/* Kessler Wärmetechnik: Demoprojekt (Website-Showcase Handwerk)
   Fiktive Marke: warmes Weiß, dunkles Blau, dezentes Kupfer. */

@font-face{
  font-family:"Inter";font-style:normal;font-weight:400 800;font-display:swap;
  src:url("assets/fonts/inter-latin.woff2") format("woff2");
  unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;
}

/* 20.9.2026: metrisch angeglichene Fallback-Schrift gegen Layoutsprung beim Schriftwechsel (CLS 0,114 auf der Startansicht 1024 px) */
@font-face{font-family:"Inter Fallback";font-style:normal;font-weight:400 500;src:local("Arial"),local("ArialMT");size-adjust:106%;ascent-override:91.4%;descent-override:22.8%;line-gap-override:0%}
@font-face{font-family:"Inter Fallback";font-style:normal;font-weight:600 800;src:local("Arial Bold"),local("Arial-BoldMT");size-adjust:104%;ascent-override:93.2%;descent-override:23.2%;line-gap-override:0%}

:root{
  --bg:#f7f3ec;
  --surface:#ffffff;
  --surface-2:#efe7d8;
  --ink:#16283b;
  --ink-soft:#3f5470;
  --muted:#5b6b80;
  --copper:#c1743f;
  --copper-deep:#9c5426;
  --copper-btn:#ab6127;
  --copper-btn-hover:#8f5220;
  --blue:#1f3b57;
  --blue-2:#2c527a;
  --line:rgba(22,40,59,.14);
  --line-soft:rgba(22,40,59,.08);
  --on-blue:#f7f3ec;
  --on-blue-muted:#c2cedb;
  --radius:18px;
  --radius-sm:12px;
  --maxw:1160px;
  --font:"Inter","Inter Fallback","Segoe UI Variable Text","Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --nav-h:76px;
  --dur:.5s;
  color-scheme:light;
}

@media (prefers-reduced-motion:reduce){
  :root{--dur:0s}
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:var(--font);font-size:16px;line-height:1.6;
  -webkit-font-smoothing:antialiased;overflow-x:hidden;
}
h1,h2,h3,h4{font-family:var(--font);font-weight:800;line-height:1.12;letter-spacing:-.015em;margin:0;text-wrap:balance}
p{margin:0}
a{color:inherit;text-decoration:none}
img,svg{display:block;max-width:100%}
ul{margin:0;padding:0;list-style:none}
button{font-family:var(--font)}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
section{padding:96px 0}
@media (max-width:720px){section{padding:64px 0}}

.is-blue{background:var(--blue);color:var(--on-blue)}
.is-blue .muted{color:var(--on-blue-muted)}
.is-surface{background:var(--surface)}

/* ---------- a11y ---------- */
.skip-link{position:absolute;left:12px;top:-64px;z-index:200;background:var(--copper-btn);color:#fff;padding:12px 18px;border-radius:10px;font-weight:700;font-size:14px;transition:top .15s}
.skip-link:focus{top:12px}
a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible{outline:2px solid var(--copper-btn);outline-offset:3px;border-radius:6px}
.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- demo banner ---------- */
.demo-banner{background:var(--ink);color:var(--on-blue);text-align:center;font-size:13px;font-weight:600;letter-spacing:.01em;padding:9px 16px;overflow-wrap:break-word}
.demo-banner strong{color:#f0b98a}
@media (max-width:400px){.demo-banner{font-size:12px}.demo-banner .banner-detail{display:none}}

/* ---------- typography helpers ---------- */
.eyebrow{display:block;font-size:12.5px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:var(--copper-deep);margin-bottom:16px}
.is-blue .eyebrow{color:#f0b98a}
.section-head{max-width:640px;margin:0 0 52px}
.section-head h2{font-size:clamp(28px,4vw,42px);margin-bottom:14px}
.section-head p{color:var(--ink-soft);font-size:17.5px;max-width:56ch}
.is-blue .section-head p{color:var(--on-blue-muted)}
.section-head.center{margin-left:auto;margin-right:auto;text-align:center}
.muted{color:var(--muted)}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:15px 26px;border-radius:999px;border:1px solid transparent;
  font-weight:700;font-size:15.5px;line-height:1.2;
  cursor:pointer;transition:transform var(--dur),background var(--dur),border-color var(--dur),color var(--dur);
  white-space:nowrap;
}
.btn:hover{transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn svg{width:18px;height:18px;flex-shrink:0}
.btn-primary{background:var(--copper-btn);color:#fff}
.btn-primary:hover{background:var(--copper-btn-hover)}
.btn-ghost{background:transparent;border-color:var(--line);color:var(--ink)}
.btn-ghost:hover{border-color:var(--copper-btn);color:var(--copper-btn)}
.is-blue .btn-ghost{border-color:rgba(247,243,236,.3);color:var(--on-blue)}
.is-blue .btn-ghost:hover{border-color:#f0b98a;color:#f0b98a}
.btn[disabled]{opacity:.45;cursor:not-allowed;transform:none}
.btn-row{display:flex;flex-wrap:wrap;gap:14px}

/* ---------- header ---------- */
header.site-header{position:sticky;top:0;z-index:90;background:rgba(247,243,236,.9);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--line-soft)}
.nav{display:flex;align-items:center;justify-content:space-between;gap:20px;height:var(--nav-h);max-width:var(--maxw);margin:0 auto;padding:0 24px}
.brand{display:flex;align-items:center;gap:11px}
.brand-mark{width:38px;height:38px;flex-shrink:0}
.brand-word{font-weight:800;font-size:18px;letter-spacing:-.01em;color:var(--ink)}
.brand-sub{font-size:11px;font-weight:600;letter-spacing:.04em;color:var(--muted);display:none;text-transform:uppercase}
@media (min-width:980px){.brand-sub{display:block;margin-top:1px}}
.nav-links{display:none;align-items:center;gap:28px}
.nav-links a{font-size:15px;font-weight:600;color:var(--ink-soft);position:relative;padding:6px 0}
.nav-links a::after{content:"";position:absolute;left:0;right:0;bottom:0;height:2px;background:var(--copper-btn);transform:scaleX(0);transform-origin:left;transition:transform .25s}
.nav-links a:hover{color:var(--ink)}
.nav-links a:hover::after{transform:scaleX(1)}
.nav-cta{display:none;padding:11px 20px;font-size:14.5px}
@media (min-width:900px){.nav-links{display:flex}.nav-cta{display:inline-flex}}
.burger{display:inline-flex;background:none;border:1px solid var(--line);border-radius:10px;padding:9px;cursor:pointer;color:var(--ink)}
@media (min-width:900px){.burger{display:none}}
.burger svg{width:22px;height:22px}
.mobile-menu{display:none;flex-direction:column;padding:8px 24px 24px;border-top:1px solid var(--line-soft);background:var(--bg)}
.mobile-menu.open{display:flex}
.mobile-menu a{padding:14px 0;font-weight:600;border-bottom:1px solid var(--line-soft);font-size:16px}
.mobile-menu .btn{margin-top:18px;align-self:flex-start}
@media (min-width:1200px){.mobile-menu{display:none !important}}

/* ---------- hero ---------- */
.hero{position:relative;overflow:hidden;padding:0;background:radial-gradient(760px 480px at 82% 20%, rgba(193,116,63,.13), transparent 60%),var(--bg)}
.hero-grid{position:relative;display:grid;grid-template-columns:1fr;gap:40px;align-items:center;padding:56px 24px 72px}
@media (min-width:960px){.hero-grid{grid-template-columns:1.05fr .95fr;padding:76px 24px 88px}}
.hero-copy h1{font-size:clamp(34px,5.4vw,58px);margin-bottom:20px}
.hero-copy .lead{font-size:19px;color:var(--ink-soft);max-width:52ch;margin-bottom:14px}
.hero-region{display:inline-flex;align-items:center;gap:8px;font-size:14.5px;font-weight:600;color:var(--copper-deep);margin-bottom:26px}
.hero-region svg{width:17px;height:17px}
.hero-art{position:relative;display:flex;justify-content:center}
.hero-art svg{width:100%;max-width:440px;height:auto}
.trust-row{display:flex;flex-wrap:wrap;gap:22px;margin-top:36px;font-size:14px;color:var(--ink-soft)}
.trust-row .item{display:flex;align-items:center;gap:8px}
.trust-row svg{width:18px;height:18px;color:var(--copper-btn);flex-shrink:0}

/* ---------- leistungen ---------- */
.leistungen-grid{display:grid;gap:24px;grid-template-columns:1fr}
@media (min-width:760px){.leistungen-grid{grid-template-columns:repeat(3,1fr)}}
.leistung-card{background:var(--surface);border:1px solid var(--line-soft);border-radius:var(--radius);overflow:hidden;display:flex;flex-direction:column}
.leistung-media{aspect-ratio:16/10;background:var(--surface-2);position:relative}
.leistung-media img{width:100%;height:100%;object-fit:cover}
.leistung-media svg{width:100%;height:100%;padding:26px}
.leistung-body{padding:26px 24px 28px;display:flex;flex-direction:column;gap:10px;flex:1}
.leistung-body h3{font-size:20px}
.leistung-body p{color:var(--ink-soft);font-size:15px}
.leistung-tag{align-self:flex-start;font-size:12px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--copper-deep);background:rgba(193,116,63,.12);padding:5px 11px;border-radius:999px}

/* ---------- projektcheck ---------- */
.check-panel{background:var(--surface);border:1px solid var(--line-soft);border-radius:24px;padding:32px 24px;max-width:680px;margin:0 auto;box-shadow:0 24px 60px -30px rgba(22,40,59,.25)}
@media (min-width:640px){.check-panel{padding:44px 48px}}
.check-progress-label{display:flex;justify-content:space-between;align-items:baseline;font-size:13.5px;font-weight:700;color:var(--ink-soft);margin-bottom:10px}
.check-progress-track{height:8px;border-radius:999px;background:var(--surface-2);overflow:hidden;margin-bottom:32px}
.check-progress-fill{width:0;height:100%;background:var(--copper-btn);border-radius:999px;transition:width var(--dur) ease} /* 20.9.2026: Startbreite jetzt im CSS (Inline-Style wird von der CSP blockiert, der Balken stand sonst voll) */
.check-step{display:none;border:0;padding:0;margin:0;min-width:0}
.check-step.active{display:block}
.check-step legend{float:left;width:100%;font-size:22px;font-weight:800;margin-bottom:6px;padding:0}
.check-step .step-hint{clear:both;color:var(--muted);font-size:14.5px;margin-bottom:24px;display:block}
.option-grid{display:grid;gap:12px;grid-template-columns:1fr 1fr}
@media (max-width:480px){.option-grid{grid-template-columns:1fr}}
.option-card{position:relative}
.option-card input{position:absolute;opacity:0;width:1px;height:1px}
.option-card label{display:flex;align-items:center;gap:10px;border:1.5px solid var(--line);border-radius:var(--radius-sm);padding:14px 16px;font-weight:600;font-size:15px;cursor:pointer;transition:border-color .2s,background .2s;color:var(--ink-soft)}
.option-card label:hover{border-color:var(--copper)}
.option-card input:checked + label{border-color:var(--copper-btn);background:rgba(193,116,63,.09);color:var(--ink)}
.option-card input:focus-visible + label{outline:2px solid var(--copper-btn);outline-offset:2px}
.check-field label.field-label{display:block;font-weight:600;font-size:15px;margin-bottom:10px;color:var(--ink)}
.check-field input[type=text]{width:100%;border:1.5px solid var(--line);border-radius:var(--radius-sm);padding:14px 16px;font-size:16px;font-family:var(--font);background:var(--surface)}
.check-field input[type=text]:focus{border-color:var(--copper-btn)}
.field-error{display:none;color:#a4341f;font-size:13.5px;font-weight:600;margin-top:8px}
.field-error.show{display:block}
.check-nav{display:flex;justify-content:space-between;gap:12px;margin-top:32px}
.check-nav .btn{padding:13px 22px}
.check-summary{display:none}
.check-summary.active{display:block}
.summary-list{display:grid;gap:14px;margin:24px 0 28px}
.summary-row{display:flex;justify-content:space-between;gap:16px;border-bottom:1px solid var(--line-soft);padding-bottom:12px;font-size:15px}
.summary-row dt{color:var(--muted);font-weight:600}
.summary-row dd{margin:0;font-weight:700;color:var(--ink);text-align:right}
.check-disclaimer{background:var(--surface-2);border-radius:var(--radius-sm);padding:16px 18px;font-size:14px;color:var(--ink-soft);line-height:1.55}
[aria-live]{}

/* ---------- ablauf ---------- */
.ablauf-list{display:grid;gap:0;grid-template-columns:1fr}
@media (min-width:860px){.ablauf-list{grid-template-columns:repeat(4,1fr);gap:20px}}
.ablauf-item{position:relative;padding:0 0 32px 56px;border-left:2px solid var(--line);}
@media (min-width:860px){.ablauf-item{border-left:none;border-top:2px solid var(--line);padding:32px 8px 0 0}}
.ablauf-item:last-child{padding-bottom:0}
.ablauf-num{position:absolute;left:-19px;top:0;width:38px;height:38px;border-radius:999px;background:var(--copper-btn);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:15px}
@media (min-width:860px){.ablauf-num{left:0;top:-19px}}
.ablauf-item h3{font-size:18px;margin-bottom:8px}
.ablauf-item p{color:var(--ink-soft);font-size:15px}

/* ---------- beispiele ---------- */
.beispiel-grid{display:grid;gap:24px;grid-template-columns:1fr}
@media (min-width:760px){.beispiel-grid{grid-template-columns:repeat(3,1fr)}}
.beispiel-card{background:var(--surface);border:1px solid var(--line-soft);border-radius:var(--radius);padding:26px 24px;display:flex;flex-direction:column;gap:12px}
.beispiel-badge{align-self:flex-start;font-size:11.5px;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--blue);background:rgba(31,59,87,.09);padding:5px 11px;border-radius:999px}
.beispiel-card svg{width:44px;height:44px;color:var(--copper-btn)}
.beispiel-card h3{font-size:18px}
.beispiel-card p{color:var(--ink-soft);font-size:14.5px}

/* ---------- faq ---------- */
.faq-list{max-width:760px;margin:0 auto;display:grid;gap:12px}
.faq-item{border:1px solid var(--line-soft);border-radius:var(--radius-sm);background:var(--surface);overflow:hidden}
.faq-q{width:100%;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:18px 20px;background:none;border:none;text-align:left;font-size:16px;font-weight:700;color:var(--ink);cursor:pointer}
.faq-q svg{width:20px;height:20px;flex-shrink:0;transition:transform var(--dur)}
.faq-q[aria-expanded=true] svg{transform:rotate(180deg)}
.faq-a{padding:0 20px;max-height:0;overflow:hidden;transition:max-height var(--dur) ease,padding var(--dur) ease}
.faq-a.open{padding:0 20px 20px;max-height:400px}
.faq-a p{color:var(--ink-soft);font-size:15px;line-height:1.65}

/* ---------- closing cta ---------- */
.closing{text-align:center}
.closing h2{font-size:clamp(28px,4.6vw,44px);margin-bottom:16px}
.closing p{color:var(--on-blue-muted);max-width:52ch;margin:0 auto 30px;font-size:17px}
.closing .btn-row{justify-content:center}
.closing-note{margin-top:20px;font-size:14.5px;color:var(--on-blue-muted)}
.closing-note a{color:#f0b98a;font-weight:700}
.closing-note a:hover{text-decoration:underline}

/* ---------- footer ---------- */
footer.site-footer{background:var(--ink);color:var(--on-blue);padding:56px 0 32px}
.footer-top{display:grid;gap:32px;grid-template-columns:1fr;margin-bottom:36px}
@media (min-width:760px){.footer-top{grid-template-columns:1.3fr 1fr 1fr}}
.footer-brand{display:flex;align-items:center;gap:10px;margin-bottom:12px}
.footer-brand svg{width:32px;height:32px}
.footer-brand span{font-weight:800;font-size:17px}
.footer-col h3{font-size:13px;text-transform:uppercase;letter-spacing:.08em;color:var(--on-blue-muted);margin-bottom:14px}
.site-footer .muted{color:var(--on-blue-muted)} /* 20.9.2026: #5b6b80 auf dunklem Footer nur 2,75:1 */
body .u-mt-20{margin-top:20px}
body .u-mt-28{margin-top:28px}
.footer-col ul{display:grid;gap:10px}
.footer-col a{font-size:14.5px;color:var(--on-blue-muted)}
.footer-col a:hover{color:var(--on-blue)}
.footer-note{font-size:13px;color:var(--on-blue-muted);max-width:56ch;line-height:1.6}
.footer-bottom{border-top:1px solid rgba(247,243,236,.14);padding-top:22px;display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px;font-size:13px;color:var(--on-blue-muted)}

/* ---------- reveal ---------- */
.reveal{opacity:0;transform:translateY(16px);transition:opacity var(--dur) ease,transform var(--dur) ease}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none}}


/* 11.10.2026: großzügige Ränder, technische Illustration, responsive Projektführung. */
:root{--radius:24px;--gutter:clamp(22px,4vw,36px)}
.wrap,.nav{padding-inline:var(--gutter)}
section[id]{scroll-margin-top:100px}
.hero-grid{padding:clamp(40px,6vw,84px) var(--gutter) 72px;gap:clamp(32px,5vw,72px);grid-template-columns:minmax(0,1fr)}
.hero-copy,.hero-art{min-width:0}.hero-copy h1{font-size:clamp(40px,5.5vw,72px);line-height:1.06;letter-spacing:-.045em;max-width:12ch}
.hero-copy .lead{font-size:18px;line-height:1.7}.hero-copy .lead.muted{font-size:15px;color:var(--muted)}
.hero-region{padding:8px 12px;border:1px solid var(--line);border-radius:999px;font-size:13px;margin-bottom:22px}
.hero-art{aspect-ratio:1;align-items:center;padding:28px;border:1px solid var(--line);border-radius:32px;background:radial-gradient(circle at center,#fff 25%,#eee8dd);box-shadow:0 32px 80px -48px rgba(22,40,59,.4);isolation:isolate}
.hero-art::before{content:"";position:absolute;inset:10%;border:1px dashed rgba(22,40,59,.2);border-radius:50%;z-index:-1}
.hero-art::after{content:"";position:absolute;inset:20%;border:1px solid rgba(193,116,63,.18);border-radius:50%;z-index:-1}
.hero-art svg{filter:drop-shadow(0 12px 8px rgba(22,40,59,.06))}
.btn{white-space:normal;max-width:100%;text-align:center;min-height:48px}.burger{flex-shrink:0;min-width:44px;min-height:44px}
.brand{min-width:0}.brand-word{font-size:clamp(15px,2vw,18px)}.brand-mark{width:34px;height:34px}
.mobile-menu{max-height:calc(100dvh - 76px);overflow-y:auto;padding-inline:var(--gutter)}
.section-head h2{letter-spacing:-.035em;line-height:1.15}.leistungen-grid,.beispiel-grid{gap:24px}
.leistung-card{box-shadow:0 16px 44px -34px rgba(22,40,59,.3)}.leistung-media{background:linear-gradient(135deg,#e8e4dc,#f7f5f0)}
.leistung-body{padding:28px}.leistung-body p,.beispiel-card p{font-size:16px;line-height:1.65}
.check-panel{padding:32px;border-radius:28px;border-color:rgba(22,40,59,.18)}
.check-step legend{font-size:clamp(23px,3vw,30px);line-height:1.2;letter-spacing:-.025em}
.option-card label{min-height:58px;line-height:1.45}.check-nav{gap:12px}.check-nav .btn{flex:0 1 auto}
.summary-row{flex-wrap:wrap}.summary-row dd{overflow-wrap:anywhere}
.faq-q{min-height:64px;line-height:1.4}.faq-a.open{max-height:900px}
.trust-row{gap:12px;margin-top:24px}.trust-row .item{line-height:1.45}
@media(min-width:960px){.hero-grid{grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr)}}
@media(min-width:900px) and (max-width:1199px){.nav-links,.nav-cta{display:none}.burger{display:inline-flex}}
@media(min-width:1200px){.nav-links{gap:20px}.brand-sub{font-size:10px}}
@media(max-width:639px){
  .hero-grid{padding-top:36px;padding-bottom:48px;gap:30px}.hero-copy h1{font-size:42px}
  .hero-copy .lead{font-size:17px}.hero-art{aspect-ratio:6/5;padding:18px;border-radius:24px}
  .hero-art svg{max-height:270px}.btn-row .btn{width:100%}.trust-row{font-size:13px}
  .check-panel{padding:26px 20px}.check-progress-label{gap:12px;font-size:12px}
  .check-nav .btn{padding:13px 16px}.option-grid{grid-template-columns:minmax(0,1fr)}
  .leistung-body,.beispiel-card{padding:24px}.brand{gap:8px}.nav{gap:12px}
}
@media(max-width:359px){.hero-copy h1{font-size:37px}.brand-word{font-size:14px}.brand-mark{width:30px}}