:root {
  --navy: #082f4f;
  --blue: #1266a7;
  --blue-dark: #0b4d80;
  --blue-soft: #eaf4fb;
  --ink: #173042;
  --muted: #5f7483;
  --line: #d8e5ee;
  --paper: #ffffff;
  --wash: #f4f8fb;
  --shadow: 0 18px 45px rgba(8, 47, 79, 0.10);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: linear-gradient(180deg, #eef6fb 0, #f8fbfd 340px, #fff 760px);
  font-family: Inter, "Noto Sans Bengali", "Hind Siliguri", "Segoe UI", Arial, sans-serif;
  line-height: 1.78;
}
a { color: inherit; }
.skip-link { position: absolute; left: -9999px; top: 0; }
.skip-link:focus { left: 1rem; top: 1rem; z-index: 10; padding: .7rem 1rem; background: #fff; border-radius: .5rem; }
.site-header {
  background: rgba(255,255,255,.96);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 5;
  backdrop-filter: blur(12px);
}
.nav-wrap {
  width: min(1180px, calc(100% - 32px));
  min-height: 76px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand { display: flex; align-items: center; gap: 11px; text-decoration: none; min-width: 245px; }
.brand-mark {
  width: 42px;
  height: 42px;
  min-width: 42px;
  max-width: 42px;
  min-height: 42px;
  max-height: 42px;
  display: grid;
  place-items: center;
  flex: 0 0 42px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--navy));
  border-radius: 13px;
  font-weight: 800;
  letter-spacing: -.04em;
}
.brand-copy { display: grid; line-height: 1.25; }
.brand-mark.brand-photo { overflow: hidden; }
.brand-mark.brand-photo img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 42px;
  max-height: 42px;
  object-fit: cover;
  border-radius: inherit;
}
.brand-copy strong { color: var(--navy); font-size: .98rem; }
.brand-copy span { color: var(--muted); font-size: .72rem; }
.menu { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 7px; }
.menu-btn {
  padding: .58rem .76rem;
  border-radius: 9px;
  color: #355568;
  font-size: .84rem;
  font-weight: 700;
  text-decoration: none;
}
.menu-btn:hover, .menu-btn:focus-visible, .menu-btn.active { color: #fff; background: var(--blue); outline: none; }
.article-shell { width: min(940px, calc(100% - 32px)); margin: 54px auto 72px; }
.back-link {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  margin-bottom: 20px;
  color: var(--blue-dark);
  font-weight: 750;
  text-decoration: none;
}
.back-link:hover { text-decoration: underline; }
.article-paper {
  padding: clamp(28px, 6vw, 72px);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: var(--shadow);
}
.article-header { padding-bottom: 32px; border-bottom: 1px solid var(--line); }
.tag {
  display: inline-flex;
  padding: .33rem .68rem;
  color: var(--blue-dark);
  background: var(--blue-soft);
  border-radius: 999px;
  font-size: .77rem;
  font-weight: 800;
  letter-spacing: .04em;
  text-transform: uppercase;
}
h1 {
  margin: 16px 0 18px;
  color: var(--navy);
  font-family: Georgia, "Noto Serif Bengali", serif;
  font-size: clamp(2rem, 5vw, 3.7rem);
  line-height: 1.12;
  letter-spacing: -.035em;
}
.byline { display: flex; flex-wrap: wrap; gap: .5rem 1.1rem; color: var(--muted); font-size: .94rem; }
.byline strong { color: var(--ink); }
.article-body { padding-top: 32px; font-family: Georgia, "Noto Serif Bengali", serif; font-size: clamp(1.04rem, 2vw, 1.17rem); }
.article-body p { margin: 0 0 1.35em; }
.article-body h2 {
  margin: 2.25em 0 .65em;
  color: var(--navy);
  font-family: Inter, "Noto Sans Bengali", "Hind Siliguri", "Segoe UI", sans-serif;
  font-size: clamp(1.28rem, 3vw, 1.75rem);
  line-height: 1.3;
}
.article-body blockquote {
  margin: 1.7em 0;
  padding: 1rem 1.2rem;
  color: #294c63;
  background: var(--blue-soft);
  border-left: 4px solid var(--blue);
  border-radius: 0 12px 12px 0;
}
.article-body blockquote p { margin: 0; }
.article-body pre {
  overflow-x: auto;
  margin: 1.6em 0;
  padding: 1rem 1.15rem;
  color: #e8f4fb;
  background: #082f4f;
  border-radius: 12px;
  font: .86rem/1.6 Consolas, "Courier New", monospace;
  white-space: pre-wrap;
}
.article-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 26px;
}
.article-nav a {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 92px;
  padding: 16px 18px;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 15px;
  text-decoration: none;
}
.article-nav a:last-child { text-align: right; }
.article-nav span { color: var(--blue-dark); font-size: .76rem; font-weight: 800; text-transform: uppercase; letter-spacing: .05em; }
.article-nav strong { margin-top: 4px; line-height: 1.35; }
.article-nav a:hover { border-color: #86b9dc; box-shadow: 0 10px 24px rgba(8, 47, 79, .08); }
footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 36px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: .82rem;
}
@media (max-width: 850px) {
  .nav-wrap { padding: 14px 0; align-items: flex-start; flex-direction: column; }
  .menu { justify-content: flex-start; }
  .site-header { position: static; }
}
@media (max-width: 600px) {
  .brand-copy span { display: none; }
  .menu-btn { padding: .5rem .55rem; font-size: .78rem; }
  .article-shell { margin-top: 28px; }
  .article-paper { border-radius: 18px; }
  .article-nav { grid-template-columns: 1fr; }
  .article-nav a:last-child { text-align: left; }
  footer { flex-direction: column; }
}
@media print {
  body { background: #fff; color: #000; }
  .site-header, .back-link, .article-nav, footer { display: none !important; }
  .article-shell { width: 100%; margin: 0; }
  .article-paper { padding: 0; border: 0; box-shadow: none; }
}