:root{
  --blue:#1B4FCC; --blue-md:#2B62E8; --sky:#EBF2FF; --sky2:#F5F8FF;
  --border:#D6E3FF; --text:#0F1C3F; --muted:#5A6A8A; --white:#FFFFFF;
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:'Inter',system-ui,sans-serif;background:var(--white);color:var(--text);line-height:1.7}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;display:block}

/* header */
.b-nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.97);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--border);padding:.75rem 1.5rem;display:flex;align-items:center;
  justify-content:space-between;gap:1rem}
.b-nav img{height:54px;object-fit:contain}
.b-nav .b-cta{background:var(--blue);color:#fff;padding:.55rem 1.2rem;border-radius:9px;
  font-weight:700;font-size:.85rem;white-space:nowrap}
.b-nav .b-cta:hover{background:#1440a8;text-decoration:none}

/* container */
.b-wrap{max-width:760px;margin:0 auto;padding:3rem 1.5rem}

/* blog list */
.b-hero{text-align:center;max-width:680px;margin:0 auto 2.5rem}
.b-tag{display:inline-block;background:var(--sky);color:var(--blue);border-radius:100px;
  padding:.3rem .95rem;font-size:.72rem;font-weight:700;letter-spacing:.09em;text-transform:uppercase;margin-bottom:.9rem}
.b-hero h1{font-size:clamp(1.7rem,4vw,2.4rem);font-weight:900;letter-spacing:-.02em;line-height:1.15;margin-bottom:.7rem}
.b-hero p{color:var(--muted);font-size:1.02rem}
.b-list{display:flex;flex-direction:column;gap:1.1rem}
.b-card{display:block;background:var(--white);border:2px solid var(--border);border-radius:16px;
  padding:1.5rem 1.6rem;transition:border-color .2s,transform .2s}
.b-card:hover{border-color:var(--blue);transform:translateY(-2px);text-decoration:none}
.b-card .b-date{font-size:.74rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--blue);margin-bottom:.45rem}
.b-card h2{font-size:1.18rem;font-weight:800;line-height:1.3;color:var(--text);margin-bottom:.4rem}
.b-card p{font-size:.92rem;color:var(--muted)}

/* article */
.b-article{max-width:720px;margin:0 auto}
.b-back{display:inline-flex;align-items:center;gap:.4rem;font-size:.85rem;font-weight:600;color:var(--muted);margin-bottom:1.5rem}
.b-back:hover{color:var(--blue)}
.b-article .b-date{font-size:.78rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--blue);margin-bottom:.7rem}
.b-article h1{font-size:clamp(1.6rem,4vw,2.3rem);font-weight:900;letter-spacing:-.02em;line-height:1.2;margin-bottom:.8rem}
.b-byline{display:flex;flex-wrap:wrap;align-items:center;gap:.5rem;font-size:.86rem;color:var(--muted);margin-bottom:1.6rem}
.b-byline .b-author{font-weight:700;color:var(--text)}
.b-byline .b-dot{opacity:.5}
.b-byline a{color:var(--blue)}
.b-source{margin-top:1.6rem;font-size:.86rem;color:var(--muted)}
.b-source a{color:var(--blue)}
/* FAQ */
.b-faq{margin-top:2.5rem;border-top:1px solid var(--border);padding-top:1.5rem}
.b-faq>h2{font-size:1.4rem;font-weight:900;letter-spacing:-.01em;margin-bottom:1rem}
.b-faq-item{border:2px solid var(--border);border-radius:14px;padding:.2rem 1.1rem;margin-bottom:.6rem;transition:border-color .2s}
.b-faq-item[open]{border-color:var(--blue)}
.b-faq-item summary{cursor:pointer;font-weight:700;padding:.9rem 0;list-style:none;font-size:.98rem}
.b-faq-item summary::-webkit-details-marker{display:none}
.b-faq-item summary::after{content:"+";float:right;color:var(--blue);font-size:1.2rem;line-height:1}
.b-faq-item[open] summary::after{content:"–"}
.b-faq-item p{padding:0 0 1rem;color:var(--muted);line-height:1.7;font-size:.95rem}
.b-cover{border-radius:16px;border:1px solid var(--border);margin-bottom:2rem;width:100%}
.b-body{font-size:1.05rem;color:#26344f}
/* lead paragraph — the opening sentence reads bigger */
.b-body > p:first-of-type{font-size:1.2rem;line-height:1.65;color:var(--text);font-weight:500;margin-bottom:1.6rem}
.b-body h2{font-size:1.4rem;font-weight:800;letter-spacing:-.01em;margin:2.3rem 0 .9rem;
  padding-left:.85rem;border-left:4px solid var(--blue);line-height:1.25}
.b-body h3{font-size:1.14rem;font-weight:800;margin:1.7rem 0 .6rem}
.b-body p{margin-bottom:1.2rem;line-height:1.78}
/* clean custom bullets instead of default dots */
.b-body ul{list-style:none;margin:0 0 1.4rem;padding:0}
.b-body ul li{position:relative;padding-left:1.6rem;margin-bottom:.75rem;line-height:1.65}
.b-body ul li::before{content:"";position:absolute;left:.1rem;top:.6em;width:7px;height:7px;
  border-radius:50%;background:var(--blue)}
.b-body ol{margin:0 0 1.4rem 1.3rem}
.b-body ol li{margin-bottom:.75rem;line-height:1.65}
.b-body blockquote{border-left:4px solid var(--blue);background:var(--sky2);padding:1.1rem 1.4rem;
  border-radius:0 14px 14px 0;margin:1.6rem 0;color:var(--text);font-size:1.08rem;font-style:italic}
.b-body blockquote p{margin:0}
.b-body strong{color:var(--text)}
.b-body em{font-style:italic}
.b-disclaimer{margin-top:2rem;padding:1rem 1.3rem;background:var(--sky2);border:1px solid var(--border);
  border-radius:12px;font-size:.85rem;color:var(--muted)}

/* article CTA */
.b-cta-box{margin-top:2.5rem;background:var(--blue);color:#fff;border-radius:18px;padding:2rem 1.8rem;text-align:center}
.b-cta-box h3{font-size:1.25rem;font-weight:900;margin-bottom:.5rem}
.b-cta-box p{color:rgba(255,255,255,.8);font-size:.95rem;margin-bottom:1.3rem}
.b-cta-box a{display:inline-block;background:#fff;color:var(--blue);font-weight:800;
  padding:.85rem 2rem;border-radius:10px;text-transform:uppercase;font-size:.9rem;letter-spacing:.02em}
.b-cta-box a:hover{opacity:.92;text-decoration:none}

/* footer */
.b-footer{background:var(--sky2);border-top:1px solid var(--border);color:var(--muted);
  text-align:center;padding:1.6rem;font-size:.82rem;margin-top:3rem}

@media(max-width:640px){
  .b-wrap{padding:2rem 1.1rem}
  .b-nav img{height:46px}
}