/* BEYONDOPTO site stylesheet
   Palette: charcoal / paper / one teal accent. No gradients-heavy styling. */

:root{
  --ink:#0f1216;
  --ink-2:#1b2229;
  --ink-3:#2c353f;
  --paper:#ffffff;
  --mist:#f5f6f7;
  --mist-2:#eceef0;
  --line:#dfe3e7;
  --muted:#5d6672;
  --accent:#0e8c92;
  --accent-dark:#0a6d72;
  --focus:#b45309;
  --radius:2px;
  --wrap:1180px;
  --font:"Inter","Helvetica Neue",Arial,"PingFang SC","Microsoft YaHei",sans-serif;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--paper);color:var(--ink);
  font-family:var(--font);font-size:16px;line-height:1.65;
  font-feature-settings:"kern" 1,"liga" 1;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;height:auto;display:block}
a{color:var(--ink);text-decoration:none}
a:hover{color:var(--accent-dark)}
h1,h2,h3,h4{margin:0;font-weight:600;letter-spacing:-.015em;line-height:1.2}
h1{font-size:clamp(1.9rem,3.2vw,2.9rem)}
h2{font-size:clamp(1.4rem,2.2vw,1.95rem)}
h3{font-size:1.12rem}
p{margin:0 0 1em}
ul,ol{margin:0 0 1em;padding-left:1.1em}
li{margin:.35em 0}
small{font-size:.82rem}

.wrap{max-width:var(--wrap);margin:0 auto;padding:0 28px}
.section{padding:64px 0}
.section--tight{padding:40px 0}
.section--mist{background:var(--mist);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.section--ink{background:var(--ink);color:#e9ecef}
.section--ink h2,.section--ink h3{color:#fff}
.section--ink a{color:#cfd6dd}

.eyebrow{
  font-size:.72rem;letter-spacing:.14em;text-transform:uppercase;
  color:var(--accent);font-weight:600;margin:0 0 14px;
}
.section--ink .eyebrow{color:#6fd0d3}
.lede{font-size:1.08rem;color:var(--muted);max-width:62ch}
.section--ink .lede{color:#b9c1c9}

/* ---------- header ---------- */
.topbar{background:var(--ink);color:#fff;font-size:.78rem;letter-spacing:.02em}
.topbar .wrap{display:flex;justify-content:space-between;align-items:center;height:34px;gap:16px}
.topbar a{color:#c9d1d9}
.topbar .tb-right{display:flex;gap:18px;align-items:center}

.site-header{position:sticky;top:0;z-index:40;background:rgba(255,255,255,.96);backdrop-filter:saturate(1.2) blur(8px);border-bottom:1px solid var(--line)}
.site-header .wrap{display:flex;align-items:center;gap:26px;height:70px}
.brand{display:flex;flex-direction:column;line-height:1.1;flex:0 0 auto}
.brand .mark{font-weight:700;font-size:1.18rem;letter-spacing:.06em}
.brand .mark span{color:var(--accent)}
.brand .sub{font-size:.6rem;letter-spacing:.16em;text-transform:uppercase;color:var(--muted);margin-top:3px}

.nav{display:flex;gap:4px;margin-left:auto;align-items:center}
.nav a{padding:9px 12px;font-size:.9rem;font-weight:500;color:var(--ink-3);border-radius:var(--radius)}
.nav a:hover,.nav a[aria-current="page"]{background:var(--mist);color:var(--ink)}
.nav .btn{margin-left:10px}

.nav-toggle{display:none;border:1px solid var(--line);background:#fff;padding:8px 10px;font-size:.85rem;border-radius:var(--radius);cursor:pointer}

.btn{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--accent);color:#fff!important;border:1px solid var(--accent);
  padding:11px 20px;font-size:.9rem;font-weight:600;border-radius:var(--radius);
  letter-spacing:.01em;transition:background .15s ease;
}
.btn:hover{background:var(--accent-dark);border-color:var(--accent-dark)}
.btn--ghost{background:transparent;color:var(--ink)!important;border-color:var(--ink-3)}
.btn--ghost:hover{background:var(--ink);color:#fff!important}
.btn--light{background:#fff;color:var(--ink)!important;border-color:#fff}
.btn--light:hover{background:var(--mist-2)}

/* ---------- hero ---------- */
.hero{background:var(--ink);color:#fff;position:relative;overflow:hidden}
.hero::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(1100px 420px at 78% -10%,rgba(14,140,146,.28),transparent 62%);
}
.hero .wrap{position:relative;z-index:1;padding-top:76px;padding-bottom:76px;display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:center}
.hero h1{color:#fff;max-width:20ch}
.hero .lede{color:#c3ccd4;margin-top:18px}
.hero .eyebrow{color:#6fd0d3}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:26px}
.hero-media img{border:1px solid rgba(255,255,255,.14);border-radius:var(--radius);background:#fff}
.hero-stats{display:flex;gap:34px;margin-top:38px;flex-wrap:wrap}
.hero-stats div{font-size:.8rem;color:#98a4af;letter-spacing:.02em}
.hero-stats strong{display:block;color:#fff;font-size:1.05rem;font-weight:600;margin-bottom:2px}

/* ---------- grids & cards ---------- */
.grid{display:grid;gap:22px}
.g2{grid-template-columns:repeat(2,1fr)}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}

.card{
  border:1px solid var(--line);background:#fff;border-radius:var(--radius);
  padding:0;display:flex;flex-direction:column;transition:border-color .15s ease,box-shadow .15s ease;
}
.card:hover{border-color:var(--ink-3);box-shadow:0 8px 24px rgba(15,18,22,.06)}
.card .thumb{aspect-ratio:4/3;flex:0 0 auto;background:var(--mist);display:flex;align-items:center;justify-content:center;overflow:hidden;border-bottom:1px solid var(--line)}
.card .thumb img{width:100%;height:100%;object-fit:contain}
.card .thumb--typo{padding:22px;background:#eceef0;position:relative}
.card .thumb--typo::before{content:"";position:absolute;top:0;left:0;width:34px;height:3px;background:var(--accent)}
.card .thumb--typo span{font-size:1.05rem;line-height:1.35;letter-spacing:.16em;text-transform:uppercase;color:#7d858f;font-weight:600;text-align:center}
.card .body{padding:18px 20px 22px;display:flex;flex-direction:column;flex:1}
.card h3{font-size:1rem;margin-bottom:6px}
.card p{font-size:.9rem;color:var(--muted);margin:0 0 12px}
.card .more{font-size:.82rem;font-weight:600;color:var(--accent);letter-spacing:.02em}

/* product list rows */
.plist{border-top:1px solid var(--line)}
.plist a{display:grid;grid-template-columns:180px 1fr auto;gap:20px;align-items:center;padding:18px 4px;border-bottom:1px solid var(--line);color:var(--ink)}
.plist a:hover{background:var(--mist)}
.plist .kind{font-size:.74rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.plist .name{font-weight:600}
.plist .desc{font-size:.88rem;color:var(--muted)}
.plist .arrow{color:var(--muted)}

/* ---------- product page ---------- */
.breadcrumb{font-size:.78rem;color:var(--muted);padding:16px 0;border-bottom:1px solid var(--line)}
.breadcrumb a{color:var(--muted)}
.breadcrumb span{color:var(--ink);font-weight:500}

.product-head{display:grid;grid-template-columns:1fr 420px;gap:48px;align-items:start;padding:44px 0 8px}
.product-head h1{margin-bottom:14px}
.product-head .lede{font-size:1rem}
.tagrow{display:flex;gap:8px;flex-wrap:wrap;margin:20px 0 0}
.tag{font-size:.74rem;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3);border:1px solid var(--line);padding:5px 9px;border-radius:var(--radius);background:var(--mist)}
.product-figure{border:1px solid var(--line);background:var(--mist);padding:18px}
.product-figure img{margin:0 auto}
.product-figure figcaption{font-size:.78rem;color:var(--muted);margin-top:10px;text-align:center}

.spec-table{width:100%;border-collapse:collapse;font-size:.9rem;margin:8px 0 0;border:1px solid var(--line)}
.spec-table th,.spec-table td{padding:11px 14px;border-bottom:1px solid var(--line);vertical-align:top;text-align:left}
.spec-table th{width:34%;background:var(--mist);font-weight:600;color:var(--ink-3)}
.spec-table tr:last-child td,.spec-table tr:last-child th{border-bottom:0}

.feature-list{list-style:none;padding:0;display:grid;gap:14px;grid-template-columns:repeat(2,1fr)}
.feature-list li{display:flex;gap:12px;align-items:flex-start;font-size:.94rem;margin:0}
.feature-list .tick{flex:0 0 18px;height:18px;margin-top:4px;border-radius:50%;background:rgba(14,140,146,.1);color:var(--accent);display:flex;align-items:center;justify-content:center;font-size:.7rem;font-weight:700}

.steps{counter-reset:s;display:grid;gap:18px;grid-template-columns:repeat(3,1fr)}
.steps>div{counter-increment:s;border-top:2px solid var(--ink);padding-top:14px;font-size:.92rem;color:var(--muted)}
.steps>div::before{content:"0" counter(s);display:block;font-size:.78rem;letter-spacing:.12em;color:var(--accent);font-weight:700;margin-bottom:6px}
.steps strong{color:var(--ink);display:block;font-size:.98rem;margin-bottom:4px}

/* faq */
.faq{border-top:1px solid var(--line)}
.faq details{border-bottom:1px solid var(--line);padding:16px 0}
.faq summary{cursor:pointer;font-weight:600;list-style:none;display:flex;justify-content:space-between;gap:16px;align-items:baseline}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--accent);font-weight:600}
.faq details[open] summary::after{content:"–"}
.faq .answer{color:var(--muted);font-size:.94rem;margin-top:10px;max-width:78ch}

/* cta band */
.cta-band{background:var(--ink);color:#fff;padding:52px 0}
.cta-band .wrap{display:flex;justify-content:space-between;align-items:center;gap:32px;flex-wrap:wrap}
.cta-band h2{color:#fff;max-width:26ch}
.cta-band p{color:#a9b3bc;margin:8px 0 0;max-width:52ch}

/* contact */
.contact-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:48px}
.contact-block{border-left:2px solid var(--accent);padding-left:16px;margin-bottom:26px}
.contact-block .k{font-size:.74rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.contact-block .v{font-weight:600;margin-top:2px}
.form-field{margin-bottom:16px}
.form-field label{display:block;font-size:.82rem;font-weight:600;margin-bottom:6px}
.form-field input,.form-field textarea,.form-field select{
  width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:var(--radius);
  font-family:inherit;font-size:.94rem;background:#fff;color:var(--ink);
}
.form-field input:focus,.form-field textarea:focus,.form-field select:focus{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}
.form-note{font-size:.82rem;color:var(--muted)}

/* about */
.split{display:grid;grid-template-columns:1fr 1fr;gap:52px;align-items:start}
.stat-strip{display:grid;grid-template-columns:repeat(4,1fr);border:1px solid var(--line);border-radius:var(--radius)}
.stat-strip div{padding:22px;border-right:1px solid var(--line)}
.stat-strip div:last-child{border-right:0}
.stat-strip .n{font-size:1.5rem;font-weight:600;line-height:1.1}
.stat-strip .l{font-size:.78rem;color:var(--muted);letter-spacing:.06em;text-transform:uppercase;margin-top:6px}

/* footer */
.site-footer{background:var(--ink);color:#a9b3bc;padding:56px 0 28px;font-size:.88rem}
.site-footer .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:36px;padding-bottom:36px;border-bottom:1px solid rgba(255,255,255,.1)}
.site-footer h4{color:#fff;font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;margin-bottom:14px}
.site-footer a{color:#a9b3bc;display:block;padding:3px 0}
.site-footer a:hover{color:#fff}
.site-footer .brand .mark{color:#fff}
.site-footer .brand .sub{color:#77828c}
.site-footer .bottom{display:flex;justify-content:space-between;gap:20px;padding-top:20px;font-size:.8rem;color:#77828c;flex-wrap:wrap}

/* utility */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.note{font-size:.84rem;color:var(--muted);border-left:2px solid var(--line);padding-left:12px;margin:20px 0}
.kv{display:grid;grid-template-columns:150px 1fr;gap:8px 16px;font-size:.92rem}
.kv .k{color:var(--muted)}
.mt0{margin-top:0}.mt24{margin-top:24px}.mt40{margin-top:40px}
.center{text-align:center}

@media (max-width:980px){
  .hero .wrap,.product-head,.contact-grid,.split{grid-template-columns:1fr}
  .hero-media{order:-1}
  .g4{grid-template-columns:repeat(2,1fr)}
  .g3{grid-template-columns:repeat(2,1fr)}
  .site-footer .cols{grid-template-columns:1fr 1fr}
  .stat-strip{grid-template-columns:1fr 1fr}
  .stat-strip div:nth-child(2){border-right:0}
}
@media (max-width:720px){
  .wrap{padding:0 18px}
  .nav{display:none}
  .nav.open{display:flex;position:absolute;top:70px;left:0;right:0;background:#fff;flex-direction:column;align-items:stretch;padding:12px 18px;border-bottom:1px solid var(--line);gap:2px}
  .nav-toggle{display:inline-block;margin-left:auto}
  .topbar .tb-right{display:none}
  .g2,.g3,.g4{grid-template-columns:1fr}
  .feature-list,.steps{grid-template-columns:1fr}
  .plist a{grid-template-columns:1fr;gap:6px}
  .section{padding:44px 0}
  .hero .wrap{padding-top:44px;padding-bottom:44px}
}