:root{--s:#475569;--t:#1A1A1B;--l:#f1f5f9;--b:#cbd5e1}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:70px}
body{margin:0;font:300 17px/1.7 "Segoe UI Variable Text Light","Segoe UI Variable Text","Segoe UI Light","Segoe UI",system-ui,sans-serif;color:var(--t);background:#fff}
h1,h2,h3,th,button,.sb,nav a,.btn{font-family:"Segoe UI Semibold","Segoe UI",system-ui,sans-serif;font-weight:600}
a{color:var(--s)}.w{max-width:1040px;margin:0 auto;padding:0 24px}
header{position:sticky;top:0;z-index:9;background:var(--s);color:#fff}
header .w{display:flex;align-items:center;gap:24px;min-height:60px;flex-wrap:wrap}
header b{font-family:"Segoe UI Semibold","Segoe UI",sans-serif;font-size:18px}
nav{display:flex;gap:18px;flex:1;flex-wrap:wrap}nav a{color:#fff;text-decoration:none;font-size:15px;opacity:.9}nav a:hover{text-decoration:underline}
.lg button{background:none;border:1px solid #fff;color:#fff;padding:3px 10px;cursor:pointer}.lg button.on{background:#fff;color:var(--s)}
.btn{display:inline-block;background:#fff;color:var(--s);padding:12px 22px;text-decoration:none;border:1px solid #fff;cursor:pointer;font-size:16px}
.btn.o{background:none;color:#fff}.btn.d{background:var(--s);color:#fff;border-color:var(--s)}
.dk{background:var(--s);color:#fff}.dk a{color:#fff}.dk a.btn{color:var(--s)}.dk a.btn.o{color:#fff}
.hero{padding:72px 0 56px}h1{font-size:clamp(34px,5vw,54px);line-height:1.15;margin:0 0 20px}
.hero p{max-width:720px;font-size:19px}
.tiers{display:grid;grid-template-columns:repeat(3,1fr);gap:0;margin:32px 0;border:1px solid rgba(255,255,255,.5)}
.tiers div{padding:16px 18px;border-right:1px solid rgba(255,255,255,.5)}.tiers div:last-child{border:0}
.tiers b{display:block;font-family:"Segoe UI Semibold","Segoe UI",sans-serif;font-size:20px}
.meta{font-size:14px;opacity:.85;margin-top:20px}
section{padding:64px 0}section.g{background:var(--l)}
h2{font-size:32px;margin:0 0 20px;line-height:1.2}h3{font-size:19px;margin:0 0 6px}
.two{display:grid;grid-template-columns:1fr 1fr;gap:32px}
.chain{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:24px 0}
.chain div,.card{border:1px solid var(--b);background:#fff;padding:18px}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
table{border-collapse:collapse;width:100%;background:#fff}th,td{border:1px solid var(--b);padding:10px 14px;text-align:left;vertical-align:top}th{background:var(--l)}
form{display:grid;gap:14px;max-width:620px}label{display:grid;gap:4px;font-size:15px}
input,select,textarea{font:inherit;padding:10px;border:1px solid var(--b);background:#fff;color:var(--t)}
.ck{display:flex;gap:10px;align-items:flex-start}.ck input{margin-top:6px}
footer{padding:40px 0;font-size:15px}footer p{margin:6px 0}
.note{border-left:4px solid var(--s);padding:8px 16px;background:var(--l)}
body:not([data-l=en]) .en,body[data-l=en] .ua{display:none}
:focus-visible{outline:3px solid #f59e0b;outline-offset:2px}
@media(max-width:760px){.two,.grid,.tiers,.chain{grid-template-columns:1fr}.tiers div{border-right:0;border-bottom:1px solid rgba(255,255,255,.5)}}

.nm{font-family:"Segoe UI Semibold","Segoe UI",sans-serif;font-weight:600;font-size:clamp(60px,10vw,104px);line-height:1;margin:0}
.sub{font-weight:300;font-size:clamp(17px,2vw,22px);margin:4px 0 0;letter-spacing:.02em}
.pn{font-family:"Segoe UI Semibold","Segoe UI",sans-serif;font-weight:600;font-size:clamp(18px,2.4vw,26px);letter-spacing:.05em;margin:30px 0 24px}
.sm{font-size:15px}iframe{width:100%;height:720px;border:1px solid var(--b)}

.nm{margin-left:-.06em}.nw{white-space:nowrap}.hero .meta{max-width:none}
.tw{overflow-x:auto;-webkit-overflow-scrolling:touch}.tw table{min-width:560px}
header .w,.w{padding-left:max(24px,env(safe-area-inset-left));padding-right:max(24px,env(safe-area-inset-right))}
@media(max-width:1024px){.chain{grid-template-columns:1fr 1fr}.hero{padding:56px 0 44px}section{padding:52px 0}}
@media(max-width:760px){
body{font-size:16px}html{scroll-padding-top:110px}
.w{padding-left:max(18px,env(safe-area-inset-left));padding-right:max(18px,env(safe-area-inset-right))}
header .w{gap:6px 12px;padding-top:8px;padding-bottom:8px}header b{order:1}.lg{order:2;margin-left:auto}
nav{order:3;width:100%;flex:none;flex-wrap:nowrap;overflow-x:auto;gap:20px;padding:6px 0 4px;-webkit-overflow-scrolling:touch}nav a{white-space:nowrap;padding:6px 0;font-size:15px}
.lg button{padding:6px 12px;font-size:15px}
.hero{padding:40px 0 36px}.hero p{font-size:17px}h2{font-size:25px}section{padding:40px 0}
.tiers div:last-child{border-bottom:0}.chain,.two{grid-template-columns:1fr}
.btn{display:block;text-align:center;margin:0 0 12px;padding:14px 18px}.hero .btn{width:100%}
input,select,textarea{font-size:16px;padding:12px}.meta{font-size:14px}
iframe{height:480px}.tw table{min-width:520px}th,td{padding:8px 10px}
footer{padding:28px 0}}
@media(max-width:380px){.nm{font-size:56px}.pn{letter-spacing:.02em}}

.tl{font-family:"Segoe UI Semibold","Segoe UI",sans-serif;font-weight:600;font-size:17px;margin:32px 0 10px}.tl+.tiers{margin-top:0}
.pn{font-size:clamp(20px,2.7vw,29px);margin:18px 0 12px}
.hero p{margin:0 0 24px}.hero .tl{margin:28px 0 10px}.hero .tiers{margin:0 0 28px}.hero .meta{margin:20px 0 0}
@media(min-width:761px){.hero{padding:56px 0 44px}}
@media(max-width:760px){.pn{margin:14px 0 10px}.hero p{margin-bottom:20px}.hero .tl{margin-top:22px}}
/* ритм шапки: G≈17px між PXEP / Platform… / ПРОТОКОЛ…; 2G до опису; 4G до «Трирівнева…» */
.hero .nm{line-height:1}
.hero .sub{line-height:1;margin:4px 0 0}
.hero .pn{line-height:1;margin:9px 0 21px}
.hero .pn+p{margin:0 0 50px}
.hero .tl{margin:0 0 10px}
@media(max-width:760px){.hero .pn{margin:8px 0 18px}.hero .pn+p{margin-bottom:38px}.hero .tl{margin-top:0}}
header{border-bottom:1px solid rgba(255,255,255,.22)}
.pol{max-width:800px}.pol h2{font-size:21px;margin:34px 0 10px}.pol ul{padding-left:22px;margin:0 0 16px}.pol li{margin-bottom:6px}
.lead{font-size:20px;line-height:1.6;max-width:820px;margin:0 0 32px;padding:4px 0 4px 20px;border-left:4px solid var(--s)}@media(max-width:760px){.lead{font-size:18px;padding-left:16px}}
.doc{max-width:820px}.doc h2{font-size:24px;margin:44px 0 12px;scroll-margin-top:90px}.doc .dh h2{font-size:26px;margin:6px 0 4px}
.doc ul,.doc ol{padding-left:22px;margin:0 0 16px}.doc li{margin-bottom:12px}.doc .toc{background:var(--l);padding:16px 16px 16px 40px;margin:0 0 8px}.doc .toc li{margin:4px 0}
.dh{border:1px solid var(--b);background:var(--l);padding:20px 24px;margin:0 0 24px}.dh p{margin:4px 0}.doc b{font-family:"Segoe UI Semibold","Segoe UI",sans-serif;font-weight:600}
@media(max-width:760px){.doc h2{font-size:21px}.dh{padding:16px}}
header .br{color:#fff;text-decoration:none}header .br:hover{opacity:.85}
.hero .pn+p{margin:0 0 26px}
.rl{border:0;border-top:1px solid rgba(15,23,42,.5);border-bottom:1px solid rgba(255,255,255,.1);height:0;margin:0 0 26px}
@media(max-width:760px){header .br{order:1}.hero .pn+p{margin-bottom:20px}.rl{margin-bottom:20px}}