/* MaterialCalc — stylesheet */
:root{
  --ink:#16211c;
  --muted:#5c6b63;
  --line:#e2e7e3;
  --bg:#f7f9f7;
  --card:#ffffff;
  --green:#1f5c3d;
  --green-soft:#eef5f0;
  --accent:#c2703a;
  --radius:14px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased;
}
a{color:var(--green);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:820px;margin:0 auto;padding:0 20px}

/* header */
.top{background:var(--green);color:#fff}
.top a{color:#fff}
.bar{display:flex;align-items:center;gap:18px;flex-wrap:wrap;padding:14px 20px}
.brand{font-weight:700;font-size:18px;display:flex;align-items:center;gap:9px;letter-spacing:.2px}
.brand:hover{text-decoration:none}
.mark{
  width:28px;height:28px;border-radius:8px;background:#fff;color:var(--green);
  display:inline-flex;align-items:center;justify-content:center;font-size:13px;font-weight:800;
}
nav.main{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto}
nav.main a{padding:6px 11px;border-radius:8px;font-size:15px;opacity:.9}
nav.main a:hover{background:rgba(255,255,255,.15);text-decoration:none;opacity:1}
nav.main a.on{background:rgba(255,255,255,.22);opacity:1;font-weight:600}

/* layout */
main{padding:26px 0 10px}
h1{font-size:31px;line-height:1.25;margin:0 0 14px;letter-spacing:-.4px}
h2{font-size:22px;margin:38px 0 12px;letter-spacing:-.2px}
h3{font-size:18px;margin:22px 0 8px}
p{margin:0 0 15px}
.lede{font-size:18px;color:#33413a}
.answer{
  background:var(--green-soft);border-left:4px solid var(--green);
  padding:13px 16px;border-radius:0 10px 10px 0;margin:0 0 24px;font-size:16.5px;
}
.fine{font-size:14px;color:var(--muted);line-height:1.55}
.crumbs{font-size:14px;color:var(--muted);margin-bottom:10px}
.crumbs a{color:var(--muted)}

/* calculator */
.calc{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px;margin:0 0 12px;box-shadow:0 1px 2px rgba(20,40,30,.04);
}
.calc-in{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:14px}
.field label{display:block;font-size:14px;font-weight:600;margin-bottom:5px;color:#2b3831}
.field .row{display:flex;align-items:center;gap:8px}
.field input,.field select{
  width:100%;font:inherit;font-size:16px;padding:10px 11px;border:1px solid #cfd8d2;
  border-radius:9px;background:#fff;color:var(--ink);
}
.field input:focus,.field select:focus{outline:2px solid #cfe3d7;border-color:var(--green)}
.field .suffix{font-size:14px;color:var(--muted);min-width:26px}
.calc-out{
  margin-top:20px;border-top:1px dashed var(--line);padding-top:18px;
  display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;
}
.res{background:var(--green-soft);border-radius:11px;padding:13px 14px}
.res span{display:block;font-size:13px;color:#41564b;margin-bottom:3px}
.res b{font-size:25px;line-height:1.15;letter-spacing:-.5px;color:var(--green);font-weight:700}
.res b em{font-size:15px;font-style:normal;font-weight:600;color:#41564b;margin-left:3px}
.res.hero{grid-column:1/-1;background:var(--green);color:#fff}
.res.hero span{color:#cfe3d7}
.res.hero b{color:#fff;font-size:34px}
.res.hero b em{color:#cfe3d7}
.ph{color:var(--muted);margin:0;font-size:15px}

/* formula */
.formula{background:#fbfcfb;border:1px solid var(--line);border-radius:11px;padding:6px 16px;margin:0 0 16px}
.formula > div{display:flex;gap:14px;align-items:baseline;padding:9px 0;border-bottom:1px solid var(--line);flex-wrap:wrap}
.formula > div:last-child{border-bottom:none}
.formula span{font-size:14px;font-weight:600;color:#41564b;min-width:96px}
.formula code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:14px;color:var(--ink);background:none;padding:0}

/* tables */
.tablewrap{overflow-x:auto;border:1px solid var(--line);border-radius:11px;background:#fff;margin-bottom:10px}
table{border-collapse:collapse;width:100%;font-size:15px;min-width:480px}
th,td{padding:10px 13px;text-align:left;border-bottom:1px solid var(--line);white-space:nowrap}
th{background:#f3f6f4;font-weight:600;font-size:14px;color:#2b3831}
tbody tr:last-child td{border-bottom:none}
td.lead{font-weight:600}

/* faq */
.faq details{background:#fff;border:1px solid var(--line);border-radius:11px;margin-bottom:8px}
.faq summary{
  cursor:pointer;padding:13px 16px;font-weight:600;font-size:16px;list-style:none;
  display:flex;justify-content:space-between;gap:12px;align-items:flex-start;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--green);font-weight:700;font-size:19px;line-height:1;flex:none}
.faq details[open] summary::after{content:"–"}
.faq details p{margin:0;padding:0 16px 15px;color:#33413a;font-size:16px}

/* cards */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:12px;margin:16px 0 8px}
.card{
  display:block;background:#fff;border:1px solid var(--line);border-radius:12px;padding:15px 16px;
  color:var(--ink);
}
.card:hover{border-color:var(--green);text-decoration:none;box-shadow:0 2px 8px rgba(20,40,30,.06)}
.card b{display:block;font-size:16.5px;margin-bottom:5px;color:var(--green)}
.card span{font-size:14.5px;color:var(--muted);line-height:1.5}
.card.big span{color:#41564b}

/* steps */
ol.steps{padding-left:20px}
ol.steps li{margin-bottom:10px}

/* footer */
footer{margin-top:44px;background:#fff;border-top:1px solid var(--line);padding:26px 0 34px}
footer p{font-size:14px;color:var(--muted);margin:10px 0 0}
nav.foot{display:flex;gap:6px;flex-wrap:wrap;font-size:14.5px}
nav.foot a{padding:4px 8px;border-radius:7px}
nav.foot a:hover{background:var(--green-soft);text-decoration:none}

@media (max-width:560px){
  body{font-size:16px}
  h1{font-size:26px}
  h2{font-size:20px}
  .bar{padding:12px 20px;gap:10px}
  nav.main{margin-left:0;width:100%}
  nav.main a{padding:5px 9px;font-size:14px}
  .res b{font-size:22px}
  .res.hero b{font-size:29px}
}