*{box-sizing:border-box}body{margin:0;background:#fff;color:#17212e;font-family:Arial,Helvetica,sans-serif}.notice{background:#edf1ff;color:#2849ca;text-align:center;font-size:12px;padding:8px}.mast,nav,.topics,main,footer{max-width:1300px;margin:auto}.mast{height:75px;display:flex;align-items:center;gap:24px;padding:0 20px}.logo{text-decoration:none;color:#15202d;font-size:26px;font-weight:850;letter-spacing:-1.4px;white-space:nowrap}.logo span,footer span{color:#294bff}.logo small{font-size:12px;letter-spacing:.1em;color:#294bff;border-left:1px solid #cbd4e0;padding-left:8px;margin-left:4px}.tagline{color:#6b7888;font-size:13px}.search{margin-left:auto;border:1px solid #d4dce5;color:#8a96a4;border-radius:3px;padding:10px 16px;width:290px;font-size:13px}.saved{font-size:13px;white-space:nowrap}header{border-bottom:1px solid #d7dfe7}nav{display:flex;gap:30px;padding:14px 20px;border-top:1px solid #e6eaf0}a{color:inherit;text-decoration:none}nav a{font-size:15px;font-weight:700}.topics{padding:13px 20px;display:flex;gap:20px;overflow:auto;white-space:nowrap;color:#59697b;font-size:12px;border-top:1px solid #e6eaf0}.topics span:first-child{color:#3154ff;font-weight:700}main{padding:24px 20px 65px}.sectionhead{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:18px}.sectionhead span{font-size:12px;color:#687a90}h1,h2,h3,p{margin:0}h1,.sectionhead h2{font-size:26px;letter-spacing:-.6px}.opening{display:grid;grid-template-columns:1.75fr 1fr .78fr;gap:28px}.middle,.stream{border-left:1px solid #d5dde6;padding-left:22px}.lead{border-bottom:1px solid #d5dde6;padding-bottom:20px;margin-bottom:20px}.meta{font:12px/1.4 monospace;color:#506178;margin-bottom:16px}.meta b{color:#264dff;font-weight:400}.meta span{color:#7c8a99}.meta i{float:right;font:18px Arial;font-style:normal;color:#4e6278}.lead h2{font-size:29px;line-height:1.17;letter-spacing:-.9px;margin-bottom:14px}.lead p,.compact p,.cards p{color:#53657a;font-size:15px;line-height:1.5;margin-bottom:16px}.image{height:220px;background:#eef1f4;border:1px solid #d4dce3;display:grid;place-items:center;color:#a3aeb9;letter-spacing:.14em;font-size:11px}.image2{background:#e8edf0}.lead small{display:block;color:#718095;font-size:11px;margin-top:7px}.compact{position:relative;border-bottom:1px solid #d5dde6;padding-bottom:18px;margin-bottom:18px}.compact h3{font-size:19px;line-height:1.27;letter-spacing:-.35px;padding-right:70px}.compact p{margin-top:10px;margin-bottom:0}.compact.divider{border-top:2px solid #3154ff;padding-top:15px}.thumb{position:absolute;right:0;top:33px;background:#e9edf1;color:#a4aeb9;width:57px;height:43px;display:grid;place-items:center;font-size:10px}.stream{border-top:2px solid #17212e;padding-top:12px}.stream h3{font-size:17px}.streamitem{border-bottom:1px solid #d5dde6;padding:16px 0}.streamitem small{font:11px monospace;color:#67788a}.streamitem p{font-size:15px;line-height:1.35;font-weight:600;margin-top:8px}.stream a{display:block;color:#3154ff;font-size:13px;margin-top:16px}.block{border-top:1px solid #cfd9e4;padding-top:25px;margin-top:28px}.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.cards article{border-top:1px solid #d5dde6;padding-top:14px}.cards h3{font-size:20px;line-height:1.25;margin:10px 0}.cardimage{height:130px;background:#edf0f3;color:#a3aeb9;display:grid;place-items:center;font-size:10px;letter-spacing:.12em}.quick{display:flex;flex-wrap:wrap;gap:20px;color:#3154ff;font-size:14px;margin-top:20px}footer{border-top:2px solid #17212e;padding:28px 20px 50px;color:#59697b;font-size:13px}footer strong{font-size:21px;color:#17212e}footer p{margin:8px 0 20px}@media(max-width:900px){.opening{grid-template-columns:1.4fr 1fr}.stream{grid-column:1/-1;border-left:0;padding-left:0}.streamitem{display:inline-block;vertical-align:top;width:48%;padding-right:18px}.tagline{display:none}}@media(max-width:600px){.mast{height:64px}.search{width:auto;flex:1;overflow:hidden;white-space:nowrap}.saved{font-size:0}.saved:first-letter{font-size:20px}nav{gap:20px;overflow:auto;white-space:nowrap}main{padding:20px}.opening{display:block}.middle,.stream{border-left:0;padding-left:0}.middle{margin-top:25px}.stream{margin-top:28px}.lead h2{font-size:25px}.image{height:180px}.cards{grid-template-columns:1fr}.streamitem{width:100%}.sectionhead h2,h1{font-size:23px}}
/* Visual tokens and typography from the current USB.RU home stylesheet. */
@font-face{font-family:Nunito;src:url('assets/nunito-cyrillic.woff2') format('woff2');font-weight:200 1000;font-display:swap;unicode-range:U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}
@font-face{font-family:Nunito;src:url('assets/nunito-latin.woff2') format('woff2');font-weight:200 1000;font-display:swap}
@font-face{font-family:'IBM Plex Mono';src:url('assets/ibm-plex-mono-cyrillic.woff2') format('woff2');font-weight:400;font-display:swap;unicode-range:U+0301,U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}
@font-face{font-family:'IBM Plex Mono';src:url('assets/ibm-plex-mono-latin.woff2') format('woff2');font-weight:400;font-display:swap}
:root{--ink:#17212c;--muted:#526171;--blue:#2447ff;--line:#d3dae2;--soft:#f1f4f7}body{font-family:Nunito,system-ui,sans-serif;color:var(--ink);line-height:1.55}.notice{background:#f2f4f6;color:var(--muted);font-size:12px}.mast,nav.primary-nav,.topic-bar,.topic-help,main,footer{max-width:1300px;margin:auto}.mast{min-height:64px;height:auto;padding:0 32px;gap:18px}.logo{display:flex;align-items:center;gap:8px;font-size:28px;letter-spacing:-.04em}.logo svg{width:28px;height:28px}.logo strong{font-weight:800;line-height:1}.tagline{border-left:1px solid var(--line);padding-left:18px;color:var(--muted);font-size:12px}.search{width:200px;border-color:var(--line);border-radius:4px;padding:6px 9px;font-size:13px;color:var(--muted)}.search span{float:right}.saved{display:flex;align-items:center;gap:6px;font-size:12px}.saved svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.6}.primary-nav{padding:0 32px;gap:30px;min-height:44px;border-top:0;border-bottom:2px solid var(--ink)}.primary-nav a{font-size:14px;font-weight:500;display:flex;align-items:center;min-height:44px}.topic-bar{display:flex;align-items:center;gap:16px;padding:0 32px;border-bottom:1px solid var(--line)}.topics{display:flex;gap:4px;padding:4px 0;margin:0;overflow-x:auto;border:0}.topics button{display:flex;flex:0 0 44px;align-items:center;justify-content:center;width:44px;height:44px;padding:10px;background:none;border:0;border-bottom:2px solid transparent;color:var(--ink);cursor:pointer}.topics button:hover{color:var(--blue);background:var(--soft)}.topics button[aria-pressed=true]{color:var(--blue);background:#edf1ff;border-bottom-color:var(--blue)}.topics svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}.topic-context{margin-left:auto;display:flex;align-items:center;gap:10px;font-size:12px}.topic-context button{border:0;background:none;color:var(--blue);font:inherit;min-height:44px;cursor:pointer}.topic-context [hidden]{display:none}.topic-help{padding:5px 32px 0;font-size:12px;color:var(--muted)}main{padding:20px 32px 65px}.opening{grid-template-columns:minmax(0,1.6fr) minmax(0,1fr) 270px}.meta,.streamitem small{font-family:'IBM Plex Mono',ui-monospace,monospace;color:var(--muted)}.meta b,.stream a,.quick{color:var(--blue)}.lead h2{font-size:30px;line-height:1.15;letter-spacing:-.035em;font-weight:700}.lead p,.compact p,.cards p{color:var(--muted);font-size:15.5px}.compact h3{font-size:19px;line-height:1.3;font-weight:650}.sectionhead h2,h1{font-size:26px;font-weight:650}.lead,.compact,.streamitem,.block,.cards article{border-color:var(--line)}.compact.divider{border-top-color:var(--blue)}.image,.cardimage,.thumb{background:var(--soft);border-color:var(--line)}.meta i{font-style:normal;font-size:0}.meta i::before{content:'♧';font-size:18px}[hidden]{display:none!important}button:focus-visible,a:focus-visible{outline:3px solid var(--blue);outline-offset:3px}
@media(max-width:1100px){.mast,.primary-nav,.topic-bar,.topic-help,main{padding-left:26px;padding-right:26px}.tagline{display:none}.opening{grid-template-columns:minmax(0,1.6fr) minmax(0,1fr) 220px}}
@media(max-width:900px){.opening{grid-template-columns:1.4fr 1fr}.stream{grid-column:1/-1}}
@media(max-width:760px){.mast,.primary-nav,.topic-bar,.topic-help,main{padding-left:20px;padding-right:20px}.mast{min-height:56px;gap:4px 12px;padding-top:8px;padding-bottom:8px;flex-wrap:wrap}.search{order:3;flex:1 1 100%;margin:4px 0 0}.saved{margin-left:auto}.saved span{display:none}.primary-nav{gap:0 13px;flex-wrap:wrap}.primary-nav a{font-size:12px;min-width:44px}.topic-bar{gap:8px}.topics{flex:1 1 auto}.topic-context{max-width:45%}.topic-help{font-size:11px}.lead h2{font-size:26px}}
@media(max-width:600px){.opening{display:block}.sectionhead h2,h1{font-size:23px}}
.meta i{font-size:initial}.meta i::before{content:none}.meta i svg{display:block;width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}
.research-filter{border:0;background:none;color:var(--blue);font:inherit;cursor:pointer;padding:4px}.research-filter[aria-pressed=true]{background:#edf1ff;text-decoration:underline}
/* Topic labels remain visible on touch screens; the tooltip also appears on keyboard focus. */
.topics button{flex:0 0 76px;width:76px;height:62px;flex-direction:column;gap:3px;padding:5px 2px}.topics svg{width:25px;height:25px;flex:none}.topic-short{font:600 9px/1.15 Nunito,system-ui,sans-serif;letter-spacing:.015em;white-space:nowrap}.topic-bar{position:relative}.topic-context{flex-shrink:0}#topic-tooltip{position:fixed;z-index:40;max-width:min(240px,calc(100vw - 16px));padding:6px 9px;border-radius:5px;background:#17212c;color:#fff;font:12px/1.3 Nunito,system-ui,sans-serif;text-align:center;pointer-events:none;box-shadow:0 3px 10px #17212c26}
@media(max-width:760px){.topics button{flex-basis:70px;width:70px}.topic-context{max-width:35%}.logo{font-size:24px}}
.filter-status{margin:-6px 0 18px;color:var(--muted);font-size:13px}
.search,.saved{opacity:.75}
.opening[data-filtered="true"]{grid-template-columns:repeat(auto-fit,minmax(min(100%,290px),1fr))}
.opening[data-filtered="true"]>.middle,.opening[data-filtered="true"]>.stream{border-left:0;padding-left:0}