.fir-hero{padding:clamp(4rem,8vw,7rem) 0 4rem;background:linear-gradient(180deg,rgba(74,124,111,.10),transparent 80%);border-bottom:1px solid var(--line)}
.fir-hero h1{font-family:var(--font-serif);font-size:clamp(2.8rem,7vw,6rem);line-height:.98;max-width:12ch;margin:.55rem 0 1.25rem}.fir-hero .lede{max-width:800px}.fir-actions{display:flex;gap:.75rem;flex-wrap:wrap;margin-top:1.6rem}
.fir-section{padding:clamp(3.8rem,7vw,6.5rem) 0}.fir-section--tint{background:var(--paper-soft,#f4f0e8);border-block:1px solid var(--line)}.fir-section h2,.fir-cta h2{font-family:var(--font-serif);font-size:clamp(2.1rem,4.8vw,4rem);line-height:1.03;max-width:16ch;margin:.5rem 0 1rem}.fir-split{display:grid;grid-template-columns:.72fr 1.28fr;gap:clamp(2rem,7vw,6rem);align-items:start}.fir-split p,.fir-wide{color:var(--ink-soft);line-height:1.7;max-width:820px}.fir-function-list{display:grid;grid-template-columns:1fr 1fr;gap:.75rem 1.5rem;list-style:none;padding:0;margin:0}.fir-function-list li{border-top:1px solid var(--line);padding:.85rem 0;line-height:1.5}.fir-function-list li::before{content:'→';color:var(--terracotta);margin-right:.55rem}.fir-three{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem;margin-top:2.1rem}.fir-three article,.fir-study{border:1px solid var(--line);background:var(--paper);padding:1.2rem}.fir-three span,.fir-study>span{font-family:var(--font-mono);font-size:.72rem;text-transform:uppercase;letter-spacing:.06em;color:var(--terracotta)}.fir-three h3,.fir-study h3{font-family:var(--font-serif);font-size:1.45rem;margin:.5rem 0}.fir-three p,.fir-study p{color:var(--ink-soft);line-height:1.62;margin-bottom:0}.fir-study-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;margin-top:2rem}.fir-study{display:flex;flex-direction:column;min-height:280px}.fir-links{display:flex;gap:1rem;flex-wrap:wrap;margin-top:auto;padding-top:1.2rem}.fir-links a{font-weight:600;text-underline-offset:3px}.fir-study--principle{background:var(--ink);color:var(--paper)}.fir-study--principle p{color:rgba(255,255,255,.72)}.fir-cta{padding:3rem 0;background:var(--ink);color:var(--paper)}.fir-cta .container{display:grid;grid-template-columns:1fr auto;gap:2rem;align-items:center}.fir-cta p{color:rgba(255,255,255,.72);max-width:760px}.fir-cta .btn{background:var(--paper);color:var(--ink)}
@media(max-width:800px){.fir-split,.fir-cta .container{grid-template-columns:1fr}.fir-function-list,.fir-study-grid{grid-template-columns:1fr}.fir-three{grid-template-columns:1fr}.fir-hero{padding-top:3rem}}@media(max-width:520px){.fir-actions .btn{width:100%;text-align:center}}