/* CONCRETE TRANSFORMER PAD CALCULATOR | USCalculators.com/concrete/transformer-pad-calculator/ */
@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@600;700;800;900&family=Inter:wght@400;500;600&display=swap');
:root{--navy:#002868;--navy-dark:#00183F;--navy-mid:#003580;--red:#BF0A30;--red-h:#9B0826;--green:#00875A;--accent:#BF0A30;--white:#fff;--charcoal:#1D1D1F;--gray:#5F6368;--border:#E0E4E8;--bg:#F7F9FC;--bg2:#fff8f8;--sh-sm:0 1px 4px rgba(0,40,104,.08)}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
body{font-family:'Inter',sans-serif;color:var(--gray);-webkit-font-smoothing:antialiased}
.calc-page{max-width:1100px;margin:0 auto;padding:32px 24px 80px}
.calc-hero{background:linear-gradient(135deg,var(--navy-dark) 0%,var(--navy) 60%,#1a0000 100%);border-radius:14px;padding:40px 40px 36px;margin-bottom:32px;position:relative;overflow:hidden}
.calc-hero::before{content:'';position:absolute;inset:0;background:radial-gradient(ellipse 50% 70% at 85% 50%,rgba(191,10,48,.18) 0%,transparent 60%);pointer-events:none}
.calc-hero-label{font-size:11px;font-weight:700;letter-spacing:1.6px;text-transform:uppercase;color:rgba(255,255,255,.5);margin-bottom:6px}
.calc-hero h1{font-family:'Montserrat',sans-serif;font-size:clamp(24px,3vw,36px);font-weight:900;color:#fff;line-height:1.15;margin-bottom:10px;position:relative;z-index:1}
.calc-hero-sub{font-size:15px;color:rgba(255,255,255,.7);line-height:1.65;max-width:680px;position:relative;z-index:1}
.calc-wrap{display:grid;grid-template-columns:420px 1fr;gap:28px;align-items:start;margin-bottom:40px}
.calc-inputs{background:#fff;border:1.5px solid var(--border);border-radius:14px;padding:28px;position:sticky;top:80px}
.inputs-title{font-family:'Montserrat',sans-serif;font-size:15px;font-weight:800;color:var(--navy);margin-bottom:20px;padding-bottom:12px;border-bottom:2px solid var(--border);display:flex;align-items:center;gap:8px}
.inputs-title .dot{width:8px;height:8px;background:var(--accent);border-radius:50%}
.field-group{margin-bottom:16px}
.field-group label{display:block;font-size:12.5px;font-weight:600;color:var(--navy);margin-bottom:5px}
.field-row{display:flex;border:1.5px solid var(--border);border-radius:8px;overflow:hidden;transition:border-color .2s}
.field-row:focus-within{border-color:var(--accent)}
.field-prefix,.field-suffix{background:var(--bg);padding:0 11px;font-size:13px;font-weight:600;color:var(--gray);display:flex;align-items:center;white-space:nowrap;border:none}
.field-row input,.field-row select{flex:1;border:none;padding:10px 12px;font-size:14px;color:var(--charcoal);outline:none;font-family:'Inter',sans-serif;background:#fff;min-width:0}
.field-hint{font-size:11px;color:var(--gray);margin-top:4px}
.field-divider{height:1px;background:var(--border);margin:18px 0}
.field-section-label{font-size:11px;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;color:var(--gray);margin-bottom:12px}
.preset-row{display:flex;gap:6px;margin-bottom:16px}
.preset-btn{flex:1;padding:8px 4px;background:var(--bg);border:1.5px solid var(--border);border-radius:7px;font-family:'Montserrat',sans-serif;font-size:10px;font-weight:700;color:var(--navy);cursor:pointer;transition:all .2s;text-align:center;line-height:1.4}
.preset-btn:hover,.preset-btn.active{background:var(--accent);color:#fff;border-color:var(--accent)}
.calc-actions{display:flex;flex-direction:column;gap:10px;margin-top:20px}
.btn-calc{padding:13px 20px;background:var(--accent);color:#fff;border:none;border-radius:9px;font-family:'Montserrat',sans-serif;font-size:14px;font-weight:800;cursor:pointer;transition:all .2s;width:100%}
.btn-calc:hover{background:var(--red-h);transform:translateY(-1px);box-shadow:0 4px 16px rgba(191,10,48,.35)}
.btn-secondary{padding:11px 16px;background:#fff;color:var(--navy);border:1.5px solid var(--border);border-radius:9px;font-family:'Montserrat',sans-serif;font-size:13px;font-weight:700;cursor:pointer;transition:all .2s;width:100%;text-align:center}
.btn-secondary:hover{border-color:var(--navy);background:var(--bg)}
.btn-whatsapp{padding:11px 16px;background:#25D366;color:#fff;border:none;border-radius:9px;font-family:'Montserrat',sans-serif;font-size:13px;font-weight:700;cursor:pointer;transition:all .2s;width:100%}
.btn-whatsapp:hover{background:#1da851;transform:translateY(-1px)}
.btn-reset{background:none;border:none;color:var(--gray);font-size:12px;cursor:pointer;text-decoration:underline;text-align:center;padding:4px}
.calc-results{background:#fff;border:1.5px solid var(--border);border-radius:14px;padding:24px}
.results-header{font-family:'Montserrat',sans-serif;font-size:15px;font-weight:800;color:var(--navy);margin-bottom:16px;display:flex;align-items:center;gap:8px}
.results-header .dot{width:8px;height:8px;background:var(--green);border-radius:50%}
.result-cards{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:20px}
.result-card{background:#fff;border:1.5px solid var(--border);border-radius:11px;padding:16px}
.result-card.primary{border-color:var(--accent);background:var(--bg2)}
.result-card.green{border-color:var(--green);background:rgba(0,135,90,.04)}
.result-label{font-size:11px;font-weight:600;color:var(--gray);margin-bottom:4px;text-transform:uppercase;letter-spacing:.4px}
.result-value{font-family:'Montserrat',sans-serif;font-size:26px;font-weight:900;color:var(--navy);line-height:1}
.result-value.accent{color:var(--accent)}
.result-value.green{color:var(--green)}
.result-unit{font-size:11.5px;color:var(--gray);margin-top:3px}
.spec-band{background:var(--navy);border-radius:10px;padding:14px 18px;margin-bottom:20px}
.sb-title{font-size:11px;font-weight:700;letter-spacing:1px;text-transform:uppercase;color:rgba(255,255,255,.5);margin-bottom:10px}
.sb-row{display:flex;justify-content:space-between;align-items:flex-start;padding:5px 0;border-bottom:1px solid rgba(255,255,255,.08);gap:12px}
.sb-row:last-child{border-bottom:none}
.sb-label{font-size:12px;color:rgba(255,255,255,.7);flex-shrink:0}
.sb-val{font-family:'Montserrat',sans-serif;font-size:12px;font-weight:800;color:#fff;text-align:right}
.sb-warn{color:#ffb3bf}
.sb-ok{color:#b3ffd0}
.utility-alert{background:rgba(191,10,48,.07);border:1.5px solid rgba(191,10,48,.2);border-radius:8px;padding:11px 14px;font-size:12.5px;color:var(--red);margin-bottom:16px;line-height:1.6;font-weight:600}
.bag-compare-table{width:100%;border-collapse:collapse;margin-bottom:20px;font-size:13px}
.bag-compare-table th{background:var(--navy);color:#fff;font-family:'Montserrat',sans-serif;font-weight:700;padding:9px 12px;text-align:left;font-size:11.5px}
.bag-compare-table td{padding:9px 12px;border-bottom:1px solid var(--border);color:var(--charcoal)}
.bag-compare-table tr.best-row td{background:rgba(0,135,90,.07);font-weight:700;color:var(--navy)}
.bag-compare-table tr:last-child td{border-bottom:none}
.chart-container{background:#fff;border:1.5px solid var(--border);border-radius:11px;padding:20px;margin-bottom:20px}
.chart-title{font-family:'Montserrat',sans-serif;font-size:13px;font-weight:700;color:var(--navy);margin-bottom:14px}
.chart-wrap{position:relative;height:200px}
.summary-box{font-size:14px;color:var(--gray);line-height:1.7;padding:12px 14px;background:var(--bg);border-radius:8px;border-left:3px solid var(--accent);margin-top:16px}
.calc-article{margin-top:48px}
.calc-article h2{font-family:'Montserrat',sans-serif;font-size:clamp(20px,2.5vw,26px);font-weight:800;color:var(--navy);margin:44px 0 14px;line-height:1.25;padding-top:8px;border-top:2px solid var(--border)}
.calc-article h2:first-child{border-top:none;margin-top:0}
.calc-article h3{font-family:'Montserrat',sans-serif;font-size:17px;font-weight:700;color:var(--navy-mid);margin:24px 0 10px}
.calc-article p{font-size:15.5px;color:var(--gray);line-height:1.82;margin-bottom:14px}
.calc-article ul,.calc-article ol{margin:10px 0 16px 24px}
.calc-article li{font-size:15.5px;color:var(--gray);line-height:1.78;margin-bottom:8px}
.calc-article strong{color:var(--charcoal)}
.calc-article a{color:var(--navy);text-decoration:underline;text-underline-offset:2px}
.example-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:20px 0}
.example-card{background:#fff;border:1.5px solid var(--border);border-radius:11px;padding:20px}
.example-card h3{font-family:'Montserrat',sans-serif;font-size:14px;font-weight:800;color:var(--accent);margin-bottom:10px}
.example-row{display:flex;justify-content:space-between;align-items:center;padding:5px 0;border-bottom:1px solid var(--border);font-size:13px}
.example-row:last-child{border-bottom:none;font-weight:700;color:var(--navy)}
.example-row span:first-child{color:var(--gray)}
.tips-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:20px 0}
.tip-card{background:var(--bg);border-left:4px solid var(--accent);border-radius:0 10px 10px 0;padding:18px}
.tip-num{font-family:'Montserrat',sans-serif;font-size:24px;font-weight:900;color:var(--accent);line-height:1;margin-bottom:6px}
.tip-title{font-family:'Montserrat',sans-serif;font-size:13.5px;font-weight:700;color:var(--navy);margin-bottom:6px}
.tip-text{font-size:13px;color:var(--gray);line-height:1.65}
.faq-list{display:flex;flex-direction:column;gap:8px;margin-top:16px}
.faq-item{border:1.5px solid var(--border);border-radius:9px;overflow:hidden}
.faq-q{display:flex;justify-content:space-between;align-items:center;padding:14px 18px;cursor:pointer;gap:12px;font-family:'Montserrat',sans-serif;font-size:14px;font-weight:700;color:var(--navy);user-select:none;transition:background .2s}
.faq-q:hover{background:var(--bg)}
.faq-q.open{background:var(--navy);color:#fff}
.faq-ic{width:22px;height:22px;border:2px solid var(--border);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:15px;flex-shrink:0;transition:all .2s}
.faq-q.open .faq-ic{background:#fff;border-color:#fff;color:var(--navy)}
.faq-a{max-height:0;overflow:hidden;transition:max-height .35s ease,padding .35s ease;font-size:14.5px;color:var(--gray);line-height:1.75;padding:0 18px}
.faq-a.open{max-height:500px;padding:14px 18px 18px}
.faq-a a{color:var(--navy);text-decoration:underline}
.related-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-top:16px}
.related-card{background:#fff;border:1.5px solid var(--border);border-radius:10px;padding:16px 14px;display:block;transition:all .2s;text-decoration:none}
.related-card:hover{border-color:var(--accent);transform:translateY(-2px);box-shadow:var(--sh-sm)}
.related-icon{font-size:22px;margin-bottom:8px}
.related-name{font-family:'Montserrat',sans-serif;font-size:12.5px;font-weight:700;color:var(--navy);line-height:1.3;margin-bottom:4px}
.related-desc{font-size:11.5px;color:var(--gray);line-height:1.5}
.disclaimer{background:var(--bg);border:1px solid var(--border);border-radius:10px;padding:20px 22px;margin-top:40px;font-size:13px;color:var(--gray);line-height:1.72}
.disclaimer strong{color:var(--charcoal)}
@media(max-width:900px){.calc-wrap{grid-template-columns:1fr}.calc-inputs{position:static}.result-cards{grid-template-columns:1fr 1fr}.example-grid{grid-template-columns:1fr}.tips-grid{grid-template-columns:1fr}.related-grid{grid-template-columns:1fr 1fr}}
@media(max-width:600px){.calc-page{padding:20px 16px 60px}.calc-hero{padding:28px 24px}.result-cards{grid-template-columns:1fr}.related-grid{grid-template-columns:1fr 1fr}}