/* Solar Math — styles */
:root{
  --ink:#11261c;
  --ink-soft:#44584e;
  --ink-faint:#6b7d74;
  --line:#dfe6e1;
  --line-soft:#edf2ee;
  --bg:#ffffff;
  --bg-tint:#f6faf7;
  --bg-sun:#fffaf0;
  --green:#0f7a4f;
  --green-dark:#0a5a3a;
  --green-tint:#e6f4ec;
  --sun:#e8991a;
  --sun-tint:#fdf1dc;
  --red:#b3401f;
  --radius:14px;
  --radius-sm:9px;
  --shadow:0 1px 2px rgba(17,38,28,.05),0 8px 24px -12px rgba(17,38,28,.14);
  --maxw:1140px;
  --font:"Inter","Open Sans","Helvetica Neue",Arial,sans-serif;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;font-family:var(--font);color:var(--ink);background:var(--bg);
  font-size:16.5px;line-height:1.65;-webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{line-height:1.22;letter-spacing:-.018em;margin:0 0 .5em}
h1{font-size:clamp(1.85rem,4.4vw,2.9rem);font-weight:800}
h2{font-size:clamp(1.35rem,2.6vw,1.9rem);font-weight:750}
h3{font-size:1.14rem;font-weight:700}
p{margin:0 0 1.05em}
a{color:var(--green);text-decoration:none}
a:hover{color:var(--green-dark)}
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{
  outline:2.5px solid var(--sun);outline-offset:2px;border-radius:4px
}
img,svg{max-width:100%}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}
.narrow{max-width:760px}

/* ---------- header ---------- */
.site-head{
  position:sticky;top:0;z-index:600;background:rgba(255,255,255,.92);
  backdrop-filter:saturate(180%) blur(12px);border-bottom:1px solid var(--line)
}
.head-in{display:flex;align-items:center;gap:22px;height:62px}
.brand{display:flex;align-items:center;gap:8px;font-weight:800;font-size:1.06rem;color:var(--ink);letter-spacing:-.02em}
.brand .mark{
  width:28px;height:28px;border-radius:8px;flex:none;
  background:conic-gradient(from 210deg,var(--sun),#f6c159,var(--green));
  display:grid;place-items:center;color:#fff;font-size:.8rem;font-weight:800
}
.nav{margin-left:auto;display:flex;gap:4px;align-items:center;flex-wrap:wrap}
.nav a{
  padding:7px 12px;border-radius:8px;font-size:.93rem;font-weight:600;color:var(--ink-soft)
}
.nav a:hover{background:var(--bg-tint);color:var(--ink)}
.nav a.cta{background:var(--green);color:#fff}
.nav a.cta:hover{background:var(--green-dark);color:#fff}

/* ---------- hero ---------- */
.hero{background:linear-gradient(170deg,var(--bg-sun),var(--bg-tint) 62%,#fff);border-bottom:1px solid var(--line-soft)}
.hero-in{padding:52px 0 40px;max-width:800px}
.eyebrow{
  display:inline-flex;align-items:center;gap:7px;font-size:.78rem;font-weight:700;
  letter-spacing:.06em;text-transform:uppercase;color:var(--green-dark);
  background:var(--green-tint);padding:5px 11px;border-radius:99px;margin-bottom:16px
}
.hero p.lede{font-size:1.1rem;color:var(--ink-soft);max-width:65ch;margin-bottom:0}

/* ---------- layout ---------- */
.cols{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:34px;align-items:start;padding:34px 0 10px}
@media(max-width:980px){.cols{grid-template-columns:1fr}}
.rail{position:sticky;top:82px;display:grid;gap:18px}
@media(max-width:980px){.rail{position:static}}

/* ---------- cards ---------- */
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.card-pad{padding:22px}
.card-head{padding:17px 22px;border-bottom:1px solid var(--line-soft);display:flex;align-items:center;gap:10px}
.card-head h2,.card-head h3{margin:0;font-size:1.05rem}
.step-n{
  width:23px;height:23px;border-radius:50%;background:var(--green);color:#fff;flex:none;
  display:grid;place-items:center;font-size:.76rem;font-weight:800
}
.stack{display:grid;gap:18px}

/* ---------- form ---------- */
.field{display:grid;gap:6px;margin-bottom:15px}
.field:last-child{margin-bottom:0}
label,.lbl{font-size:.86rem;font-weight:650;color:var(--ink)}
.hint{font-size:.79rem;color:var(--ink-faint);line-height:1.5}
input[type=text],input[type=number],input[type=email],select,textarea{
  width:100%;padding:9px 11px;font:inherit;font-size:.95rem;color:var(--ink);
  background:#fff;border:1px solid var(--line);border-radius:var(--radius-sm)
}
input:hover,select:hover{border-color:#c3cec7}
.row{display:grid;grid-template-columns:1fr 1fr;gap:13px}
.row-3{display:grid;grid-template-columns:repeat(3,1fr);gap:13px}
@media(max-width:560px){.row,.row-3{grid-template-columns:1fr}}
.inline-unit{display:flex;align-items:center;gap:8px}
.inline-unit input{flex:1}
.inline-unit .u{font-size:.84rem;color:var(--ink-faint);font-weight:600;white-space:nowrap}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 18px;font:inherit;font-size:.95rem;font-weight:700;cursor:pointer;
  border-radius:var(--radius-sm);border:1px solid transparent;background:var(--green);color:#fff
}
.btn:hover{background:var(--green-dark)}
.btn.ghost{background:#fff;border-color:var(--line);color:var(--ink)}
.btn.ghost:hover{background:var(--bg-tint)}
.btn.block{width:100%}
.btn.lg{padding:14px 22px;font-size:1.02rem}
.btn:disabled{opacity:.55;cursor:not-allowed}

.seg{display:flex;gap:0;background:var(--bg-tint);border:1px solid var(--line);border-radius:var(--radius-sm);padding:3px}
.seg button{
  flex:1;padding:8px 6px;font:inherit;font-size:.87rem;font-weight:650;cursor:pointer;
  background:none;border:0;border-radius:6px;color:var(--ink-soft)
}
.seg button[aria-selected=true]{background:#fff;color:var(--ink);box-shadow:0 1px 3px rgba(17,38,28,.12)}
.hidden{display:none!important}

/* ---------- map ---------- */
#map{height:290px;border-radius:var(--radius-sm);border:1px solid var(--line);z-index:1}
.map-tools{display:flex;gap:9px;margin-bottom:12px;flex-wrap:wrap}
.map-tools input{flex:1;min-width:180px}
.loc-readout{
  margin-top:11px;font-size:.85rem;color:var(--ink-soft);background:var(--bg-tint);
  border:1px solid var(--line-soft);border-radius:var(--radius-sm);padding:9px 12px
}
.loc-readout strong{color:var(--ink)}

/* ---------- appliances ---------- */
.appl{display:grid;gap:7px}
.appl-row{
  display:grid;grid-template-columns:1fr 74px 74px 30px;gap:8px;align-items:center;
  font-size:.88rem
}
.appl-row.hd{font-size:.76rem;font-weight:700;color:var(--ink-faint);text-transform:uppercase;letter-spacing:.04em}
.appl-row input,.appl-row select{padding:7px 8px;font-size:.88rem}
.appl-row .x{
  background:none;border:1px solid var(--line);border-radius:6px;cursor:pointer;
  color:var(--ink-faint);font-size:1rem;line-height:1;padding:5px 0;width:30px
}
.appl-row .x:hover{border-color:var(--red);color:var(--red)}

/* ---------- results ---------- */
.kpis{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:1px;background:var(--line-soft)}
.kpi{background:#fff;padding:18px 20px}
.kpi .k{font-size:.78rem;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--ink-faint)}
.kpi .v{font-size:1.65rem;font-weight:800;letter-spacing:-.03em;margin-top:3px;line-height:1.1}
.kpi .s{font-size:.82rem;color:var(--ink-faint);margin-top:2px}
.kpi.hi .v{color:var(--green)}
.kpi.sun .v{color:var(--sun)}

table.spec{width:100%;border-collapse:collapse;font-size:.92rem}
table.spec th,table.spec td{padding:10px 22px;text-align:left;border-bottom:1px solid var(--line-soft)}
table.spec th{font-weight:650;color:var(--ink-soft);width:52%}
table.spec td{font-weight:700;text-align:right}
table.spec tr:last-child th,table.spec tr:last-child td{border-bottom:0}

.note{
  font-size:.86rem;color:var(--ink-soft);background:var(--bg-sun);
  border:1px solid #f3e2c2;border-left:3px solid var(--sun);
  border-radius:var(--radius-sm);padding:12px 15px;margin:0
}
.note.warn{background:#fdf0ec;border-color:#f2d2c7;border-left-color:var(--red)}
.note strong{color:var(--ink)}
.chart-wrap{padding:18px 22px 22px;overflow-x:auto}
.legend{display:flex;gap:16px;font-size:.82rem;color:var(--ink-faint);margin-top:10px;flex-wrap:wrap}
.legend i{width:11px;height:11px;border-radius:3px;display:inline-block;margin-right:6px;vertical-align:-1px}

/* ---------- ads ---------- */
.ad{
  margin:26px 0;display:flex;align-items:center;justify-content:center;
  min-height:92px;background:var(--bg-tint);border:1px dashed var(--line);
  border-radius:var(--radius-sm);color:var(--ink-faint);font-size:.76rem;
  letter-spacing:.07em;text-transform:uppercase;font-weight:650
}
.ad-rail{min-height:300px;margin:0}
.ad-label{font-size:.68rem;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-faint);margin-bottom:5px;font-weight:650}

/* ---------- prose ---------- */
.prose{max-width:none}
.prose h2{margin-top:1.9em}
.prose h3{margin-top:1.5em}
.prose ul,.prose ol{padding-left:1.25em;margin:0 0 1.05em}
.prose li{margin-bottom:.4em}
.prose table{width:100%;border-collapse:collapse;font-size:.93rem;margin:0 0 1.3em}
.prose th,.prose td{padding:9px 12px;border:1px solid var(--line);text-align:left}
.prose th{background:var(--bg-tint);font-weight:700}
.prose blockquote{
  margin:0 0 1.2em;padding:2px 0 2px 18px;border-left:3px solid var(--green-tint);
  color:var(--ink-soft);font-style:normal
}
.prose code{background:var(--bg-tint);padding:2px 6px;border-radius:5px;font-size:.92em;font-family:inherit;font-weight:650}
.formula{
  background:var(--bg-tint);border:1px solid var(--line);border-radius:var(--radius-sm);
  padding:15px 18px;margin:0 0 1.2em;font-weight:650;line-height:1.75
}

/* ---------- faq ---------- */
details.faq{border-bottom:1px solid var(--line-soft);padding:2px 0}
details.faq summary{
  cursor:pointer;padding:14px 30px 14px 0;font-weight:650;list-style:none;position:relative
}
details.faq summary::-webkit-details-marker{display:none}
details.faq summary::after{
  content:"+";position:absolute;right:4px;top:12px;font-size:1.25rem;color:var(--green);font-weight:700
}
details.faq[open] summary::after{content:"\2013"}
details.faq .a{padding:0 0 14px;color:var(--ink-soft);font-size:.95rem}
details.faq .a p:last-child{margin-bottom:0}

/* ---------- blog ---------- */
.post-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(265px,1fr));gap:18px}
.post-card{
  display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);
  border-radius:var(--radius);padding:20px;box-shadow:var(--shadow);color:var(--ink)
}
.post-card:hover{border-color:#c3cec7;color:var(--ink)}
.post-card .tag{font-size:.73rem;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--sun);margin-bottom:8px}
.post-card h3{font-size:1.04rem;margin-bottom:7px}
.post-card p{font-size:.9rem;color:var(--ink-soft);margin-bottom:12px;flex:1}
.post-card .more{font-size:.86rem;font-weight:700;color:var(--green)}
.post-meta{font-size:.85rem;color:var(--ink-faint);margin-bottom:26px}
.post-meta span+span::before{content:"·";margin:0 8px}
.toc{background:var(--bg-tint);border:1px solid var(--line-soft);border-radius:var(--radius-sm);padding:16px 20px;margin:0 0 1.8em}
.toc .lbl{font-size:.78rem;letter-spacing:.05em;text-transform:uppercase;color:var(--ink-faint);margin-bottom:8px}
.toc ol{margin:0;padding-left:1.2em;font-size:.93rem}
.toc li{margin-bottom:3px}
.next-prev{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;margin-top:34px}

/* ---------- footer ---------- */
.site-foot{background:var(--bg-tint);border-top:1px solid var(--line);margin-top:56px;padding:40px 0 30px;font-size:.9rem}
.foot-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:28px}
@media(max-width:800px){.foot-grid{grid-template-columns:1fr 1fr}}
.foot-grid h4{font-size:.8rem;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-faint);margin-bottom:11px}
.foot-grid ul{list-style:none;margin:0;padding:0}
.foot-grid li{margin-bottom:7px}
.foot-grid a{color:var(--ink-soft)}
.foot-grid a:hover{color:var(--green)}
.foot-bar{border-top:1px solid var(--line);margin-top:30px;padding-top:20px;color:var(--ink-faint);font-size:.84rem}
.disclaimer{background:#fff;border:1px solid var(--line);border-radius:var(--radius-sm);padding:14px 17px;font-size:.84rem;color:var(--ink-soft);margin-bottom:26px}
.skip{position:absolute;left:-9999px}
.skip:focus{left:12px;top:12px;z-index:999;background:#fff;padding:10px 14px;border-radius:8px;box-shadow:var(--shadow)}
@media print{.site-head,.site-foot,.ad,.rail,.map-tools{display:none}}

/* ---------- mobile header ---------- */
@media(max-width:760px){
  .head-in{height:auto;min-height:56px;gap:10px;padding-top:9px;padding-bottom:9px;flex-wrap:nowrap}
  .brand{font-size:.98rem;white-space:nowrap;flex:none}
  .brand .mark{width:25px;height:25px}
  .nav{gap:2px;flex-wrap:nowrap;overflow:visible}
  .nav a{padding:6px 8px;font-size:.87rem}
  .nav a:not(.cta):not(.nav-guides){display:none}
  .nav a.cta{padding:7px 12px;white-space:nowrap}
}
@media(max-width:430px){
  .brand .bt{display:none}
  .brand .mark{width:29px;height:29px;font-size:.9rem}
}
@media(max-width:560px){
  .hero-in{padding:36px 0 30px}
  .kpi{padding:15px 16px}
  .kpi .v{font-size:1.45rem}
  table.spec th,table.spec td{padding:9px 16px}
  .card-pad,.card-head{padding-left:16px;padding-right:16px}
  .chart-wrap{padding-left:14px;padding-right:14px}
  .appl-row{grid-template-columns:1fr 58px 58px 28px;gap:6px}
  .prose table{font-size:.86rem;display:block;overflow-x:auto;white-space:nowrap}
}