/* ==========================================================================
   North RF — Precision RF & Microwave Components
   Design system: DARK THEME — deep navy base + signal cyan accents
   Page, cards and tables share one continuous navy surface;
   product photos are cool-toned and fade into the card at the bottom.
   ========================================================================== */

/* Self-hosted Inter — the de-facto standard for Western B2B sites.
   latin subset only; Chinese pages switch to YaHei/PingFang via lang.js. */
@font-face{font-family:'Inter';font-style:normal;font-weight:400;font-display:swap;src:url('fonts/inter-latin-400.woff2') format('woff2')}
@font-face{font-family:'Inter';font-style:normal;font-weight:600;font-display:swap;src:url('fonts/inter-latin-600.woff2') format('woff2')}
@font-face{font-family:'Inter';font-style:normal;font-weight:700;font-display:swap;src:url('fonts/inter-latin-700.woff2') format('woff2')}

:root{
  --navy-900:#071a2f;
  --navy-800:#0b2545;
  --navy-700:#13315c;
  --navy-600:#1b4173;
  --cyan:#22a6d6;
  --cyan-dk:#1583ae;
  --cyan-lt:rgba(34,166,214,.14);
  --ink:#e6edf4;
  --head:#f4f8fc;
  --sub:#9db4c9;
  --muted:#7d94ab;
  --line:#1d3a5f;
  --line-dk:#2a4a73;
  --bg:#071a2f;
  --soft:#0a2038;
  --soft-2:#0e2a4a;
  --imgbg:#d2dee9;

  --shadow-sm:0 1px 3px rgba(0,0,0,.35);
  --shadow:0 4px 16px rgba(0,0,0,.4);
  --shadow-lg:0 12px 40px rgba(0,0,0,.5);

  --r-sm:4px;
  --r:8px;
  --r-lg:14px;

  --wrap:1200px;
  --font:'Inter',-apple-system,BlinkMacSystemFont,"Segoe UI","Helvetica Neue",Arial,"Noto Sans",sans-serif;
  --mono:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font);
  color:var(--ink);
  background:var(--bg);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  font-size:16px;
}
::selection{background:rgba(34,166,214,.4);color:#fff}
img{max-width:100%;display:block}
a{color:#bfd9ea;text-decoration:none;transition:color .18s}
a:hover{color:var(--cyan)}
ul{list-style:none}

.wrap{max-width:var(--wrap);margin:0 auto;padding:0 28px}

/* ---------- Typography ---------- */
h1,h2,h3,h4{line-height:1.2;font-weight:700;letter-spacing:-.015em;color:var(--head)}
h1{font-size:2.85rem}
h2{font-size:2.05rem}
h3{font-size:1.28rem}
h4{font-size:1.05rem}

.eyebrow{
  display:inline-block;font-size:.75rem;font-weight:700;letter-spacing:.14em;
  text-transform:uppercase;color:#4db7e2;margin-bottom:14px;
}
.lead{font-size:1.1rem;color:var(--sub);max-width:760px}
.sec-sub{color:var(--sub);max-width:720px;margin-top:14px}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:9px;
  padding:13px 26px;border-radius:var(--r-sm);
  font-size:.94rem;font-weight:600;letter-spacing:.01em;
  border:1.5px solid transparent;cursor:pointer;
  transition:all .2s;white-space:nowrap;
}
.btn-primary{background:var(--cyan);color:#fff}
.btn-primary:hover{background:var(--cyan-dk);color:#fff;transform:translateY(-1px);box-shadow:var(--shadow)}
.btn-ghost{background:transparent;color:#fff;border-color:rgba(255,255,255,.42)}
.btn-ghost:hover{background:rgba(255,255,255,.1);color:#fff;border-color:rgba(255,255,255,.75)}
.btn-outline{background:var(--soft-2);color:var(--ink);border-color:var(--line-dk)}
.btn-outline:hover{border-color:var(--cyan);color:#7fd4ef;background:rgba(34,166,214,.08)}

/* ==========================================================================
   HEADER
   ========================================================================== */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(7,26,47,.92);
  backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:74px}
.brand{display:flex;align-items:center;gap:11px;font-weight:700;font-size:1.18rem;color:var(--head);letter-spacing:-.01em}
.brand:hover{color:var(--head)}
.brand-mark{
  width:36px;height:36px;border-radius:var(--r-sm);flex:0 0 auto;
  background:linear-gradient(135deg,var(--navy-700),var(--cyan));
  display:flex;align-items:center;justify-content:center;
  color:#fff;font-size:.82rem;font-weight:800;letter-spacing:.02em;
}
.brand-sub{display:block;font-size:.63rem;font-weight:500;color:var(--muted);letter-spacing:.14em;text-transform:uppercase;line-height:1;margin-top:3px}

.nav{display:flex;align-items:center;gap:2px}
.nav > li > a{
  display:block;padding:9px 14px;font-size:.92rem;font-weight:500;
  color:#c9dbea;border-radius:var(--r-sm);
}
.nav > li > a:hover,.nav > li > a.active{background:var(--cyan-lt);color:#7fd4ef}

.nav-toggle{display:none;background:none;border:0;font-size:1.5rem;color:#c9dbea;cursor:pointer;padding:6px}

/* ==========================================================================
   HERO
   ========================================================================== */
.hero{
  position:relative;overflow:hidden;color:#fff;
  background:linear-gradient(140deg,var(--navy-900) 0%,var(--navy-800) 45%,var(--navy-600) 100%);
  padding:96px 0 108px;
}
.hero::before{
  content:"";position:absolute;inset:0;opacity:.5;
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.05) 1px,transparent 1px);
  background-size:56px 56px;
  mask-image:radial-gradient(ellipse at 68% 32%,#000 12%,transparent 68%);
  -webkit-mask-image:radial-gradient(ellipse at 68% 32%,#000 12%,transparent 68%);
}
.hero::after{
  content:"";position:absolute;width:620px;height:620px;border-radius:50%;
  right:-160px;top:-220px;
  background:radial-gradient(circle,rgba(34,166,214,.30),transparent 68%);
  pointer-events:none;
}
.hero .wrap{position:relative;z-index:2}
.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:64px;align-items:center}

.hero h1{color:#fff;font-size:3.05rem;margin-bottom:22px}
.hero h1 .accent{color:var(--cyan)}
.hero p{color:rgba(255,255,255,.82);font-size:1.1rem;max-width:600px;margin-bottom:32px}
.hero-actions{display:flex;flex-wrap:wrap;gap:14px}

.hero-panel{
  background:rgba(255,255,255,.055);
  border:1px solid rgba(255,255,255,.15);
  border-radius:var(--r-lg);
  padding:26px;backdrop-filter:blur(6px);
}
.hero-panel-title{
  font-size:.74rem;letter-spacing:.15em;text-transform:uppercase;
  color:var(--cyan);font-weight:700;margin-bottom:16px;
}
.spec-row{
  display:flex;justify-content:space-between;align-items:center;
  padding:11px 0;border-bottom:1px solid rgba(255,255,255,.11);font-size:.9rem;
}
.spec-row:last-child{border-bottom:0}
.spec-row dt{color:rgba(255,255,255,.65)}
.spec-row dd{color:#fff;font-weight:600;font-family:var(--mono);font-size:.88rem}

/* ---------- Interface chips ---------- */
.chips{display:flex;flex-wrap:wrap;gap:9px}
.chip{
  padding:6px 13px;border-radius:100px;font-size:.82rem;font-weight:600;
  background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);
  color:#fff;font-family:var(--mono);letter-spacing:.02em;
}
.chip:hover{background:rgba(255,255,255,.18);color:#fff}

/* ==========================================================================
   STATS STRIP
   ========================================================================== */
.stats{background:var(--navy-900);border-top:1px solid rgba(255,255,255,.07);padding:0}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr)}
.stat{padding:26px 22px;text-align:center;border-right:1px solid rgba(255,255,255,.08)}
.stat:last-child{border-right:0}
.stat b{display:block;font-size:1.6rem;color:#fff;font-weight:700;letter-spacing:-.02em}
.stat span{font-size:.78rem;color:rgba(255,255,255,.62);letter-spacing:.06em;text-transform:uppercase}

/* ==========================================================================
   SECTIONS
   ========================================================================== */
.section{padding:88px 0}
.section.alt{background:var(--soft)}
.section-head{margin-bottom:48px;max-width:820px}
.section-head.center{text-align:center;margin-left:auto;margin-right:auto}

.grid{display:grid;gap:24px}
.g2{grid-template-columns:repeat(2,1fr)}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}

/* ---------- Product cards ---------- */
.pcard{
  background:var(--navy-800);border:1px solid var(--line);border-radius:var(--r);
  padding:28px 26px;transition:all .22s;position:relative;display:flex;flex-direction:column;
}
.pcard:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:var(--cyan)}
/* Image band at the top of product cards — photo fades into the card below */
.pcard-img{
  height:150px;margin:-28px -26px 22px;border-radius:var(--r) var(--r) 0 0;
  overflow:hidden;background:var(--imgbg);border-bottom:1px solid var(--line);
}
.pcard-img img{
  width:100%;height:100%;object-fit:cover;display:block;transition:transform .35s;
  -webkit-mask-image:linear-gradient(180deg,#000 52%,rgba(0,0,0,.45) 82%,rgba(0,0,0,.08) 100%);
  mask-image:linear-gradient(180deg,#000 52%,rgba(0,0,0,.45) 82%,rgba(0,0,0,.08) 100%);
}
.pcard:hover .pcard-img img{transform:scale(1.05)}
/* Blueprint-style tile for categories without photography */
.pcard-img.img-dark{
  background:linear-gradient(135deg,#0e2a4a 0%,#1b4173 100%);
  display:flex;align-items:center;justify-content:center;color:#7cc4e8;
  border-bottom:1px solid #1d3a5f;
}
.pcard-img.img-dark svg{width:46px;height:46px;stroke-width:1.3;opacity:.95}
.pcard-img.img-dark::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  -webkit-mask-image:linear-gradient(180deg,#000 52%,rgba(0,0,0,.45) 82%,rgba(0,0,0,.08) 100%);
  mask-image:linear-gradient(180deg,#000 52%,rgba(0,0,0,.45) 82%,rgba(0,0,0,.08) 100%);
  background:linear-gradient(180deg,transparent 60%,var(--navy-800) 100%);
}
.pcard-icon{
  width:46px;height:46px;border-radius:var(--r-sm);background:var(--cyan-lt);
  display:flex;align-items:center;justify-content:center;margin-bottom:18px;
  color:#5fc3e8;font-size:1.2rem;
}
.pcard h3{margin-bottom:9px}
.pcard p{color:var(--sub);font-size:.92rem;margin-bottom:16px;flex:1}
.pcard-meta{font-size:.8rem;color:var(--muted);font-family:var(--mono);padding-top:14px;border-top:1px solid var(--line)}
.pcard-link{font-size:.86rem;font-weight:600;color:#5fc3e8;margin-top:12px;display:inline-flex;align-items:center;gap:6px}
.pcard:hover .pcard-link{gap:10px}

/* ---------- Feature list ---------- */
.feat{display:flex;gap:16px}
.feat-ico{
  width:40px;height:40px;flex:0 0 auto;border-radius:var(--r-sm);
  background:var(--cyan-lt);color:#5fc3e8;
  display:flex;align-items:center;justify-content:center;font-weight:800;font-size:.95rem;
}
.feat h4{margin-bottom:5px;font-size:1rem}
.feat p{color:var(--sub);font-size:.9rem}

/* ---------- Tables ---------- */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--r);background:var(--navy-800)}
table{width:100%;border-collapse:collapse;font-size:.89rem;min-width:600px}
thead th{
  background:var(--navy-700);color:#fff;text-align:left;
  padding:13px 16px;font-weight:600;font-size:.79rem;
  letter-spacing:.06em;text-transform:uppercase;white-space:nowrap;
}
tbody td{padding:12px 16px;border-bottom:1px solid var(--line);color:var(--ink)}
tbody tr:last-child td{border-bottom:0}
tbody tr:nth-child(even){background:var(--soft)}
tbody tr:hover{background:var(--cyan-lt)}
td.mono,th.mono{font-family:var(--mono);font-size:.84rem}

/* ---------- Callout ---------- */
.callout{
  border-left:3px solid var(--cyan);background:rgba(34,166,214,.1);
  border-radius:0 var(--r-sm) var(--r-sm) 0;padding:18px 22px;margin:26px 0;
  font-size:.93rem;color:#c6e2f2;
}
.callout strong{color:var(--head)}

/* ---------- CTA band ---------- */
.cta-band{
  background:linear-gradient(135deg,var(--navy-800),var(--navy-600));
  border:1px solid var(--line);
  color:#fff;border-radius:var(--r-lg);padding:52px 48px;
  display:flex;align-items:center;justify-content:space-between;gap:36px;flex-wrap:wrap;
}
.cta-band h2{color:#fff;font-size:1.75rem;margin-bottom:9px}
.cta-band p{color:rgba(255,255,255,.78);max-width:520px}

/* ---------- Breadcrumb ---------- */
.crumb{background:var(--soft);border-bottom:1px solid var(--line);padding:14px 0;font-size:.85rem;color:var(--sub)}
.crumb a{color:var(--sub)}
.crumb a:hover{color:var(--cyan)}
.crumb span{margin:0 8px;color:var(--muted)}

/* ---------- Page hero (inner pages) ---------- */
.page-hero{
  background:linear-gradient(135deg,var(--navy-900),var(--navy-600));
  color:#fff;padding:62px 0;
}
.page-hero h1{color:#fff;font-size:2.35rem;margin-bottom:12px}
.page-hero p{color:rgba(255,255,255,.78);max-width:720px}

/* ---------- Contact ---------- */
.contact-grid{display:grid;grid-template-columns:1fr 1.15fr;gap:52px}
.contact-info li{display:flex;gap:14px;padding:16px 0;border-bottom:1px solid var(--line)}
.contact-info li:last-child{border-bottom:0}
.ci-ico{
  width:38px;height:38px;flex:0 0 auto;border-radius:var(--r-sm);
  background:var(--cyan-lt);color:#5fc3e8;
  display:flex;align-items:center;justify-content:center;font-size:1rem;
}
.ci-label{font-size:.76rem;text-transform:uppercase;letter-spacing:.1em;color:var(--muted);font-weight:600}
.ci-val{color:var(--ink);font-weight:600;font-size:.96rem}
.ci-val a{color:#5fc3e8}

.form-field{margin-bottom:18px}
.form-field label{display:block;font-size:.86rem;font-weight:600;margin-bottom:7px;color:#d5e4f0}
.form-field input,.form-field select,.form-field textarea{
  width:100%;padding:11px 14px;border:1px solid var(--line-dk);border-radius:var(--r-sm);
  font-family:inherit;font-size:.93rem;color:var(--ink);background:var(--soft);transition:border-color .18s;
}
.form-field input::placeholder,.form-field textarea::placeholder{color:#64809a}
.form-field input:focus,.form-field select:focus,.form-field textarea:focus{
  outline:0;border-color:var(--cyan);box-shadow:0 0 0 3px rgba(34,166,214,.18);
}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.form-note{font-size:.8rem;color:var(--muted);margin-top:14px}

/* ---------- Footer ---------- */
.site-footer{background:var(--navy-900);color:rgba(255,255,255,.7);padding:64px 0 30px;font-size:.9rem;border-top:1px solid var(--line)}
.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1.2fr;gap:44px;margin-bottom:44px}
.site-footer h4{color:#fff;font-size:.82rem;letter-spacing:.12em;text-transform:uppercase;margin-bottom:18px}
.site-footer a{color:rgba(255,255,255,.7)}
.site-footer a:hover{color:var(--cyan)}
.site-footer li{margin-bottom:10px}
.site-footer .brand{color:#fff;margin-bottom:16px}
.site-footer .brand-sub{color:rgba(255,255,255,.5)}
.footer-desc{color:rgba(255,255,255,.55);font-size:.88rem;max-width:300px}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.11);padding-top:26px;
  display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;
  font-size:.83rem;color:rgba(255,255,255,.5);
}

/* ==========================================================================
   RESPONSIVE
   ========================================================================== */
@media (max-width:1024px){
  .hero-grid{grid-template-columns:1fr;gap:44px}
  .hero h1{font-size:2.5rem}
  .g4{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr;gap:34px}
  .contact-grid{grid-template-columns:1fr;gap:40px}
}
@media (max-width:820px){
  .nav{
    display:none;position:absolute;top:74px;left:0;right:0;background:var(--navy-800);
    flex-direction:column;align-items:stretch;gap:0;padding:10px 18px 18px;
    border-bottom:1px solid var(--line);box-shadow:var(--shadow);
  }
  .nav.open{display:flex}
  .nav > li > a{padding:12px 10px}
  .nav-toggle{display:block}
  .stats-grid{grid-template-columns:repeat(2,1fr)}
  .stat{border-bottom:1px solid rgba(255,255,255,.08)}
  .stat:nth-child(2){border-right:0}
  h1{font-size:2.05rem}
  .hero{padding:64px 0 76px}
  .hero h1{font-size:2.05rem}
  .section{padding:62px 0}
  .g3,.g2{grid-template-columns:1fr}
  .cta-band{padding:38px 26px}
  .form-row{grid-template-columns:1fr}
}
@media (max-width:520px){
  .wrap{padding:0 20px}
  .g4{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .hero h1{font-size:1.78rem}
  .hero-actions .btn{width:100%;justify-content:center}
}

/* ==========================================================================
   GALLERY & PRODUCT PHOTOS — photos fade into the navy page at the bottom
   ========================================================================== */
.gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.gallery-item{position:relative;border-radius:var(--r);overflow:hidden;border:1px solid var(--line);background:var(--navy-800);box-shadow:var(--shadow-sm)}
.gallery-item img{
  width:100%;height:225px;object-fit:cover;display:block;transition:transform .35s;
  -webkit-mask-image:linear-gradient(180deg,#000 55%,rgba(0,0,0,.35) 85%,rgba(0,0,0,.05) 100%);
  mask-image:linear-gradient(180deg,#000 55%,rgba(0,0,0,.35) 85%,rgba(0,0,0,.05) 100%);
}
.gallery-item:hover img{transform:scale(1.04)}
.gallery-item figcaption{
  position:absolute;left:0;right:0;bottom:0;padding:30px 16px 12px;
  background:linear-gradient(transparent,rgba(7,26,47,.92));
  color:#fff;font-size:.88rem;font-weight:600;letter-spacing:.01em;
}

.sec-photos{display:flex;gap:14px;flex-wrap:wrap;margin:-10px 0 32px}
.sec-photos img{
  height:150px;width:auto;border-radius:var(--r);border:1px solid var(--line);object-fit:cover;
  background:var(--imgbg);
  -webkit-mask-image:linear-gradient(180deg,#000 55%,rgba(0,0,0,.4) 85%,rgba(0,0,0,.06) 100%);
  mask-image:linear-gradient(180deg,#000 55%,rgba(0,0,0,.4) 85%,rgba(0,0,0,.06) 100%);
}
.sec-photos img.render{width:150px;height:150px;object-fit:cover}

@media (max-width:820px){
  .gallery{grid-template-columns:repeat(2,1fr)}
  .gallery-item img{height:180px}
  .sec-photos img{height:110px}
  .sec-photos img.render{width:110px;height:110px}
}
@media (max-width:520px){
  .gallery{grid-template-columns:1fr}
}

/* ---------- Privacy / legal pages ---------- */
.wrap.narrow{max-width:860px}
.legal-block{margin-bottom:36px}
.legal-block h2{font-size:1.28rem;margin-bottom:12px}
.legal-block p{color:var(--sub);margin-bottom:10px}
.legal-block ul{list-style:disc;padding-left:24px;margin:10px 0}
.legal-block li{color:var(--sub);margin-bottom:9px;font-size:.95rem}
.legal-block strong{color:var(--ink)}