============================================
   56D Index Page - Bangladesh SEO
   Mobile-First Responsive Design
   ============================================ */

/* CSS Variables - Dark Red Theme */
:root {
  --color-primary: #0d2318;
  --color-primary-light: #2a7a50;
  --color-secondary: #2a7a50;
  --color-secondary-hover: #1a4a30;
  --color-success: #1a4a30;
  --color-dark: #0d2318;
  --color-dark-bg: #0d2318;
  --color-text: #050e08;
  --color-text-light: #1a4a30;
  --color-bg: #c8f0dc;
  --color-bg-alt: #4db88a;
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-size-base: 1rem;
  --line-height: 1.6;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --max-width: 800px;
  --header-height: 60px;
  --border-radius: 8px;
  --shadow: 0 2px 8px rgba(5,14,8,0.08);
}

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

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

body {
  margin: 0;
  font-family: var(--font-main);
  overflow-x: hidden;
  font-size: var(--font-size-base);
  line-height: var(--line-height);
  color: var(--color-text);
  background: var(--color-bg);
  word-wrap: break-word;
  overflow-wrap: break-word;
}

/* Skip Link - Acessibilidade */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--color-primary);
  color: #c8f0dc;
  text-decoration: none;
  border-radius: var(--border-radius);
  z-index: 9999;
  transition: top 0.2s;
}

.skip-link:focus {
  top: var(--spacing-sm);
}

/* ========== Site Header - Fixed ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--color-dark);
  border-bottom: 3px solid var(--color-primary);
  overflow-x: hidden;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
}

/* ----- Mobile ----- */
.header-row-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem var(--spacing-md);
  min-height: 56px;
}

.logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.logo img {
  display: block;
  max-width: 150px;
  max-height: 60px;
  width: auto;
  height: auto;
  object-fit: contain;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  padding: 8px;
  background: none;
  border: none;
  cursor: pointer;
  flex-shrink: 0;
}

.nav-toggle span {
  width: 22px;
  height: 2.5px;
  background: rgba(200,240,220,0.9);
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7.5px) rotate(-45deg);
}

.header-row-mobile-btns {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 0.75rem 0;
  background: var(--color-dark);
  gap: var(--spacing-xs);
  box-sizing: border-box;
}

.header-row-mobile-btns .btn-header {
  flex: 1;
  max-width: calc(50% - 0.25rem);
  padding: 12px 16px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  text-align: center;
  border-radius: 999px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  border: none;
  -webkit-tap-highlight-color: transparent;
}

.header-row-mobile-btns .btn-login {
  background: rgba(200,240,220,0.12);
  color: #c8f0dc;
  border: 1px solid rgba(200,240,220,0.3);
}

.header-row-mobile-btns .btn-login:hover,
.header-row-mobile-btns .btn-login:active {
  background: rgba(200,240,220,0.22);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(5,14,8,0.25);
}

.header-row-mobile-btns .btn-register {
  background: var(--color-secondary);
  color: #c8f0dc;
}

.header-row-mobile-btns .btn-register:hover,
.header-row-mobile-btns .btn-register:active {
  background: var(--color-secondary-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(42,122,80,0.5);
}

.main-nav {
  display: none;
  flex-basis: 100%;
  background: var(--color-bg);
  padding: var(--spacing-md);
  border-top: 1px solid rgba(13,35,24,0.15);
  max-height: 70vh;
  overflow-y: auto;
}

.main-nav.is-open {
  display: block;
}

/* 企业排列：移动端导航采用两列网格布局 */
.main-nav .nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.25rem 1rem;
}

.main-nav .nav-list li {
  border-bottom: 1px solid rgba(13,35,24,0.08);
}

.main-nav .nav-list li:nth-last-child(-n+2) {
  border-bottom: none;
}

.main-nav .nav-list a {
  display: block;
  padding: 14px 16px;
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  line-height: 1.4;
  text-align: left;
  border-radius: 6px;
  transition: background 0.2s, color 0.2s;
  letter-spacing: 0.02em;
}

.main-nav .nav-list a:hover {
  background: var(--color-bg-alt);
  color: var(--color-secondary);
}

.header-btns {
  display: none;
}

/* ----- Desktop (≥900px) ----- */
@media (min-width: 900px) {
  .nav-toggle {
    display: none;
  }

  .header-row-mobile-btns {
    display: none;
  }

  .header-row-top {
    flex-wrap: nowrap;
    padding: 0.5rem 1rem;
    min-height: 52px;
  }

  .header-btns {
    display: flex;
    gap: 0.5rem;
    margin-left: auto;
    flex-shrink: 0;
  }

  .header-btns .btn-header {
    padding: 8px 18px;
    font-size: 0.875rem;
    font-weight: 600;
    text-decoration: none;
    text-align: center;
    border-radius: 999px;
    transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
  }

  .header-btns .btn-login {
    background: transparent;
    color: rgba(200,240,220,0.9);
    border: 2px solid rgba(200,240,220,0.5);
  }

  .header-btns .btn-login:hover {
    background: rgba(200,240,220,0.15);
    color: #c8f0dc;
    border-color: rgba(200,240,220,0.7);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(5,14,8,0.3);
  }

  .header-btns .btn-register {
    background: var(--color-secondary);
    color: #c8f0dc;
    border: 2px solid var(--color-secondary);
  }

  .header-btns .btn-register:hover {
    background: var(--color-secondary-hover);
    border-color: var(--color-secondary-hover);
    color: #c8f0dc;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(42,122,80,0.4);
  }

  .main-nav {
    display: flex !important;
    flex: 1;
    justify-content: center;
    margin: 0 1rem;
    padding: 0;
    background: transparent;
    border: none;
    flex-basis: auto;
    width: auto;
  }

  .main-nav .nav-list {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.2rem 0.4rem;
  }

  .main-nav .nav-list li {
    border: none;
  }

  .main-nav .nav-list a {
    padding: 6px 10px;
    font-size: 0.85rem;
    font-weight: 500;
    color: rgba(200,240,220,0.9);
    border-radius: 6px;
    text-align: left;
    border: none;
  }

  .main-nav .nav-list a:hover {
    background: rgba(200,240,220,0.1);
    color: #c8f0dc;
  }

  .logo img {
    max-height: 50px;
  }

  .main-content {
    padding: var(--spacing-lg);
    padding-top: 50px;
  }

  .article-header h1 {
    font-size: 2rem;
  }

  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
  h4 { font-size: 1.15rem; }
  h5 { font-size: 1.08rem; }
  h6 { font-size: 1rem; }
}

/* Main Content - Top padding for fixed header */
.main-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-md);
  padding-top: 160px;
  padding-bottom: var(--spacing-xl);
  padding-left: max(var(--spacing-md), env(safe-area-inset-left));
  padding-right: max(var(--spacing-md), env(safe-area-inset-right));
}

/* ========== Mobile Responsive ========== */
@media (max-width: 599px) {
  .main-content {
    padding: var(--spacing-sm);
    padding-top: 160px;
    padding-bottom: var(--spacing-xl);
    padding-left: max(var(--spacing-sm), env(safe-area-inset-left));
    padding-right: max(var(--spacing-sm), env(safe-area-inset-right));
  }

  .header-row-top {
    padding-left: max(var(--spacing-md), env(safe-area-inset-left));
    padding-right: max(var(--spacing-md), env(safe-area-inset-right));
  }

  .header-row-mobile-btns {
    padding-left: max(0px, env(safe-area-inset-left));
    padding-right: max(0px, env(safe-area-inset-right));
  }

  .article-header h1 {
    font-size: clamp(1.25rem, 5vw, 1.5rem);
  }

  h2 { font-size: clamp(1.1rem, 4vw, 1.25rem); }
  h3 { font-size: clamp(1rem, 3vw, 1.1rem); }
  h4 { font-size: clamp(0.95rem, 2.5vw, 1.05rem); }
  h5 { font-size: clamp(0.9rem, 2vw, 1rem); }
  h6 { font-size: clamp(0.85rem, 1.5vw, 0.95rem); }

  .comparison-table {
    font-size: 0.8rem;
  }

  .comparison-table th,
  .comparison-table td {
    padding: 0.5rem 0.4rem;
  }

  .cta-box {
    padding: var(--spacing-md);
  }

  .btn-primary {
    min-height: 44px;
    padding: 12px var(--spacing-md);
  }

  .back-to-top {
    bottom: max(var(--spacing-md), env(safe-area-inset-bottom));
    right: max(var(--spacing-md), env(safe-area-inset-right));
  }
}

.article-content {
  max-width: 100%;
}

/* ========== H1-H6 Headings ========== */
.article-header h1,
h1 {
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.3;
  margin: 0 0 var(--spacing-md);
  color: var(--color-dark);
  letter-spacing: -0.02em;
}

.article-header h1 {
  font-size: 1.5rem;
}

h2 {
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1.35;
  margin: var(--spacing-xl) 0 var(--spacing-sm);
  color: var(--color-primary);
  padding-bottom: var(--spacing-xs);
  border-bottom: 2px solid var(--color-primary);
  letter-spacing: -0.01em;
}

h3 {
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.4;
  margin: var(--spacing-lg) 0 var(--spacing-xs);
  color: var(--color-dark);
}

h4 {
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.4;
  margin: var(--spacing-md) 0 var(--spacing-xs);
  color: var(--color-dark);
}

h5 {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.45;
  margin: var(--spacing-md) 0 var(--spacing-xs);
  color: var(--color-text);
}

h6 {
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.45;
  margin: var(--spacing-sm) 0 var(--spacing-xs);
  color: var(--color-text-light);
}

/* Hero Section */
.hero-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding-bottom: var(--spacing-lg);
}

.hero-section h1 {
  margin: var(--spacing-sm) 0;
  font-size: clamp(1.25rem, 4vw, 1.75rem);
}

.hero-section .hero-logo {
  max-width: 150px;
  max-height: 120px;
  width: auto;
  height: auto;
  margin: var(--spacing-sm) 0;
  object-fit: contain;
}

.hero-section .btn-hero {
  display: inline-block;
  padding: 14px 32px;
  font-weight: 700;
  font-size: 1.1rem;
  text-decoration: none;
  color: #c8f0dc;
  background: var(--color-secondary);
  border-radius: 999px;
  transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
  margin-top: var(--spacing-sm);
}

.hero-section .btn-hero:hover {
  background: var(--color-secondary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(42,122,80,0.4);
}

/* Sections */
section {
  margin-bottom: var(--spacing-xl);
}

p {
  margin: 0 0 var(--spacing-sm);
  text-align: justify;
}

/* Figures */
figure {
  margin: var(--spacing-md) 0;
}

img {
  max-width: 100%;
  height: auto;
}

figure img {
  display: block;
  border-radius: var(--border-radius);
}

figcaption {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-top: var(--spacing-xs);
  text-align: center;
}

/* Tables */
.comparison-table {
  width: 100%;
  min-width: 280px;
  border-collapse: collapse;
  margin: var(--spacing-md) 0;
  font-size: 0.9rem;
  overflow-x: auto;
  display: block;
  -webkit-overflow-scrolling: touch;
}

.comparison-table caption {
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  text-align: left;
}

.comparison-table thead {
  background: var(--color-primary);
  color: #c8f0dc;
}

.comparison-table tbody tr:hover {
  background: #4db88a;
}

.comparison-table th,
.comparison-table td {
  padding: var(--spacing-sm);
  border: 1px solid #4db88a;
  text-align: left;
}

.comparison-table tbody tr:nth-child(even) {
  background: var(--color-bg-alt);
}

/* Lists */
.benefits-list,
ul, ol {
  margin: 0 0 var(--spacing-md);
  padding-left: 1.25rem;
}

.benefits-list li {
  margin-bottom: var(--spacing-sm);
}

/* FAQ */
.faq-section dl {
  margin: 0;
}

.faq-list dt {
  font-weight: 600;
  margin-top: var(--spacing-md);
  color: var(--color-primary);
}

.faq-list dt:first-child {
  margin-top: 0;
}

.faq-list dd {
  margin: var(--spacing-xs) 0 0;
  padding-left: 0;
}

/* CTA Box */
.cta-box {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: #c8f0dc;
  padding: var(--spacing-lg);
  border-radius: var(--border-radius);
  text-align: center;
  margin: var(--spacing-xl) 0;
}

.cta-box p {
  margin-bottom: var(--spacing-sm);
  text-align: center;
}

.btn-primary {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-lg);
  background: var(--color-secondary);
  color: #c8f0dc;
  text-decoration: none;
  font-weight: 700;
  border-radius: var(--border-radius);
  transition: background 0.2s, transform 0.1s;
}

.btn-primary:hover {
  background: var(--color-secondary-hover);
  transform: scale(1.02);
}

/* Footer */
.site-footer {
  background: var(--color-dark-bg);
  color: #c8f0dc;
  padding: var(--spacing-lg) var(--spacing-md);
  margin-top: var(--spacing-xl);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  text-align: center;
}

.footer-inner p {
  text-align: center;
  margin-bottom: var(--spacing-md);
  font-size: 0.9rem;
}

.footer-nav ul {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--spacing-md);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-sm);
}

.footer-nav a {
  color: rgba(200,240,220,0.9);
  text-decoration: none;
}

.footer-nav a:hover {
  text-decoration: underline;
}

.copyright {
  font-size: 0.8rem;
  opacity: 0.8;
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-md);
  right: var(--spacing-md);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: #c8f0dc;
  text-decoration: none;
  border-radius: 50%;
  font-size: 1.25rem;
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s, visibility 0.2s;
  z-index: 50;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--color-secondary-hover);
  color: #c8f0dc;
}

/* Links */
a {
  color: var(--color-primary);
}

a:hover {
  text-decoration: underline;
}

/* ============================================
   Tablet (min-width: 600px)
   ============================================ */
@media (min-width: 600px) {
  .article-header h1 {
    font-size: 1.75rem;
  }

  h2 { font-size: 1.4rem; }
  h3 { font-size: 1.2rem; }
  h4 { font-size: 1.1rem; }
  h5 { font-size: 1.05rem; }
  h6 { font-size: 1rem; }

  .comparison-table {
    display: table;
  }
}

/* ============================================
   Desktop (min-width: 900px) - Merged with PC Layout above
   ============================================ */
@media (min-width: 900px) {
  :root {
    --max-width: 900px;
  }
}

/* ========== Content Blocks & Cards ========== */
.content-block {
  margin-bottom: var(--spacing-xl);
}

.card-grid {
  display: grid;
  gap: var(--spacing-md);
  margin: var(--spacing-md) 0;
}

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

.card-grid-4 {
  grid-template-columns: 1fr;
}

.card-grid-6 {
  grid-template-columns: 1fr;
}

.card-grid-8 {
  grid-template-columns: 1fr 1fr;
}

@media (min-width: 600px) {
  .card-grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }

  .card-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .card-grid-6 {
    grid-template-columns: repeat(2, 1fr);
  }

  .card-grid-8 {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media (min-width: 900px) {
  .card-grid-4 {
    grid-template-columns: repeat(4, 1fr);
  }

  .card-grid-6 {
    grid-template-columns: repeat(6, 1fr);
  }

  .card-grid-8 {
    grid-template-columns: repeat(4, 1fr);
  }
}

.card {
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-2px);
}

.card-bordered {
  border: 2px solid var(--color-primary);
  background: var(--color-bg);
}

.card-elevated {
  background: var(--color-bg);
  box-shadow: 0 4px 12px rgba(13,35,24,0.12);
}

.card-outline {
  border: 1px solid #4db88a;
  background: #c8f0dc;
}

.card-solid {
  background: linear-gradient(135deg, var(--color-bg-alt), #4db88a);
}

.card img {
  width: 100%;
  height: auto;
  border-radius: 6px;
  margin-bottom: var(--spacing-sm);
}

.card h4 {
  margin-top: 0;
}

.hero-sub {
  text-align: center;
  padding: var(--spacing-xl) var(--spacing-md);
  background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
  border-radius: var(--border-radius);
  margin-bottom: var(--spacing-xl);
}

.hero-sub h1 {
  margin-bottom: var(--spacing-sm);
}

.hero-sub p {
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.feature-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  align-items: flex-start;
  margin: var(--spacing-md) 0;
}

.feature-row figure {
  flex: 1 1 280px;
  margin: 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-sm);
  margin: var(--spacing-md) 0;
}

@media (min-width: 600px) {
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.stat-box {
  text-align: center;
  padding: var(--spacing-md);
  background: var(--color-bg-alt);
  border-radius: var(--border-radius);
}

.stat-box strong {
  display: block;
  font-size: 1.25rem;
  color: var(--color-primary);
}

/* ============================================
   Print Styles
   ============================================ */
@media print {
  .site-header,
  .nav-toggle,
  .back-to-top,
  .cta-box,
  .btn-primary {
    display: none !important;
  }

  body {
    font-size: 12pt;
  }

  a {
    color: #050e08;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
  }
}