/* =========================================================
   Führer Luft & Klima – Stylesheet
   Farben aus dem Logo: Blau (LUFT), Grün (KLIMA), Schwarz (FÜHRER)
   Keine externen Ressourcen (DSGVO-freundlich, keine Google Fonts)
   ========================================================= */

:root {
  /* Logofarben */
  --blau:        #2B4B9C;
  --blau-dunkel: #1D3570;
  --blau-hell:   #4F71C4;
  --gruen:       #2E7D32;
  --gruen-dunkel:#1F5B23;
  --gruen-hell:  #56A75B;
  --schwarz:     #14181F;

  /* Neutrale Töne */
  --grau-900: #1B2027;
  --grau-700: #444C58;
  --grau-500: #6B7480;
  --grau-200: #DCE2EC;
  --grau-100: #EFF3F9;
  --grau-50:  #F7F9FC;
  --weiss:    #FFFFFF;

  --grad-blau:  linear-gradient(135deg, var(--blau-dunkel) 0%, var(--blau) 55%, var(--blau-hell) 100%);
  --grad-gruen: linear-gradient(135deg, var(--gruen-dunkel) 0%, var(--gruen) 60%, var(--gruen-hell) 100%);
  --grad-duo:   linear-gradient(120deg, var(--blau-dunkel) 0%, var(--blau) 45%, var(--gruen) 100%);

  --radius:    18px;
  --radius-sm: 10px;
  --schatten:      0 2px 6px rgba(20, 24, 31, .06), 0 12px 32px rgba(20, 24, 31, .08);
  --schatten-hoch: 0 8px 20px rgba(27, 43, 92, .14), 0 24px 60px rgba(27, 43, 92, .16);

  --breite: 1180px;
  --sp: clamp(1rem, 2.5vw, 2rem);
}

/* ---------- Basis ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: clamp(1rem, .96rem + .2vw, 1.075rem);
  line-height: 1.65;
  color: var(--grau-700);
  background: var(--weiss);
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  color: var(--schwarz);
  line-height: 1.15;
  letter-spacing: -.02em;
  margin: 0 0 .5em;
  font-weight: 750;
}
h1 { font-size: clamp(2.1rem, 1.4rem + 3vw, 3.6rem); }
h2 { font-size: clamp(1.65rem, 1.2rem + 1.8vw, 2.5rem); }
h3 { font-size: clamp(1.15rem, 1rem + .6vw, 1.4rem); }
p  { margin: 0 0 1.1em; }

a { color: var(--blau); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--gruen); }

img { max-width: 100%; display: block; }

:focus-visible {
  outline: 3px solid var(--gruen-hell);
  outline-offset: 3px;
  border-radius: 4px;
}

.wrap { width: min(100% - 2.5rem, var(--breite)); margin-inline: auto; }

.skip {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--blau); color: #fff; padding: .8rem 1.2rem; border-radius: 0 0 8px 0;
}
.skip:focus { left: 0; color: #fff; }

/* ---------- Kopfzeile / Seitenleiste ----------
   Mobil: klassische Kopfleiste mit Burger-Menü.
   Ab 1100 px: fixe vertikale Navigation links (wie auf der bisherigen Website). */

.topbar {
  background: var(--schwarz);
  color: #C9D2E4;
  font-size: .85rem;
}
.topbar .wrap {
  display: flex; flex-wrap: wrap; gap: .4rem 1.6rem;
  align-items: center; justify-content: flex-end;
  min-height: 40px;
}
.topbar a { color: #E7ECF6; text-decoration: none; font-weight: 600; }
.topbar a:hover { color: var(--gruen-hell); }
.topbar span { display: inline-flex; align-items: center; gap: .45rem; }

.sidebar {
  position: sticky; top: 0; z-index: 60;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: .7rem 1.25rem;
  background: rgba(255,255,255,.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--grau-200);
}
.logo { display: block; flex: 0 0 auto; }
.logo img { width: clamp(170px, 22vw, 230px); height: auto; }

.nav-toggle {
  display: inline-flex; align-items: center; gap: .5rem;
  border: 1px solid var(--grau-200); background: var(--weiss);
  border-radius: var(--radius-sm); padding: .55rem .8rem;
  font: inherit; font-weight: 650; color: var(--schwarz); cursor: pointer;
}
.nav-toggle .bars { display: grid; gap: 4px; }
.nav-toggle .bars i { display: block; width: 20px; height: 2px; background: var(--blau); border-radius: 2px; }

.nav { display: none; position: absolute; inset: 100% 0 auto 0; padding: .6rem 1.25rem 1.2rem;
       background: var(--weiss); border-bottom: 1px solid var(--grau-200); box-shadow: var(--schatten); }
.nav.open { display: block; }
.nav ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .1rem; }
.nav a {
  display: block; padding: .8rem .6rem; border-radius: var(--radius-sm);
  color: var(--grau-900); text-decoration: none; font-weight: 620; font-size: .99rem;
  border-bottom: 1px solid var(--grau-100);
}
.nav a:hover { background: var(--grau-100); color: var(--blau); }
.nav a[aria-current="page"] { color: var(--blau); }
.nav .btn { margin: .9rem 0 0; text-align: center; }
.side-foot { display: none; }

/* Desktop: vertikale Navigation links */
@media (min-width: 1100px) {
  .sidebar {
    position: fixed; inset: 0 auto 0 0; width: 288px;
    flex-direction: column; align-items: stretch; justify-content: flex-start;
    gap: 0; padding: 1.75rem 1.4rem 1.4rem;
    background: var(--weiss);
    border-bottom: 0; border-right: 1px solid var(--grau-200);
    overflow-y: auto;
  }
  .sidebar .logo { margin-bottom: 1.9rem; }
  .sidebar .logo img { width: 100%; max-width: 230px; }
  .nav-toggle { display: none; }

  .nav { display: block; position: static; padding: 0; background: none; border: 0; box-shadow: none; }
  .nav ul { gap: .15rem; }
  .nav a {
    position: relative; padding: .72rem .9rem; border-bottom: 0;
    border-radius: var(--radius-sm); font-size: 1.02rem; font-weight: 650;
  }
  .nav a::before {
    content: ""; position: absolute; left: 0; top: 50%; transform: translateY(-50%);
    width: 3px; height: 0; border-radius: 3px; background: var(--gruen);
    transition: height .18s ease;
  }
  .nav a:hover::before { height: 55%; }
  .nav a[aria-current="page"] { background: var(--grau-100); color: var(--blau); }
  .nav a[aria-current="page"]::before { height: 62%; }
  .nav .btn { margin: 1.1rem 0 0; width: 100%; }

  .side-foot {
    display: block; margin-top: auto; padding-top: 1.6rem;
    border-top: 1px solid var(--grau-200); font-size: .88rem; color: var(--grau-500);
  }
  .side-foot strong { display: block; color: var(--grau-900); font-size: .95rem; margin-bottom: .35rem; }
  .side-foot a { text-decoration: none; font-weight: 650; }
  .side-foot p { margin: 0 0 .8rem; line-height: 1.5; }

  .site { margin-left: 288px; }
  .topbar { display: none; }
  :root { --breite: 1120px; }
  .wrap { width: min(100% - 3.5rem, var(--breite)); margin-inline: 0 auto; }
  .wrap, .site-footer .wrap { margin-inline: auto; }
}

@media (min-width: 1600px) {
  .sidebar { width: 320px; }
  .site { margin-left: 320px; }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
  padding: .85rem 1.5rem; border-radius: 999px;
  font-weight: 700; font-size: 1rem; text-decoration: none; border: 2px solid transparent;
  cursor: pointer; transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn--primary { background: var(--grad-blau); color: #fff; box-shadow: 0 8px 20px rgba(43,75,156,.28); }
.btn--primary:hover { color: #fff; box-shadow: 0 12px 28px rgba(43,75,156,.34); }
.btn--gruen { background: var(--grad-gruen); color: #fff; box-shadow: 0 8px 20px rgba(46,125,50,.28); }
.btn--gruen:hover { color: #fff; }
.btn--ghost { background: transparent; color: var(--weiss); border-color: rgba(255,255,255,.6); }
.btn--ghost:hover { background: rgba(255,255,255,.14); color: #fff; border-color: #fff; }
.btn--outline { background: var(--weiss); color: var(--blau); border-color: var(--grau-200); }
.btn--outline:hover { border-color: var(--blau); color: var(--blau); }
.btn--sm { padding: .6rem 1.1rem; font-size: .93rem; }

/* Buttons in der Navigation: die .nav-a-Regeln dürfen die Buttonfarben nicht überschreiben */
.nav a.btn, .nav a.btn:hover, .nav a.btn:focus { color: #fff; }
.nav a.btn--primary, .nav a.btn--primary:hover { background: var(--grad-blau); }
.nav a.btn--gruen, .nav a.btn--gruen:hover { background: var(--grad-gruen); }
.nav a.btn::before { content: none; }
.nav a.btn[aria-current="page"] { box-shadow: 0 8px 20px rgba(43,75,156,.28); }

/* ---------- Hero ---------- */
.hero {
  position: relative; isolation: isolate;
  background: var(--grad-duo); color: #fff;
  padding: clamp(3.5rem, 8vw, 6.5rem) 0 clamp(3rem, 7vw, 5.5rem);
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: -2;
  background-image: var(--hero-img, none);
  background-size: cover; background-position: center;
  opacity: .28;
}
.hero::after {
  content: ""; position: absolute; z-index: -1;
  right: -12%; top: -35%; width: 60vw; aspect-ratio: 1;
  background: radial-gradient(circle at 40% 40%, rgba(86,167,91,.55), transparent 62%);
}
.hero-grid { display: grid; gap: clamp(2rem, 5vw, 4rem); align-items: center; }
@media (min-width: 900px) { .hero-grid { grid-template-columns: 1.15fr .85fr; } }

.hero h1 { color: #fff; }
.hero h1 em { font-style: normal; color: #A8F0AE; }
.hero .lead { font-size: clamp(1.05rem, 1rem + .45vw, 1.3rem); color: #DDE5F5; max-width: 46ch; }
.eyebrow {
  display: inline-flex; align-items: center; gap: .55rem;
  background: rgba(255,255,255,.13); border: 1px solid rgba(255,255,255,.24);
  color: #fff; font-size: .82rem; font-weight: 700; letter-spacing: .09em; text-transform: uppercase;
  padding: .4rem .95rem; border-radius: 999px; margin-bottom: 1.2rem;
}
.eyebrow::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--gruen-hell); }
.hero-actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1.8rem; }

.hero-card {
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.22);
  border-radius: var(--radius); padding: clamp(1.4rem, 3vw, 2rem);
  backdrop-filter: blur(6px);
}
.hero-card h2 { color: #fff; font-size: 1.25rem; }
.hero-card ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .75rem; }
.hero-card li { display: flex; gap: .7rem; color: #E4EAF7; font-size: .98rem; }
.hero-card li::before {
  content: ""; flex: 0 0 auto; width: 22px; height: 22px; border-radius: 50%; margin-top: .1rem;
  background: var(--gruen-hell) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23fff' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E") center/13px no-repeat;
}

/* ---------- Sektionen ---------- */
section { padding: clamp(3rem, 7vw, 5.5rem) 0; }
.sec-grau { background: var(--grau-50); }
.sec-head { max-width: 62ch; margin-bottom: clamp(2rem, 4vw, 3rem); }
.sec-head.center { margin-inline: auto; text-align: center; }
.sec-head .kicker {
  display: block; color: var(--gruen); font-weight: 750;
  letter-spacing: .12em; text-transform: uppercase; font-size: .8rem; margin-bottom: .7rem;
}
.sec-head p { font-size: 1.08rem; color: var(--grau-500); margin-bottom: 0; }

/* ---------- Karten ---------- */
.cards { display: grid; gap: 1.4rem; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.cards--4 { grid-template-columns: repeat(auto-fit, minmax(235px, 1fr)); }
.card {
  background: var(--weiss); border: 1px solid var(--grau-200); border-radius: var(--radius);
  padding: 1.7rem 1.6rem; box-shadow: var(--schatten);
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
  display: flex; flex-direction: column;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--schatten-hoch); border-color: transparent; }
.card h3 { margin-bottom: .45rem; }
.card p { color: var(--grau-500); font-size: .98rem; }
.card ul { margin: 0 0 1.1rem; padding-left: 1.1rem; color: var(--grau-500); font-size: .95rem; }
.card ul li { margin-bottom: .3rem; }
.card .more { margin-top: auto; font-weight: 700; text-decoration: none; font-size: .95rem; }
.card .more::after { content: " →"; }

.ikon {
  width: 52px; height: 52px; border-radius: 14px; margin-bottom: 1.1rem;
  display: grid; place-items: center; background: var(--grad-blau);
}
.ikon svg { width: 26px; height: 26px; stroke: #fff; fill: none; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; }
.ikon--gruen { background: var(--grad-gruen); }

/* ---------- Split (Text + Bild) ---------- */
.split { display: grid; gap: clamp(2rem, 5vw, 3.5rem); align-items: center; }
@media (min-width: 880px) { .split { grid-template-columns: 1fr 1fr; } .split.rev > *:first-child { order: 2; } }

.shot {
  position: relative; border-radius: var(--radius); overflow: hidden;
  background: var(--grad-duo); box-shadow: var(--schatten-hoch);
  min-height: 260px; aspect-ratio: 4 / 3;
}
.shot img { width: 100%; height: 100%; object-fit: cover; }
.shot::after {
  content: attr(data-label); position: absolute; left: 1rem; bottom: 1rem;
  background: rgba(20,24,31,.72); color: #fff; font-size: .78rem; font-weight: 650;
  padding: .35rem .8rem; border-radius: 999px; backdrop-filter: blur(4px);
}
.shot--flach { aspect-ratio: 16 / 9; }

/* ---------- Liste mit Haken ---------- */
.checks { list-style: none; margin: 0 0 1.5rem; padding: 0; display: grid; gap: .7rem; }
.checks li { display: flex; gap: .75rem; align-items: flex-start; }
.checks li::before {
  content: ""; flex: 0 0 auto; width: 22px; height: 22px; border-radius: 50%; margin-top: .18rem;
  background: rgba(46,125,50,.12) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%232E7D32' stroke-width='3.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E") center/13px no-repeat;
}

/* ---------- Ablauf / Schritte ---------- */
.steps { counter-reset: step; display: grid; gap: 1.3rem; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.step {
  position: relative; background: var(--weiss); border: 1px solid var(--grau-200);
  border-radius: var(--radius); padding: 2.4rem 1.5rem 1.5rem;
}
.step::before {
  counter-increment: step; content: counter(step, decimal-leading-zero);
  position: absolute; top: 1.2rem; left: 1.5rem;
  font-size: 1.6rem; font-weight: 800; color: transparent;
  background: var(--grad-duo); -webkit-background-clip: text; background-clip: text;
}
.step h3 { margin-top: 1.4rem; font-size: 1.1rem; }
.step p { font-size: .95rem; color: var(--grau-500); margin: 0; }

/* ---------- Kennzahlen ---------- */
.stats { display: grid; gap: 1.2rem; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }
.stat { text-align: center; padding: 1.5rem 1rem; border-radius: var(--radius); background: var(--weiss); border: 1px solid var(--grau-200); }
.stat b { display: block; font-size: clamp(1.9rem, 1.4rem + 1.6vw, 2.6rem); color: var(--blau); line-height: 1.1; }
.stat span { font-size: .92rem; color: var(--grau-500); }

/* ---------- Zitat ---------- */
.quote {
  border-left: 5px solid var(--gruen); background: var(--weiss);
  padding: 1.6rem 1.8rem; border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: var(--schatten); font-size: 1.1rem; color: var(--grau-900);
}
.quote footer { margin-top: .8rem; font-size: .9rem; color: var(--grau-500); font-weight: 650; }

/* ---------- CTA-Band ---------- */
.cta { background: var(--grad-duo); color: #fff; text-align: center; }
.cta h2 { color: #fff; }
.cta p { color: #DCE4F5; max-width: 55ch; margin-inline: auto; }
.cta .hero-actions { justify-content: center; }

/* ---------- Kontakt ---------- */
.kontakt-grid { display: grid; gap: 2.5rem; }
@media (min-width: 900px) { .kontakt-grid { grid-template-columns: .9fr 1.1fr; } }

.infobox { background: var(--weiss); border: 1px solid var(--grau-200); border-radius: var(--radius); padding: 1.8rem; box-shadow: var(--schatten); }
.infobox + .infobox { margin-top: 1.3rem; }
.infobox h3 { font-size: 1.1rem; }
.infobox dl { margin: 0; display: grid; grid-template-columns: auto 1fr; gap: .5rem 1.1rem; font-size: .97rem; }
.infobox dt { font-weight: 700; color: var(--grau-900); }
.infobox dd { margin: 0; }

form .feld { margin-bottom: 1.1rem; }
form label { display: block; font-weight: 650; color: var(--grau-900); margin-bottom: .35rem; font-size: .95rem; }
form input, form select, form textarea {
  width: 100%; padding: .8rem .95rem; font: inherit; color: var(--grau-900);
  border: 1px solid var(--grau-200); border-radius: var(--radius-sm); background: var(--weiss);
}
form input:focus, form select:focus, form textarea:focus { border-color: var(--blau); outline: none; box-shadow: 0 0 0 3px rgba(43,75,156,.15); }
form textarea { min-height: 150px; resize: vertical; }
.feld-zeile { display: grid; gap: 1.1rem; }
@media (min-width: 620px) { .feld-zeile { grid-template-columns: 1fr 1fr; } }
.dsgvo { display: flex; gap: .7rem; align-items: flex-start; font-size: .9rem; color: var(--grau-500); }
.dsgvo input { width: auto; margin-top: .25rem; }

/* ---------- FAQ ---------- */
.faq details {
  background: var(--weiss); border: 1px solid var(--grau-200); border-radius: var(--radius-sm);
  padding: 1.1rem 1.3rem; margin-bottom: .8rem;
}
.faq summary { font-weight: 700; color: var(--grau-900); cursor: pointer; list-style: none; display: flex; justify-content: space-between; gap: 1rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--gruen); font-size: 1.4rem; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq details[open] summary { margin-bottom: .7rem; }
.faq p { margin: 0; font-size: .97rem; color: var(--grau-500); }

/* ---------- Seitenkopf (Unterseiten) ---------- */
.pagehead {
  background: var(--grad-duo); color: #fff; position: relative; isolation: isolate;
  padding: clamp(2.6rem, 6vw, 4.5rem) 0;
}
.pagehead::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background-image: var(--hero-img, none); background-size: cover; background-position: center; opacity: .22;
}
.pagehead h1 { color: #fff; margin-bottom: .3rem; }
.pagehead p { color: #DCE4F5; max-width: 58ch; margin: 0; font-size: 1.08rem; }
.crumbs { font-size: .85rem; color: #B9C6E4; margin-bottom: 1rem; }
.crumbs a { color: #DCE4F5; text-decoration: none; }
.crumbs a:hover { color: #fff; }

/* ---------- Fußzeile ---------- */
.site-footer { background: var(--schwarz); color: #A9B4C7; padding: clamp(2.8rem, 6vw, 4rem) 0 1.5rem; font-size: .95rem; }
.footer-grid { display: grid; gap: 2rem; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.site-footer h4 { color: #fff; font-size: 1rem; margin-bottom: .9rem; }
.site-footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .5rem; }
.site-footer a { color: #C7D1E2; text-decoration: none; }
.site-footer a:hover { color: var(--gruen-hell); }
.footer-logo { background: #fff; border-radius: 12px; padding: .7rem .9rem; display: inline-block; margin-bottom: 1rem; }
.footer-logo img { width: 190px; }
.footer-bottom {
  margin-top: 2.5rem; padding-top: 1.2rem; border-top: 1px solid rgba(255,255,255,.12);
  display: flex; flex-wrap: wrap; gap: .6rem 1.5rem; justify-content: space-between; font-size: .87rem;
}

/* ---------- Sonstiges ---------- */
.tag {
  display: inline-block; background: rgba(46,125,50,.1); color: var(--gruen-dunkel);
  font-size: .78rem; font-weight: 700; letter-spacing: .04em; text-transform: uppercase;
  padding: .25rem .7rem; border-radius: 999px; margin-bottom: .8rem;
}
.tag--blau { background: rgba(43,75,156,.1); color: var(--blau-dunkel); }
.hinweis {
  background: #FFF8E1; border: 1px solid #F2DFA4; border-left: 5px solid #E0B33C;
  border-radius: var(--radius-sm); padding: 1rem 1.2rem; font-size: .93rem; color: #6B5312;
}
.prose { max-width: 74ch; }
.prose h2 { margin-top: 2.2rem; }
.prose h3 { margin-top: 1.6rem; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}