:root{
  --ink:#17221b;
  --muted:#647067;
  --green:#236b45;
  --green-dark:#174d32;
  --green-soft:#eaf5ee;
  --cream:#f7f7f2;
  --card:#ffffff;
  --line:#e2e7e1;
  --accent:#e9b949;
  --shadow:0 12px 32px rgba(25,45,34,.08);
  --radius:18px;
  --max:1180px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--cream);color:var(--ink);
  font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  line-height:1.6;
}
a{color:inherit;text-decoration:none}
.container{width:min(calc(100% - 36px),var(--max));margin:auto}
.site-header{
  background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50;
}
.nav{height:74px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{display:flex;align-items:center;gap:11px;font-weight:800;font-size:19px;letter-spacing:-.02em}
.logo{
  width:38px;height:38px;border-radius:11px;background:var(--green);
  color:#fff;display:grid;place-items:center;font-weight:900;box-shadow:0 5px 15px rgba(35,107,69,.2)
}
.nav-links{display:flex;align-items:center;gap:24px;color:#46534a;font-size:14px;font-weight:600}
.nav-links a:hover{color:var(--green)}
.nav-cta{padding:10px 15px;border-radius:10px;background:var(--green);color:#fff!important}
.menu-btn{display:none;border:1px solid var(--line);background:#fff;border-radius:10px;padding:8px 11px;font-size:18px}

.hero{padding:76px 0 55px;background:
  radial-gradient(circle at 80% 20%,rgba(233,185,73,.20),transparent 30%),
  linear-gradient(135deg,#f8fbf7 0%,#eef7f0 100%);
}
.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:55px;align-items:center}
.eyebrow{
  display:inline-flex;gap:8px;align-items:center;background:var(--green-soft);
  color:var(--green-dark);padding:7px 11px;border-radius:999px;font-size:12px;font-weight:800;text-transform:uppercase;letter-spacing:.08em
}
h1{font-size:clamp(40px,5vw,66px);line-height:1.02;letter-spacing:-.055em;margin:18px 0 20px}
.hero p{font-size:18px;color:#556158;max-width:680px;margin:0 0 26px}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;justify-content:center;border:0;cursor:pointer;padding:13px 18px;border-radius:12px;font-weight:800;font-size:14px}
.btn-primary{background:var(--green);color:#fff;box-shadow:0 8px 20px rgba(35,107,69,.18)}
.btn-primary:hover{background:var(--green-dark)}
.btn-secondary{background:#fff;border:1px solid var(--line);color:var(--ink)}
.hero-card{background:#fff;border:1px solid var(--line);border-radius:24px;padding:25px;box-shadow:var(--shadow)}
.mini-result{background:#f4f8f4;border-radius:15px;padding:17px;margin-top:14px}
.mini-result strong{display:block;font-size:29px;letter-spacing:-.04em}
.mini-row{display:flex;justify-content:space-between;font-size:13px;color:var(--muted);padding:8px 0;border-bottom:1px solid #dfe8e1}
.mini-row:last-child{border:0}

.section{padding:70px 0}
.section-head{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:28px}
.section h2{font-size:34px;line-height:1.1;letter-spacing:-.04em;margin:0}
.section-head p{color:var(--muted);max-width:620px;margin:7px 0 0}
.search-wrap{display:flex;gap:10px;max-width:620px;margin:0 auto 24px}
.search{width:100%;border:1px solid var(--line);background:#fff;border-radius:13px;padding:14px 16px;font-size:15px;outline:none}
.search:focus{border-color:var(--green);box-shadow:0 0 0 3px rgba(35,107,69,.1)}
.filters{display:flex;justify-content:center;gap:8px;flex-wrap:wrap;margin-bottom:28px}
.filter{border:1px solid var(--line);background:#fff;border-radius:999px;padding:8px 14px;font-weight:700;color:#59645d;cursor:pointer}
.filter.active,.filter:hover{background:var(--green);color:#fff;border-color:var(--green)}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:17px}
.tool-card{
  background:#fff;border:1px solid var(--line);border-radius:17px;padding:21px;
  transition:.2s ease;position:relative;min-height:205px;display:flex;flex-direction:column
}
.tool-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:#cbd8ce}
.tool-icon{width:42px;height:42px;border-radius:12px;background:var(--green-soft);display:grid;place-items:center;font-size:20px;margin-bottom:16px}
.tool-card h3{font-size:19px;margin:0 0 7px;letter-spacing:-.025em}
.tool-card p{font-size:14px;color:var(--muted);margin:0 0 16px}
.card-link{margin-top:auto;color:var(--green);font-weight:800;font-size:14px}
.empty{display:none;text-align:center;color:var(--muted);padding:35px}

.ad-slot{
  border:1px dashed #ccd5ce;border-radius:12px;background:#fbfcfa;
  color:#9aa49d;text-align:center;font-size:11px;letter-spacing:.08em;text-transform:uppercase;
  min-height:82px;display:grid;place-items:center;margin:28px 0
}
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.feature{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px}
.feature h3{margin:10px 0 6px;font-size:18px}.feature p{margin:0;color:var(--muted);font-size:14px}
.feature-icon{font-size:25px}

.cta{background:var(--green-dark);color:#fff;border-radius:26px;padding:42px;margin:20px 0}
.cta h2{margin:0 0 10px;font-size:32px}.cta p{color:#d4e2d9;margin:0 0 20px;max-width:650px}
.cta .btn-secondary{background:#fff}

.site-footer{background:#142019;color:#d7e0da;padding:50px 0 25px;margin-top:50px}
.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:35px}
.footer-brand{font-size:20px;font-weight:800;color:#fff}.footer-copy{color:#9eaca2;font-size:13px;max-width:330px}
.footer-col h4{color:#fff;margin:0 0 12px;font-size:13px;text-transform:uppercase;letter-spacing:.08em}
.footer-col a{display:block;color:#aebbb2;font-size:13px;margin:8px 0}.footer-col a:hover{color:#fff}
.copyright{border-top:1px solid #29372f;margin-top:35px;padding-top:18px;color:#8e9c93;font-size:12px;display:flex;justify-content:space-between;gap:15px}

.calc-hero{padding:45px 0 30px;background:linear-gradient(135deg,#f8fbf7,#edf6ef)}
.breadcrumb{font-size:13px;color:var(--muted);margin-bottom:20px}.breadcrumb a{color:var(--green);font-weight:700}
.calc-layout{display:grid;grid-template-columns:1fr 390px;gap:25px;align-items:start}
.calc-panel,.result-panel,.info-card,.faq-card{background:#fff;border:1px solid var(--line);border-radius:20px;box-shadow:0 8px 24px rgba(25,45,34,.05)}
.calc-panel{padding:26px}.calc-panel h1{font-size:42px;margin:0 0 10px}.calc-intro{color:var(--muted);margin:0 0 22px}
.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.field label{display:block;font-weight:800;font-size:13px;margin-bottom:7px}
.field input,.field select{
  width:100%;padding:12px 13px;border:1px solid #d5ddd7;border-radius:11px;background:#fff;font-size:15px;outline:none
}
.field input:focus,.field select:focus{border-color:var(--green);box-shadow:0 0 0 3px rgba(35,107,69,.09)}
.unit{position:relative}.unit span{position:absolute;right:12px;top:12px;color:#849088;font-size:13px}
.calc-actions{display:flex;gap:10px;margin-top:20px}.calc-actions .btn{flex:1}
.result-panel{padding:25px;position:sticky;top:95px;background:#173b29;color:#fff}
.result-label{font-size:12px;text-transform:uppercase;letter-spacing:.1em;color:#b8d2c1;font-weight:800}
.result-main{font-size:45px;line-height:1.05;letter-spacing:-.05em;font-weight:900;margin:8px 0 18px}
.result-unit{font-size:16px;color:#d1e1d6;font-weight:700}
.result-lines{border-top:1px solid rgba(255,255,255,.16);margin-top:18px;padding-top:10px}
.result-line{display:flex;justify-content:space-between;gap:15px;padding:9px 0;color:#d8e4dc;font-size:13px}.result-line strong{color:#fff}
.result-note{font-size:12px;color:#b8cbbf;margin-top:15px}
.assumption{margin-top:22px;background:#f4f8f4;border:1px solid #dce7df;border-radius:14px;padding:15px;font-size:13px;color:#5b685f}
.assumption strong{display:block;color:var(--ink);margin-bottom:3px}
.content-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:25px}
.info-card{padding:23px}.info-card h2{font-size:22px;margin:0 0 10px}.info-card p{color:var(--muted);font-size:14px}
.info-card ul{margin:8px 0;padding-left:20px;color:#59655d;font-size:14px}
.faq-card{padding:0;overflow:hidden}.faq-card h2{padding:22px 23px;margin:0;font-size:22px}
.faq{border-top:1px solid var(--line);padding:16px 23px}.faq summary{font-weight:800;cursor:pointer}.faq p{color:var(--muted);font-size:14px;margin:10px 0 0}
.related{margin-top:35px}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.related-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:17px}.related-card strong{display:block;margin-bottom:4px}.related-card span{font-size:13px;color:var(--muted)}

.page-hero{padding:60px 0 35px}.page-hero h1{font-size:46px}.prose{max-width:820px}.prose h2{margin-top:34px}.prose p,.prose li{color:#56625a}
.notice{background:#fff8e7;border:1px solid #f0ddab;border-radius:14px;padding:16px;color:#66552c}

@media(max-width:900px){
  .hero-grid,.calc-layout{grid-template-columns:1fr}
  .result-panel{position:static}
  .grid{grid-template-columns:repeat(2,1fr)}
  .feature-grid,.footer-grid{grid-template-columns:1fr 1fr}
  .content-grid{grid-template-columns:1fr}
}
@media(max-width:680px){
  .container{width:min(calc(100% - 24px),var(--max))}
  .nav{height:66px}.nav-links{display:none}.menu-btn{display:block}
  .nav.open .nav-links{display:flex;position:absolute;left:12px;right:12px;top:66px;background:#fff;border:1px solid var(--line);padding:14px;border-radius:14px;flex-direction:column;align-items:stretch;box-shadow:var(--shadow)}
  .hero{padding:50px 0 35px}.hero h1{font-size:42px}
  .grid,.feature-grid,.footer-grid,.related-grid{grid-template-columns:1fr}
  .section{padding:48px 0}.section-head{display:block}
  .field-grid{grid-template-columns:1fr}
  .calc-panel h1{font-size:35px}.result-main{font-size:39px}
  .copyright{display:block}.copyright span{display:block;margin-top:8px}
}

/* SEO content system */
.jump-links{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px 20px;margin:25px 0}.jump-links strong{display:block;margin-bottom:8px}.jump-links a{display:inline-block;color:var(--green);font-weight:700;margin:5px 16px 5px 0;font-size:14px}.content-wide{max-width:900px;margin:0 auto}.content-wide h2{font-size:30px;line-height:1.15;letter-spacing:-.035em;margin:38px 0 10px}.content-wide h3{font-size:21px;margin:25px 0 8px}.content-wide p,.content-wide li{color:#56625a}.content-wide ul{padding-left:21px}.formula-card{background:#f1f7f2;border:1px solid #d7e5da;border-radius:16px;padding:18px 20px;margin:20px 0}.formula-card strong{display:block;color:var(--green-dark);margin-bottom:6px}.example-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:20px;margin:20px 0;box-shadow:0 8px 24px rgba(25,45,34,.04)}.seo-table{width:100%;border-collapse:collapse;margin:18px 0 8px;background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden}.seo-table th,.seo-table td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--line);font-size:14px}.seo-table th{background:#f2f7f3;color:var(--green-dark)}.seo-table tr:last-child td{border-bottom:0}.update-line{color:#7a857d;font-size:12px;margin-top:10px}.footer-method{display:inline-block;color:#cfe0d5;font-size:13px;font-weight:700;margin-top:5px}.author-box{display:flex;gap:14px;align-items:flex-start;background:#f7faf7;border:1px solid var(--line);border-radius:16px;padding:17px 19px;margin:24px 0}.author-mark{width:42px;height:42px;border-radius:12px;background:var(--green);color:#fff;display:grid;place-items:center;font-weight:900;flex:0 0 auto}.author-box p{margin:2px 0;color:var(--muted);font-size:13px}.guide-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px}.guide-card h3{margin:0 0 6px;font-size:18px}.guide-card p{color:var(--muted);font-size:14px;margin:0 0 10px}.guide-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.seo-intro{font-size:18px;color:#536158;max-width:820px}.note-list{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin:16px 0}.note-list>div{background:#fff;border:1px solid var(--line);border-radius:14px;padding:15px}.note-list strong{display:block;margin-bottom:3px}@media(max-width:680px){.guide-grid,.note-list{grid-template-columns:1fr}.content-wide h2{font-size:26px}.seo-table{display:block;overflow-x:auto;white-space:nowrap}}

/* SEO content system */
.jump-links{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px 20px;margin:25px 0}.jump-links strong{display:block;margin-bottom:8px}.jump-links a{display:inline-block;color:var(--green);font-weight:700;margin:5px 16px 5px 0;font-size:14px}.content-wide{max-width:900px;margin:0 auto}.content-wide h2{font-size:30px;line-height:1.15;letter-spacing:-.035em;margin:38px 0 10px}.content-wide h3{font-size:21px;margin:25px 0 8px}.content-wide p,.content-wide li{color:#56625a}.content-wide ul{padding-left:21px}.formula-card{background:#f1f7f2;border:1px solid #d7e5da;border-radius:16px;padding:18px 20px;margin:20px 0}.formula-card strong{display:block;color:var(--green-dark);margin-bottom:6px}.example-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:20px;margin:20px 0;box-shadow:0 8px 24px rgba(25,45,34,.04)}.seo-table{width:100%;border-collapse:collapse;margin:18px 0 8px;background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden}.seo-table th,.seo-table td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--line);font-size:14px}.seo-table th{background:#f2f7f3;color:var(--green-dark)}.seo-table tr:last-child td{border-bottom:0}.update-line{color:#7a857d;font-size:12px;margin-top:10px}.footer-method{display:inline-block;color:#cfe0d5;font-size:13px;font-weight:700;margin-top:5px}.author-box{display:flex;gap:14px;align-items:flex-start;background:#f7faf7;border:1px solid var(--line);border-radius:16px;padding:17px 19px;margin:24px 0}.author-mark{width:42px;height:42px;border-radius:12px;background:var(--green);color:#fff;display:grid;place-items:center;font-weight:900;flex:0 0 auto}.author-box p{margin:2px 0;color:var(--muted);font-size:13px}.guide-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px}.guide-card h3{margin:0 0 6px;font-size:18px}.guide-card p{color:var(--muted);font-size:14px;margin:0 0 10px}.guide-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.seo-intro{font-size:18px;color:#536158;max-width:820px}.note-list{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin:16px 0}.note-list>div{background:#fff;border:1px solid var(--line);border-radius:14px;padding:15px}.note-list strong{display:block;margin-bottom:3px}@media(max-width:680px){.guide-grid,.note-list{grid-template-columns:1fr}.content-wide h2{font-size:26px}.seo-table{display:block;overflow-x:auto;white-space:nowrap}}


/* Monetization-ready ad placements: three unobtrusive slots per page. Replace each slot's placeholder with the approved ad code after AdSense approval. */
.ad-slot{min-height:90px;padding:14px 16px;box-sizing:border-box;}
.ad-slot-top{margin-top:18px;margin-bottom:18px;}
.ad-slot-middle{margin-top:32px;margin-bottom:32px;}
.ad-slot-bottom{margin-top:18px;margin-bottom:18px;}
.ad-slot[aria-label="Advertisement"]{font-size:10px;}