:root{
  --bg:#f5f7fb;
  --surface:#ffffff;
  --text:#101418;
  --muted:#5a6872;
  --line:rgba(21,34,50,.10);
  --brand:#517b96;
  --shadow:0 20px 50px rgba(18,34,48,.08);
  --radius-xl:28px;
  --radius-lg:20px;
  --container:min(900px, calc(100vw - 32px));
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Inter,"Noto Sans","Noto Sans Arabic","Noto Sans Devanagari","Noto Sans JP","Noto Sans KR","Noto Sans SC","Noto Sans TC","Noto Sans Thai",system-ui,sans-serif;
  color:var(--text);
  background:radial-gradient(circle at top right, rgba(81,123,150,.14), transparent 28%),linear-gradient(180deg,#fbfdff 0%, var(--bg) 100%);
}
body.rtl{direction:rtl}
.page-shell{width:var(--container);margin:0 auto;padding:34px 0 52px}
.article-head{
  background:linear-gradient(180deg, rgba(255,255,255,.96), rgba(255,255,255,.92));
  border:1px solid var(--line);
  border-radius:var(--radius-xl);
  box-shadow:var(--shadow);
  padding:30px 32px 24px;
}
.article-head h1{margin:0;font-size:clamp(1.9rem,4vw,3rem);line-height:1.08;letter-spacing:-0.04em}
.article{margin-top:20px;display:grid;gap:16px}
.section-card{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--radius-lg);
  box-shadow:0 12px 34px rgba(18,34,48,.05);
  padding:26px 28px;
}
.section-card h2{margin:0 0 12px;font-size:1.18rem;line-height:1.3;letter-spacing:-0.02em}
.section-card p{margin:0;color:var(--muted);line-height:1.8}
@media (max-width:700px){
  .page-shell{padding:20px 0 38px}
  .article-head{padding:24px 18px 20px}
  .section-card{padding:22px 18px}
}