/* Navigation/catalog edition: contained presentation changes, no lesson overrides. */
.site-header{height:92px}.brand{gap:12px}.brand-mark{width:43px;height:44px;object-fit:contain}.brand-name{font-size:1.27rem}.brand-name>span{font-size:.65rem;margin-top:7px}.nav{gap:28px;font-size:.91rem}.nav .contact{margin-left:6px}.nav>a{min-height:44px;display:flex;align-items:center}.nav-wrap{gap:24px}
:where(a,button,input,select,summary):focus-visible{outline:3px solid #446cf0;outline-offset:4px}
.platform-head{padding:34px 0 32px}.platform-head .breadcrumbs{margin-bottom:22px}.platform-head h1{font-size:clamp(2.3rem,4.1vw,3.8rem)}
.platform-hero{padding:56px 0 42px;max-width:1010px}.platform-hero h1{font-size:clamp(2.6rem,4.7vw,4.4rem);margin:19px 0 24px;line-height:1.11}.platform-hero h1 em{font-style:normal;color:var(--blue)}.platform-intro{max-width:640px;font-size:1.12rem;color:var(--muted);line-height:1.75}.platform-hero .actions{margin-top:26px;gap:24px}
.home-catalog,.home-logic,.home-investigate{border-top:1px solid var(--line);padding:35px 0 43px}.platform-home .section-heading{margin-bottom:23px;align-items:flex-end}.platform-home .section-heading h2{font-size:clamp(1.85rem,3vw,2.6rem);margin-top:13px}.platform-home .section-heading .text-link{flex-shrink:0}.home-subjects{display:grid;grid-template-columns:1fr 1fr;gap:24px}.home-subject{display:flex;gap:28px;padding:26px 30px;border:1px solid var(--line);background:var(--soft)}.home-subject-mark{font:italic 3.5rem/1.1 Georgia,serif;color:#7892af;padding-top:16px;min-width:60px}.home-subject h3{font-size:1.6rem;margin:7px 0}.home-subject p:not(.eyebrow){color:var(--muted);font-size:.9rem}.home-subject .text-link{display:inline-block;margin-top:16px}.home-catalog-note,.home-section-lead{color:var(--muted);max-width:760px;font-size:.94rem;margin-top:18px}.home-section-lead{margin:0 0 25px}.home-logic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.home-investigate .chaos-opening{padding:15px 0 28px;gap:45px}.home-investigate .chaos-intro h2{font-size:clamp(2rem,3.2vw,3rem);margin:20px 0}.home-investigate .chaos-topline{font-size:.78rem}.home-author{display:grid;grid-template-columns:150px 1fr;gap:35px;padding:40px 0 55px;border-top:1px solid var(--line);align-items:center;max-width:950px}.home-author img{width:150px;height:200px;object-fit:cover}.home-author h2{font-size:2.1rem;margin:12px 0 18px}.home-author p:not(.eyebrow){color:var(--muted);max-width:660px}.home-author .actions{margin-top:22px;gap:25px}
.about-navigation{display:flex;flex-wrap:wrap;gap:12px 26px;padding:25px 0 0;font-size:.93rem}.about-navigation a{border-bottom:1px solid var(--line);padding:5px 0}.about-approach{display:grid;grid-template-columns:1fr 1fr;gap:70px;padding:36px 0 50px;border-top:1px solid var(--line)}.about-approach h2{font-size:2.3rem;margin:14px 0 20px}.about-approach p:not(.eyebrow),.about-author p:not(.eyebrow),.about-lessons p:not(.eyebrow){color:var(--muted);margin:15px 0}.about-learning-steps{counter-reset:learn;list-style:none;padding:0;margin:0}.about-learning-steps li{position:relative;padding:14px 0 18px 42px;border-bottom:1px solid var(--line)}.about-learning-steps li:before{counter-increment:learn;content:counter(learn,decimal-leading-zero);position:absolute;left:0;color:#7488a1}.about-learning-steps strong{font-weight:500;display:block}.about-learning-steps span{display:block;color:var(--muted);font-size:.9rem;margin-top:5px}.about-author{display:grid;grid-template-columns:minmax(200px,360px) minmax(0,1fr);gap:65px;align-items:center;padding:50px 0;border-top:1px solid var(--line)}.about-author picture{display:block}.about-author img{width:100%;height:auto}.about-author h2{font-size:2.8rem;margin-top:14px}.about-author .about-author-role{color:var(--ink);font-size:1.13rem}.about-author .actions{margin-top:28px}.about-project .portfolio-cta{display:none}.about-project .portfolio-facts{margin-top:10px}.about-lessons{display:grid;grid-template-columns:1.2fr 1fr;gap:60px;padding:40px 0 65px;border-top:1px solid var(--line)}.about-lessons h2{font-size:2.4rem;margin:14px 0 22px}.about-lesson-links{display:flex;flex-direction:column;gap:22px;align-items:flex-start;justify-content:center}.legacy-context{padding:12px 0;color:var(--muted);font-size:.9rem}.legacy-context a{color:var(--blue)}
@media(min-width:901px) and (max-width:1120px){.nav{gap:17px;font-size:.85rem}.wrap{width:calc(100% - 64px)}.nav-wrap{gap:18px}}
@media(max-width:900px){.site-header{height:80px}.nav{top:79px;font-size:1rem;gap:12px}.nav .contact{margin-left:0}.brand-mark{width:35px;height:38px}.brand-name{font-size:1.15rem}.brand-name>span{font-size:.6rem}.home-logic-grid{grid-template-columns:1fr}.home-subject{padding:22px;gap:16px}.home-subject-mark{font-size:2.5rem;min-width:45px}.about-author{gap:35px}.about-approach{gap:35px}.home-investigate .chaos-opening{gap:25px}}
@media(max-width:650px){.nav-wrap{gap:12px}.brand{gap:8px}.brand-name{font-size:1.06rem}.brand-name>span{font-size:.55rem;letter-spacing:.3em}.brand-mark{width:31px;height:35px}.platform-hero{padding:33px 0}.platform-hero h1{font-size:clamp(2.18rem,8.4vw,3rem)}.platform-intro{font-size:1rem}.platform-hero .actions{align-items:flex-start;gap:18px}.platform-home .section-heading{display:block}.platform-home .section-heading>.text-link{display:inline-block;margin-top:18px}.home-subjects{grid-template-columns:1fr;gap:15px}.home-subject{padding:21px}.home-catalog,.home-logic,.home-investigate{padding:27px 0 32px}.home-author{grid-template-columns:80px 1fr;gap:20px;padding:28px 0 36px;align-items:start}.home-author img{width:80px;height:107px}.home-author h2{font-size:1.75rem}.home-author p:not(.eyebrow){font-size:.92rem}.home-author .actions{gap:15px}.about-approach,.about-author,.about-lessons{grid-template-columns:1fr;gap:28px;padding:30px 0}.about-author picture{max-width:330px}.about-author h2{font-size:2.25rem}.about-lessons h2,.about-approach h2{font-size:2rem}.about-navigation{gap:7px 19px}.about-project .section{padding-top:32px;padding-bottom:32px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

.olympiad-variant .archive-task-markers{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0 18px}