:root{--bg:#f7f9fc;--surface:#fff;--text:#172033;--muted:#68738a;--line:#dce3ee;--primary:#2457c5;--secondary:#18a39b;--math:#3157c8;--info:#008d84;--radius:22px;--shadow:0 16px 50px rgba(23,32,51,.08)}
:root[data-theme="graphite"]{--bg:#fafaf8;--surface:#fff;--text:#232323;--muted:#68645e;--line:#e4e0d9;--primary:#33383f;--secondary:#d99819;--math:#a96a00;--info:#267a73}
:root[data-theme="digital"]{--bg:#f8f7fc;--surface:#fff;--text:#25223a;--muted:#706b89;--line:#e2dff0;--primary:#5445b8;--secondary:#0b8993;--math:#6554c0;--info:#07858c}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,system-ui,-apple-system,"Segoe UI",Arial,sans-serif;line-height:1.65}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}.container{width:min(1180px,calc(100% - 40px));margin:auto}.content-narrow{width:min(820px,calc(100% - 40px))}.skip-link{position:absolute;left:-9999px}.skip-link:focus{left:16px;top:16px;z-index:9999;background:#fff;padding:10px}.site-header{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--bg) 86%,transparent);backdrop-filter:blur(18px);border-bottom:1px solid var(--line)}.header__inner{min-height:76px;display:flex;align-items:center;gap:26px}.site-brand{color:var(--text);margin-right:auto}.brand{display:flex;align-items:center;gap:12px}.brand__mark{width:46px;height:46px;color:var(--primary)}.brand__mark svg{width:100%;height:100%;fill:currentColor}.brand__text{display:grid}.brand__text strong{font-size:16px}.brand__text small{color:var(--muted);font-size:11px;letter-spacing:.06em}.site-nav ul{display:flex;align-items:center;gap:20px;list-style:none;margin:0;padding:0}.site-nav a{color:var(--text);font-size:14px;font-weight:650}.header-actions{display:flex;align-items:center;gap:8px;position:relative}.theme-switcher,.nav-toggle{border:1px solid var(--line);background:var(--surface);color:var(--text);padding:9px 12px;border-radius:999px;cursor:pointer}.theme-menu{position:absolute;right:70px;top:48px;background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:8px;box-shadow:var(--shadow);min-width:150px}.theme-menu button{width:100%;text-align:left;border:0;background:none;padding:9px;border-radius:9px;cursor:pointer;color:var(--text)}.theme-menu button:hover{background:var(--bg)}.nav-toggle{display:none}.button{display:inline-flex;align-items:center;justify-content:center;border:0;border-radius:12px;padding:12px 18px;background:var(--primary);color:#fff;font-weight:700;cursor:pointer}.button:hover{text-decoration:none;filter:brightness(.96)}.button--small{padding:8px 12px;font-size:13px}.hero{padding:72px 0 52px}.hero-grid{display:grid;grid-template-columns:1.08fr .92fr;align-items:center;gap:60px}.eyebrow{margin:0 0 12px;color:var(--primary);font-size:12px;font-weight:800;text-transform:uppercase;letter-spacing:.12em}.hero h1,.page-head h1{font-size:clamp(40px,6vw,76px);line-height:1.02;letter-spacing:-.055em;margin:0 0 22px}.page-head h1{font-size:clamp(38px,5vw,62px)}.hero__lead{max-width:680px;font-size:20px;color:var(--muted);margin-bottom:28px}.hero-art{color:var(--primary);background:linear-gradient(145deg,color-mix(in srgb,var(--primary) 8%,transparent),color-mix(in srgb,var(--secondary) 9%,transparent));border:1px solid var(--line);border-radius:36px;overflow:hidden}.hero-art svg{display:block;width:100%}.hero-art text{font:600 26px ui-monospace,SFMono-Regular,Consolas,monospace;fill:currentColor}.quick-links{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}.quick-links a,.tax-chips a,.tax-chips span{background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:6px 10px;color:var(--text);font-size:12px}.section{padding:70px 0}.section--soft{background:color-mix(in srgb,var(--primary) 4%,var(--bg))}.section-head{display:flex;justify-content:space-between;align-items:flex-end;gap:20px;margin-bottom:28px}.section-head h2{font-size:clamp(30px,4vw,46px);letter-spacing:-.04em;margin:0}.feature-grid,.post-grid,.ei-card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.feature-card,.post-card,.ei-card{display:block;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:26px;color:var(--text);box-shadow:0 1px 0 rgba(0,0,0,.02);transition:.2s transform,.2s box-shadow}.feature-card:hover,.post-card:hover,.ei-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);text-decoration:none}.feature-card span{font-weight:900;color:var(--muted)}.feature-card h3,.post-card h3,.ei-card h3{font-size:24px;letter-spacing:-.025em;margin:22px 0 8px}.feature-card.math{border-top:4px solid var(--math)}.feature-card.info{border-top:4px solid var(--info)}.feature-card.exams{border-top:4px solid var(--secondary)}.post-card h2{font-size:24px}.meta{color:var(--muted);font-size:13px}.page-head{margin-bottom:34px}.prose{font-size:18px}.prose h2{margin-top:2em;font-size:34px;letter-spacing:-.03em}.prose h3{margin-top:1.8em;font-size:25px}.prose img{max-width:100%;height:auto;border-radius:18px}.prose table{width:100%;border-collapse:collapse}.prose td,.prose th{border:1px solid var(--line);padding:10px}.material-actions{display:flex;gap:10px;flex-wrap:wrap;margin:0 0 26px}.material-stats{color:var(--muted);font-size:13px}.tax-chips{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:16px}.site-footer{border-top:1px solid var(--line);padding:50px 0;margin-top:50px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:40px}.footer-grid ul{list-style:none;margin:0;padding:0}.footer-grid .brand__mark{width:40px}.footer-grid p{color:var(--muted);font-size:14px}.ei-box{border:1px solid var(--line);border-left:4px solid var(--primary);border-radius:16px;padding:18px 20px;background:var(--surface);margin:24px 0}.ei-box--answer{border-left-color:var(--secondary)}.ei-box--warning{border-left-color:#d99819}.ei-code{position:relative;background:#111827;color:#e5e7eb;padding:20px;border-radius:16px;overflow:auto}.ei-code button{position:absolute;right:10px;top:10px}.ei-table-wrap{overflow:auto}.ei-search{display:grid;grid-template-columns:2fr repeat(3,1fr) auto;gap:10px;background:var(--surface);border:1px solid var(--line);padding:12px;border-radius:18px}.ei-search input,.ei-search select{width:100%;border:1px solid var(--line);background:var(--bg);color:var(--text);padding:12px;border-radius:11px}.hero .ei-search{grid-template-columns:1fr auto}.hero .ei-search .ei-advanced{display:none}.ei-task-reveal{border:1px solid var(--line);border-radius:14px;margin:14px 0;background:var(--surface)}.ei-task-reveal summary{padding:14px 16px;font-weight:750;cursor:pointer}.ei-task-reveal>div{padding:0 16px 16px}.ei-float-max{position:fixed;right:22px;bottom:22px;z-index:45;border-radius:999px;box-shadow:var(--shadow)}
@media(max-width:920px){.site-nav{display:none;position:absolute;left:20px;right:20px;top:72px;background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:14px;box-shadow:var(--shadow)}.site-nav.is-open{display:block}.site-nav ul{display:grid}.nav-toggle{display:inline-flex}.header-actions .theme-switcher{display:none}.hero-grid,.footer-grid{grid-template-columns:1fr}.hero-art{order:-1;max-height:260px}.feature-grid,.post-grid,.ei-card-grid{grid-template-columns:1fr 1fr}.ei-search{grid-template-columns:1fr 1fr}.ei-search button{grid-column:span 2}}
@media(max-width:620px){.container,.content-narrow{width:min(100% - 24px,1180px)}.brand__text small{display:none}.header__inner{gap:8px}.header-actions{display:none}.hero{padding-top:38px}.hero h1{font-size:46px}.feature-grid,.post-grid,.ei-card-grid{grid-template-columns:1fr}.ei-search{grid-template-columns:1fr}.ei-search button{grid-column:auto}.section{padding:48px 0}}
@media print{.site-header,.site-footer,.material-actions,.ei-float-max,.ei-search,.no-print{display:none!important}body{background:#fff;color:#000;font-size:11pt}.section{padding:0}.container,.content-narrow{width:100%;max-width:none}.page-head h1{font-size:22pt}.prose{font-size:11pt}.ei-task-reveal{border:0}.ei-task-reveal summary{display:none}.ei-task-reveal>div{display:block!important;padding:0}.ei-card{box-shadow:none}}
/* Theme settings 1.1 */
.brand__custom{display:flex;align-items:center;justify-content:center;max-width:54px;height:48px;overflow:hidden}.brand__image{display:block;max-width:54px;max-height:48px;width:auto;height:auto;object-fit:contain}.hero--math-bg{position:relative;isolation:isolate;overflow:hidden}.hero--math-bg .hero-bg-layer{position:absolute;inset:0;z-index:-2;background-image:linear-gradient(90deg,var(--bg) 0%,color-mix(in srgb,var(--bg) 88%,transparent) 42%,color-mix(in srgb,var(--bg) 75%,transparent) 100%),var(--eia-hero-bg);background-size:cover;background-position:center;opacity:var(--eia-hero-bg-opacity,.18);pointer-events:none}.hero--math-bg:after{content:"";position:absolute;inset:0;z-index:-1;background:linear-gradient(180deg,color-mix(in srgb,var(--bg) 30%,transparent),var(--bg) 100%);pointer-events:none}.hero-copy{position:relative}.section--about{padding-top:28px}.about-panel{display:grid;grid-template-columns:.8fr 1.2fr;gap:60px;align-items:start;background:var(--surface);border:1px solid var(--line);border-radius:30px;padding:42px;box-shadow:var(--shadow)}.about-panel h2{font-size:clamp(30px,4vw,46px);letter-spacing:-.04em;margin:0}.about-panel p{font-size:18px;color:var(--muted);margin-top:0}@media(max-width:760px){.about-panel{grid-template-columns:1fr;gap:20px;padding:26px}.hero--math-bg .hero-bg-layer{background-image:linear-gradient(180deg,color-mix(in srgb,var(--bg) 74%,transparent),var(--bg)),var(--eia-hero-bg)}}

/* MAX comments */
.ei-max-comment-list{list-style:none;margin:1rem 0 1.5rem;padding:0;display:grid;gap:1rem}
.ei-max-comment{margin:0;padding:0}
.ei-max-comment .comment-body{border:1px solid var(--line,#dfe5ee);border-radius:16px;padding:1rem 1.1rem;background:var(--surface,#fff)}
.ei-max-comment .comment-meta{margin-bottom:.65rem}
.ei-max-comment .comment-content p:last-child{margin-bottom:0}
.ei-max-source-badge{display:inline-block;margin-left:.4rem;padding:.15rem .42rem;border-radius:999px;font-size:.72rem;font-weight:700;letter-spacing:.03em;background:rgba(36,87,197,.10);color:var(--primary,#2457c5)}

.hero-task-code{margin-top:18px;padding-top:16px;border-top:1px solid var(--line);max-width:520px}.hero-task-code__hint{margin:0 0 7px;color:var(--muted);font-size:13px}.ei-active-filters{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:16px}.ei-active-filters span{padding:6px 10px;border:1px solid var(--line);border-radius:999px;background:var(--surface);font-size:12px}