.lecture-hero{padding:clamp(3.5rem,8vw,7rem) 0 4rem;background:radial-gradient(circle at 85% 20%,#d9eaff 0,transparent 30%),var(--paper)}.lecture-hero h1{font-size:clamp(2.5rem,6vw,5rem);max-width:16ch}.lecture-shell{display:grid;grid-template-columns:220px minmax(0,1fr);gap:clamp(2rem,5vw,5rem);width:min(calc(100% - 2rem),var(--content));margin:auto}.lecture-nav{position:sticky;top:1rem;align-self:start;padding:1rem 0}.lecture-nav button{display:none}.lecture-nav a{display:block;padding:.5rem .75rem;border-left:2px solid var(--line);color:var(--muted);text-decoration:none;font-size:.88rem}.lecture-nav a.is-active{color:var(--blue);border-color:var(--blue);font-weight:800}.lecture-content{min-width:0}.learning-section{padding:clamp(4rem,8vw,7rem) 0;border-top:1px solid var(--line)}.learning-section:first-child{border-top:0}.learning-section>p,.learning-section>ul,.learning-section>.equation{max-width:var(--reading)}.section-number{font-variant-numeric:tabular-nums;color:var(--blue);font-weight:850}.equation{font-size:clamp(1rem,2.4vw,1.35rem);padding:1rem 0;overflow-x:auto}.concept-bridge{display:grid;grid-template-columns:repeat(5,auto);align-items:center;gap:.6rem;margin:2rem 0;overflow-x:auto;padding-bottom:.5rem}.concept-bridge span{white-space:nowrap;padding:.7rem 1rem;border:1px solid var(--line);border-radius:999px;background:#fff}.concept-bridge b{color:var(--blue)}pre{overflow:auto;background:#101827;color:#e8eef7;padding:1.4rem;border-radius:var(--radius);font-size:.88rem;line-height:1.65;tab-size:4}pre code{font:inherit}.two-plots{display:grid;grid-template-columns:1fr 1fr;gap:1rem}.convolution-steps{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem;padding:0;list-style:none;counter-reset:conv}.convolution-steps li{counter-increment:conv;padding:1rem;border-top:2px solid var(--blue)}.convolution-steps li:before{content:counter(conv);display:block;font-weight:900;color:var(--blue);margin-bottom:.5rem}.summary-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:1rem}.summary-grid div{padding:1.2rem;border-top:2px solid var(--blue)}

/* Ordered concept chain: wraps without clipping and becomes vertical on small screens. */
.concept-bridge{display:flex;flex-wrap:wrap;align-items:center;gap:.6rem;overflow:visible;padding:0;list-style:none}
.concept-bridge li{display:flex;align-items:center;white-space:nowrap;padding:.7rem 1rem;border:1px solid var(--line);border-radius:999px;background:#fff}
.concept-bridge li:not(:last-child)::after{content:"→";color:var(--blue);font-weight:850;margin-left:1.6rem;margin-right:-2.45rem;position:relative;z-index:1}