/* Layout: nautical-chart atlas — sticky top bar, hero with survey figures, tabbed index (process | module) with scaled step bars, method, footer */
:root{
  --paper:#EEF1FD; --sheet:#FFFFFF; --ink:#141B3D; --muted:#5D6485; --line:#D9DDEC;
  --sea:#3550D8; --sea-soft:#E3E7FB; --ochre:#8A5CF6; --empty:#E6E9F8;
  --hero-a:#DDE4FF; --hero-b:#ECE3FF; --band-a:#2B3FC4; --band-b:#6A45E0; --bar-bg:#182848; --bar-btn:#2B4AA8;
  --display:"Plus Jakarta Sans", "Segoe UI", system-ui, sans-serif;
  --body:"IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --mono:"IBM Plex Mono", ui-monospace, Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --paper:#0F1226; --sheet:#171B36; --ink:#E8EAF7; --muted:#A0A6C8; --line:#2A3058;
  --sea:#7C8CFF; --sea-soft:#22285A; --ochre:#B191FF; --empty:#20254A;
  --hero-a:#1A2152; --hero-b:#2A1F57; --band-a:#2B3A9E; --band-b:#5A3BB8; --bar-bg:#232B5C; --bar-btn:#2B4AA8; color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#0F1226; --sheet:#171B36; --ink:#E8EAF7; --muted:#A0A6C8; --line:#2A3058;
  --sea:#7C8CFF; --sea-soft:#22285A; --ochre:#B191FF; --empty:#20254A;
  --hero-a:#1A2152; --hero-b:#2A1F57; --band-a:#2B3A9E; --band-b:#5A3BB8; --bar-bg:#232B5C; --bar-btn:#2B4AA8; color-scheme:dark}
*{box-sizing:border-box}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--body);font-size:16px;line-height:1.55}
body::before{content:"";position:fixed;inset:0 0 auto;height:env(safe-area-inset-top,0px);z-index:10;background:var(--paper)}
a{color:var(--sea)}
a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible{outline:2px solid var(--ochre);outline-offset:2px}
.wrap{max-width:1120px;margin:0 auto;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
h1,h2,h3{font-family:var(--display);text-wrap:balance;margin:0}
.label{font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}

/* top bar */
header.top{position:sticky;top:env(safe-area-inset-top,0px);z-index:5;background:var(--paper);border-bottom:1px solid var(--line)}
header.top .wrap{display:flex;align-items:center;gap:24px;padding-block:14px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--display);font-weight:700;font-size:18px;color:var(--ink);text-decoration:none}
.brand .mark{flex:none;display:block}
.news{background:linear-gradient(120deg,var(--band-a),var(--band-b));color:#fff}
.news .wrap{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:28px;align-items:center}
.news h2{line-height:1.1;font-size:clamp(26px,3.5vw,36px);letter-spacing:-.02em}
.news p{margin:6px 0 0;opacity:.8;max-width:52ch}
.news form{display:flex;gap:10px;flex-wrap:wrap}
.news input[type=email]{flex:1;min-width:0;padding:12px 14px;border-radius:6px;border:1px solid rgba(255,255,255,.5);background:#fff;color:#141B3D;font:15px var(--body)}
.news button{background:#fff;color:#2B3FC4;border:0;border-radius:6px;padding:12px 18px;font:600 15px var(--body);cursor:pointer}
.news .msg{flex-basis:100%;margin:0;font-size:14px;opacity:1}
.hp{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}
@media (max-width:720px){.news .wrap{grid-template-columns:1fr}}
nav.main{display:flex;gap:18px;flex-wrap:wrap;flex:1}
nav.main a{color:var(--muted);text-decoration:none;font-size:14px}
nav.main a:hover,nav.main a[aria-current]{color:var(--ink)}
.btn{display:inline-block;background:var(--ink);color:var(--paper);border:0;border-radius:4px;padding:8px 14px;font:500 14px var(--body);text-decoration:none;cursor:pointer}

/* hero */
.hero{position:relative;padding-block:56px 40px;border-bottom:1px solid var(--line);background:linear-gradient(135deg,var(--hero-a),var(--hero-b))}
.hero::before{content:"";position:absolute;inset:0;pointer-events:none;background-image:radial-gradient(var(--line) 1.3px,transparent 1.5px);background-size:24px 24px;-webkit-mask-image:linear-gradient(to bottom,#000 10%,transparent 90%);mask-image:linear-gradient(to bottom,#000 10%,transparent 90%)}
.hero .wrap{position:relative;display:grid;gap:28px}
.pill{display:inline-flex;gap:8px;align-items:center;font-family:var(--mono);font-size:12px;background:var(--sheet);border:1px solid var(--line);border-radius:999px;padding:4px 12px;width:max-content;max-width:100%}
.pill i{width:8px;height:8px;border-radius:50%;background:var(--ochre)}
.hero h1{font-size:clamp(44px,8vw,88px);font-weight:800;letter-spacing:-.025em;line-height:.95}
.hero p.lead{max-width:62ch;font-size:19px;color:var(--muted);margin:0}
.hero p.lead strong{color:var(--ink);font-weight:500}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:0;background:var(--sheet);border:1px solid var(--line);border-radius:6px;overflow:hidden}
.stat{padding:16px 18px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);margin:0 -1px -1px 0}
.stat b{display:block;font-family:var(--display);font-size:32px;font-weight:700;font-variant-numeric:tabular-nums;line-height:1.1}
.stat span{font-size:13px;color:var(--muted)}
.stat.date b{font-family:var(--mono);font-size:20px;font-weight:500;padding-block:7px}

/* index */
section{padding-block:48px}
.sechead{display:flex;justify-content:space-between;align-items:end;gap:16px;flex-wrap:wrap;margin-bottom:20px}
.sechead h2{font-size:clamp(28px,4vw,40px);font-weight:700;letter-spacing:-.02em}
.tabs{display:inline-flex;border:1px solid var(--line);border-radius:6px;overflow:hidden;background:var(--sheet)}
.tabs button{border:0;background:none;padding:9px 16px;font:500 14px var(--body);color:var(--muted);cursor:pointer}
.tabs button[aria-selected="true"]{background:var(--ink);color:var(--paper)}
.tools{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin-bottom:16px}
.tools input{flex:1;min-width:0;max-width:420px;padding:10px 12px;border:1px solid var(--line);border-radius:6px;background:var(--sheet);color:var(--ink);font:15px var(--body)}
.tools label{display:flex;gap:6px;align-items:center;font-size:14px;color:var(--muted)}

.area{background:var(--sheet);border:1px solid var(--line);border-radius:6px;margin-bottom:10px}
.area summary{list-style:none;cursor:pointer;display:grid;grid-template-columns:52px minmax(0,1fr) minmax(80px,220px) 56px;gap:14px;align-items:center;padding:14px 16px}
.area summary::-webkit-details-marker{display:none}
.code{font-family:var(--mono);font-size:13px;color:var(--sea);background:var(--sea-soft);border-radius:4px;padding:3px 0;text-align:center}
.area .name{font-family:var(--display);font-weight:500;font-size:19px;min-width:0}
.area .name small{display:block;font-family:var(--body);font-size:13px;color:var(--muted)}
.bar{height:8px;background:var(--empty);border-radius:4px;overflow:hidden}
.bar i{display:block;height:100%;background:linear-gradient(90deg,var(--sea),var(--ochre));border-radius:4px}
.num{font-family:var(--mono);font-variant-numeric:tabular-nums;text-align:right;font-weight:500}
.subs{border-top:1px solid var(--line);padding:6px 16px 12px}
.sub{display:grid;grid-template-columns:52px minmax(0,1fr) minmax(80px,220px) 56px;gap:14px;align-items:center;padding:7px 0;font-size:15px;border-bottom:1px dashed var(--line)}
.sub:last-child{border-bottom:0}
.sub .c{font-family:var(--mono);font-size:12px;color:var(--muted);text-align:center}
.sub.none{color:var(--muted)}
.sub .bar i{background:var(--ochre)}
.soon{font-family:var(--mono);font-size:11px;color:var(--muted);text-align:right;grid-column:span 2;white-space:nowrap}
.modgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:12px}
.mod{background:var(--sheet);border:1px solid var(--line);border-radius:6px;padding:16px;display:grid;gap:10px}
.mod .row{display:flex;justify-content:space-between;align-items:center;gap:10px}
.mod .code{padding:3px 8px}
.mod h3{font-size:18px;font-weight:500}
.mod .num{font-size:22px;font-family:var(--display);font-weight:700}
.mod .procs{font-size:13px;color:var(--muted)}
.empty-msg{color:var(--muted);padding:20px 0}

/* method */
.method{background:var(--sheet);border-block:1px solid var(--line)}
.steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:28px;margin-top:24px}
.steps div{display:grid;gap:6px;align-content:start}
.steps b{font-family:var(--display);font-size:18px;font-weight:500}
.steps p{margin:0;color:var(--muted);font-size:15px}
.steps .k{font-family:var(--mono);font-size:12px;color:var(--ochre)}
.walk{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:12px;margin-top:20px}
.walk a{display:grid;gap:4px;padding:18px;border:1px solid var(--line);border-radius:6px;text-decoration:none;color:var(--ink);background:var(--paper)}
.walk a:hover{border-color:var(--sea)}
.walk a span{color:var(--muted);font-size:14px}

footer{padding-block:40px;font-size:14px;color:var(--muted)}
footer .wrap{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap}
footer nav{display:flex;gap:16px;flex-wrap:wrap}
footer a{color:var(--muted)}
@media (max-width:620px){
  nav.main{order:3;flex-basis:100%;gap:14px}
  .area summary,.sub{grid-template-columns:44px minmax(0,1fr) 48px}
  .area summary .bar,.sub .bar{display:none}
  .soon{grid-column:auto;white-space:normal}
}
@media (prefers-reduced-motion:no-preference){.bar i{transition:width .5s ease}}
.lang{display:inline-flex;border:1px solid var(--line);border-radius:4px;overflow:hidden}
.lang button{border:0;background:var(--sheet);color:var(--muted);padding:7px 10px;font:500 13px var(--mono);cursor:pointer}
.lang button[aria-pressed="true"]{background:var(--sea);color:var(--paper)}
.secbar{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;background:var(--bar-bg);color:#fff;border-radius:12px;padding:14px 16px 14px 22px;margin-bottom:14px}
.secbar b{font-size:15px;font-weight:600}
.secbar .acts{display:flex;gap:10px;flex-wrap:wrap}
.secbar button{background:#fff;color:var(--bar-btn);border:0;border-radius:999px;padding:10px 20px;font:600 15px var(--body);cursor:pointer}
.secbar button:hover{background:#E3E7FB}

/* ---------- Multi-page components ---------- */
[hidden]{display:none!important}
*{box-sizing:border-box}
img{max-width:100%}
html:not([data-lang="fr"]) .i18n[lang="fr"], html[data-lang="fr"] .i18n[lang="en"]{display:none}
nav.main a[aria-current="page"]{color:var(--ink);font-weight:600}
.page-hero{position:relative;padding-block:64px 48px;border-bottom:1px solid var(--line);background:linear-gradient(135deg,var(--hero-a),var(--hero-b))}
.page-hero::before{content:"";position:absolute;inset:0;pointer-events:none;background-image:radial-gradient(var(--line) 1.3px,transparent 1.5px);background-size:24px 24px;-webkit-mask-image:linear-gradient(to bottom,#000 10%,transparent 90%);mask-image:linear-gradient(to bottom,#000 10%,transparent 90%)}
.page-hero .wrap{position:relative;display:grid;gap:22px}
.page-hero h1{font-size:clamp(40px,7vw,76px);font-weight:800;letter-spacing:-.025em;line-height:1}
.page-hero .lead{max-width:62ch;font-size:19px;color:var(--muted);margin:0}
.eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--sea)}
.ctas{display:flex;gap:12px;flex-wrap:wrap}
.btn-main,.btn-ghost{display:inline-flex;align-items:center;gap:8px;border-radius:999px;padding:12px 22px;font:600 15px var(--body);text-decoration:none}
.btn-main{background:linear-gradient(120deg,var(--band-a),var(--band-b));color:#fff}
.btn-ghost{background:var(--sheet);color:var(--sea);border:1px solid var(--line)}
.btn-main:hover{filter:brightness(1.08)} .btn-ghost:hover{border-color:var(--sea)}
.block{padding-block:56px}
.block.alt{background:var(--sheet);border-block:1px solid var(--line)}
.block h2{font-size:clamp(28px,4vw,40px);font-weight:700;letter-spacing:-.02em;margin-top:6px}
.block .intro{max-width:64ch;color:var(--muted);margin:10px 0 0;font-size:17px}
.head-row{display:flex;justify-content:space-between;align-items:end;gap:16px;flex-wrap:wrap;margin-bottom:24px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px}
.cards.two{grid-template-columns:repeat(auto-fill,minmax(340px,1fr))}
.card{background:var(--sheet);border:1px solid var(--line);border-radius:10px;padding:22px;display:flex;flex-direction:column;gap:10px;min-width:0}
.block.alt .card{background:var(--paper)}
.card h3{font-size:21px;font-weight:600;line-height:1.2}
.card p{margin:0;color:var(--muted);font-size:15px}
.card .more{margin-top:auto;padding-top:6px;font-weight:600;color:var(--sea);text-decoration:none}
.card .more:hover{text-decoration:underline}
a.card{text-decoration:none;color:inherit} a.card:hover{border-color:var(--sea)}
.tag{display:inline-flex;align-items:center;gap:6px;width:max-content;max-width:100%;font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--sea);background:var(--sea-soft);border-radius:999px;padding:4px 10px}
.tag.live::before{content:"";width:7px;height:7px;border-radius:50%;background:#1E9E6A}
.tag.soon{color:var(--muted);background:var(--empty)}
.quote{font-style:italic;color:var(--ink)!important;border-left:3px solid var(--ochre);padding-left:12px}
.chips{display:flex;gap:10px;flex-wrap:wrap}
.chip{padding:9px 16px;border-radius:999px;border:1px solid var(--line);background:var(--sheet);color:var(--ink);text-decoration:none;font-size:15px}
.chip:hover,.chip[aria-pressed="true"]{border-color:var(--sea);color:var(--sea)}
.chip[aria-pressed="true"]{background:var(--sea-soft)}
.pillars{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:24px}
.pillars div{display:grid;gap:6px;align-content:start}
.pillars b{font-family:var(--display);font-size:22px}
.pillars p{margin:0;color:var(--muted)}
.flow{display:flex;gap:10px;flex-wrap:wrap;align-items:center;font-family:var(--mono);font-size:13px;color:var(--muted)}
.flow span{background:var(--sheet);border:1px solid var(--line);border-radius:6px;padding:6px 12px;color:var(--ink)}
.prose{max-width:70ch} .prose h2{font-size:26px;margin-top:36px} .prose p,.prose li{color:var(--ink);font-size:17px} .prose .muted{color:var(--muted)}
.articles{display:grid;gap:14px}
.article{background:var(--sheet);border:1px solid var(--line);border-radius:10px;padding:22px;display:grid;gap:8px;scroll-margin-top:90px}
.article:target{border-color:var(--sea);box-shadow:0 0 0 3px var(--sea-soft)}
.article h3{font-size:21px;font-weight:600;line-height:1.25}
.article p{margin:0;color:var(--muted)}
.article .meta{display:flex;gap:10px;flex-wrap:wrap;align-items:center;font-size:13px;color:var(--muted);font-family:var(--mono)}
.searchrow{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:14px}
.searchrow input{flex:1;min-width:0;max-width:460px;padding:11px 14px;border:1px solid var(--line);border-radius:8px;background:var(--sheet);color:var(--ink);font:15px var(--body)}
.count{font-family:var(--mono);font-size:12px;color:var(--muted);margin:14px 0}
.editions{display:grid;gap:0;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:var(--sheet)}
.edition{display:grid;grid-template-columns:150px minmax(0,1fr) auto;gap:16px;align-items:center;padding:16px 20px;border-bottom:1px solid var(--line)}
.edition:last-child{border-bottom:0}
.edition time{font-family:var(--mono);font-size:13px;color:var(--muted)}
.edition b{font-weight:500}
.lessons{display:grid;gap:10px;counter-reset:l}
.lesson{background:var(--sheet);border:1px solid var(--line);border-radius:10px}
.lesson summary{cursor:pointer;list-style:none;padding:16px 20px;display:flex;gap:14px;align-items:center;font-family:var(--display);font-size:19px;font-weight:500}
.lesson summary::-webkit-details-marker{display:none}
.lesson summary::before{counter-increment:l;content:counter(l);display:grid;place-items:center;flex:none;width:30px;height:30px;border-radius:50%;background:var(--sea-soft);color:var(--sea);font:600 14px var(--mono)}
.lesson .body{padding:0 20px 18px 64px;color:var(--muted)}
.lesson .body p{margin:0 0 10px}
.lesson code,.prose code{font-family:var(--mono);font-size:14px;background:var(--empty);border-radius:4px;padding:1px 6px;color:var(--ink)}
.person{display:grid;grid-template-columns:auto minmax(0,1fr);gap:20px;align-items:center}
.avatar{width:84px;height:84px;border-radius:50%;background:linear-gradient(135deg,var(--sea),var(--ochre));color:#fff;display:grid;place-items:center;font:700 28px var(--display)}
.notice{background:var(--sea-soft);border-radius:8px;padding:12px 16px;color:var(--ink);font-size:15px}
@media (max-width:620px){
  .edition{grid-template-columns:1fr}
  .cards.two{grid-template-columns:1fr}
  .lesson .body{padding-left:20px}
  .person{grid-template-columns:1fr}
}