/* ========================================================
   WATER INTAKE CALCULATOR – Professional Stylesheet
   Palette: cyan #00d4ff → teal #00b4d8 → deep ocean #0077b6 + sand #fff8e7
   ======================================================== */

:root{
  --primary:#0077b6;
  --primary-2:#00b4d8;
  --primary-3:#00d4ff;
  --accent:#ffd166;
  --bg:#f0fbff;
  --bg-2:#ffffff;
  --text:#0b1f3a;
  --muted:#4d6079;
  --border:#d9ecf5;
  --shadow:0 10px 30px rgba(0,119,182,.10);
  --shadow-lg:0 20px 50px rgba(0,119,182,.18);
  --radius:18px;
  --radius-sm:10px;
  --maxw:1180px;
  --font-body:'Inter',system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
  --font-head:'Poppins',var(--font-body);
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;font-family:var(--font-body);color:var(--text);
  background:
    radial-gradient(1200px 600px at 90% -10%, #d6f5ff 0%, transparent 60%),
    radial-gradient(1000px 500px at -10% 10%, #e2f6ff 0%, transparent 55%),
    var(--bg);
  line-height:1.65;-webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}

.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* ============ SKIP LINK ============ */
.skip-link{position:absolute;left:-9999px;top:0;background:var(--primary);color:#fff;padding:10px 16px;border-radius:0 0 8px 0;z-index:9999}
.skip-link:focus{left:0}

/* ============ HEADER ============ */
.site-header{
  position:sticky;top:0;z-index:50;background:rgba(255,255,255,.88);
  backdrop-filter:saturate(150%) blur(12px);border-bottom:1px solid var(--border);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:72px;gap:16px}
.logo{display:flex;align-items:center;gap:10px;font-family:var(--font-head);font-size:20px;color:var(--text)}
.logo:hover{text-decoration:none}
.logo-text b{color:var(--primary);font-weight:800}
.logo-text span{color:var(--primary-2);font-weight:700}
.logo-mark{display:inline-flex}
.main-nav ul{display:flex;gap:6px;list-style:none;margin:0;padding:0}
.main-nav a{padding:10px 14px;border-radius:10px;color:var(--text);font-weight:500;font-size:15px}
.main-nav a:hover{background:#e2f6ff;text-decoration:none;color:var(--primary)}
.main-nav .btn-link{background:var(--primary);color:#fff}
.main-nav .btn-link:hover{background:var(--primary-2);color:#fff}

.nav-toggle{display:none;background:none;border:0;width:42px;height:42px;cursor:pointer}
.nav-toggle span{display:block;height:3px;width:24px;margin:5px auto;background:var(--text);border-radius:3px;transition:.25s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(8px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-8px) rotate(-45deg)}

/* ============ HERO ============ */
.hero{padding:60px 0 30px;position:relative;overflow:hidden}
.hero::before{
  content:"";position:absolute;inset:0;
  background:
    radial-gradient(600px 300px at 80% 20%,rgba(0,212,255,.18),transparent 70%),
    radial-gradient(500px 250px at 10% 80%,rgba(0,119,182,.12),transparent 70%);
  z-index:-1;
}
.hero-grid{display:grid;grid-template-columns:1.05fr 1fr;gap:48px;align-items:center}
.eyebrow{
  display:inline-block;background:#fff;border:1px solid var(--border);
  padding:6px 14px;border-radius:999px;font-size:13px;font-weight:600;color:var(--primary);
  box-shadow:var(--shadow);
}
.hero h1{font-family:var(--font-head);font-size:clamp(28px,4.6vw,52px);line-height:1.1;margin:14px 0 14px;font-weight:800;letter-spacing:-.5px}
.gradient-text{
  background:linear-gradient(90deg,var(--primary),var(--primary-3));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.lead{font-size:18px;color:var(--muted);margin:0 0 18px}
.hero-bullets{list-style:none;padding:0;margin:0;display:grid;gap:6px;font-weight:500}
.hero-bullets li{font-size:15px}

/* ============ CALCULATOR CARD ============ */
.calc-card{
  background:linear-gradient(180deg,#fff,#f6fcff);
  border:1px solid var(--border);border-radius:24px;
  box-shadow:var(--shadow-lg);overflow:hidden;
}
.calc-tabs{display:flex;background:#e2f6ff;padding:6px;gap:6px;flex-wrap:wrap}
.tab{
  flex:1;min-width:120px;border:0;background:transparent;padding:12px 8px;border-radius:14px;
  font-weight:600;cursor:pointer;color:var(--muted);font-size:14px;transition:.2s;
}
.tab.active{background:#fff;color:var(--primary);box-shadow:0 4px 14px rgba(0,119,182,.15)}
.tab:hover{color:var(--primary)}
.calc-body{padding:24px 24px 28px}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-bottom:14px}
.form-row.single{grid-template-columns:1fr}
.form-field label{display:block;font-weight:600;margin-bottom:6px;font-size:14px;color:var(--text)}
.form-field input,.form-field select{
  width:100%;padding:13px 14px;font-size:16px;border:2px solid var(--border);
  border-radius:12px;background:#fff;color:var(--text);font-family:inherit;font-weight:500;
  transition:.15s;
}
.form-field input:focus,.form-field select:focus{outline:none;border-color:var(--primary-2);box-shadow:0 0 0 4px rgba(0,180,216,.15)}
.weight-wrap{position:relative}
.weight-wrap .unit-label{position:absolute;right:14px;top:50%;transform:translateY(-50%);color:var(--muted);font-weight:700;pointer-events:none;font-size:14px}
.weight-wrap input{padding-right:48px}

.btn-primary{
  margin-top:8px;width:100%;padding:16px 20px;border:0;border-radius:14px;cursor:pointer;
  font-weight:700;font-size:17px;color:#fff;
  background:linear-gradient(135deg,var(--primary),var(--primary-3));
  box-shadow:0 10px 24px rgba(0,119,182,.35);transition:.2s;
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 14px 30px rgba(0,119,182,.45)}
.btn-primary span{display:inline-block;margin-left:6px;transition:.2s}
.btn-primary:hover span{transform:translateX(4px)}

/* ============ RESULT ============ */
.result{margin-top:22px}
.result-hero{
  background:linear-gradient(135deg,var(--primary),var(--primary-3));
  color:#fff;border-radius:16px;padding:22px 18px;text-align:center;
  box-shadow:0 12px 30px rgba(0,119,182,.25);position:relative;overflow:hidden;
}
.result-hero::before{
  content:"💧";position:absolute;font-size:120px;opacity:.12;right:-10px;top:-20px;
}
.result-hero .label{font-size:13px;text-transform:uppercase;letter-spacing:2px;opacity:.85;font-weight:600;margin-bottom:6px}
.result-hero .big-number{font-family:var(--font-head);font-size:44px;font-weight:800;line-height:1.05;margin:0}
.result-hero .sub{margin-top:6px;opacity:.95;font-weight:500;font-size:14px}

.result-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:14px}
.result-card{
  background:#fff;border:1.5px solid var(--border);border-radius:12px;padding:12px 8px;text-align:center;
}
.result-card .rc-val{font-family:var(--font-head);font-size:18px;font-weight:800;color:var(--text)}
.result-card .rc-meta{font-size:11px;color:var(--muted);margin-top:2px;text-transform:uppercase;letter-spacing:1px;font-weight:600}

.glass-bar{margin-top:14px;background:#e2f6ff;border-radius:12px;padding:12px 14px;font-size:14px;color:var(--muted);text-align:center}
.glass-bar b{color:var(--primary);font-weight:700}

.result-tips{margin-top:12px;background:#fff8e7;border-left:4px solid var(--accent);
  padding:12px 14px;font-size:13.5px;color:#5a4a10;border-radius:8px}

/* ============ SECTIONS ============ */
section{padding:60px 0}
.section-title{font-family:var(--font-head);font-size:clamp(24px,3.4vw,38px);text-align:center;font-weight:800;margin:0 0 10px;letter-spacing:-.3px}
.section-sub{text-align:center;color:var(--muted);max-width:760px;margin:0 auto 36px;font-size:17px}

/* ============ HOW IT WORKS ============ */
.how-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.how-card{
  background:#fff;border:1px solid var(--border);border-radius:var(--radius);
  padding:24px 20px;text-align:center;box-shadow:var(--shadow);transition:.25s;
}
.how-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.how-num{
  width:46px;height:46px;border-radius:14px;margin:0 auto 14px;
  background:linear-gradient(135deg,var(--primary),var(--primary-3));
  color:#fff;font-weight:800;font-size:20px;display:flex;align-items:center;justify-content:center;
  font-family:var(--font-head);
}
.how-card h3{margin:0 0 6px;font-family:var(--font-head);font-size:18px}
.how-card p{margin:0;color:var(--muted);font-size:14.5px}

/* ============ TABLES ============ */
.table-wrap{overflow-x:auto;background:#fff;border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow)}
.age-table{width:100%;border-collapse:collapse;min-width:560px}
.age-table th,.age-table td{padding:14px 16px;text-align:left;border-bottom:1px solid var(--border);font-size:15px}
.age-table th{background:#e2f6ff;font-family:var(--font-head);font-weight:700;color:var(--primary)}
.age-table tr:last-child td{border-bottom:0}
.age-table tr:hover td{background:#f6fcff}
.footnote{text-align:center;color:var(--muted);font-size:13.5px;margin-top:14px}

/* ============ ARTICLE ============ */
.article{padding:60px 0;background:#fff;border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.article-grid{display:grid;grid-template-columns:1fr 200px;gap:40px;align-items:start}
.article-body h2{font-family:var(--font-head);font-size:32px;margin:0 0 16px;letter-spacing:-.3px}
.article-body h3{font-family:var(--font-head);font-size:22px;margin:30px 0 10px;color:var(--primary)}
.article-body p,.article-body li{font-size:16.5px;color:#1f2c44}
.article-body ul,.article-body ol{padding-left:22px}
.article-body li{margin:4px 0}
.article-body blockquote{
  border-left:4px solid var(--primary-2);background:#f0fbff;padding:14px 18px;
  margin:14px 0;border-radius:8px;font-size:16px;color:var(--text);
}

/* ============ FAQ ============ */
.faq details{
  background:#fff;border:1px solid var(--border);border-radius:14px;padding:16px 20px;
  margin-bottom:12px;box-shadow:0 4px 14px rgba(0,119,182,.05);
}
.faq summary{cursor:pointer;font-weight:700;font-size:17px;list-style:none;display:flex;justify-content:space-between;align-items:center}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:24px;color:var(--primary);font-weight:300;transition:.2s}
.faq details[open] summary::after{transform:rotate(45deg)}
.faq details p{margin:12px 0 0;color:var(--muted)}

/* ============ FOOTER ============ */
.site-footer{background:#0a1929;color:#c5d4e6;padding:60px 0 0;margin-top:40px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1.2fr;gap:30px;padding-bottom:36px}
.site-footer h4{color:#fff;font-family:var(--font-head);font-size:16px;margin:0 0 14px;letter-spacing:.3px}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin:6px 0}
.site-footer a{color:#c5d4e6}
.site-footer a:hover{color:#fff}
.logo-footer .logo-text b,.logo-footer .logo-text span{color:#fff}
.logo-footer .logo-text{color:#fff}
.footer-bottom{border-top:1px solid #1c3147;padding:18px 0;font-size:14px;color:#94a8c2;text-align:center}
.footer-bottom p{margin:0}

/* ============ AD STYLES ============ */
.ad-wrap{
  display:flex;flex-direction:column;align-items:center;gap:6px;
  margin:24px auto;padding:14px;background:#fff;
  border:1px dashed var(--border);border-radius:var(--radius-sm);max-width:780px;
}
.ad-label{font-size:11px;text-transform:uppercase;letter-spacing:1.5px;color:#7d8da3;font-weight:600}
.ad-desktop{display:block}
.ad-mobile{display:none}
.ad-rect{max-width:340px}
.ad-banner{max-width:520px}

/* ============ STICKY BOTTOM ============ */
.sticky-bottom-ad{
  position:fixed;left:50%;bottom:8px;transform:translateX(-50%);
  background:#fff;border:1px solid var(--border);border-radius:12px;
  padding:6px 8px 6px 8px;box-shadow:0 -4px 18px rgba(0,0,0,.12);
  z-index:9998;display:flex;flex-direction:column;align-items:center;gap:2px;
}
.sticky-bottom-ad .ad-label{font-size:9px;letter-spacing:1px}
.ad-close{
  position:absolute;top:-10px;right:-10px;width:26px;height:26px;border-radius:50%;
  background:#fff;border:1.5px solid var(--border);color:var(--text);
  font-size:18px;line-height:1;cursor:pointer;box-shadow:0 4px 10px rgba(0,0,0,.1);
  display:flex;align-items:center;justify-content:center;font-weight:700;
}
.ad-close:hover{background:var(--primary);color:#fff;border-color:var(--primary)}

/* ============ SIDEBAR ADS (hidden until scroll into article) ============ */
.article-aside{
  position:sticky;top:90px;display:flex;flex-direction:column;gap:24px;
  opacity:0;visibility:hidden;transform:translateY(20px);
  transition:opacity .5s ease, transform .5s ease, visibility .5s;
}
.article-aside.show{opacity:1;visibility:visible;transform:translateY(0)}
.sidebar-ad{
  position:relative;background:#fff;border:1px solid var(--border);
  border-radius:12px;padding:8px;display:flex;flex-direction:column;
  align-items:center;gap:4px;box-shadow:var(--shadow);
}
.sidebar-ad.hidden{display:none}

/* ============ RESPONSIVE ============ */
@media (max-width:980px){
  .hero-grid{grid-template-columns:1fr;gap:30px}
  .how-grid{grid-template-columns:repeat(2,1fr)}
  .article-grid{grid-template-columns:1fr}
  .article-aside{position:static;flex-direction:row;flex-wrap:wrap;justify-content:center}
  .footer-grid{grid-template-columns:1fr 1fr;gap:24px}
}
@media (max-width:720px){
  section{padding:44px 0}
  .hero{padding:36px 0 20px}
  .main-nav ul{
    position:absolute;top:72px;left:0;right:0;background:#fff;
    flex-direction:column;gap:0;padding:10px 16px 18px;
    border-bottom:1px solid var(--border);
    box-shadow:0 12px 24px rgba(0,0,0,.06);display:none;
  }
  .main-nav.open ul{display:flex}
  .main-nav a{display:block;padding:12px 14px}
  .nav-toggle{display:block}
  .how-grid{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .ad-desktop{display:none}
  .ad-mobile{display:block}
  .result-grid{grid-template-columns:repeat(2,1fr)}
  .form-row{grid-template-columns:1fr}
  .calc-body{padding:20px 16px 24px}
  .result-hero .big-number{font-size:36px}
  .tab{font-size:13px;padding:10px 6px;min-width:0}
}
@media (max-width:480px){
  .footer-grid{grid-template-columns:1fr}
  .how-grid{grid-template-columns:1fr}
  .logo-text{font-size:18px}
  .result-grid{grid-template-columns:1fr 1fr}
}

@media print{
  .site-header,.site-footer,.ad-wrap,.sticky-bottom-ad,.article-aside,#container-e2c2c3904bed6a40219fb955812671f3{display:none!important}
}