/* ===================================================================
   ESAMBER North America — Design System
   Reverse-engineered to align with the ESAMBER global brand
   (www.esamber.com). Light, clean, precision-instrument industrial
   B2B look: white-dominant surfaces, generous whitespace, hairline
   rules, flat cards, the ESAMBER signal orange #e86f00 as the single
   loud accent, a calibrated green #0F7F3B as the secondary/data accent,
   #262626 ink, and an English-eyebrow-over-large-heading rhythm that
   mirrors esamber.com's "PRODUCT CENTER / 产品中心" module pattern.
   Anti-slop: real type scale, no gradient soup, no glassmorphism,
   no purple. Brand-consistent extension of the parent site.
   =================================================================== */

:root {
  /* ---- Brand palette (sampled from esamber.com) ---- */
  --orange:      #e86f00;   /* ESAMBER signal orange — primary accent */
  --orange-dk:   #c95f00;
  --orange-soft: #fdf0e3;   /* tint for focus rings / soft fills */
  --green:       #0f7f3b;   /* ESAMBER secondary green — data / status */
  --green-dk:    #0b6630;
  --green-soft:  #e8f4ec;

  /* Neutrals — esamber is a light, paper-white site */
  --ink:        #262626;    /* ESAMBER body ink (#262626) */
  --ink-2:      #1d1d1d;    /* footer / deep band */
  --slate:      #37383c;
  --steel:      #555555;
  --muted:      #707070;
  --muted-2:    #999999;
  --line:       #ececec;    /* hairline dividers */
  --line-2:     #e1e1e1;
  --paper:      #ffffff;
  --paper-2:    #f7f7f7;    /* esamber section grey */
  --paper-3:    #f0f0f0;
  --text:       #262626;
  --text-inv:   #f5f5f5;

  /* Aliases kept so existing class hooks (--signal*) keep working */
  --signal:      var(--orange);
  --signal-dk:   var(--orange-dk);
  --signal-soft: var(--orange-soft);

  /* ---- Typography ---- */
  /* esamber uses a Futura-style display + clean grotesk body. We map
     display to a geometric/Futura-adjacent stack, body to a clean sans. */
  --display: "Futura PT", "Futura", "Century Gothic", "Jost",
             "Trebuchet MS", -apple-system, "Segoe UI", Arial, sans-serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei",
          "PingFang SC", Roboto, Helvetica, Arial, sans-serif;
  --mono: "Space Mono", "SFMono-Regular", ui-monospace, Menlo, Consolas, monospace;

  /* ---- Rhythm ---- */
  --maxw: 1280px;
  --gap:  clamp(1rem, 2vw, 1.75rem);
  --pad-section: clamp(4rem, 9vw, 8rem);
  --radius: 2px;        /* esamber is near-square / very subtle rounding */
  --radius-lg: 6px;
  --shadow: 0 1px 2px rgba(38,38,38,.03), 0 6px 22px rgba(38,38,38,.05);
  --shadow-lg: 0 2px 6px rgba(38,38,38,.05), 0 18px 48px rgba(38,38,38,.09);
  --ease: cubic-bezier(.22,.61,.36,1);
}

/* ---------- Reset ---------- */
*,*::before,*::after { box-sizing: border-box; }
* { margin: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--sans);
  color: var(--text);
  background: var(--paper);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
img,svg { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
ul { list-style: none; padding: 0; }

/* ---------- Type ---------- */
h1,h2,h3,h4 {
  font-family: var(--display);
  line-height: 1.12; letter-spacing: -0.01em; font-weight: 600; color: var(--ink);
}
h1 { font-size: clamp(2.3rem, 5.2vw, 3.9rem); font-weight: 700; }
h2 { font-size: clamp(1.85rem, 3.4vw, 2.75rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); font-weight: 600; }
p  { color: var(--muted); }
.lead { font-size: clamp(1.02rem, 1.45vw, 1.2rem); color: var(--steel); line-height: 1.7; }

/* eyebrow = esamber's uppercase English label above a big title */
.eyebrow {
  font-family: var(--display);
  font-size: .82rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted-2);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: .6rem;
}
.eyebrow::before {
  content: "";
  width: 26px; height: 2px; background: var(--orange); display: inline-block;
}

/* ---------- Layout ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: clamp(1.1rem, 4vw, 2.5rem); }
section { padding-block: var(--pad-section); }
.section-tight { padding-block: clamp(3rem, 6vw, 5rem); }
.grid { display: grid; gap: var(--gap); }
.cols-2 { grid-template-columns: repeat(2, 1fr); }
.cols-3 { grid-template-columns: repeat(3, 1fr); }
.cols-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 960px){ .cols-3,.cols-4 { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 680px){ .cols-2,.cols-3,.cols-4 { grid-template-columns: 1fr; } }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .55rem;
  padding: .85rem 1.5rem;
  font-weight: 600; font-size: .94rem; letter-spacing: .01em;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: transform .25s var(--ease), background .2s var(--ease), border-color .2s, color .2s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--orange); color: #fff; }
.btn-primary:hover { background: var(--orange-dk); }
.btn-dark { background: var(--ink); color: var(--text-inv); }
.btn-dark:hover { background: #000; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-2); }
.btn-ghost:hover { border-color: var(--orange); color: var(--orange-dk); }
/* inverted ghost — for dark .band sections */
.btn-ghost-inv { background: transparent; color: var(--text-inv); border-color: rgba(255,255,255,.28); }
.btn-ghost-inv:hover { border-color: var(--orange); color: var(--orange); }
/* hero is light now, so its ghost-inv reads as a light-surface ghost */
.hero .btn-ghost-inv { color: var(--ink); border-color: var(--line-2); }
.hero .btn-ghost-inv:hover { border-color: var(--orange); color: var(--orange-dk); }
.btn .arr { transition: transform .25s var(--ease); }
.btn:hover .arr { transform: translateX(3px); }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 74px; }
.brand { display: flex; align-items: center; gap: .7rem; font-weight: 700; letter-spacing: .01em; color: var(--ink); }
.brand .mark {
  width: 36px; height: 36px; border-radius: var(--radius);
  background: var(--orange); color: #fff;
  display: grid; place-items: center;
  font-family: var(--display); font-weight: 700; font-size: 1.05rem;
  position: relative; overflow: hidden;
}
.brand .mark::after { content:""; position:absolute; inset:0; border-bottom: 3px solid var(--ink); }
.brand b { font-size: 1.12rem; font-family: var(--display); letter-spacing: .06em; }
.brand small { display:block; font-size:.58rem; letter-spacing:.16em; color: var(--muted-2); font-weight:600; text-transform: uppercase; margin-top: -1px; }
.nav-links { display: flex; align-items: center; gap: .25rem; }
.nav-links a {
  padding: .55rem .9rem; border-radius: var(--radius);
  font-size: .92rem; font-weight: 500; color: var(--steel);
  position: relative;
  transition: color .15s;
}
.nav-links a::after {
  content:""; position:absolute; left:.9rem; right:.9rem; bottom:.35rem; height:2px;
  background: var(--orange); transform: scaleX(0); transform-origin: left; transition: transform .2s var(--ease);
}
.nav-links a:hover, .nav-links a.active { color: var(--ink); }
.nav-links a:hover::after, .nav-links a.active::after { transform: scaleX(1); }
.nav-cta { display: flex; align-items: center; gap: .6rem; }
.nav-toggle { display: none; width: 42px; height: 42px; border: 1px solid var(--line-2); border-radius: var(--radius); background:#fff; }
.nav-toggle span { display:block; width:18px; height:2px; background: var(--ink); margin: 3px auto; transition: .25s; }
@media (max-width: 900px){
  .nav-links, .nav-cta .btn-ghost { display: none; }
  .nav-toggle { display: block; }
  .nav.open .nav-links {
    display: flex; flex-direction: column; align-items: stretch;
    position: absolute; left: 0; right: 0; top: 74px;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: .75rem clamp(1.1rem,4vw,2.5rem) 1.25rem; gap: .15rem;
    box-shadow: var(--shadow);
  }
  .nav.open .nav-links a { padding: .85rem .6rem; }
  .nav.open .nav-links a::after { display: none; }
}

/* ---------- Hero ---------- */
/* esamber's hero is bright: white/very-light with imagery & big type.
   We render a light hero with a faint technical grid + warm orange glow. */
.hero {
  position: relative;
  background: linear-gradient(180deg, #ffffff 0%, var(--paper-2) 100%);
  color: var(--ink);
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  padding-block: clamp(4.5rem, 10vw, 8rem) clamp(3.5rem, 7vw, 6rem);
}
/* technical blueprint grid background — subtle on light */
.hero::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(38,38,38,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(38,38,38,.035) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at 72% 28%, #000 0%, transparent 72%);
  pointer-events: none;
}
.hero::after {
  content:""; position:absolute; top:-18%; right:-8%; width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(232,111,0,.10), transparent 60%);
  pointer-events: none;
}
.hero .wrap { position: relative; z-index: 2; }
.hero h1 { color: var(--ink); max-width: 17ch; }
.hero h1 em { font-style: normal; color: var(--orange); }
.hero .lead { color: var(--steel); max-width: 56ch; margin-top: 1.4rem; }
.hero-cta { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 2.2rem; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 2.6rem; margin-top: 3.4rem; padding-top: 2rem; border-top: 1px solid var(--line-2); }
.hero-meta .stat .n { font-size: 2.1rem; font-weight: 700; color: var(--ink); font-family: var(--display); letter-spacing: -.01em; }
.hero-meta .stat .n::after { content:""; display:block; width:24px; height:3px; background:var(--orange); margin-top:.4rem; }
.hero-meta .stat .l { font-size: .8rem; color: var(--muted); letter-spacing: .03em; margin-top:.5rem; }

/* badge row */
.badge-row { display:flex; flex-wrap:wrap; gap:.5rem; margin-top: 1.6rem; }
.badge {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .06em;
  padding: .42rem .75rem; border: 1px solid var(--line-2); border-radius: 99px;
  color: var(--steel); background: #fff;
}

/* ---------- Section headers ---------- */
.sec-head { max-width: 62ch; margin-bottom: clamp(2rem, 4vw, 3.2rem); }
.sec-head h2 { margin-top: .8rem; }
.sec-head p { margin-top: .9rem; }
.sec-head.center { margin-inline: auto; text-align: center; }
.sec-head.center .eyebrow { justify-content: center; }

/* ---------- Cards ---------- */
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 1.8rem; transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s;
  position: relative; height: 100%; display: flex; flex-direction: column;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--line-2); }
.card .idx { font-family: var(--mono); font-size: .72rem; color: var(--muted-2); letter-spacing: .1em; }
.card h3 { margin: .6rem 0 .5rem; }
.card p { font-size: .94rem; }

/* value cards */
.value-card .ico {
  width: 48px; height: 48px; border-radius: var(--radius); display: grid; place-items: center;
  background: var(--orange-soft); color: var(--orange-dk); margin-bottom: 1.2rem;
}
.value-card .ico svg { width: 22px; height: 22px; }

/* product card */
.prod-card { padding: 0; overflow: hidden; }
.prod-card .thumb {
  aspect-ratio: 16/10; background: var(--paper-2);
  display: grid; place-items: center; border-bottom: 1px solid var(--line);
  position: relative; overflow: hidden;
}
.prod-card .thumb .device { width: 76%; }
.prod-card .tag {
  position: absolute; top: 14px; left: 14px;
  font-family: var(--mono); font-size: .66rem; letter-spacing: .08em;
  background: var(--orange); color: #fff; padding: .35rem .6rem; border-radius: var(--radius);
}
.prod-card .body { padding: 1.5rem 1.7rem 1.8rem; display: flex; flex-direction: column; flex: 1; }
.prod-card .cat { font-family: var(--display); font-size: .74rem; color: var(--orange-dk); letter-spacing: .12em; text-transform: uppercase; font-weight: 600; }
.prod-card h3 { margin: .55rem 0 .35rem; }
.prod-card .cn { color: var(--muted); font-size: .88rem; margin-bottom: .8rem; }
.prod-card p { font-size: .9rem; }
.prod-card .foot { margin-top: auto; padding-top: 1.2rem; display: flex; align-items: center; justify-content: space-between; }
.prod-card .price { font-family: var(--mono); font-size: .8rem; color: var(--steel); }
.prod-card .more { font-weight: 600; font-size: .9rem; color: var(--orange-dk); display: inline-flex; gap: .4rem; align-items: center; }
.prod-card .more .arr { transition: transform .25s var(--ease); }
.prod-card:hover .more .arr { transform: translateX(3px); }
.prod-card:hover .thumb .device { transform: scale(1.02); transition: transform .4s var(--ease); }

/* device illustration (pure CSS) — light bezel, orange/green signal LED */
.dev {
  width: 72%; aspect-ratio: 5/3; border-radius: var(--radius-lg); position: relative;
  background: linear-gradient(160deg, #fafafa, #ededed);
  border: 1px solid var(--line-2);
  box-shadow: 0 14px 30px rgba(38,38,38,.10), inset 0 1px 0 rgba(255,255,255,.7);
}
.dev::before { content:""; position:absolute; inset: 12% 10%; border-radius: var(--radius); background: #2a2a2a; box-shadow: inset 0 0 0 1px rgba(255,255,255,.04); }
.dev::after { content:""; position:absolute; left: 14%; bottom: 14%; width: 26%; height: 5px; border-radius: 4px; background: var(--orange); box-shadow: 0 0 12px rgba(232,111,0,.6); }
.dev.a::after { background: var(--orange); box-shadow: 0 0 12px rgba(232,111,0,.6); }
.dev.b::after { background: var(--green); box-shadow: 0 0 12px rgba(15,127,59,.6); }
.dev.c::after { background: var(--orange-dk); box-shadow: 0 0 12px rgba(201,95,0,.6); }
.dev.d::after { background: var(--green-dk); box-shadow: 0 0 12px rgba(11,102,48,.6); }

/* ---------- Spec table ---------- */
.spec-table { width: 100%; border-collapse: collapse; font-size: .94rem; }
.spec-table tr { border-bottom: 1px solid var(--line); }
.spec-table tr:last-child { border-bottom: none; }
.spec-table th {
  text-align: left; padding: .95rem 1rem .95rem 0; width: 38%;
  font-weight: 600; color: var(--ink); vertical-align: top;
  font-family: var(--mono); font-size: .8rem; letter-spacing: .02em;
}
.spec-table td { padding: .95rem 0; color: var(--steel); vertical-align: top; }

/* ---------- Feature list ---------- */
.flist li { display: flex; gap: .8rem; padding: .55rem 0; color: var(--steel); font-size: .96rem; }
.flist li svg { flex: none; width: 18px; height: 18px; color: var(--green); margin-top: .28rem; }

/* ---------- Strip / dark band ---------- */
.band { background: var(--ink); color: var(--text-inv); }
.band h2, .band h3 { color: #fff; }
.band p { color: rgba(245,245,245,.72); }
.band .eyebrow { color: rgba(245,245,245,.65); }
.band .eyebrow::before { background: var(--orange); }

/* ---------- Applications ---------- */
.app-row {
  display: grid; grid-template-columns: 220px 1fr; gap: 2rem;
  padding: 2.1rem 0; border-bottom: 1px solid var(--line); align-items: start;
}
@media (max-width: 760px){ .app-row { grid-template-columns: 1fr; gap: .8rem; } }
.app-row .who { font-family: var(--display); font-size: .78rem; color: var(--orange-dk); letter-spacing: .1em; text-transform: uppercase; font-weight: 600; }
.app-row h3 { margin-top: .4rem; }
.app-tags { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: 1rem; }
.app-tags a { font-size: .8rem; padding: .35rem .75rem; border: 1px solid var(--line-2); border-radius: 99px; color: var(--steel); transition: .2s; }
.app-tags a:hover { border-color: var(--orange); color: var(--orange-dk); }

/* ---------- Guides ---------- */
.guide-card .kicker { font-family: var(--display); font-size: .74rem; letter-spacing: .12em; color: var(--muted-2); text-transform: uppercase; font-weight: 600; }
.dl-row { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 1.15rem 1.35rem; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; transition: .2s; }
.dl-row:hover { border-color: var(--orange); box-shadow: var(--shadow); }
.dl-row .meta { display: flex; align-items: center; gap: .9rem; }
.dl-row .ext { font-family: var(--mono); font-size: .68rem; background: var(--ink); color:#fff; padding: .3rem .5rem; border-radius: var(--radius); }
.dl-row .dl { color: var(--orange-dk); font-weight: 600; font-size: .9rem; }

/* ---------- Forms ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.1rem; }
@media (max-width: 640px){ .form-grid { grid-template-columns: 1fr; } }
.field { display: flex; flex-direction: column; gap: .4rem; }
.field.full { grid-column: 1 / -1; }
.field label { font-size: .82rem; font-weight: 600; color: var(--ink); }
.field label .req { color: var(--orange); }
.field input, .field select, .field textarea {
  font: inherit; font-size: .95rem; padding: .82rem .95rem;
  border: 1px solid var(--line-2); border-radius: var(--radius); background: #fff; color: var(--text);
  transition: border-color .15s, box-shadow .15s;
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--orange); box-shadow: 0 0 0 3px var(--orange-soft);
}
.field textarea { resize: vertical; min-height: 130px; }
.form-note { font-size: .82rem; color: var(--muted-2); margin-top: .3rem; }
.form-ok { display:none; padding: 1rem 1.2rem; background: var(--green-soft); border:1px solid var(--green); border-radius: var(--radius); color: var(--green-dk); font-weight:600; font-size:.92rem; }
.form-ok.show { display: block; }

/* contact info cards */
.info-card { padding: 1.6rem; border:1px solid var(--line); border-radius: var(--radius-lg); background: var(--paper-2); }
.info-card .k { font-family: var(--display); font-size: .74rem; letter-spacing: .12em; text-transform: uppercase; color: var(--muted-2); font-weight: 600; }
.info-card .v { margin-top: .5rem; font-weight: 600; color: var(--ink); font-size: 1.05rem; }
.info-card .v.todo { color: var(--orange-dk); }

/* ---------- CTA band ---------- */
.cta-band { text-align: center; }
.cta-band .btns { display: flex; gap: .8rem; justify-content: center; flex-wrap: wrap; margin-top: 2rem; }

/* ---------- Footer ---------- */
.site-footer { background: var(--ink-2); color: rgba(245,245,245,.7); padding-block: 4rem 2rem; }
.site-footer h4 { color: #fff; font-size: .8rem; letter-spacing: .12em; text-transform: uppercase; font-family: var(--display); font-weight: 600; margin-bottom: 1rem; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 2.5rem; }
@media (max-width: 820px){ .footer-grid { grid-template-columns: 1fr 1fr; gap: 2rem; } }
@media (max-width: 480px){ .footer-grid { grid-template-columns: 1fr; } }
.site-footer a { color: rgba(245,245,245,.6); font-size: .92rem; transition: color .15s; }
.site-footer a:hover { color: var(--orange); }
.site-footer .fbrand b { color: #fff; font-size: 1.25rem; font-family: var(--display); letter-spacing: .06em; }
.site-footer .fbrand p { font-size: .9rem; margin-top: .8rem; max-width: 38ch; }
.footer-links li { padding: .3rem 0; }
.footer-bottom {
  margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid rgba(255,255,255,.1);
  display: flex; flex-wrap: wrap; gap: 1rem; justify-content: space-between; align-items: center;
  font-size: .82rem; color: rgba(245,245,245,.45);
}
.footer-bottom .ext { color: var(--orange); font-weight: 600; }

/* ---------- Breadcrumb ---------- */
.crumb { font-family: var(--mono); font-size: .76rem; color: var(--muted-2); letter-spacing: .04em; padding-top: 2rem; }
.crumb a:hover { color: var(--ink); }
.crumb span { color: var(--ink); }

/* ---------- Page hero (sub pages) ---------- */
.page-hero {
  background: linear-gradient(180deg, #ffffff 0%, var(--paper-2) 100%);
  color: var(--ink);
  border-bottom: 1px solid var(--line);
  padding-block: clamp(3.5rem, 7vw, 6rem) clamp(3rem, 6vw, 5rem); position: relative; overflow: hidden;
}
.page-hero::before { content:""; position:absolute; inset:0;
  background-image: linear-gradient(rgba(38,38,38,.03) 1px, transparent 1px), linear-gradient(90deg, rgba(38,38,38,.03) 1px, transparent 1px);
  background-size: 56px 56px; mask-image: radial-gradient(circle at 82% 18%, #000, transparent 68%); }
.page-hero .wrap { position: relative; z-index: 2; }
.page-hero h1 { color: var(--ink); }
.page-hero .lead { color: var(--steel); margin-top: 1rem; max-width: 60ch; }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce){ .reveal { opacity:1; transform:none; transition:none; } html{scroll-behavior:auto;} }

/* ---------- Utility ---------- */
.mt-1{margin-top:.5rem}.mt-2{margin-top:1rem}.mt-3{margin-top:1.5rem}.mt-4{margin-top:2.5rem}
.text-center{text-align:center}
.divider { height:1px; background: var(--line); border:0; }
.pill-note { display:inline-block; font-family:var(--mono); font-size:.72rem; letter-spacing:.06em; color:var(--orange-dk); background: var(--orange-soft); padding:.35rem .7rem; border-radius:99px; }

/* section alternation — esamber alternates white / #f7f7f7 bands.
   Apply .tinted to a content section for the light-grey ESAMBER band. */
.tinted { background: var(--paper-2); }