@font-face {
  font-family: "Noto Sans Bengali";
  src: url("/assets/fonts/noto-sans-bengali.woff2") format("woff2");
  font-display: swap;
  font-style: normal;
  font-weight: 400 700;
}

:root {
  color-scheme: light;
  --bg: #f5f7fb;
  --bg-strong: #edf3ff;
  --surface: #ffffff;
  --surface-alt: #f8fafc;
  --text: #162033;
  --muted: #4d5f7a;
  --accent: #0d5bd7;
  --accent-strong: #0b43a8;
  --accent-soft: rgba(13, 91, 215, 0.08);
  --rule: #dfe8f3;
  --chip: #ebf1ff;
  --shadow: 0 18px 45px rgba(20, 31, 56, 0.08);
  --body-glow: rgba(13, 91, 215, 0.12);
  --radius: 18px;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0b0b0c;
  --bg-strong: #141416;
  --surface: #151517;
  --surface-alt: #1c1c1f;
  --text: #f1f1f3;
  --muted: #b6b6bd;
  --accent: #b7bdff;
  --accent-strong: #d4d7ff;
  --accent-soft: rgba(255, 255, 255, 0.08);
  --rule: #35353b;
  --chip: #292930;
  --shadow: 0 18px 45px rgba(0, 0, 0, 0.24);
  --body-glow: rgba(255, 255, 255, 0.035);
}

* { box-sizing: border-box; }

html {
  background: var(--bg);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at top left, var(--body-glow), transparent 32%),
    var(--bg);
  font-family: "Noto Sans Bengali", "Nirmala UI", "Vrinda", sans-serif;
  font-size: 1.08rem;
  line-height: 1.8;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; }

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover { text-decoration: underline; }

a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 1rem;
  padding: .7rem .9rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 10px;
  z-index: 10;
}
.skip-link:focus { left: 1rem; }

.site-shell {
  max-width: 1120px;
  margin: 0 auto;
  padding: 1.25rem 1.25rem 4rem;
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 0.5rem 0 1.25rem;
  border-bottom: 1px solid var(--rule);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.icon-link,
.theme-toggle {
  display: inline-flex;
  width: 2.5rem;
  height: 2.5rem;
  align-items: center;
  justify-content: center;
  padding: 0;
  color: var(--muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.icon-link:hover,
.theme-toggle:hover {
  color: var(--text);
  background: var(--accent-soft);
  border-color: var(--rule);
  text-decoration: none;
}

.icon-link svg,
.theme-toggle svg {
  width: 1.25rem;
  height: 1.25rem;
  fill: currentColor;
}

.theme-toggle svg {
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.8;
}

.theme-icon-moon { display: none; }
:root[data-theme="dark"] .theme-icon-sun { display: none; }
:root[data-theme="dark"] .theme-icon-moon { display: block; }

.brand-block {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.brand {
  color: var(--text);
  font-size: clamp(1.2rem, 2vw, 1.9rem);
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
}

.tagline {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  align-items: center;
}

.site-nav a {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.5rem 0.8rem;
  border-radius: 999px;
  transition: background 0.2s ease, color 0.2s ease;
}

.site-nav a:hover {
  background: var(--accent-soft);
  color: var(--accent-strong);
  text-decoration: none;
}

.page-content {
  max-width: 960px;
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: 2rem;
  padding: 2.5rem 0 1.5rem;
  align-items: center;
}

.hero-copy h1 {
  margin: 0 0 0.8rem;
  font-size: clamp(2.1rem, 4vw, 3.6rem);
  line-height: 1.15;
  letter-spacing: -0.04em;
}

.lead {
  margin: 0;
  color: var(--muted);
  font-size: 1.08rem;
  max-width: 60ch;
}

.hero-panel {
  background: linear-gradient(180deg, var(--surface), var(--surface-alt));
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.2rem 1.25rem;
}

.panel-label {
  display: inline-block;
  margin-bottom: 0.8rem;
  padding: 0.4rem 0.7rem;
  background: var(--chip);
  color: var(--accent-strong);
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
}

.hero-panel ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
}

.hero-panel li + li { margin-top: 0.55rem; }

.section {
  padding-top: 2rem;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 1rem;
  margin-bottom: 1rem;
}

.section-header h2 {
  margin: 0;
  font-size: clamp(1.6rem, 2vw, 2.1rem);
}

.section-subtitle {
  margin: 0;
  color: var(--muted);
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.1rem;
}

.guide-card {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  padding: 1.2rem 1.15rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.6);
  box-shadow: 0 10px 24px rgba(14, 29, 53, 0.04);
}

.guide-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
}

.pill {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.7rem;
  background: var(--chip);
  color: var(--accent-strong);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.guide-card h3 {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.4;
}

.english-title {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.guide-card ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.guide-card li + li { margin-top: 0.4rem; }

.standards-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.standard-card {
  padding: 1.2rem 1.15rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--surface);
}

.standard-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.standard-card p {
  margin: 0;
  color: var(--muted);
}

.info-callout {
  margin-top: 1.2rem;
  padding: 1.1rem 1.2rem;
  background: var(--surface-alt);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

.info-callout h3 {
  margin: 0 0 0.5rem;
}

code,
pre {
  font-family: "SFMono-Regular", "Consolas", monospace;
  font-size: 0.9rem;
}

pre {
  margin: 1rem 0 0;
  padding: 1rem 1.1rem;
  overflow-x: auto;
  border-radius: 12px;
  background: #0f172a;
  color: #e2e8f0;
  border: 1px solid rgba(148, 163, 184, 0.3);
}

main article {
  max-width: 760px;
  margin: 0 auto;
}

article h1,
article h2,
article h3 {
  line-height: 1.35;
}

article h1 {
  margin: 2.2rem 0 0.9rem;
  font-size: clamp(2rem, 5vw, 3rem);
}

article h2 {
  margin-top: 2.5rem;
  font-size: 1.55rem;
}

article h3 {
  margin-top: 2rem;
  font-size: 1.2rem;
}

.metadata {
  margin: 0 0 2.1rem;
  padding: 1rem 1.15rem;
  background: rgba(13, 91, 215, 0.04);
  border: 1px solid var(--rule);
  border-left: 4px solid var(--accent);
  border-radius: 12px;
  line-height: 1.7;
}

.metadata p { margin: 0.2rem 0; }
.metadata strong { color: var(--text); }

article p,
article ul,
article ol,
article blockquote {
  margin: 1.1rem 0;
}

article ul,
article ol {
  padding-left: 1.4rem;
}

article blockquote {
  margin-left: 0;
  padding: 0.5rem 1rem;
  border-left: 4px solid var(--accent);
  background: rgba(13, 91, 215, 0.04);
  color: var(--muted);
}

.disclaimer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.95rem;
}

.pagination {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2.5rem;
}

.pagination a:last-child { text-align: right; }

footer {
  margin-top: 4rem;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.6;
  text-align: center;
}

@media (max-width: 760px) {
  .hero,
  .standards-grid {
    grid-template-columns: 1fr;
  }

  .site-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 560px) {
  .site-shell { padding-left: 1rem; padding-right: 1rem; }
  .pagination { display: block; }
  .pagination a { display: block; margin: 0.5rem 0; }
  .pagination a:last-child { text-align: left; }
}