/* OTSENTINEL – control-room engineering drawing: steel paper, instrument navy, signal teal; one amber for hazard/security-level tags.
   Layout: 1180px measure, generous bands, diagrams as the hero detail. */
:root{
  --bg:#F4F6F7;          /* drawing paper / steel */
  --surface:#FFFFFF;
  --band:#E9EEF0;        /* alternate band */
  --ink:#13263A;         /* instrument navy text */
  --muted:#4E6072;
  --line:#C9D3DA;
  --accent:#0E8C86;      /* signal teal */
  --accent-ink:#FFFFFF;
  --accent-soft:#D7EEEC;
  --amber:#B86E00;       /* hazard / SL tags (AA on white) */
  --amber-soft:#FBEBD2;
  --hero:#0F2133;        /* hero panel */
  --hero-ink:#E8EEF2;
  --hero-muted:#A8B8C6;
  --hero-line:#2C4258;
  --focus:#0E8C86;
  --font-display:"Barlow Semi Condensed","Arial Narrow",Arial,sans-serif;
  --font-body:"Source Sans 3","Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --font-mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --step--1:.875rem; --step-0:1.0625rem; --step-1:1.25rem; --step-2:1.6rem; --step-3:2.1rem; --step-4:clamp(2.2rem,4.6vw,3.4rem);
  --radius:6px;
  --max:1180px;
}
@media (prefers-color-scheme: dark){ :root:not([data-theme="light"]){
  --bg:#0B1520; --surface:#111E2B; --band:#0E1A26; --ink:#E5ECF1; --muted:#9FB0BF; --line:#24384B;
  --accent:#36C2B9; --accent-ink:#06201E; --accent-soft:#10302F; --amber:#F2B35A; --amber-soft:#3A2A12;
  --hero:#08111A; --hero-ink:#E5ECF1; --hero-muted:#9FB0BF; --hero-line:#22364A; --focus:#36C2B9; color-scheme:dark; } }
:root[data-theme="dark"]{
  --bg:#0B1520; --surface:#111E2B; --band:#0E1A26; --ink:#E5ECF1; --muted:#9FB0BF; --line:#24384B;
  --accent:#36C2B9; --accent-ink:#06201E; --accent-soft:#10302F; --amber:#F2B35A; --amber-soft:#3A2A12;
  --hero:#08111A; --hero-ink:#E5ECF1; --hero-muted:#9FB0BF; --hero-line:#22364A; --focus:#36C2B9; color-scheme:dark; }

*{box-sizing:border-box}
[hidden]{display:none!important}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font-body);font-size:var(--step-0);line-height:1.6;-webkit-font-smoothing:antialiased}
body::before{content:"";position:fixed;inset:0 0 auto;height:env(safe-area-inset-top,0px);z-index:60;background:var(--surface)}
img,svg{max-width:100%}
a{color:var(--accent);text-underline-offset:3px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:3px solid var(--focus);outline-offset:3px;border-radius:3px}
h1,h2,h3{font-family:var(--font-display);line-height:1.12;text-wrap:balance;margin:0;font-weight:600;letter-spacing:.005em}
h1{font-size:var(--step-4)} h2{font-size:var(--step-3)} h3{font-size:var(--step-1)}
p{margin:0}
.wrap{max-width:var(--max);margin-inline:auto;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
.band{padding-block:clamp(48px,7vw,88px)}
.band.alt{background:var(--band)}
.stack{display:grid;gap:16px}
.eyebrow{font-family:var(--font-mono);font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;color:var(--accent)}
.lede{font-size:var(--step-1);color:var(--muted);max-width:62ch}
.prose{max-width:68ch}
.prose p,.prose ul{margin:0 0 1em}
.prose h2{font-size:var(--step-2);margin:1.6em 0 .5em}
.prose li{margin:.3em 0}
.muted{color:var(--muted)}
.skip{position:absolute;left:-999px;top:8px;background:var(--surface);padding:8px 12px;z-index:100}
.skip:focus{left:16px}

/* Header */
.site-header{position:sticky;top:env(safe-area-inset-top,0px);z-index:50;background:var(--surface);border-bottom:1px solid var(--line)}
.site-header .wrap{display:flex;align-items:center;gap:24px;min-height:68px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);flex-shrink:0}
.brand svg{width:40px;height:40px}
.brand .word{font-family:var(--font-display);font-weight:700;font-size:1.55rem;letter-spacing:.06em;line-height:1}
.brand .word b{color:var(--accent);font-weight:700}
.brand .brand-slogan{display:block;font-family:var(--font-display);font-weight:600;font-size:.8rem;letter-spacing:.005em;color:var(--muted);margin-top:4px;line-height:1.1;white-space:nowrap}
.brand .brand-tag{display:block;font-family:var(--font-mono);font-size:.6rem;letter-spacing:.14em;color:var(--muted);margin-top:3px;font-weight:400}
.nav{display:flex;gap:4px;margin-left:auto;align-items:center}
.nav a{color:var(--ink);text-decoration:none;font-weight:600;font-size:.98rem;padding:8px 12px;border-radius:var(--radius)}
.nav a:hover{background:var(--band)}
.nav a[aria-current="page"]{color:var(--accent)}
.btn{display:inline-flex;align-items:center;gap:8px;font-weight:700;text-decoration:none;border-radius:var(--radius);padding:12px 20px;border:2px solid var(--accent);transition:transform .15s ease,background .15s ease,color .15s ease;font-family:var(--font-body);font-size:1rem;cursor:pointer}
.btn-primary{background:var(--accent);color:var(--accent-ink)}
.btn-primary:hover{transform:translateY(-1px)}
.btn-ghost{background:transparent;color:inherit;border-color:currentColor}
.btn-ghost:hover{background:rgba(127,127,127,.12)}
.nav .btn{margin-left:8px;padding:9px 16px;color:var(--accent-ink)}
.menu-toggle{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:var(--radius);color:var(--ink);font:600 .95rem var(--font-body);padding:8px 12px;cursor:pointer}
@media (max-width:920px){
  .menu-toggle{display:inline-block}
  .nav{display:none;position:absolute;left:0;right:0;top:100%;background:var(--surface);border-bottom:1px solid var(--line);flex-direction:column;align-items:stretch;padding:8px max(16px,env(safe-area-inset-right,0px)) 16px max(16px,env(safe-area-inset-left,0px))}
  .nav.open{display:flex}
  .nav .btn{margin:8px 0 0;justify-content:center}
}

/* Hero */
.hero{background:var(--hero);color:var(--hero-ink);overflow:hidden}
.hero .wrap{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);gap:clamp(24px,4vw,56px);align-items:center;padding-block:clamp(48px,7vw,96px)}
.hero h1{color:var(--hero-ink)}
.hero .eyebrow{color:var(--accent)}
.hero .lede{color:var(--hero-muted);margin-top:18px}
.hero .subhead{margin-top:18px;max-width:32ch;font-family:var(--font-display);font-weight:600;font-size:clamp(1.25rem,1.1rem + .8vw,1.65rem);line-height:1.3;color:var(--hero-ink,#E8F1F4)}
.hero .slogan{margin-top:22px;padding-left:14px;border-left:3px solid #36C2B9;font-family:var(--font-display);font-weight:600;font-size:clamp(1.25rem,1.1rem + .6vw,1.5rem);letter-spacing:.01em;color:#36C2B9}
.slogan-foot{font-family:var(--font-display);font-weight:600;color:var(--accent);margin:0}
.hero .actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:28px}
.hero .btn-ghost{color:var(--hero-ink)}
.hero-copy{animation:rise .7s ease-out both}
@media (max-width:860px){.hero .wrap{grid-template-columns:1fr}}
@keyframes rise{from{transform:translateY(10px)}to{transform:none}}

/* Purdue / zone diagram */
.diagram{width:100%;height:auto;display:block}
.diagram .lvl{fill:none;stroke:var(--hero-line);stroke-width:1}
.diagram .lvl-label{fill:var(--hero-muted);font:500 10px var(--font-mono);letter-spacing:.08em}
.diagram .zone{fill:rgba(255,255,255,.03);stroke:var(--hero-muted);stroke-width:1.2;rx:4}
.diagram .zone-name{fill:var(--hero-ink);font:600 12px var(--font-body)}
.diagram .zone-sub{fill:var(--hero-muted);font:400 10px var(--font-body)}
.diagram .conduit{stroke:var(--accent);stroke-width:2.2;fill:none}
.diagram .pulse{stroke:var(--accent);stroke-width:2.2;fill:none;stroke-dasharray:4 10;animation:flow 2.4s linear infinite}
.diagram .fw{fill:var(--hero);stroke:var(--accent);stroke-width:1.6}
.diagram .sl{fill:var(--amber-soft);stroke:none}
.diagram .sl-text{fill:var(--amber);font:600 9.5px var(--font-mono)}
.diagram .zsl-text{font-size:8px}
.diagram .dmz{stroke-dasharray:5 4}
@keyframes flow{to{stroke-dashoffset:-28}}
.diagram-caption{font-family:var(--font-mono);font-size:.72rem;color:var(--hero-muted);margin-top:8px;letter-spacing:.04em}

/* Cards & grids */
.grid{display:grid;gap:20px}
.grid-3{grid-template-columns:repeat(auto-fit,minmax(min(100%,300px),1fr))}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(min(100%,420px),1fr))}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px;display:flex;flex-direction:column;gap:10px;min-width:0}
a.card{color:inherit;text-decoration:none;transition:border-color .15s ease,transform .15s ease}
a.card:hover{border-color:var(--accent);transform:translateY(-2px)}
.card .go{margin-top:auto;font-weight:700;color:var(--accent)}
.section-head{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:end;gap:16px;margin-bottom:28px}
.section-head .lede{margin-top:10px}
.tag{display:inline-block;font-family:var(--font-mono);font-size:.72rem;letter-spacing:.06em;padding:3px 8px;border-radius:4px;background:var(--accent-soft);color:var(--ink)}
.tag.amber{background:var(--amber-soft);color:var(--amber)}
.why{display:grid;gap:28px;grid-template-columns:repeat(auto-fit,minmax(min(100%,260px),1fr))}
.why div{border-top:3px solid var(--accent);padding-top:14px}
.why p{color:var(--muted);margin-top:6px}

/* Method (a real sequence) */
.method{list-style:none;padding:0;margin:0;display:grid;gap:0;grid-template-columns:repeat(5,minmax(0,1fr));counter-reset:step}
.method li{position:relative;padding:20px 18px 0 0;counter-increment:step}
.method li::before{content:counter(step,decimal-leading-zero);font-family:var(--font-mono);font-size:.8rem;color:var(--accent);display:block;margin-bottom:8px}
.method li::after{content:"";position:absolute;top:0;left:0;right:0;height:2px;background:var(--line)}
.method li:first-child::after{background:var(--accent)}
.method p{color:var(--muted);font-size:.98rem;margin-top:6px}
@media (max-width:860px){.method{grid-template-columns:1fr}.method li{padding:16px 0 12px 0}}

/* Sectors */
.tier{display:grid;grid-template-columns:minmax(0,240px) minmax(0,1fr);gap:24px;padding-block:28px;border-top:1px solid var(--line)}
.tier:first-of-type{border-top:0}
.tier h3{font-size:var(--step-2)}
.tier .note{color:var(--muted);margin-top:6px}
@media (max-width:760px){.tier{grid-template-columns:1fr}}
.sector{scroll-margin-top:90px}
.sector dl{margin:0;display:grid;gap:4px}
.sector dt{font-family:var(--font-mono);font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.sector dd{margin:0 0 8px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:6px 14px;font-weight:600;font-size:.95rem;color:var(--ink);text-decoration:none}
a.chip:hover{border-color:var(--accent);color:var(--accent)}

/* Standards */
.std{display:grid;gap:8px}
.std .code{font-family:var(--font-display);font-size:1.5rem;font-weight:700;color:var(--ink)}
.std-strip{display:flex;flex-wrap:wrap;gap:10px}

/* Service page */
.svc-layout{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(0,1fr);gap:40px;align-items:start}
@media (max-width:860px){.svc-layout{grid-template-columns:1fr}}
.checklist{list-style:none;margin:0;padding:0;display:grid;gap:10px}
.checklist li{padding-left:28px;position:relative}
.checklist li::before{content:"";position:absolute;left:0;top:.45em;width:14px;height:8px;border-left:2.5px solid var(--accent);border-bottom:2.5px solid var(--accent);transform:rotate(-45deg)}
.aside{position:sticky;top:96px}
.kv{display:grid;gap:4px;padding-block:12px;border-top:1px solid var(--line)}
.kv:first-child{border-top:0;padding-top:0}
.kv .k{font-family:var(--font-mono);font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}

/* Page header */
.page-head{background:var(--surface);border-bottom:1px solid var(--line)}
.page-head .wrap{padding-block:clamp(40px,6vw,72px)}
.page-head .lede{margin-top:14px}
.crumb{font-family:var(--font-mono);font-size:.75rem;letter-spacing:.06em;color:var(--muted);margin-bottom:12px}
.crumb a{color:var(--muted)}

/* Insights */
.post-meta{font-family:var(--font-mono);font-size:.78rem;color:var(--muted)}

/* Team */
.person{display:grid;grid-template-columns:96px minmax(0,1fr);gap:20px;align-items:start}
.avatar{width:96px;height:96px;border-radius:50%;background:var(--accent-soft);display:grid;place-items:center;font-family:var(--font-display);font-weight:700;font-size:2rem;color:var(--accent)}
@media (max-width:480px){.person{grid-template-columns:1fr}}

/* Contact & forms */
.form{display:grid;gap:16px}
.form .row{display:grid;gap:16px;grid-template-columns:repeat(auto-fit,minmax(min(100%,220px),1fr))}
.field{display:grid;gap:6px}
.field label{font-weight:600;font-size:.95rem}
.field input,.field select,.field textarea{font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:11px 12px;width:100%}
.field textarea{min-height:150px;resize:vertical}
.field input:focus,.field select:focus,.field textarea:focus{outline:2px solid var(--focus);outline-offset:1px;border-color:var(--focus)}
.consent{display:flex;gap:10px;align-items:flex-start;font-size:.92rem;color:var(--muted)}
.notice{border-left:4px solid var(--accent);background:var(--accent-soft);padding:12px 16px;border-radius:4px}
.notice.warn{border-color:var(--amber);background:var(--amber-soft)}
.copy-row{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.copy-row code{font-family:var(--font-mono);font-size:.95rem;background:var(--band);padding:6px 10px;border-radius:4px;user-select:all;overflow-wrap:anywhere}
.hp{position:absolute;left:-9999px}

/* CTA band */
.cta-band{background:var(--hero);color:var(--hero-ink)}
.cta-band .wrap{display:flex;flex-wrap:wrap;gap:24px;justify-content:space-between;align-items:center;padding-block:48px}
.cta-band p{color:var(--hero-muted);margin-top:8px;max-width:56ch}

/* Footer */
.site-footer{background:var(--surface);border-top:1px solid var(--line);font-size:.95rem}
.site-footer .wrap{padding-block:48px 24px}
.foot-grid{display:grid;gap:32px;grid-template-columns:minmax(0,1.4fr) repeat(3,minmax(0,1fr))}
@media (max-width:860px){.foot-grid{grid-template-columns:1fr 1fr}}
@media (max-width:480px){.foot-grid{grid-template-columns:1fr}}
.foot-grid h4{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin:0 0 10px;font-weight:500}
.foot-grid ul{list-style:none;margin:0;padding:0;display:grid;gap:6px}
.foot-grid a{color:var(--ink);text-decoration:none}
.foot-grid a:hover{color:var(--accent)}
.legal{margin-top:32px;padding-top:16px;border-top:1px solid var(--line);color:var(--muted);font-size:.85rem;display:grid;gap:4px}

@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* Drop-down menus */
.dd{position:relative;display:flex;align-items:center}
.dd-btn{background:none;border:0;color:var(--muted);cursor:pointer;padding:8px 4px;margin-left:-8px;font-size:.8rem;border-radius:var(--radius)}
.dd-btn:hover{color:var(--accent)}
.dd-menu{position:absolute;top:100%;left:0;min-width:260px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 12px 32px rgba(10,25,40,.14);padding:8px;display:none;flex-direction:column;z-index:70}
.dd-menu a{padding:9px 12px;font-weight:500;white-space:nowrap}
.dd:hover .dd-menu,.dd:focus-within .dd-menu,.dd.open .dd-menu{display:flex}
@media (max-width:920px){
  .dd{flex-wrap:wrap}
  .dd-top{flex:1}
  .dd-btn{margin-left:0;padding:8px 12px;font-size:1rem}
  .dd-menu{position:static;box-shadow:none;border:0;border-left:2px solid var(--line);border-radius:0;margin-left:12px;min-width:0;width:100%;padding:0 0 0 8px}
  .dd:hover .dd-menu,.dd:focus-within .dd-menu{display:none}
  .dd.open .dd-menu{display:flex}
  .dd-menu a{white-space:normal}
}
.grid-4{grid-template-columns:repeat(auto-fit,minmax(min(100%,250px),1fr))}

/* Project lifecycle strip (a real sequence) */
.lifecycle{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(8,minmax(0,1fr));gap:0;counter-reset:st}
.lifecycle li{position:relative;padding:22px 10px 0 0;display:grid;gap:4px;font-size:.95rem}
.lifecycle li::before{content:"";position:absolute;top:6px;left:0;right:0;height:2px;background:var(--accent)}
.lifecycle li::after{content:"";position:absolute;top:1px;left:0;width:12px;height:12px;border-radius:50%;background:var(--surface);border:2px solid var(--accent)}
.lifecycle .code,.stages .code{font-family:var(--font-mono);font-size:.78rem;letter-spacing:.08em;color:var(--amber);font-weight:600;display:block}
@media (max-width:960px){.lifecycle{grid-template-columns:repeat(4,minmax(0,1fr));row-gap:20px}}
@media (max-width:520px){.lifecycle{grid-template-columns:repeat(2,minmax(0,1fr))}}

/* Stage table */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);background:var(--surface)}
.stages{border-collapse:collapse;width:100%;min-width:620px;font-size:.96rem}
.stages th,.stages td{text-align:left;vertical-align:top;padding:12px 14px;border-top:1px solid var(--line)}
.stages thead th{border-top:0;font-family:var(--font-mono);font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);font-weight:500;background:var(--band)}
.stages tbody th{font-weight:600;min-width:170px}

/* Standards groups */
.std-group{padding-top:40px;scroll-margin-top:90px}
.std-group-head{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:end;gap:12px;margin-bottom:18px;border-bottom:2px solid var(--ink);padding-bottom:12px}
.std-group-head h2{font-size:var(--step-2)}
.tier{scroll-margin-top:90px}

/* Chat panel */
.chat-launch{position:fixed;right:calc(20px + env(safe-area-inset-right,0px));bottom:calc(20px + env(safe-area-inset-bottom,0px));z-index:80;display:flex;align-items:center;gap:8px;background:var(--hero);color:var(--hero-ink);border:1px solid var(--hero-line);border-radius:999px;padding:10px 16px 10px 12px;font:700 .95rem var(--font-body);cursor:pointer;box-shadow:0 10px 28px rgba(10,25,40,.25)}
.chat-launch:hover{transform:translateY(-1px)}
.chat{position:fixed;right:calc(20px + env(safe-area-inset-right,0px));bottom:calc(84px + env(safe-area-inset-bottom,0px));z-index:90;width:min(380px,calc(100vw - 32px));max-height:calc(100vh - 120px);overflow:auto;background:var(--surface);border:1px solid var(--line);border-radius:10px;box-shadow:0 18px 48px rgba(10,25,40,.28)}
.chat-head{display:flex;justify-content:space-between;align-items:start;gap:12px;padding:16px 18px;background:var(--hero);color:var(--hero-ink);border-radius:10px 10px 0 0}
.chat-head strong{display:block;font-family:var(--font-display);font-size:1.2rem}
.chat-head button{background:none;border:0;color:var(--hero-ink);font-size:1.1rem;cursor:pointer;padding:4px 8px}
.chat-status{display:inline-flex;align-items:center;gap:6px;font-size:.82rem;color:var(--hero-muted);margin-top:4px}
.chat-status::before{content:"";width:8px;height:8px;border-radius:50%;background:var(--amber)}
.chat-status.on::before{background:#2BB673}
.chat form{padding:16px 18px 18px}
@media (max-width:480px){.chat-launch span{display:none}.chat-launch{padding:12px}}

.pager{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,260px),1fr));gap:16px;margin-top:40px}
.trust-band{display:flex;flex-wrap:wrap;gap:24px;justify-content:space-between;align-items:center}
.prose .table-wrap{margin:0 0 1.2em}
.prose .stages{min-width:0;table-layout:fixed}
.prose .stages tbody th{min-width:0}
.prose{max-width:74ch}

/* Confirmation after sending */
.done-view{display:grid;gap:12px;justify-items:start;scroll-margin-top:96px}
.chat .done-view{padding:22px 18px 20px}
.done-mark{width:44px;height:44px;border-radius:50%;display:grid;place-items:center;background:var(--accent);color:var(--accent-ink);font-size:1.4rem;font-weight:700}