:root{
  --text:#091317;
  --background:#f5f9fb;
  --primary:#4da2c2;
  --secondary:#93c9de;
  --accent:#62b4d4;
  --ink:var(--text);
  --muted:#536a74;
  --blue:var(--primary);
  --blue2:var(--accent);
  --deep:#091317;
  --pale:#d3e7ef;
  --pale2:#edf6f9;
  --line:#93c9de;
  --white:#ffffff;
  --shadow:0 18px 50px rgba(9,19,23,.10);
  --radius:22px;--max:1180px
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--background);line-height:1.65}a{color:inherit}.container{width:min(calc(100% - 40px),var(--max));margin:auto}
.site-header{position:sticky;top:0;z-index:100;background:rgba(245,249,251,.96);backdrop-filter:blur(16px);border-bottom:1px solid rgba(147,201,222,.45)}
.nav{min-height:76px;display:flex;align-items:center;gap:24px}.logo{font-weight:800;text-decoration:none;letter-spacing:-.04em;font-size:1.15rem;display:flex;align-items:center;gap:9px;white-space:nowrap}.logo-mark{width:30px;height:30px;flex:0 0 30px;border-radius:50% 50% 50% 12px;background:linear-gradient(145deg,var(--blue2),var(--blue));transform:rotate(45deg);position:relative}.logo-mark:after{content:"";position:absolute;width:9px;height:9px;background:var(--white);border-radius:50%;top:6px;left:6px;opacity:.8}
.desktop-nav{display:flex;align-items:center;justify-content:center;gap:4px;flex:1}.nav-menu-group{position:relative}.nav-menu-trigger{appearance:none;border:0;background:transparent;color:var(--text);font:inherit;font-size:.92rem;font-weight:700;padding:12px 12px;border-radius:12px;cursor:pointer;display:flex;align-items:center;gap:6px}.nav-menu-trigger span{font-size:.8em;color:var(--blue)}.nav-menu-trigger:hover,.nav-menu-trigger:focus-visible{background:var(--pale);color:var(--blue);outline:none}.nav-dropdown{position:absolute;top:calc(100% + 6px);left:0;min-width:245px;padding:9px;background:var(--white);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);opacity:0;visibility:hidden;transform:translateY(-6px);transition:.16s ease}.nav-menu-group:hover .nav-dropdown,.nav-menu-group:focus-within .nav-dropdown,.nav-menu-trigger[aria-expanded="true"]+.nav-dropdown{opacity:1;visibility:visible;transform:none}.nav-dropdown ul,.mobile-nav ul{list-style:none;margin:0;padding:0}.nav-dropdown a{display:block;padding:9px 11px;border-radius:10px;text-decoration:none;color:#294b57;font-size:.9rem}.nav-dropdown a:hover,.nav-dropdown a:focus-visible{background:var(--pale);color:var(--blue);outline:none}
.header-cta{display:inline-flex;align-items:center;justify-content:center;padding:11px 16px;border-radius:999px;background:var(--blue);color:var(--text)!important;text-decoration:none;font-weight:800;font-size:.88rem;white-space:nowrap;box-shadow:0 8px 20px rgba(77,162,194,.24)}.header-cta:hover{background:#3b8daa;transform:translateY(-1px)}
.mobile-menu-toggle{display:none;margin-left:auto;width:44px;height:44px;border:1px solid var(--line);border-radius:12px;background:var(--background);align-items:center;justify-content:center;flex-direction:column;gap:5px;cursor:pointer}.mobile-menu-toggle span{width:20px;height:2px;background:var(--deep);border-radius:2px;transition:.18s}.mobile-menu-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}.mobile-menu-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}.mobile-menu-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.mobile-nav{background:var(--white);border-top:1px solid var(--line);box-shadow:0 15px 30px rgba(8,63,83,.08)}.mobile-nav-inner{padding:10px 0 20px}.mobile-home{display:block;text-decoration:none;font-weight:800;color:var(--blue);padding:12px 0}.mobile-nav details{border-top:1px solid var(--line);padding:0}.mobile-nav summary{cursor:pointer;list-style:none;font-weight:800;padding:15px 0}.mobile-nav summary::-webkit-details-marker{display:none}.mobile-nav summary:after{content:"+";float:right;color:var(--blue);font-weight:900}.mobile-nav details[open] summary:after{content:"−"}.mobile-nav li a{display:block;text-decoration:none;padding:9px 12px 9px 4px;color:#36545f}.mobile-nav li a:hover{color:var(--blue)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 18px;border-radius:999px;text-decoration:none;font-weight:800;border:1px solid transparent;transition:.2s}.btn-primary{background:var(--blue);color:var(--text)!important;box-shadow:0 8px 20px rgba(77,162,194,.24)}.btn-primary:hover{transform:translateY(-1px);background:#3b8daa}.btn-light{background:var(--background);color:var(--deep)!important;border-color:var(--line);box-shadow:0 5px 16px rgba(8,63,83,.06)}.btn-light:hover{background:#eaf5f9;border-color:var(--secondary)}.btn-accent{background:var(--background);color:var(--deep)!important;border:1px solid rgba(255,255,255,.7);box-shadow:0 8px 22px rgba(0,0,0,.12)}.btn-accent:hover{background:#e7f5fa;transform:translateY(-1px)}
.hero{background:radial-gradient(circle at 78% 15%,rgba(38,184,218,.30),transparent 30%),linear-gradient(135deg,#effcff 0%,#e4f7fb 45%,#f8fdfe 100%);padding:82px 0 76px;overflow:hidden}.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:55px;align-items:center}.eyebrow{text-transform:uppercase;letter-spacing:.14em;font-size:.76rem;font-weight:800;color:var(--blue)}h1{font-size:clamp(2.45rem,6vw,4.8rem);line-height:1.02;letter-spacing:-.055em;margin:14px 0 22px}h2{font-size:clamp(1.8rem,3vw,2.6rem);line-height:1.12;letter-spacing:-.035em;margin:0 0 14px}h3{font-size:1.18rem;line-height:1.25;margin:0 0 8px}.lead{font-size:1.18rem;color:#536a74;max-width:650px}.hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:28px}.hero-art{min-height:430px;border-radius:34px;position:relative;overflow:hidden;box-shadow:var(--shadow);background:radial-gradient(circle at 45% 32%,rgba(255,255,255,.95) 0 9%,transparent 10%),radial-gradient(circle at 63% 55%,rgba(255,255,255,.55) 0 4%,transparent 5%),linear-gradient(160deg,#78d9ed 0%,#0c8caf 52%,#063f63 100%)}.hero-art:before{content:"";position:absolute;inset:-20% -10%;background:radial-gradient(ellipse at 50% 65%,rgba(255,255,255,.55),transparent 34%);transform:rotate(-8deg)}.hero-art:after{content:"WATER • FILTER • KNOWLEDGE";position:absolute;bottom:24px;left:26px;color:rgba(255,255,255,.9);font-size:.72rem;font-weight:800;letter-spacing:.18em}
.section{padding:78px 0}.section.alt{background:var(--pale2)}.section-head{max-width:760px;margin-bottom:32px}.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}.card{background:var(--white);border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:0 8px 28px rgba(8,63,83,.05)}.card:hover{box-shadow:var(--shadow)}.card p{color:var(--muted);margin-bottom:0}.card-link{text-decoration:none}.icon{width:46px;height:46px;border-radius:15px;background:var(--pale);display:grid;place-items:center;color:var(--blue);font-size:1.25rem;margin-bottom:18px}.pill{display:inline-block;padding:6px 10px;border-radius:999px;background:var(--pale);color:var(--blue);font-size:.75rem;font-weight:800}.article-hero{padding:64px 0 45px;background:linear-gradient(135deg,#effcff,#f8fdfe)}.article-hero .container{max-width:900px}.article-hero h1{font-size:clamp(2.3rem,5vw,4rem)}.meta{color:var(--muted);font-size:.9rem}.article{max-width:820px;margin:auto;padding:45px 0 85px}.article h2{margin-top:46px}.article h3{margin-top:28px}.article p,.article li{font-size:1.06rem;color:#243b44}.article ul,.article ol{padding-left:25px}.callout{padding:24px 26px;border-radius:18px;background:var(--pale);border-left:4px solid var(--blue);margin:30px 0}.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:18px;margin:28px 0}table{width:100%;border-collapse:collapse;min-width:620px;background:var(--white)}th,td{text-align:left;padding:15px;border-bottom:1px solid var(--line);vertical-align:top}th{background:#edf6f9;font-size:.86rem}td{color:#36545f}.checklist{display:grid;gap:10px;margin:20px 0}.check{display:flex;gap:10px;align-items:flex-start}.check b{color:var(--blue)}.quote{font-size:1.3rem;line-height:1.45;font-weight:650;color:#214a5b;padding:24px 0}.faq{border-top:1px solid var(--line)}details{padding:17px 0;border-bottom:1px solid var(--line)}summary{cursor:pointer;font-weight:750}.breadcrumbs{font-size:.82rem;color:var(--muted);margin-bottom:18px}.breadcrumbs a{text-decoration:none}.technical-note{max-width:820px;margin:0 auto 25px;padding:25px 28px;background:#f1f8fa;border:1px solid var(--line);border-radius:18px}.technical-note h2{font-size:1.45rem;margin:0 0 9px}.technical-note p{margin:0;color:#405a65;font-size:1.02rem}.affiliate-section{padding-top:36px}.affiliate-card{display:flex;align-items:center;justify-content:space-between;gap:30px;padding:32px 36px;border-radius:26px;background:linear-gradient(135deg,var(--primary),#2f7894);color:#fff}.affiliate-card h2{margin-bottom:8px}.affiliate-card p{margin:0;color:#e8f6fa;max-width:720px}.affiliate-note{font-size:.75rem;color:#647d87;margin:9px 4px 0}.cta{padding:46px;border-radius:30px;background:linear-gradient(135deg,var(--primary),#2f7894);color:white}.cta p{color:#e8f6fa}.badges{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0}.badge{background:var(--background);border:1px solid rgba(255,255,255,.4);padding:7px 11px;border-radius:999px;font-size:.78rem}.footer{background:#091317;color:#dceef3;padding:54px 0 25px}.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:40px}.footer a{color:#dceef3;text-decoration:none}.footer small{color:#9db8c2}.footer-logo{color:white}.disclosure{font-size:.83rem;color:#607984;margin-top:18px}
@media(max-width:1050px){.desktop-nav{gap:0}.nav-menu-trigger{padding:10px 8px;font-size:.85rem}.header-cta{font-size:.8rem;padding:10px 13px}}
@media(max-width:900px){.hero-grid,.grid-3,.grid-2,.footer-grid{grid-template-columns:1fr}.desktop-nav,.header-cta{display:none}.mobile-menu-toggle{display:flex}.nav{min-height:70px}.hero{padding-top:55px}.hero-art{min-height:300px}.affiliate-card{align-items:flex-start;flex-direction:column}.affiliate-card .btn{width:100%}}
@media(max-width:520px){.container{width:min(calc(100% - 28px),var(--max))}.hero{padding:44px 0 50px}.hero-art{min-height:230px;border-radius:24px}.section{padding:58px 0}.affiliate-card{padding:26px 22px}.btn{width:auto}.hero-actions .btn{width:100%}}

/* Requested Sküma voucher styling */
.skuma-voucher-code { color: #ccffff !important; }
.affiliate-highlight {
  margin: 28px 0 36px;
  padding: 24px 26px;
  border-radius: 18px;
  background: #06384a;
  color: #fff;
  box-shadow: 0 10px 28px rgba(0,0,0,.10);
}
.affiliate-highlight h3 { color:#fff; margin:0 0 8px; }
.affiliate-highlight p { color:#e8fbff; }
.affiliate-highlight .skuma-voucher-code { color:#ccffff !important; font-weight:700; }
.affiliate-highlight .disclosure { color:#b9dbe3; font-size:.82rem; }

.expanded-content h3 { margin-top: 32px; margin-bottom: 10px; }
.expanded-content p { max-width: 78ch; }
.source-notes ul { padding-left: 1.2rem; }
.source-notes li { margin: .45rem 0; }

.expanded-content, .expanded-detail, .technical-note, .expanded-checklist, .micro-detail { line-height: 1.72; }
.expanded-content h2, .technical-note h2, .expanded-detail h2 { margin-bottom: 18px; }
.expanded-content h3 { margin-top: 30px; }
.source-notes a { text-decoration: underline; }


/* Accessible water-theme controls */
.btn-primary:focus-visible,.header-cta:focus-visible,.btn-light:focus-visible,.btn-accent:focus-visible,.mobile-menu-toggle:focus-visible{outline:3px solid var(--secondary);outline-offset:3px;}
.affiliate-highlight .btn-primary{background:var(--accent);color:var(--text)!important;}
.skuma-voucher-code{color:#ccffff !important;}


/* 2026 SEO/UX polish */
:focus-visible{outline:3px solid #0b6f91;outline-offset:3px}
.skip-link{position:absolute;left:-9999px;top:8px;z-index:9999;background:#fff;padding:10px 14px;border-radius:8px}.skip-link:focus{left:8px}
.article p,.article li{max-width:76ch}.article>p:first-child{font-size:1.12rem}
.comparison-table th:first-child,.comparison-table td:first-child{font-weight:750;color:var(--deep)}
.pros-cons{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:28px 0}.pros-cons>div{background:var(--white);border:1px solid var(--line);border-radius:18px;padding:22px}.pros-cons h3{margin-top:0}.pros-cons li{margin:.45rem 0}
.faq-page details{background:var(--white);padding:0;border:1px solid var(--line);border-radius:16px;margin:12px 0;overflow:hidden}.faq-page details+details{margin-top:12px}.faq-page summary{padding:18px 52px 18px 20px;position:relative;list-style:none}.faq-page summary::-webkit-details-marker{display:none}.faq-page summary:after{content:'+';position:absolute;right:20px;top:14px;font-size:1.5rem;color:var(--blue)}.faq-page details[open] summary:after{content:'−'}.faq-answer{padding:0 20px 20px}.faq-answer p:last-child{margin-bottom:0}
.jump-links{display:flex;flex-wrap:wrap;gap:9px;margin:24px 0}.jump-links a{background:var(--pale);padding:8px 12px;border-radius:999px;text-decoration:none;font-weight:700;font-size:.88rem}
@media(max-width:700px){.pros-cons{grid-template-columns:1fr}.table-wrap{margin-left:calc((100vw - 100%)/-2);margin-right:calc((100vw - 100%)/-2);border-radius:0;border-left:0;border-right:0}.table-wrap table{min-width:680px}.article{padding-left:14px;padding-right:14px}.article-hero{padding-top:44px}.article-hero h1{font-size:clamp(2.05rem,10vw,3rem)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}

/* PureWaterGuide responsive brand assets */
.logo-mark{display:none}
.brand-logo{display:flex;flex:0 1 260px;max-width:260px;min-width:170px;padding:4px 0}
.brand-logo img{display:block;width:100%;height:auto;max-height:68px;object-fit:contain;object-position:left center}
.footer-logo{display:block;max-width:290px}
.footer-logo a{display:block}
.footer-logo img{display:block;width:100%;height:auto;filter:drop-shadow(0 2px 3px rgba(0,0,0,.18))}
@media(max-width:1050px){.brand-logo{max-width:225px}}
@media(max-width:900px){.brand-logo{max-width:205px;min-width:155px}.brand-logo img{max-height:60px}}
@media(max-width:420px){.brand-logo{max-width:178px;min-width:145px}.nav{gap:10px}}

/* 2026-10 responsive logo sizing correction
   Do not cap the logo by height: doing so made this artwork render much narrower
   than the allocated brand area. Width now controls scaling at each breakpoint. */
.site-header .nav{min-height:104px}
.brand-logo{flex:0 0 clamp(280px,24vw,360px);width:clamp(280px,24vw,360px);max-width:360px;min-width:0;padding:8px 0}
.brand-logo img{display:block;width:100%;height:auto;max-height:none;object-fit:contain;object-position:left center}
.footer-logo{max-width:380px;width:min(100%,380px)}
.footer-logo img{width:100%;height:auto;max-height:none}
@media(max-width:1100px){
  .site-header .nav{min-height:92px}
  .brand-logo{flex-basis:260px;width:260px;max-width:260px}
}
@media(max-width:900px){
  .site-header .nav{min-height:88px}
  .brand-logo{flex-basis:250px;width:250px;max-width:250px}
}
@media(max-width:600px){
  .site-header .nav{min-height:82px}
  .brand-logo{flex-basis:min(230px,calc(100vw - 92px));width:min(230px,calc(100vw - 92px));max-width:none}
  .footer-logo{width:min(100%,320px)}
}
@media(max-width:380px){
  .brand-logo{flex-basis:min(205px,calc(100vw - 84px));width:min(205px,calc(100vw - 84px))}
}