/* WasserRechner — "Wasserwerk": klares Blau + Stahlgrau, Tropfen/Rohr-Motive, technisch-sauber */
:root{
  --blau:#0f6fb4; --blau-dunkel:#0a3a5e; --tropfen:#33b5e8; --eis:#e9f4fb;
  --stahl:#5d7285; --stahl-d:#33414e; --bg:#f4f9fd; --paper:#ffffff;
  --ink:#1e2c38; --mut:#57707f; --line:#d3e3ee; --radius:10px;
  --sans:-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --mono:ui-monospace,"Roboto Mono",Menlo,Consolas,monospace;
  --shadow:0 4px 18px rgba(10,58,94,.10); --lift:0 14px 34px rgba(10,58,94,.16);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--sans);background:var(--bg);color:var(--ink);line-height:1.75;-webkit-font-smoothing:antialiased}
.container{max-width:1080px;margin:0 auto;padding:0 24px}
h1,h2,h3{font-weight:800;line-height:1.25;color:var(--blau-dunkel)}
header.site{background:var(--blau-dunkel);position:sticky;top:0;z-index:50}
header.site .bar{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:10px;padding:13px 0}
.brand{font-size:1.35rem;font-weight:800;color:#fff;text-decoration:none;display:inline-flex;align-items:center;gap:10px}
.brand .drop{width:38px;height:38px;border-radius:50%;background:linear-gradient(135deg,var(--tropfen),var(--blau));display:inline-flex;align-items:center;justify-content:center;flex:0 0 auto}
.brand .drop svg{width:20px;height:20px;fill:#fff}
.brand em{font-style:normal;color:var(--tropfen)}
nav.main a{color:#cfe3f2;text-decoration:none;margin-left:22px;font-size:.88rem;font-weight:600}
nav.main a:hover{color:var(--tropfen)}
.hero{position:relative;padding:100px 0 84px;background:url('../images/hero.webp') center/cover}
.hero::before{content:"";position:absolute;inset:0;background:linear-gradient(100deg,rgba(10,58,94,.94),rgba(10,58,94,.55))}
.hero .container{position:relative;z-index:1}
.badge{display:inline-flex;align-items:center;gap:8px;background:rgba(51,181,232,.16);border:1px solid rgba(51,181,232,.65);color:#aee2f8;font-size:.76rem;font-weight:800;letter-spacing:.14em;text-transform:uppercase;padding:8px 18px;margin-bottom:20px;border-radius:999px}
.badge svg{width:14px;height:14px;fill:var(--tropfen)}
.hero h1{color:#fff;font-size:2.9rem;max-width:680px;margin-bottom:16px}
.hero h1 .w{color:var(--tropfen)}
.hero p.lead{color:#cfe3f2;font-size:1.12rem;max-width:640px;margin-bottom:30px}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap}
.btn-wasser{display:inline-block;background:linear-gradient(135deg,var(--blau),#0a4f80);color:#fff;text-decoration:none;padding:15px 38px;font-weight:800;border-radius:999px;box-shadow:0 10px 26px rgba(15,111,180,.45);transition:transform .15s}
.btn-wasser:hover{transform:translateY(-3px)}
.btn-leer{display:inline-block;border:2px solid rgba(255,255,255,.5);color:#fff;text-decoration:none;padding:13px 34px;font-weight:700;border-radius:999px}
.btn-leer:hover{background:rgba(255,255,255,.1)}
.wave{line-height:0;background:var(--bg)}
.wave svg{display:block;width:100%;height:46px}
section.block{padding:64px 0}
.sec-pre{color:var(--blau);font-size:.78rem;font-weight:800;letter-spacing:.14em;text-transform:uppercase;font-family:var(--mono)}
.sec-title{font-size:2.1rem;margin:8px 0 12px}
.sec-sub{color:var(--mut);max-width:720px;margin-bottom:34px;font-size:1.02rem}
.wgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(310px,1fr));gap:22px}
.wcard{background:var(--paper);border-radius:var(--radius);text-decoration:none;color:var(--ink);box-shadow:var(--shadow);transition:transform .16s,box-shadow .16s;display:flex;flex-direction:column;overflow:hidden;border:1px solid var(--line);border-top:5px solid var(--blau)}
.wcard:hover{transform:translateY(-6px);box-shadow:var(--lift);border-top-color:var(--tropfen)}
.wcard .ph{height:130px;background-size:cover;background-position:center;border-bottom:1px solid var(--line)}
.wcard .tx{padding:20px 24px 24px;flex:1}
.wcard .no{font-family:var(--mono);font-size:.72rem;color:var(--blau);letter-spacing:.08em;font-weight:700;display:flex;align-items:center;gap:7px}
.wcard .no svg{width:13px;height:13px;fill:var(--tropfen)}
.wcard .tx h3{font-size:1.18rem;margin:6px 0 8px}
.wcard .tx p{font-size:.92rem;color:var(--mut);margin-bottom:12px}
.wcard .go{font-weight:800;color:var(--blau-dunkel);font-size:.9rem}
.wcard .go span{color:var(--tropfen)}
.split{display:grid;grid-template-columns:1fr 1fr;gap:44px;align-items:center;margin:48px 0}
.split.flip>div:first-child{order:2}
.split img{width:100%;height:auto;border-radius:var(--radius);box-shadow:var(--shadow)}
.split h3{font-size:1.45rem;margin-bottom:10px}
.split p{color:var(--mut);margin-bottom:12px}
.more{color:var(--blau);font-weight:800;text-decoration:none}
.more:hover{text-decoration:underline}
table.ref{width:100%;border-collapse:collapse;margin:26px 0;font-size:.94rem;background:var(--paper);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
table.ref th{background:var(--blau-dunkel);color:#fff;text-align:left;padding:12px 16px;font-size:.8rem;letter-spacing:.06em;text-transform:uppercase}
table.ref td{padding:11px 16px;border-bottom:1px solid var(--line)}
table.ref tr:last-child td{border-bottom:none}
table.ref tr:nth-child(even) td{background:var(--eis)}
.crumbs{font-size:.84rem;color:var(--mut);margin:26px 0 6px}
.crumbs a{color:var(--blau);text-decoration:none}
.pagehead h1{font-size:2.5rem;margin:8px 0 10px}
.pagehead h1 .w{color:var(--tropfen)}
.pagehead>p{color:var(--mut);font-size:1.08rem;max-width:760px;margin-bottom:22px}
.pimg{margin:18px 0 30px}
.pimg img{width:100%;max-height:300px;object-fit:cover;border-radius:var(--radius);box-shadow:var(--shadow)}
.calc{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:34px;margin:0 0 34px;max-width:720px}
.field{margin-bottom:18px}
.field label{display:block;font-weight:700;font-size:.92rem;margin-bottom:6px;color:var(--blau-dunkel)}
.field .hint{font-size:.82rem;color:var(--mut);margin-top:4px}
.field input,.field select{width:100%;padding:12px 14px;border:2px solid var(--line);border-radius:8px;font-size:1rem;font-family:var(--sans);background:#fbfdff}
.field input:focus,.field select:focus{outline:none;border-color:var(--blau)}
.field input.invalid{border-color:#c0392b}
.error{display:none;color:#c0392b;font-size:.82rem;margin-top:5px;font-weight:600}
.btn-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.calc-btn{background:linear-gradient(135deg,var(--blau),#0a4f80);color:#fff;border:none;padding:14px 42px;font-size:1rem;font-weight:800;border-radius:999px;cursor:pointer}
.calc-btn:hover{filter:brightness(1.08)}
.reset-btn{background:none;border:2px solid var(--line);color:var(--stahl);padding:12px 30px;font-size:.95rem;font-weight:700;border-radius:999px;cursor:pointer}
.result{display:none;margin-top:26px;background:var(--blau-dunkel);border-radius:var(--radius);padding:26px;color:#fff;box-shadow:var(--shadow)}
.result.show{display:block}
.result .rt{font-family:var(--mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--tropfen);margin-bottom:10px}
.result .big{font-family:var(--mono);font-size:2.4rem;font-weight:800;color:#fff;margin-bottom:14px}
.result .big small{font-size:1rem;color:#aee2f8;font-weight:600}
.rrow{display:flex;justify-content:space-between;gap:12px;padding:9px 0;border-top:1px solid rgba(255,255,255,.14);font-size:.94rem}
.rrow span{color:#aee2f8}.rrow strong{font-family:var(--mono);color:#fff}
.note{margin-top:16px;font-size:.84rem;color:#aee2f8;border-top:1px solid rgba(255,255,255,.14);padding-top:14px}
article.prose{max-width:800px}
article.prose h2{font-size:1.6rem;margin:34px 0 12px}
article.prose h3{font-size:1.2rem;margin:24px 0 8px}
article.prose p{margin-bottom:14px;color:#2c3e4d}
article.prose ul,article.prose ol{margin:0 0 16px 22px;color:#2c3e4d}
article.prose li{margin-bottom:7px}
.example{background:var(--eis);border-left:5px solid var(--blau);border-radius:0 8px 8px 0;padding:16px 20px;margin:18px 0}
.formel{background:#fff;border:2px dashed var(--tropfen);border-radius:var(--radius);padding:16px 20px;margin:18px 0;font-family:var(--mono);font-size:1.02rem;color:var(--blau-dunkel)}
.warnbox{background:#fdf3e7;border-left:5px solid #d98a1f;border-radius:0 8px 8px 0;padding:16px 20px;margin:22px 0;font-size:.94rem}
.warnbox strong{color:#8a5a10}
details.faq{background:var(--paper);border:1px solid var(--line);border-left:5px solid var(--blau);border-radius:8px;margin-bottom:12px;padding:16px 20px}
details.faq summary{font-weight:800;cursor:pointer;color:var(--blau-dunkel);font-size:1.02rem}
details.faq p{margin-top:10px;color:var(--mut)}
footer.site{background:var(--blau-dunkel);color:#a8c6da;padding:56px 0 30px;margin-top:70px}
footer.site .fgrid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:34px;margin-bottom:34px}
footer.site h4{color:#fff;font-size:.82rem;letter-spacing:.1em;text-transform:uppercase;margin-bottom:12px}
footer.site a{color:#a8c6da;text-decoration:none;display:block;margin-bottom:8px;font-size:.92rem}
footer.site a:hover{color:var(--tropfen)}
footer.site .bottom{border-top:1px solid rgba(255,255,255,.12);padding-top:22px;font-size:.82rem}
@media(max-width:760px){
  .hero h1{font-size:2rem}
  .pagehead h1{font-size:1.8rem}
  .split{grid-template-columns:1fr}
  .split.flip>div:first-child{order:0}
  footer.site .fgrid{grid-template-columns:1fr 1fr}
  nav.main a{margin:6px 12px 6px 0}
}