.feat-hero{padding:2.5rem 0 2rem;background:#fff;border-bottom:1px solid #ddd}
.feat-hero-grid{display:grid;grid-template-columns:1fr 1fr;gap:2rem;align-items:start}
.feat-hero h1{font-size:clamp(1.3rem,3vw,1.75rem);font-weight:700;color:#1a1a1a;margin-bottom:.65rem;line-height:1.35}
.feat-hero h1 em{color:#800020;font-style:normal}
.feat-hero p{color:#555;font-size:.9rem;margin-bottom:1rem;line-height:1.6;font-style:italic}
.feat-trust{display:flex;flex-wrap:wrap;gap:.65rem}
.feat-trust div{background:#faf8f5;border:1px solid #ddd;padding:.5rem .85rem;font-size:.78rem;text-align:center}
.feat-trust strong{display:block;color:#800020;font-size:1rem;font-weight:700}
.feat-trust span{color:#555;font-size:.7rem}

.theorem-stack{display:flex;flex-direction:column;gap:0;max-width:680px;margin:0 auto}
.theorem-layer{background:#fff;border:1px solid #ddd;padding:1.1rem 1.2rem;margin-bottom:-1px}
.theorem-layer::before{content:"Theorem";display:block;font-size:.65rem;color:#800020;font-style:italic;margin-bottom:.25rem}
.theorem-layer:nth-child(1){border-left:5px solid #800020}
.theorem-layer:nth-child(2){border-left:5px solid #1a1a1a}
.theorem-layer:nth-child(3){border-left:5px solid #555}
.theorem-tag{font-size:.68rem;color:#555;margin-bottom:.35rem;font-style:italic}
.theorem-layer h3{font-size:.95rem;color:#1a1a1a;font-weight:700;margin-bottom:.35rem}
.theorem-layer p{font-size:.82rem;color:#555;line-height:1.5}

.axiom-channels{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem}
.axiom-ch{background:#faf8f5;border:1px solid #ddd;padding:1.1rem;text-align:center}
.axiom-ch .num{font-size:1.1rem;color:#800020;font-weight:700;display:block;margin-bottom:.35rem;font-style:italic}
.axiom-ch h3{font-size:.9rem;color:#1a1a1a;margin-bottom:.35rem;font-weight:700}
.axiom-ch p{font-size:.8rem;color:#555;line-height:1.5}

.proof-row{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem}
.proof-item{background:#fff;border:1px dashed #800020;padding:1rem;text-align:center}
.proof-item::before{content:"Q.E.D.";display:block;font-size:.65rem;color:#800020;font-style:italic;margin-bottom:.35rem}
.proof-item h3{font-size:.88rem;color:#1a1a1a;margin-bottom:.3rem;font-weight:700}
.proof-item p{font-size:.78rem;color:#555;line-height:1.45}

.feat-matrix{display:grid;grid-template-columns:1fr 1fr;gap:1rem}
.feat-matrix-col{background:#fff;border:1px solid #ddd}
.feat-matrix-col .mh{padding:.55rem 1rem;background:#1a1a1a;font-size:.72rem;color:#800020;font-style:italic}
.feat-matrix-col ul{padding:1rem 1.1rem}
.feat-matrix-col li{font-size:.82rem;color:#555;padding:.28rem 0;border-bottom:1px solid #eee;line-height:1.45}
.feat-matrix-col li:last-child{border-bottom:none}

.feat-cta{background:#1a1a1a;padding:2.5rem 0;text-align:center;border-top:3px solid #800020}
.feat-cta h2{font-size:clamp(1.05rem,2.6vw,1.35rem);color:#faf8f5;margin-bottom:.4rem;font-weight:700}
.feat-cta p{color:#aaa;font-size:.86rem;margin-bottom:1rem;font-style:italic}
.feat-img{border:2px solid #1a1a1a;overflow:hidden}

@media(max-width:900px){
  .feat-hero-grid,.axiom-channels,.proof-row,.feat-matrix{grid-template-columns:1fr}
}