:root {
  --ink: #16233b;
  --navy: #292b40;
  --muted: #4c5a72;
  --teal: #0ea5a4;
  --teal-deep: #0d8a89;
  --blue: #2563eb;
  --sky: #38bdf8;
  --green: #34d399;
  --glass-bg: rgba(255, 255, 255, 0.55);
  --glass-strong: rgba(255, 255, 255, 0.72);
  --glass-border: rgba(255, 255, 255, 0.65);
  --glass-line: rgba(255, 255, 255, 0.45);
  --shadow: 0 18px 50px rgba(20, 60, 90, 0.16);
  --shadow-sm: 0 8px 24px rgba(20, 60, 90, 0.12);
  --radius: 22px;
  --radius-sm: 14px;
  --max: 1160px;
  --font: "Inter", "Segoe UI", "Helvetica Neue", Arial, system-ui, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  position: relative;
  background: linear-gradient(160deg, #d5f4f2 0%, #e4f0ff 42%, #eafaf1 100%);
  min-height: 100vh;
}

/* Layered gradient blobs behind the frosted panels */
.bg-blobs { position: fixed; inset: 0; z-index: -1; overflow: hidden; pointer-events: none; }
.bg-blobs span { position: absolute; border-radius: 50%; filter: blur(70px); opacity: 0.55; }
.bg-blobs .b1 { width: 460px; height: 460px; background: radial-gradient(circle at 30% 30%, #5eead4, #0ea5a4); top: -120px; left: -80px; }
.bg-blobs .b2 { width: 520px; height: 520px; background: radial-gradient(circle at 30% 30%, #93c5fd, #2563eb); top: 30%; right: -160px; }
.bg-blobs .b3 { width: 420px; height: 420px; background: radial-gradient(circle at 30% 30%, #bbf7d0, #34d399); bottom: -140px; left: 20%; }
.bg-blobs .b4 { width: 360px; height: 360px; background: radial-gradient(circle at 30% 30%, #a5f3fc, #38bdf8); top: 62%; left: -120px; opacity: 0.4; }

img { max-width: 100%; display: block; }
a { color: var(--teal-deep); text-decoration: none; transition: color 0.15s ease; }
a:hover { color: var(--blue); }
.container { max-width: var(--max); margin: 0 auto; padding: 0 22px; }
.section-tag { display: inline-block; font-size: 0.78rem; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; color: var(--teal-deep); background: rgba(14, 165, 164, 0.12); border: 1px solid rgba(14, 165, 164, 0.25); padding: 6px 15px; border-radius: 999px; margin-bottom: 16px; }

/* ---------- Buttons ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; background: linear-gradient(135deg, var(--teal), var(--blue)); color: #fff; padding: 13px 26px; border-radius: 999px; font-weight: 700; font-size: 0.95rem; border: none; cursor: pointer; transition: transform 0.15s ease, box-shadow 0.15s ease; box-shadow: 0 10px 24px rgba(37, 99, 235, 0.28); }
.btn:hover { transform: translateY(-2px); color: #fff; box-shadow: 0 14px 30px rgba(37, 99, 235, 0.4); }
.btn-ghost { background: rgba(255, 255, 255, 0.5); color: var(--ink); border: 1px solid var(--glass-border); box-shadow: none; -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px); }
.btn-ghost:hover { background: rgba(255, 255, 255, 0.8); color: var(--teal-deep); box-shadow: var(--shadow-sm); }

/* ---------- Top bar ---------- */
.topbar { background: rgba(41, 43, 64, 0.85); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px); color: #d3dbe8; font-size: 0.85rem; }
.topbar .container { display: flex; flex-wrap: wrap; gap: 8px 26px; align-items: center; justify-content: center; padding: 9px 22px; }
.topbar span { display: inline-flex; align-items: center; gap: 7px; }
.topbar a { color: #d3dbe8; }
.topbar a:hover { color: #fff; }

/* ---------- Header ---------- */
.site-header { position: sticky; top: 0; z-index: 60; background: rgba(255, 255, 255, 0.6); -webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px); border-bottom: 1px solid var(--glass-line); }
.site-header .container { display: flex; align-items: center; justify-content: space-between; gap: 18px; padding-top: 12px; padding-bottom: 12px; }
.brand { display: flex; align-items: center; gap: 12px; min-width: 0; }
.brand img { height: 34px; width: auto; flex-shrink: 0; }
.brand .name { font-weight: 800; color: var(--navy); font-size: 1.15rem; line-height: 1.1; min-width: 0; }
.brand .name small { display: block; font-weight: 500; color: var(--muted); font-size: 0.68rem; letter-spacing: 1px; text-transform: uppercase; }
.nav { display: flex; align-items: center; gap: 22px; }
.nav a { color: var(--ink); font-weight: 600; font-size: 0.95rem; }
.nav a:hover { color: var(--teal-deep); }
.nav a.btn { color: #fff; }
.menu-toggle { display: none; background: rgba(255,255,255,0.5); border: 1px solid var(--glass-border); border-radius: 10px; width: 44px; height: 42px; font-size: 1.5rem; color: var(--navy); cursor: pointer; }

/* ---------- Hero ---------- */
.hero { padding: 74px 0 40px; }
.hero .container { max-width: 960px; text-align: center; }
.hero h1 { font-size: clamp(2rem, 5vw, 3.4rem); line-height: 1.1; font-weight: 800; color: var(--navy); letter-spacing: -0.5px; }
.hero h1 .grad { background: linear-gradient(120deg, var(--teal), var(--blue)); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero p.lead { margin: 22px auto 0; font-size: 1.18rem; max-width: 720px; color: var(--muted); }
.hero .cta-row { margin-top: 32px; display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.hero .trust { margin-top: 30px; display: flex; flex-wrap: wrap; gap: 12px 30px; justify-content: center; font-size: 0.9rem; color: var(--muted); font-weight: 600; }
.hero .trust span { display: inline-flex; align-items: center; gap: 8px; }

/* ---------- Glass card base ---------- */
.glass { background: var(--glass-bg); -webkit-backdrop-filter: blur(18px); backdrop-filter: blur(18px); border: 1px solid var(--glass-border); border-radius: var(--radius); box-shadow: var(--shadow); }

/* ---------- Kostencheck / Calculator ---------- */
.calc { padding: 26px 0 74px; }
.calc-shell { max-width: 940px; margin: 0 auto; padding: 40px; }
.calc-head { text-align: center; margin-bottom: 30px; }
.calc-head .section-tag { background: rgba(37, 99, 235, 0.12); border-color: rgba(37, 99, 235, 0.25); color: var(--blue); }
.calc-head h2 { font-size: clamp(1.6rem, 3.4vw, 2.1rem); color: var(--navy); margin-bottom: 8px; }
.calc-head p { color: var(--muted); max-width: 620px; margin: 0 auto; }
.calc-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px 22px; }
.calc-field { display: flex; flex-direction: column; }
.calc-field label { font-size: 0.82rem; font-weight: 700; margin-bottom: 6px; color: var(--ink); }
.calc-field input, .calc-field select { padding: 12px 14px; border: 1px solid rgba(255,255,255,0.7); border-radius: 12px; font-family: inherit; font-size: 0.95rem; background: rgba(255, 255, 255, 0.7); color: var(--ink); }
.calc-field input:focus, .calc-field select:focus { outline: none; border-color: var(--teal); box-shadow: 0 0 0 3px rgba(14, 165, 164, 0.2); background: #fff; }
.calc-actions { margin-top: 26px; text-align: center; }
.calc-result { margin-top: 26px; background: rgba(255, 255, 255, 0.6); border: 1px solid var(--glass-border); border-radius: var(--radius-sm); padding: 28px; text-align: center; display: none; }
.calc-result.show { display: block; }
.calc-result .btu { font-size: 2.5rem; font-weight: 800; background: linear-gradient(120deg, var(--teal), var(--blue)); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.calc-result .kw { font-size: 1.2rem; color: var(--teal-deep); font-weight: 700; margin-top: 4px; }
.calc-result p { color: var(--muted); margin-top: 10px; font-size: 0.92rem; }
.calc-note { text-align: center; color: var(--muted); font-size: 0.82rem; margin-top: 18px; opacity: 0.85; }

/* ---------- Section wrapper ---------- */
.section { padding: 60px 0; }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 44px; }
.section-head h2 { font-size: clamp(1.7rem, 3.6vw, 2.3rem); color: var(--navy); line-height: 1.15; }
.section-head p { color: var(--muted); margin-top: 12px; font-size: 1.05rem; }

/* ---------- Option cards (Klimaanlage / Wärmepumpe) ---------- */
.options-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 26px; }
.option-card { padding: 34px; display: flex; flex-direction: column; gap: 14px; transition: transform 0.18s ease, box-shadow 0.18s ease; }
.option-card:hover { transform: translateY(-4px); box-shadow: 0 22px 55px rgba(20,60,90,0.2); }
.option-card .opt-ico { width: 60px; height: 60px; border-radius: 16px; display: inline-flex; align-items: center; justify-content: center; font-size: 1.8rem; background: linear-gradient(135deg, rgba(14,165,164,0.18), rgba(37,99,235,0.18)); border: 1px solid var(--glass-border); }
.option-card h3 { font-size: 1.4rem; color: var(--navy); }
.option-card p { color: var(--muted); font-size: 0.98rem; }
.option-card ul { list-style: none; margin-top: 4px; }
.option-card li { position: relative; padding-left: 26px; margin-bottom: 8px; color: var(--ink); font-size: 0.95rem; }
.option-card li::before { content: "\2713"; position: absolute; left: 0; color: var(--teal-deep); font-weight: 800; }
.option-card .btn { margin-top: auto; align-self: flex-start; }

/* ---------- Intro line ---------- */
.intro { padding: 20px 0 10px; }
.intro .glass { max-width: 900px; margin: 0 auto; padding: 40px; text-align: center; }
.intro h2 { font-size: clamp(1.5rem, 3.4vw, 2.1rem); color: var(--navy); line-height: 1.2; }
.intro p { color: var(--muted); margin-top: 16px; font-size: 1.06rem; }

/* ---------- Knowledge grid ---------- */
.know-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.know-card { display: block; padding: 26px; transition: transform 0.18s ease, box-shadow 0.18s ease; }
.know-card:hover { transform: translateY(-4px); box-shadow: 0 22px 55px rgba(20,60,90,0.2); }
.know-card .num { display: inline-flex; align-items: center; justify-content: center; width: 42px; height: 42px; border-radius: 12px; font-weight: 800; color: #fff; background: linear-gradient(135deg, var(--teal), var(--blue)); margin-bottom: 14px; }
.know-card h3 { font-size: 1.1rem; color: var(--navy); line-height: 1.3; margin-bottom: 8px; }
.know-card p { color: var(--muted); font-size: 0.92rem; }
.know-card .more { display: inline-block; margin-top: 12px; font-weight: 700; color: var(--teal-deep); font-size: 0.9rem; }

/* ---------- Article (title-image-text) blocks ---------- */
.article { padding: 46px 0; }
.article .glass { padding: 20px; }
.article-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 8px; align-items: stretch; }
.article:nth-of-type(even) .article-grid { grid-template-columns: 1fr 1.05fr; }
.article:nth-of-type(even) .article-media { order: -1; }
.article-text { padding: 26px 24px; }
.article-number { display: inline-flex; align-items: center; justify-content: center; width: 52px; height: 52px; border-radius: 14px; background: linear-gradient(135deg, var(--teal), var(--blue)); color: #fff; font-weight: 800; font-size: 1.4rem; margin-bottom: 16px; box-shadow: var(--shadow-sm); }
.article-text h3 { font-size: clamp(1.3rem, 2.6vw, 1.6rem); color: var(--navy); line-height: 1.2; margin-bottom: 14px; }
.article-text p { color: var(--muted); margin-bottom: 12px; font-size: 1.01rem; }
.article-media { border-radius: var(--radius-sm); overflow: hidden; min-height: 260px; }
.article-media img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- Steps ---------- */
.steps-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.step-card { padding: 32px; text-align: center; position: relative; }
.step-card .step-n { width: 58px; height: 58px; margin: 0 auto 18px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.4rem; font-weight: 800; color: #fff; background: linear-gradient(135deg, var(--teal), var(--blue)); box-shadow: var(--shadow-sm); }
.step-card h3 { color: var(--navy); font-size: 1.2rem; margin-bottom: 10px; }
.step-card p { color: var(--muted); font-size: 0.96rem; }

/* ---------- Advantages ---------- */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.adv-card { padding: 28px; text-align: center; }
.adv-card .adv-ico { font-size: 2rem; margin-bottom: 12px; }
.adv-card h3 { color: var(--navy); font-size: 1.08rem; margin-bottom: 8px; }
.adv-card p { color: var(--muted); font-size: 0.92rem; }

/* ---------- FAQ ---------- */
.faq-wrap { max-width: 840px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }
.faq-item { padding: 4px 24px; overflow: hidden; }
.faq-q { width: 100%; text-align: left; background: none; border: none; cursor: pointer; font-family: inherit; font-size: 1.05rem; font-weight: 700; color: var(--navy); padding: 20px 0; display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.faq-q .plus { flex-shrink: 0; width: 28px; height: 28px; border-radius: 50%; background: linear-gradient(135deg, var(--teal), var(--blue)); color: #fff; display: inline-flex; align-items: center; justify-content: center; font-size: 1.2rem; line-height: 1; transition: transform 0.2s ease; }
.faq-item.open .faq-q .plus { transform: rotate(45deg); }
.faq-a { max-height: 0; opacity: 0; transition: max-height 0.28s ease, opacity 0.2s ease, padding 0.2s ease; color: var(--muted); }
.faq-item.open .faq-a { max-height: 320px; opacity: 1; padding-bottom: 20px; }

/* ---------- Final CTA + Form ---------- */
.cta-section { padding: 60px 0 80px; }
.cta-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: stretch; }
.cta-intro { padding: 40px; display: flex; flex-direction: column; justify-content: center; }
.cta-intro h2 { font-size: clamp(1.7rem, 3.4vw, 2.2rem); color: var(--navy); margin-bottom: 14px; }
.cta-intro p { color: var(--muted); margin-bottom: 16px; }
.cta-intro ul { list-style: none; margin-top: 10px; }
.cta-intro li { padding-left: 28px; position: relative; margin-bottom: 12px; font-weight: 600; color: var(--ink); }
.cta-intro li::before { content: "\2713"; position: absolute; left: 0; color: var(--teal-deep); font-weight: 800; }

.form-card { padding: 36px; }
.form-card h3 { color: var(--navy); margin-bottom: 6px; font-size: 1.35rem; }
.form-card .sub { color: var(--muted); font-size: 0.92rem; margin-bottom: 20px; }
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 0.83rem; font-weight: 700; margin-bottom: 6px; color: var(--ink); }
.field input, .field select, .field textarea { width: 100%; padding: 12px 14px; border: 1px solid rgba(255,255,255,0.7); border-radius: 12px; font-family: inherit; font-size: 0.95rem; background: rgba(255, 255, 255, 0.7); color: var(--ink); }
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--teal); box-shadow: 0 0 0 3px rgba(14, 165, 164, 0.2); background: #fff; }
.form-card .btn { width: 100%; }
.form-note { font-size: 0.8rem; color: var(--muted); margin-top: 12px; text-align: center; }
.form-success { display: none; background: rgba(52, 211, 153, 0.18); border: 1px solid rgba(52, 211, 153, 0.5); color: #0f6b48; padding: 16px; border-radius: 12px; margin-top: 16px; font-weight: 700; text-align: center; }
.form-success.show { display: block; }

/* ---------- Footer ---------- */
.site-footer { background: rgba(41, 43, 64, 0.9); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px); color: #c4c9d6; padding: 56px 0 24px; margin-top: 20px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1.2fr; gap: 38px; }
.site-footer h4 { color: #fff; margin-bottom: 16px; font-size: 1.05rem; }
.site-footer p, .site-footer li { color: #aab1c2; font-size: 0.92rem; margin-bottom: 10px; }
.site-footer ul { list-style: none; }
.site-footer a { color: #aab1c2; }
.site-footer a:hover { color: #fff; }
.footer-brand img { height: 30px; margin-bottom: 14px; background: #fff; padding: 9px 13px; border-radius: 10px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.12); margin-top: 38px; padding-top: 20px; text-align: center; font-size: 0.85rem; color: #8891a5; }

/* ---------- Subpages ---------- */
.page-hero { padding: 54px 0 30px; }
.page-hero .glass { max-width: 900px; margin: 0 auto; padding: 40px; text-align: center; }
.page-hero h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); color: var(--navy); }
.page-hero p { color: var(--muted); margin-top: 10px; }
.doc { padding: 20px 0 70px; }
.doc .glass { max-width: 900px; margin: 0 auto; padding: 42px; }
.doc h2 { color: var(--navy); font-size: 1.4rem; margin: 28px 0 12px; }
.doc h2:first-child { margin-top: 0; }
.doc h3 { color: var(--teal-deep); font-size: 1.1rem; margin: 22px 0 8px; }
.doc p, .doc li { color: var(--muted); margin-bottom: 12px; }
.doc ul { margin: 0 0 14px 22px; }
.info-table { width: 100%; border-collapse: collapse; margin: 20px 0; }
.info-table td { padding: 12px 14px; border: 1px solid var(--glass-border); font-size: 0.95rem; }
.info-table td:first-child { font-weight: 700; color: var(--ink); width: 38%; background: rgba(255,255,255,0.5); }

.contact-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin-bottom: 30px; }
.contact-card { padding: 28px; text-align: center; }
.contact-card .ico { font-size: 1.9rem; margin-bottom: 10px; }
.contact-card h3 { color: var(--navy); margin-bottom: 8px; }
.contact-card p, .contact-card a { color: var(--muted); font-size: 0.95rem; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .site-header .container { gap: 12px; position: relative; }
  .nav { display: none; }
  .menu-toggle { display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; }
  .nav.open { display: flex; flex-direction: column; align-items: stretch; position: absolute; top: calc(100% + 8px); left: 22px; right: 22px; background: var(--glass-strong); -webkit-backdrop-filter: blur(18px); backdrop-filter: blur(18px); padding: 18px; gap: 14px; border: 1px solid var(--glass-border); border-radius: var(--radius-sm); box-shadow: var(--shadow); }
  .nav.open a { width: 100%; }
  .nav.open .btn { text-align: center; }
  .options-grid, .cta-grid { grid-template-columns: 1fr; }
  .know-grid, .steps-grid { grid-template-columns: 1fr 1fr; }
  .adv-grid { grid-template-columns: 1fr 1fr; }
  .calc-grid { grid-template-columns: 1fr 1fr; }
  .article-grid, .article:nth-of-type(even) .article-grid { grid-template-columns: 1fr; }
  .article:nth-of-type(even) .article-media { order: 0; }
  .article-media { min-height: 230px; }
  .footer-grid { grid-template-columns: 1fr; }
  .contact-cards { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .container { padding: 0 16px; }
  .topbar .container { justify-content: flex-start; gap: 6px 16px; font-size: 0.78rem; }
  .brand img { height: 28px; }
  .brand .name { font-size: 0.98rem; }
  .brand .name small { display: none; }
  .know-grid, .steps-grid, .adv-grid, .calc-grid { grid-template-columns: 1fr; }
  .calc-shell, .intro .glass, .doc .glass, .page-hero .glass, .cta-intro, .form-card, .option-card { padding: 26px 20px; }
}