.btu-section .btu-intro{display:grid;grid-template-columns:1.2fr 1fr;gap:48px;align-items:center}
.btu-intro-copy{font-size:16px;line-height:1.7;color:var(--muted);max-width:460px;margin-top:15px}
.btu-explainer{padding:3px 0 3px 24px;border-left:3px solid #a6d7cb}
.btu-explainer h3{font-size:17px;letter-spacing:-.02em;margin-bottom:9px}
.btu-explainer p{font-size:14px;line-height:1.8;color:var(--muted)}.btu-explainer strong{font-weight:600;color:var(--ink)}
.btu-conditions[open]>summary:after,.btu-method[open]>summary:after{content:'−';transform:none}
.header-contact{display:inline-flex;align-items:center;gap:12px;min-height:44px;padding:8px 0;color:var(--teal);font-weight:650;font-size:14px;border-bottom:2px solid transparent;white-space:nowrap}
.header-contact:hover,.header-contact[aria-current]{border-color:var(--teal)}
.hero-direct{display:inline-flex;align-items:center;gap:10px;min-height:48px;color:#e1eeef;font-size:14px;text-decoration:underline;text-underline-offset:5px}
.hero-direct .icon{width:20px;height:20px;color:var(--mint)}.hero-direct:hover{color:var(--mint)}
.hero .actions{align-items:center}.service{cursor:default}.service:hover,.service:focus-within{border-color:#cddddd;box-shadow:none;transform:none}.service .tags{margin-bottom:0;margin-top:22px}.service p{flex:1}
.service-help{gap:24px;padding:25px 28px}.service-help>a.button{background:transparent;border:1px solid var(--teal);border-radius:10px;padding:12px 18px;color:var(--teal);font-size:14px}.service-help>a.button:hover{background:#daeee5}.service-help h3{font-size:19px}.footer-bottom{padding-bottom:28px}
.btu-section{padding-block:64px}.btu-section .section-head{align-items:center}.btu-section .section-head>p{max-width:350px}.btu-section .section-head h2{font-size:clamp(28px,3vw,40px)}
.btu-tool{border:1px solid #bdd3d0;border-radius:18px;overflow:hidden;background:#f6faf8}.btu-tool>summary{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:23px 28px;min-height:96px}.btu-tool>summary:after{content:none}.btu-tool>summary:hover{background:#edf7f1}.btu-tool>summary:focus-visible{outline-offset:-5px}.btu-invitation{display:flex;align-items:center;gap:18px;font-size:18px;line-height:1.5;letter-spacing:-.02em}.btu-invitation>i{background:#dcefe8;border-radius:12px;padding:12px;color:var(--teal)}.btu-invitation small{display:block;font-size:14px;color:var(--muted);font-weight:400;letter-spacing:0}.btu-open-label{display:flex;align-items:center;gap:18px;color:var(--teal);font-size:14px;white-space:nowrap}.btu-open-label:after{content:'+';font-size:25px;font-weight:400}.btu-tool[open] .btu-open-label:after{content:'−'}
.btu-grid{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid #c5d8d2}.btu-grid>*{min-width:0}.btu-grid form{padding:32px;border-radius:0;background:white}.btu-form-heading{display:flex;align-items:center;gap:14px;margin-bottom:26px}.btu-step{display:inline-flex;align-items:center;justify-content:center;width:32px;height:32px;border:1px solid #c2d6d0;border-radius:50%;color:var(--teal);font-size:11px;font-weight:650;flex-shrink:0}.btu-form-heading h3{font-size:20px;line-height:1.35;margin:0 0 5px;letter-spacing:-.025em}.btu-form-heading p{font-size:13px;color:var(--muted)}
#btu-form label,#btu-form legend{font-size:14px;font-weight:600;line-height:1.5}#btu-form label{display:block}#btu-form .btu-unit{float:right;font-weight:400;color:var(--muted)}#btu-form input[type=text]{font-size:16px;padding:12px 14px;min-height:50px;margin-top:8px;border-radius:9px}#btu-form .field-error{display:block;font-size:12px;line-height:1.5;margin-top:5px}#btu-form input[aria-invalid=true]{border-color:#b52d34}.btu-mode{display:inline-flex;align-items:center;gap:10px;min-height:44px;text-align:left;border:0;background:transparent;color:var(--teal);font-size:13px;padding:6px 0;margin-bottom:12px;text-decoration:underline;text-underline-offset:4px}.btu-mode:hover{color:#09534f}.btu-dimensions{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-bottom:22px}.btu-height{margin:6px 0 22px}.btu-height legend{margin-bottom:10px}.btu-height-options{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px}#btu-form .btu-height-options label{position:relative;cursor:pointer}.btu-height-options input{position:absolute;opacity:0;width:1px;height:1px}.btu-height-options span{display:block;padding:11px 5px;text-align:center;border:1px solid #ccdbd7;border-radius:9px;color:var(--ink);background:#f8faf9;transition:background .16s,border-color .16s}.btu-height-options small{display:block;font-size:11px;font-weight:400;margin-top:3px}.btu-height-options input:checked+span{color:white;background:var(--navy);border-color:var(--navy)}.btu-height-options input:focus-visible+span{outline:3px solid var(--teal);outline-offset:3px}.btu-height-options label:hover span{border-color:var(--teal)}#btu-custom-height{margin-bottom:20px}.btu-people{margin-top:4px}.btu-assumption{font-size:12px;line-height:1.7;color:var(--muted);margin-top:20px}
.btu-conditions{border-top:1px solid var(--line);margin-top:15px}.btu-conditions summary{font-size:13px;color:var(--teal);padding-block:17px}.btu-conditions summary:after{top:10px}#btu-form .btu-conditions label{display:flex;align-items:flex-start;gap:12px;font-size:13px;font-weight:400;min-height:44px;margin-bottom:10px;cursor:pointer}#btu-form input[type=checkbox]{width:18px;height:18px;min-height:18px;flex-shrink:0;accent-color:var(--teal);margin:2px 0 0;padding:0}.btu-conditions p{font-size:12px;padding:0 0 18px}
.btu-result{display:flex;flex-direction:column;background:var(--navy);color:white;padding:32px}.btu-result-heading{display:flex;align-items:center;gap:13px;margin-bottom:28px}.btu-result-heading .btu-step{color:var(--mint);border-color:#ffffff3b}.btu-result-heading p{font-size:11px;font-weight:650;letter-spacing:.12em;color:#b8d3d8}.btu-result h3{font-family:Poppins,Inter,sans-serif;font-size:27px;line-height:1.4;letter-spacing:-.035em;max-width:360px}.btu-number{font-size:clamp(27px,2.5vw,38px);font-weight:650;line-height:1.35;letter-spacing:-.045em;color:var(--mint);margin:18px 0 4px;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.btu-result-copy{font-size:15px;line-height:1.8;color:#d1e1e7;margin-top:17px}.btu-summary{margin:28px 0 0;font-size:14px}.btu-summary>div{display:flex;justify-content:space-between;gap:14px;border-top:1px solid #ffffff24;padding:13px 0}.btu-summary dt{color:#b9cfd8}.btu-summary dd{margin:0;text-align:right;font-weight:600}.btu-result-note{font-size:12px;line-height:1.8;color:#b9cfd8;margin-top:auto;padding-top:28px}.btu-consult{margin-top:24px;gap:10px;justify-content:center;font-size:14px;min-height:52px}.btu-consult>span:first-of-type{font-size:14px;line-height:1.5;flex:1}.btu-consult .icon{width:20px;height:20px}.btu-send-note{font-size:11px;text-align:center;color:#b9cfd8;margin-top:12px;line-height:1.7}.btu-result a:focus-visible{outline-color:var(--mint)}
.btu-method{border:0;background:#f3f8f5;padding:0 28px}.btu-method summary{font-size:13px;padding-block:18px;color:var(--teal)}.btu-method summary:after{top:11px}.btu-method p{font-size:13px;padding:0 22px 15px 0;line-height:1.8;max-width:950px}.btu-method a,.btu-no-script a{text-decoration:underline;text-underline-offset:3px;color:var(--teal)}.btu-no-script{padding:24px;font-size:14px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media(max-width:1100px){.nav-wrap{gap:18px}.btu-grid form,.btu-result{padding:25px}.btu-consult{padding-inline:14px}.btu-form-heading{gap:10px}.btu-form-heading h3{font-size:18px}}
@media(min-width:761px) and (max-width:900px){.nav-wrap{gap:14px}nav{gap:12px}nav a{font-size:12px}.header-contact{font-size:13px;gap:6px}.brand{width:140px}.btu-grid{grid-template-columns:1fr 1fr}.btu-grid form,.btu-result{padding:22px}.btu-result h3{font-size:24px}}
@media(max-width:760px){.nav-wrap{gap:12px}.header .brand{margin-right:auto;width:140px}.header-contact{order:1;font-size:13px;gap:6px}.menu-toggle{order:2;flex-shrink:0}.header nav{order:3}.hero .actions{align-items:stretch}.hero-direct{align-self:flex-start;font-size:14px}.service-help{display:block;padding:22px}.service-help>a.button{margin:18px 0 0;white-space:normal;justify-content:center;width:100%;gap:15px}.service-help h3{font-size:19px}.btu-section{padding-block:42px}.btu-tool{border-radius:14px}.btu-tool>summary{padding:19px;align-items:flex-start;flex-direction:column;gap:12px}.btu-invitation{font-size:17px;gap:12px}.btu-invitation>i{padding:9px}.btu-invitation small{font-size:13px}.btu-open-label{justify-content:space-between;width:100%;min-height:36px}.btu-grid{grid-template-columns:1fr}.btu-grid form,.btu-result{padding:24px}.btu-result{min-height:340px}.btu-result h3{font-size:26px;max-width:none}.btu-number{font-size:32px}.btu-result-heading{margin-bottom:20px}.btu-method{padding-inline:24px}.btu-form-heading h3{font-size:19px}.btu-section .section-head>p{max-width:none}.footer-bottom{padding-bottom:28px}}
@media(max-width:375px){.header .brand{width:115px}.nav-wrap{gap:10px}.header-contact{font-size:12px}.header-contact span{display:none}.btu-grid form,.btu-result{padding:20px}.btu-invitation{font-size:15px}.btu-invitation small{font-size:12px}.btu-number{font-size:27px}.btu-form-heading h3{font-size:17px}.btu-height-options{gap:6px}.btu-height-options small{font-size:10px}.btu-method{padding-inline:20px}}
@media(prefers-reduced-motion:reduce){.btu-height-options span{transition:none}}
.btu-tool>summary .btu-open-label{background:var(--mint);color:var(--deep);border:1px solid #73cfb8;border-radius:10px;min-height:48px;padding:10px 17px;font-weight:650;gap:14px;transition:background .18s,box-shadow .18s}
.btu-tool>summary:hover .btu-open-label{background:#a5f3df;box-shadow:0 3px 12px #08233312}
.btu-tool[open]>summary .btu-open-label{background:transparent;border-color:#adc9c2;color:var(--teal);box-shadow:none}
.btu-invitation>i{flex-shrink:0}.btu-invitation small{max-width:480px;margin-top:4px}
@media(max-width:900px){.btu-section .btu-intro{gap:28px;grid-template-columns:1fr 1fr}.btu-tool>summary{gap:20px}.btu-invitation small{max-width:340px}}
@media(max-width:760px){.btu-section .btu-intro{grid-template-columns:1fr;gap:22px}.btu-explainer{padding-left:17px}.btu-intro-copy{font-size:15px;margin-top:12px}.btu-explainer h3{font-size:16px}.btu-section .btu-intro .eyebrow{font-size:10px;letter-spacing:.1em}.btu-tool>summary{gap:18px}.btu-invitation{align-items:flex-start}.btu-invitation small{font-size:13px;line-height:1.6}.btu-tool>summary .btu-open-label{justify-content:center;width:100%}}