:root{
    --charcoal:#15181A;
    --charcoal-2:#1C2123;
    --panel:#222826;
    --line:#363D3A;
    --site-green:#7CB518;
    --site-green-bright:#93D125;
    --green-deep:#2F6B3A;
    --concrete:#CFCCC2;
    --concrete-dim:#9A9890;
    --cream:#F4F2EC;
    --cream-2:#EAE7DD;
    --ink:#171A18;
    --max:1180px;
    --r:4px;
    --logo:url('nw-tanks-logo.png');
  }

  *{box-sizing:border-box;margin:0;padding:0}
  html{scroll-behavior:smooth}
  body{
    font-family:'IBM Plex Sans',system-ui,sans-serif;
    background:var(--charcoal);
    color:var(--concrete);
    line-height:1.6;
    -webkit-font-smoothing:antialiased;
    overflow-x:hidden;
  }
  h1,h2,h3{font-family:'Archivo',sans-serif;line-height:1.04;letter-spacing:-0.01em;color:#fff}
  a{color:inherit;text-decoration:none}
  .wrap{max-width:var(--max);margin:0 auto;padding:0 24px}

  /* mono utility label — the engineering vernacular */
  .label{
    font-family:'IBM Plex Mono',monospace;
    font-size:.7rem;
    letter-spacing:.18em;
    text-transform:uppercase;
    color:var(--site-green);
    display:inline-flex;
    align-items:center;
    gap:.55rem;
  }
  .label::before{
    content:"";
    width:22px;height:1px;background:var(--site-green);display:inline-block;
  }

  /* ---------- header ---------- */
  header{
    position:sticky;top:0;z-index:60;
    background:rgba(21,24,26,.86);
    backdrop-filter:blur(10px);
    border-bottom:1px solid var(--line);
  }
  .nav{display:flex;align-items:center;justify-content:space-between;height:90px}
  .brand{display:flex;flex-direction:column;line-height:1}
  .brand .b1{font-family:'Archivo';font-weight:900;font-size:1.18rem;color:#fff;letter-spacing:.01em}
  .brand .b1 span{color:var(--site-green)}
  .brand .b2{font-family:'IBM Plex Mono';font-size:.6rem;letter-spacing:.26em;color:var(--concrete-dim);text-transform:uppercase;margin-top:3px}
  .navlinks{display:flex;gap:30px;align-items:center}
  .navlinks a{font-size:.92rem;color:var(--concrete);transition:color .2s}
  .navlinks a:hover{color:var(--site-green)}
  .callbtn{
    display:inline-flex;align-items:center;gap:9px;
    background:var(--site-green);color:var(--ink)!important;
    font-family:'Archivo';font-weight:700;font-size:.95rem;
    padding:11px 18px;border-radius:var(--r);transition:transform .15s,background .2s;
  }
  .callbtn:hover{background:var(--site-green-bright);transform:translateY(-1px)}
  .burger{display:none;background:none;border:1px solid var(--line);border-radius:var(--r);padding:9px 11px;cursor:pointer}
  .burger span{display:block;width:20px;height:2px;background:var(--concrete);margin:4px 0}

  /* ---------- hero ---------- */
  .hero{position:relative;padding:78px 0 70px;border-bottom:1px solid var(--line);overflow:hidden}
  .hero-grid{display:grid;grid-template-columns:1.05fr 1fr;gap:54px;align-items:center}
  .hero h1{font-size:clamp(2.4rem,5vw,4.05rem);font-weight:800;margin:22px 0 0}
  .hero h1 em{font-style:normal;color:var(--site-green)}
  .hero .sub{font-size:1.12rem;color:var(--concrete);max-width:33ch;margin-top:20px}
  .hero-cta{display:flex;flex-wrap:wrap;gap:14px;margin-top:32px}
  .btn-primary{
    display:inline-flex;align-items:center;gap:10px;
    background:var(--site-green);color:var(--ink);
    font-family:'Archivo';font-weight:700;font-size:1.02rem;
    padding:15px 26px;border-radius:var(--r);transition:transform .15s,background .2s;border:none;cursor:pointer;
  }
  .btn-primary:hover{background:var(--site-green-bright);transform:translateY(-2px)}
  .btn-ghost{
    display:inline-flex;align-items:center;gap:10px;
    border:1px solid var(--line);color:#fff;
    font-family:'Archivo';font-weight:600;font-size:1.02rem;
    padding:15px 26px;border-radius:var(--r);transition:border-color .2s,color .2s;
  }
  .btn-ghost:hover{border-color:var(--site-green);color:var(--site-green)}

  .trust-strip{display:flex;flex-wrap:wrap;gap:10px 26px;margin-top:38px;padding-top:26px;border-top:1px solid var(--line)}
  .trust-strip div{font-family:'IBM Plex Mono';font-size:.72rem;letter-spacing:.08em;color:var(--concrete-dim);display:flex;align-items:center;gap:8px}
  .trust-strip svg{flex-shrink:0}

  /* cross-section signature */
  .section-svg{width:100%;height:auto;display:block}
  .draw{stroke-dasharray:1;stroke-dashoffset:0}

  /* ---------- generic section ---------- */
  .band{padding:84px 0}
  .band-light{background:var(--cream);color:var(--ink)}
  .band-light h2,.band-light h3{color:var(--ink)}
  .band-light .label{color:var(--green-deep)}
  .band-light .label::before{background:var(--green-deep)}
  .sec-head{max-width:60ch;margin-bottom:46px}
  .sec-head h2{font-size:clamp(1.9rem,3.6vw,2.9rem);font-weight:800;margin-top:16px}
  .sec-head p{margin-top:16px;font-size:1.06rem;color:var(--concrete-dim)}
  .band-light .sec-head p{color:#5c5f58}

  /* ---------- services ---------- */
  .svc-lead{
    border:1px solid var(--line);border-radius:var(--r);
    background:linear-gradient(160deg,var(--charcoal-2),var(--panel));
    padding:34px;margin-bottom:18px;position:relative;overflow:hidden;
  }
  .svc-lead::after{content:"";position:absolute;right:-40px;top:-40px;width:160px;height:160px;border:1px solid var(--site-green);opacity:.12;border-radius:50%}
  .svc-lead .tag{font-family:'IBM Plex Mono';font-size:.66rem;letter-spacing:.2em;color:var(--site-green);text-transform:uppercase}
  .svc-lead h3{font-size:1.7rem;font-weight:800;margin:12px 0 10px}
  .svc-lead p{color:var(--concrete);max-width:62ch}
  .svc-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
  .svc{border:1px solid var(--line);border-radius:var(--r);padding:26px;background:var(--charcoal-2);transition:transform .18s,border-color .18s}
  .svc:hover{transform:translateY(-4px);border-color:var(--site-green)}
  .svc .ico{width:40px;height:40px;color:var(--site-green);margin-bottom:16px}
  .svc h3{font-size:1.18rem;font-weight:700;margin-bottom:8px}
  .svc p{font-size:.95rem;color:var(--concrete-dim)}

  /* ---------- why / rules ---------- */
  .why-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:30px}
  .why .n{font-family:'IBM Plex Mono';font-size:.78rem;color:var(--green-deep);letter-spacing:.1em}
  .why h3{font-size:1.32rem;font-weight:700;margin:12px 0 8px}
  .why p{color:#5c5f58;font-size:1rem}
  .rules{
    margin-top:54px;border:1px solid var(--cream-2);background:#fff;border-radius:var(--r);
    padding:38px;display:grid;grid-template-columns:auto 1fr auto;gap:30px;align-items:center;
  }
  .rules .badge{font-family:'IBM Plex Mono';font-size:.72rem;letter-spacing:.16em;color:var(--green-deep);border:1px solid var(--green-deep);border-radius:var(--r);padding:8px 12px;white-space:nowrap;text-transform:uppercase}
  .rules h3{font-size:1.4rem;font-weight:800;margin-bottom:8px;color:var(--ink)}
  .rules p{color:#5c5f58;max-width:64ch}

  /* ---------- areas ---------- */
  .areas-grid{display:grid;grid-template-columns:1.1fr 1fr;gap:48px;align-items:start}
  .area-block{margin-bottom:30px}
  .area-block h3{font-size:1.05rem;font-weight:700;color:#fff;margin-bottom:12px;display:flex;align-items:center;gap:10px}
  .area-block h3 .dot{width:8px;height:8px;background:var(--site-green);border-radius:50%}
  .pills{display:flex;flex-wrap:wrap;gap:9px}
  .pill{font-family:'IBM Plex Mono';font-size:.78rem;border:1px solid var(--line);border-radius:30px;padding:7px 15px;color:var(--concrete);transition:border-color .2s,color .2s}
  .pill:hover{border-color:var(--site-green);color:var(--site-green)}
  .area-note{border-left:2px solid var(--site-green);padding:6px 0 6px 20px;color:var(--concrete-dim);font-size:.96rem;margin-top:4px}

  /* ---------- quote / contact ---------- */
  .contact-grid{display:grid;grid-template-columns:1fr 1.1fr;gap:54px;align-items:start}
  .contact-left h2{font-size:clamp(1.9rem,3.6vw,2.8rem);font-weight:800;margin:16px 0}
  .contact-left p{color:var(--concrete);font-size:1.06rem;max-width:42ch}
  .bigcall{display:inline-flex;align-items:center;gap:14px;margin-top:30px;font-family:'Archivo';font-weight:900;font-size:1.9rem;color:#fff}
  .band-light .bigcall{color:var(--ink)}
  .band-light .contact-left p{color:#4d5049}
  .bigcall:hover{color:var(--site-green)}
  .bigcall .pre{display:block;font-family:'IBM Plex Mono';font-size:.7rem;letter-spacing:.2em;color:var(--site-green);font-weight:500;margin-bottom:4px}
  .form{background:var(--charcoal-2);border:1px solid var(--line);border-radius:var(--r);padding:32px}
  .field{margin-bottom:18px}
  .field label{display:block;font-family:'IBM Plex Mono';font-size:.68rem;letter-spacing:.14em;text-transform:uppercase;color:var(--concrete-dim);margin-bottom:7px}
  .field input,.field select,.field textarea{
    width:100%;background:var(--charcoal);border:1px solid var(--line);border-radius:var(--r);
    padding:13px 14px;color:#fff;font-family:'IBM Plex Sans';font-size:.98rem;transition:border-color .2s;
  }
  .field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--site-green)}
  .field textarea{resize:vertical;min-height:96px}
  .row2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
  .form .btn-primary{width:100%;justify-content:center;margin-top:6px}
  .form-note{font-size:.8rem;color:var(--concrete-dim);margin-top:14px;text-align:center}
  .form-success{display:none;text-align:center;padding:20px 0}
  .form-success.show{display:block}
  .form-success h3{color:var(--site-green);font-size:1.3rem;margin-bottom:10px}

  /* ---------- footer ---------- */
  footer{background:var(--charcoal);border-top:1px solid var(--line);padding:54px 0 30px}
  .foot-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:40px;margin-bottom:40px}
  .foot-grid h4{font-family:'IBM Plex Mono';font-size:.7rem;letter-spacing:.16em;text-transform:uppercase;color:var(--site-green);margin-bottom:16px}
  .foot-grid p,.foot-grid a{display:block;color:var(--concrete-dim);font-size:.92rem;margin-bottom:9px}
  .foot-grid a:hover{color:var(--site-green)}
  .foot-bottom{border-top:1px solid var(--line);padding-top:22px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;font-family:'IBM Plex Mono';font-size:.72rem;color:var(--concrete-dim)}

  /* ---------- reveal ---------- */
  .reveal{opacity:0;transform:translateY(22px);transition:opacity .7s ease,transform .7s ease}
  .reveal.in{opacity:1;transform:none}

  /* ---------- responsive ---------- */
  @media(max-width:900px){
    .hero-grid,.areas-grid,.contact-grid{grid-template-columns:1fr;gap:40px}
    .svc-grid,.why-grid{grid-template-columns:1fr 1fr}
    .foot-grid{grid-template-columns:1fr 1fr}
    .rules{grid-template-columns:1fr;text-align:left;gap:18px}
    .hero .sub{max-width:none}
  }
  @media(max-width:640px){
    .navlinks{
      display:none;position:absolute;top:74px;left:0;right:0;
      flex-direction:column;gap:0;background:var(--charcoal-2);border-bottom:1px solid var(--line);padding:8px 0;
    }
    .navlinks.open{display:flex}
    .navlinks a{padding:14px 24px;width:100%;border-top:1px solid var(--line)}
    .navlinks .callbtn{margin:12px 24px;justify-content:center}
    .burger{display:block}
    .nav{height:74px}
    .logo-mark{width:58px;height:58px}
    .svc-grid,.why-grid,.foot-grid{grid-template-columns:1fr}
    .row2{grid-template-columns:1fr}
    .band{padding:60px 0}
    .trust-strip{gap:10px 18px}
  }
  @media(prefers-reduced-motion:reduce){
    *{scroll-behavior:auto!important}
    .reveal{transition:none;opacity:1;transform:none}
  }
  .logo-mark{display:block;width:72px;height:72px;background:var(--logo) center/contain no-repeat}
  .logo-mark-foot{width:74px;height:74px;margin-bottom:4px}
  .social-ico{display:inline-flex;align-items:center;justify-content:center;color:var(--concrete);transition:color .2s,transform .15s}
  .social-ico:hover{color:var(--site-green);transform:translateY(-1px)}
  .foot-social{display:inline-flex;align-items:center;gap:10px;margin-top:18px;color:var(--concrete-dim);font-size:.9rem;transition:color .2s}
  .foot-social svg{flex-shrink:0}
  .foot-social:hover{color:var(--site-green)}

/* ---------- accreditations strip ---------- */
.acc-strip{display:flex;flex-wrap:wrap;justify-content:center;gap:14px 40px;padding:30px 0;border-bottom:1px solid var(--line)}
.acc-strip .acc{display:flex;align-items:center;gap:11px;font-family:'IBM Plex Mono';font-size:.78rem;letter-spacing:.06em;color:var(--concrete);text-transform:uppercase}
.acc-strip .acc svg{color:var(--site-green);flex-shrink:0}

/* ---------- gallery ---------- */
.gallery-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.gallery-item{aspect-ratio:4/3;border:1px solid var(--line);border-radius:var(--r);background:var(--charcoal-2);display:flex;align-items:center;justify-content:center;text-align:center;color:var(--concrete-dim);overflow:hidden;position:relative}
.gallery-item img{width:100%;height:100%;object-fit:cover}
.gallery-item .ph{font-family:'IBM Plex Mono';font-size:.72rem;letter-spacing:.1em;padding:18px}
.gallery-item .ph svg{display:block;margin:0 auto 10px;color:var(--line)}

/* ---------- reviews ---------- */
.rev-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.review-card{border:1px solid var(--line);border-radius:var(--r);padding:26px;background:var(--charcoal-2)}
.review-card .stars{color:var(--site-green);font-size:1rem;letter-spacing:3px;margin-bottom:12px}
.review-card p{color:var(--concrete);font-size:.96rem;font-style:italic}
.review-card .who{margin-top:14px;font-family:'IBM Plex Mono';font-size:.74rem;letter-spacing:.06em;color:var(--concrete-dim)}
.review-cta{margin-top:30px;text-align:center}

/* ---------- FAQ (native details) ---------- */
.faq-list{max-width:820px;margin:0 auto}
.faq-item{border-bottom:1px solid var(--line)}
.band-light .faq-item{border-bottom:1px solid var(--line)}
.faq-item summary{cursor:pointer;list-style:none;padding:22px 0;font-family:'Archivo';font-weight:700;font-size:1.08rem;color:#fff;display:flex;justify-content:space-between;align-items:center;gap:20px}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:"+";font-family:'IBM Plex Mono';font-size:1.5rem;color:var(--green-deep);transition:transform .2s;line-height:1}
.faq-item[open] summary::after{content:"\2212"}
.faq-item .faq-a{padding:0 0 24px;color:var(--concrete);font-size:1rem;max-width:72ch}
.faq-item .faq-a a{color:var(--site-green);text-decoration:underline}
/* FAQ on light bands */
.band-light .faq-item{border-bottom:1px solid var(--cream-2)}
.band-light .faq-item summary{color:var(--ink)}
.band-light .faq-item summary::after{color:var(--green-deep)}
.band-light .faq-item .faq-a{color:#4d5049}
.band-light .faq-item .faq-a a{color:var(--green-deep)}

/* ---------- sub-page hero + breadcrumb + prose ---------- */
.subhero{padding:54px 0 46px;border-bottom:1px solid var(--line);position:relative}
.breadcrumb{font-family:'IBM Plex Mono';font-size:.72rem;letter-spacing:.08em;color:var(--concrete-dim);margin-bottom:18px;text-transform:uppercase}
.breadcrumb a{color:var(--concrete-dim)}
.breadcrumb a:hover{color:var(--site-green)}
.subhero h1{font-size:clamp(2rem,4.2vw,3.1rem);font-weight:800;max-width:18ch}
.subhero .lead{margin-top:18px;font-size:1.12rem;color:var(--concrete);max-width:60ch}
.subhero .hero-cta{margin-top:28px}
.prose{max-width:760px}
.prose h2{font-size:1.7rem;font-weight:800;margin:40px 0 14px}
.prose h3{font-size:1.2rem;font-weight:700;margin:26px 0 8px;color:#fff}
.band-light .prose h3{color:var(--ink)}
.prose p{margin-bottom:16px;color:var(--concrete)}
.band-light .prose p{color:#4d5049}
.prose ul{margin:0 0 18px 0;padding-left:0;list-style:none}
.prose ul li{position:relative;padding-left:26px;margin-bottom:10px;color:var(--concrete)}
.band-light .prose ul li{color:#4d5049}
.prose ul li::before{content:"";position:absolute;left:0;top:9px;width:9px;height:9px;background:var(--site-green);border-radius:2px}
.related{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:20px}
.related a{border:1px solid var(--line);border-radius:var(--r);padding:20px;background:var(--charcoal-2);transition:border-color .2s,transform .18s;display:block}
.related a:hover{border-color:var(--site-green);transform:translateY(-3px)}
.related a .t{font-family:'Archivo';font-weight:700;color:#fff;font-size:1.05rem}
.related a .d{font-size:.86rem;color:var(--concrete-dim);margin-top:6px}

/* service card learn-more */
.svc .more{display:inline-flex;align-items:center;gap:6px;margin-top:14px;font-family:'IBM Plex Mono';font-size:.74rem;letter-spacing:.08em;color:var(--site-green);text-transform:uppercase}
.svc:hover .more{gap:10px}
a.svc{text-decoration:none}

@media(max-width:900px){ .gallery-grid,.rev-grid,.related{grid-template-columns:1fr 1fr} }
@media(max-width:640px){ .gallery-grid,.rev-grid,.related{grid-template-columns:1fr} .acc-strip{gap:14px 24px} }

/* ---------- sticky mobile call bar ---------- */
.sticky-call{display:none}
@media(max-width:820px){
  body{padding-bottom:60px}
  .sticky-call{position:fixed;left:0;right:0;bottom:0;z-index:200;display:flex;align-items:center;justify-content:center;gap:10px;height:58px;background:var(--site-green);color:#15181A;font-family:'Archivo',sans-serif;font-weight:800;font-size:1.08rem;text-decoration:none;box-shadow:0 -6px 22px rgba(0,0,0,.28)}
  .sticky-call svg{stroke:#15181A}
  .sticky-call:active{background:var(--green-deep);color:#fff}
  .sticky-call:active svg{stroke:#fff}
}
/* ---------- advice hub ---------- */
.article-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:8px}
.article-card{border:1px solid var(--line);border-radius:var(--r);padding:26px;background:var(--charcoal-2);transition:border-color .2s,transform .18s;display:block}
.article-card:hover{border-color:var(--site-green);transform:translateY(-3px)}
.article-card .cat{font-family:'IBM Plex Mono';font-size:.7rem;letter-spacing:.1em;color:var(--site-green);text-transform:uppercase}
.article-card h3{font-size:1.16rem;font-weight:800;margin:10px 0 8px;color:#fff}
.article-card p{font-size:.92rem;color:var(--concrete-dim)}
.article-meta{font-family:'IBM Plex Mono';font-size:.74rem;letter-spacing:.06em;color:var(--concrete-dim);margin-bottom:10px}
.prose .callout{border-left:3px solid var(--site-green);background:var(--charcoal-2);padding:16px 20px;border-radius:8px;margin:20px 0}
.band-light .prose .callout{background:#fff}
.cost-table{width:100%;border-collapse:collapse;margin:14px 0 8px;font-size:.95rem}
.cost-table th,.cost-table td{text-align:left;padding:11px 14px;border-bottom:1px solid var(--line)}
.band-light .cost-table th,.band-light .cost-table td{border-bottom:1px solid var(--cream-2)}
.cost-table th{font-family:'IBM Plex Mono';font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;color:var(--concrete-dim)}
.cost-table td:last-child{font-weight:700;white-space:nowrap}
@media(max-width:900px){.article-grid{grid-template-columns:1fr 1fr}}
@media(max-width:640px){.article-grid{grid-template-columns:1fr}}