/* Dichroptics — static site stylesheet. No build step. */
:root{
  --navy:#0b1f3a; --navy-2:#13315c; --ink:#1b2433; --muted:#556275; --line:#dde3ec;
  --bg:#ffffff; --bg-soft:#f4f7fb; --accent:#1d5fd1; --accent-dark:#164aa5; --ok:#0f7b4f;
  --spectrum:linear-gradient(90deg,#6a00c9 0%,#3b2cff 14%,#0091ff 28%,#00b8b0 40%,#3fbf3f 52%,#d6d200 64%,#ff9a00 78%,#e8261c 92%,#8b0000 100%);
  --radius:10px; --shadow:0 1px 2px rgba(11,31,58,.06),0 4px 16px rgba(11,31,58,.06);
  --maxw:1140px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.6;font-size:16px}
img,svg{max-width:100%}
a{color:var(--accent)}
a:hover{color:var(--accent-dark)}
:focus-visible{outline:3px solid #ffb000;outline-offset:2px}
h1,h2,h3{color:var(--navy);line-height:1.25;margin:0 0 .5em}
h1{font-size:clamp(1.9rem,4vw,2.8rem);letter-spacing:-.01em}
h2{font-size:clamp(1.4rem,2.6vw,1.9rem)}
h3{font-size:1.15rem}
p{margin:0 0 1em}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}
.skip-link{position:absolute;left:-999px;top:0;background:#fff;color:var(--navy);padding:8px 12px;z-index:100}
.skip-link:focus{left:8px;top:8px}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);border:0}

/* Header */
.spectrum-bar{height:4px;background:var(--spectrum)}
.site-header{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
.header-inner{display:flex;align-items:center;justify-content:space-between;min-height:64px;gap:16px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--navy);font-weight:700;font-size:1.2rem}
.brand svg{width:32px;height:32px}
.brand small{display:block;font-weight:400;font-size:.72rem;color:var(--muted);letter-spacing:.02em}
.nav ul{list-style:none;margin:0;padding:0;display:flex;gap:4px;flex-wrap:wrap}
.nav a{display:block;padding:8px 12px;border-radius:6px;text-decoration:none;color:var(--ink);font-weight:500;font-size:.95rem}
.nav a:hover{background:var(--bg-soft);color:var(--navy)}
.nav a[aria-current="page"]{color:var(--accent);background:#eaf1fd}
.nav .nav-cta{background:var(--navy);color:#fff}
.nav .nav-cta:hover{background:var(--navy-2);color:#fff}
.nav-toggle{display:none;background:none;border:1px solid var(--line);border-radius:6px;padding:8px 10px;cursor:pointer;color:var(--navy);font:inherit}
@media (max-width:860px){
  .js .nav-toggle{display:inline-flex;align-items:center;gap:6px}
  .js .nav{display:none;position:absolute;left:0;right:0;top:100%;background:#fff;border-bottom:1px solid var(--line);box-shadow:var(--shadow)}
  .js .nav.open{display:block}
  .js .nav ul{flex-direction:column;padding:8px 20px 16px}
  .nav ul{gap:0}
  .header-inner{position:relative;flex-wrap:wrap}
}

/* Buttons */
.btn{display:inline-block;padding:12px 20px;border-radius:8px;font-weight:600;text-decoration:none;border:2px solid transparent;cursor:pointer;font-size:1rem;line-height:1.2}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-dark);color:#fff}
.btn-outline{border-color:#fff;color:#fff}
.btn-outline:hover{background:rgba(255,255,255,.12);color:#fff}
.btn-ghost{border-color:var(--accent);color:var(--accent);background:#fff}
.btn-ghost:hover{background:#eaf1fd}
.btn-sm{padding:8px 14px;font-size:.92rem}

/* Hero */
.hero{background:radial-gradient(1200px 400px at 80% -10%,#1c3f74 0%,transparent 60%),var(--navy);color:#e8eef8;padding:64px 0 56px;position:relative;overflow:hidden}
.hero h1{color:#fff;max-width:18ch}
.hero p.lead{font-size:1.15rem;max-width:56ch;color:#cfdbee}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:40px;align-items:center}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin:24px 0 12px}
.hero .fine{font-size:.85rem;color:#a9bad3}
.hero-graphic{background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.12);border-radius:14px;padding:16px}
@media (max-width:860px){.hero-grid{grid-template-columns:1fr}.hero{padding:44px 0 40px}}

.page-hero{background:var(--bg-soft);border-bottom:1px solid var(--line);padding:40px 0 28px}
.page-hero p{color:var(--muted);max-width:70ch;margin:0}

section.block{padding:56px 0}
section.block.alt{background:var(--bg-soft)}
.section-head{display:flex;justify-content:space-between;align-items:end;gap:16px;flex-wrap:wrap;margin-bottom:24px}
.section-head p{color:var(--muted);margin:0;max-width:60ch}

/* Cards */
.grid{display:grid;gap:20px}
.grid-3{grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(300px,1fr))}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow);display:flex;flex-direction:column}
.card h3{margin-bottom:4px}
.card .sku{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.82rem;color:var(--muted)}
.card .desc{color:var(--muted);font-size:.95rem;margin:8px 0 12px}
.card .price{margin-top:auto;padding-top:12px;border-top:1px dashed var(--line)}
.price strong{font-size:1.25rem;color:var(--navy)}
.price .single{display:block;font-size:.88rem;color:var(--muted)}
.tag{display:inline-block;font-size:.75rem;font-weight:600;letter-spacing:.03em;text-transform:uppercase;color:var(--accent-dark);background:#eaf1fd;border-radius:999px;padding:2px 10px;margin-bottom:8px}
.mini-spec{list-style:none;padding:0;margin:0 0 8px;font-size:.9rem}
.mini-spec li{display:flex;justify-content:space-between;gap:10px;border-bottom:1px solid #eef1f6;padding:4px 0}
.mini-spec li span:first-child{color:var(--muted)}
.curve{display:block;width:100%;height:auto;margin:6px 0 4px;border-radius:6px}
.curve-caption{font-size:.72rem;color:var(--muted);margin:0 0 8px}

.features{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px}
.feature{padding:20px;border-radius:var(--radius);background:#fff;border:1px solid var(--line)}
.feature .icon{width:40px;height:40px;border-radius:10px;display:grid;place-items:center;background:#eaf1fd;color:var(--accent);margin-bottom:10px}
.feature h3{font-size:1.05rem}
.feature p{color:var(--muted);font-size:.95rem;margin:0}

/* Tables */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);background:#fff}
table{border-collapse:collapse;width:100%;font-size:.93rem}
th,td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--line);vertical-align:top}
thead th{background:var(--navy);color:#fff;font-weight:600;position:sticky;top:0}
tbody tr:nth-child(even){background:#fafbfd}
td.mono,.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.88rem}
.on-request{color:var(--muted);font-style:italic}
.spec-table th{background:var(--bg-soft);color:var(--navy);width:42%;font-weight:600}

/* Products page */
.filter-bar{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 24px}
.filter-bar button{font:inherit;font-size:.92rem;border:1px solid var(--line);background:#fff;color:var(--ink);padding:8px 14px;border-radius:999px;cursor:pointer}
.filter-bar button[aria-pressed="true"]{background:var(--navy);color:#fff;border-color:var(--navy)}
.product{display:grid;grid-template-columns:1fr 1.25fr;gap:28px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:24px;margin-bottom:24px;box-shadow:var(--shadow);scroll-margin-top:90px}
.product[hidden]{display:none}
.product .pricebox{background:var(--bg-soft);border-radius:8px;padding:14px 16px;margin:12px 0}
.product .pricebox strong{font-size:1.35rem;color:var(--navy)}
.product .note{font-size:.88rem;color:var(--muted)}
.product-group-title{margin:36px 0 16px;padding-bottom:8px;border-bottom:2px solid var(--line)}
@media (max-width:860px){.product{grid-template-columns:1fr;padding:18px}}

/* Steps */
.steps{counter-reset:step;list-style:none;padding:0;margin:0;display:grid;gap:16px}
.steps li{position:relative;padding:18px 18px 18px 64px;background:#fff;border:1px solid var(--line);border-radius:var(--radius)}
.steps li::before{counter-increment:step;content:counter(step);position:absolute;left:18px;top:18px;width:32px;height:32px;border-radius:50%;background:var(--navy);color:#fff;display:grid;place-items:center;font-weight:700}
.steps h3{margin:0 0 4px;font-size:1.05rem}
.steps p{margin:0;color:var(--muted)}

.callout{border-left:4px solid var(--accent);background:#f2f6fd;padding:14px 18px;border-radius:0 8px 8px 0;margin:20px 0}
.callout.warn{border-color:#c98a00;background:#fff8e6}
.prose{max-width:75ch}
.prose ul{padding-left:1.2em}
.prose li{margin-bottom:.4em}

/* Forms */
form.inquiry{display:grid;grid-template-columns:1fr 1fr;gap:16px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}
form.inquiry .full{grid-column:1/-1}
label{display:block;font-weight:600;font-size:.92rem;margin-bottom:4px;color:var(--navy)}
label .req{color:#b42318}
input,select,textarea{width:100%;font:inherit;padding:10px 12px;border:1px solid #c3ccd8;border-radius:8px;background:#fff;color:var(--ink)}
input:focus,select:focus,textarea:focus{border-color:var(--accent);outline:2px solid #b9d0f7}
textarea{min-height:140px;resize:vertical}
.hp{position:absolute;left:-5000px}
.form-help{font-size:.85rem;color:var(--muted)}
@media (max-width:640px){form.inquiry{grid-template-columns:1fr;padding:18px}}

/* CTA band */
.cta-band{background:var(--navy);color:#dbe5f3;border-radius:14px;padding:32px;display:flex;gap:20px;justify-content:space-between;align-items:center;flex-wrap:wrap;position:relative;overflow:hidden}
.cta-band::after{content:"";position:absolute;left:0;right:0;bottom:0;height:4px;background:var(--spectrum)}
.cta-band h2{color:#fff;margin:0 0 4px}
.cta-band p{margin:0}

/* Footer */
.site-footer{background:#08172b;color:#b7c3d6;margin-top:56px;font-size:.92rem}
.site-footer a{color:#dbe5f3}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:28px;padding:40px 0 24px}
.footer-grid h2{color:#fff;font-size:1rem;margin-bottom:10px}
.footer-grid ul{list-style:none;padding:0;margin:0}
.footer-grid li{margin-bottom:6px}
.footer-legal{border-top:1px solid #1d2f4a;padding:16px 0 28px;font-size:.82rem;color:#8d9bb2}
@media (max-width:760px){.footer-grid{grid-template-columns:1fr}}
@media print{.site-header,.site-footer,.nav-toggle{display:none}}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
.mini-spec li{display:grid;grid-template-columns:40% 1fr;gap:10px}
.mini-spec li span:last-child{text-align:right}
.compare-table{min-width:880px}
.compare-table td.mono:not(:first-child){white-space:nowrap}
.compare-table td:first-child{min-width:190px}
/* Measured-curve charts */
.chart{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:8px;background:#fff}
.chart-thumb{margin:8px 0 6px}
.chart-link{display:block}
.chart-fig{margin:10px 0 12px}
.chart-fig .curve-caption{margin-top:6px;font-size:.78rem;color:var(--muted)}
.product{grid-template-columns:1.1fr 1fr}
.cmp-specs{margin:0;padding-left:1.1em;font-size:.88rem}
.cmp-specs li{margin-bottom:2px}
.compare-table td:first-child{min-width:230px;max-width:260px}
.compare-table td:first-child .chart{max-width:240px}