/* ═══════════════════════════════════════════════════════════════
   ELBSONNE ENERGIE — Landingpage Design System (lp.css)
   Premium-Fassaden-Optik: Schwarz-Glas · Anthrazit-Platten · Fugen · Gelbe Lichtkanten
   ═══════════════════════════════════════════════════════════════ */
:root {
  --color-black: #0B0B0C;
  --color-charcoal: #1A1A1A;
  --color-charcoal-light: #242424;
  --color-gray: #828282;
  --color-white: #FFFFFF;
  --color-yellow: #FFFF00;
  --color-cream: #B8B8B8;
  --line: rgba(255, 255, 255, 0.07);
  --line-strong: rgba(255, 255, 255, 0.17);
  --card-bg: linear-gradient(180deg, rgba(52, 52, 52, 0.94) 0%, rgba(36, 36, 36, 0.9) 45%, rgba(24, 24, 24, 0.94) 100%);
  --card-surface:
    linear-gradient(180deg, rgba(255, 255, 255, 0.09) 0%, rgba(255, 255, 255, 0.02) 32%, transparent 50%),
    var(--card-bg);
  --r-md: 16px;
  --r-lg: 24px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }
body {
  background: var(--color-charcoal);
  color: var(--color-white);
  font-family: 'Manrope', 'Inter', sans-serif;
  line-height: 1.75;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 2000;
  pointer-events: none;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='0.55'/%3E%3C/svg%3E");
}
::selection { background: var(--color-yellow); color: var(--color-black); }
h1, h2, h3, h4 { font-weight: 700; line-height: 1.15; letter-spacing: -0.02em; }
h1 { font-size: clamp(2.2rem, 4.6vw, 3.4rem); letter-spacing: -0.03em; line-height: 1.1; }
h1 span { color: var(--color-yellow); }
h2 { font-size: clamp(1.5rem, 2.6vw, 2.1rem); letter-spacing: -0.02em; margin-bottom: 1.1rem; }
h3 { font-size: 1.1rem; }
p { font-weight: 400; }
a { color: var(--color-yellow); text-decoration: none; }
a:hover { text-decoration: underline; }
strong { color: var(--color-white); font-weight: 600; }

.container { max-width: 1160px; margin: 0 auto; padding: 0 2rem; }
.section-tag {
  display: inline-block;
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--color-yellow);
  margin-bottom: 1.1rem;
}

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.6rem;
  min-height: 50px; padding: 0.9rem 2rem;
  border-radius: 999px;
  font-family: 'Manrope', sans-serif; font-weight: 700; font-size: 0.92rem;
  text-decoration: none; cursor: pointer; border: none;
  transition: transform 0.35s cubic-bezier(0.22, 1, 0.36, 1), box-shadow 0.35s, color 0.25s, border-color 0.25s;
}
.btn-primary {
  background: linear-gradient(180deg, #FFFF00, #E4E400);
  color: #141414;
  box-shadow: 0 6px 22px rgba(255, 255, 0, 0.18), inset 0 1px 0 rgba(255, 255, 255, 0.45);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 38px rgba(255, 255, 0, 0.3); text-decoration: none; }
.btn-ghost {
  background: rgba(255, 255, 255, 0.02);
  color: var(--color-white);
  border: 1px solid var(--line-strong);
}
.btn-ghost:hover { transform: translateY(-2px); border-color: rgba(255, 255, 0, 0.55); color: var(--color-yellow); text-decoration: none; }

/* ── Navigation ── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  display: flex; align-items: center; justify-content: space-between;
  padding: 1.6rem 2rem;
  background: linear-gradient(180deg, rgba(15, 15, 15, 0.94), rgba(15, 15, 15, 0.82));
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
nav .logo img { height: 108px; width: auto; display: block; }
nav ul { display: flex; align-items: center; gap: 0.2rem; list-style: none; }
nav ul a {
  color: #A3A3A3; font-size: 0.86rem; font-weight: 500;
  padding: 0.55rem 0.95rem; border-radius: 999px;
  transition: color 0.25s, background 0.25s;
}
nav ul a:hover { color: var(--color-white); background: rgba(255, 255, 255, 0.05); text-decoration: none; }
nav ul a.cta {
  background: linear-gradient(180deg, #FFFF00, #E4E400); color: #141414; font-weight: 700;
  box-shadow: 0 4px 16px rgba(255, 255, 0, 0.2);
}
nav ul a.cta:hover { transform: translateY(-1px); text-decoration: none; }

/* ── Hero mit 3D-Bild (Fassaden-Optik) ── */
.lp-hero {
  position: relative;
  min-height: 72vh;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
  padding: 9rem 4vw 5rem;
  text-align: center;
}
.lp-hero-bg {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: cover; object-position: center 30%;
  z-index: 0;
}
.lp-hero-overlay {
  position: absolute; inset: 0; z-index: 1;
  background:
    radial-gradient(ellipse 55% 45% at 50% 40%, rgba(255, 255, 0, 0.05) 0%, transparent 72%),
    linear-gradient(115deg, transparent 36%, rgba(255, 255, 255, 0.05) 44%, rgba(255, 255, 255, 0.015) 50%, transparent 57%),
    linear-gradient(180deg, rgba(11, 11, 12, 0.94) 0%, rgba(21, 21, 21, 0.72) 45%, #1A1A1A 97%);
}
.lp-hero-overlay::before {
  content: '';
  position: absolute; inset: 0;
  background:
    repeating-linear-gradient(0deg, transparent 0 104px, rgba(255, 255, 255, 0.03) 104px 105px),
    repeating-linear-gradient(90deg, transparent 0 168px, rgba(255, 255, 255, 0.022) 168px 169px);
  opacity: 0.6;
}
.lp-hero-overlay::after {
  content: '';
  position: absolute; top: 0; left: 8%; right: 8%; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 0, 0.45), transparent);
}
.lp-hero-inner { position: relative; z-index: 2; max-width: 880px; }
.lp-hero h1 { margin-bottom: 1.4rem; }
.lp-hero p {
  color: #A3A3A3; font-size: 1.05rem; font-weight: 300;
  max-width: 660px; margin: 0 auto 2.4rem; line-height: 1.8;
}
.lp-hero .btn { margin: 0 0.45rem 0.6rem; }

/* ── Sektionen (Fassaden-Platten + Fugen) ── */
section {
  position: relative;
  padding: 5.5rem 0;
  background: linear-gradient(180deg, var(--color-charcoal) 0%, #161617 100%);
}
section::before {
  content: '';
  position: absolute; inset: 0; pointer-events: none; z-index: 0;
  background-image:
    linear-gradient(135deg, #242425 0%, #1A1A1B 45%, transparent 66%) 0 0 / 45% 55% no-repeat,
    linear-gradient(315deg, #0E0E0F 0%, #141415 50%, transparent 68%) 100% 100% / 50% 55% no-repeat,
    repeating-linear-gradient(0deg, transparent 0 160px, rgba(255, 255, 255, 0.04) 160px 161px),
    repeating-linear-gradient(90deg, transparent 0 260px, rgba(255, 255, 255, 0.028) 260px 261px);
  opacity: 0.7;
}
section > .container { position: relative; z-index: 1; }

/* ── Content ── */
.lp-content { max-width: 820px; }
.lp-content p { color: #A3A3A3; font-size: 0.98rem; font-weight: 300; line-height: 1.85; margin-bottom: 1.2rem; }
.lp-content h2 { margin-top: 2.4rem; }
.lp-content ul { list-style: none; margin: 0 0 1.4rem; }
.lp-content ul li {
  color: #A3A3A3; font-size: 0.95rem; font-weight: 300; line-height: 1.75;
  padding: 0.55rem 0 0.55rem 1.6rem; position: relative;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}
.lp-content ul li::before {
  content: '';
  position: absolute; left: 0; top: 1.05em;
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--color-yellow); opacity: 0.85;
}
.lp-highlight {
  border-left: 2px solid var(--color-yellow);
  background: rgba(255, 255, 255, 0.03);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  padding: 1.1rem 1.4rem;
  color: var(--color-cream);
  font-size: 0.95rem;
  margin: 1.6rem 0 2rem;
  line-height: 1.7;
}

/* ── FAQ ── */
.lp-faq { background: var(--color-black); }
.lp-faq details {
  background: var(--card-surface);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--r-md);
  padding: 1.2rem 1.5rem;
  margin-bottom: 0.8rem;
  box-shadow: 0 14px 36px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.07);
  transition: border-color 0.3s;
}
.lp-faq details[open] { border-color: rgba(255, 255, 0, 0.3); }
.lp-faq summary {
  cursor: pointer;
  font-weight: 600; font-size: 0.95rem;
  list-style: none;
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
}
.lp-faq summary::after { content: '▾'; color: #828282; transition: transform 0.3s; }
.lp-faq details[open] summary::after { transform: rotate(180deg); color: var(--color-yellow); }
.lp-faq summary::-webkit-details-marker { display: none; }
.lp-faq p { color: #A3A3A3; font-size: 0.88rem; font-weight: 300; margin-top: 0.9rem; line-height: 1.75; }

/* ── CTA-Box ── */
.lp-cta-inner {
  display: flex; align-items: center; justify-content: space-between; gap: 2rem;
  background: var(--card-surface);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-top: 1px solid rgba(255, 255, 0, 0.4);
  border-radius: var(--r-lg);
  padding: 2.2rem 2.5rem;
  flex-wrap: wrap;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55), inset 0 1px 0 rgba(255, 255, 255, 0.08);
}
.lp-cta-inner p { color: #A3A3A3; font-size: 0.85rem; margin-top: 0.35rem; font-weight: 300; }

/* ── Sticky CTA ── */
.sticky-cta {
  position: fixed; bottom: 1.6rem; right: 1.6rem; z-index: 1500;
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 52px; padding: 0.85rem 1.6rem;
  background: linear-gradient(180deg, #FFFF00, #E4E400);
  color: #141414;
  border-radius: 999px;
  font-family: 'Manrope', sans-serif; font-weight: 700; font-size: 0.9rem;
  text-decoration: none;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), 0 6px 22px rgba(255, 255, 0, 0.25), inset 0 1px 0 rgba(255, 255, 255, 0.45);
  transition: transform 0.35s, box-shadow 0.35s;
}
.sticky-cta:hover { transform: translateY(-2px); text-decoration: none; box-shadow: 0 16px 40px rgba(0, 0, 0, 0.55), 0 10px 30px rgba(255, 255, 0, 0.35); }

/* ── Footer ── */
footer {
  background: var(--color-black);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 4rem 0 2rem;
  position: relative;
}
footer::before {
  content: '';
  position: absolute; top: -1px; left: 15%; right: 15%; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 0, 0.3), transparent);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
}
.footer-grid h4 {
  font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.22em;
  color: #828282; margin-bottom: 1.2rem;
}
.footer-grid p { color: #828282; font-size: 0.86rem; font-weight: 300; line-height: 1.8; }
.footer-grid ul { list-style: none; display: flex; flex-direction: column; gap: 0.6rem; }
.footer-grid ul a { color: #828282; font-size: 0.86rem; transition: color 0.25s, padding-left 0.25s; }
.footer-grid ul a:hover { color: var(--color-yellow); padding-left: 3px; text-decoration: none; }
.footer-bottom {
  margin-top: 3rem; padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem;
  color: #828282; font-size: 0.76rem;
}
.footer-bottom a { color: #828282; margin-left: 1.4rem; }
.footer-bottom a:hover { color: var(--color-yellow); }

/* ── Responsive ── */
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  nav { padding: 1.2rem 1.2rem; }
  nav .logo img { height: 84px; }
  nav ul a { font-size: 0.78rem; padding: 0.5rem 0.65rem; }
  nav ul a.cta { padding: 0.5rem 0.9rem; }
  .lp-hero { min-height: 64vh; padding: 7.5rem 1.5rem 4rem; }
  section { padding: 4rem 0; }
  section::before { opacity: 0.45; }
  .lp-cta-inner { padding: 1.8rem 1.5rem; }
  .lp-cta-inner .btn { width: 100%; }
  .footer-grid { grid-template-columns: 1fr; gap: 2.2rem; }
  .sticky-cta { bottom: 1.2rem; right: 1.2rem; min-height: 48px; padding: 0.7rem 1.2rem; font-size: 0.82rem; }
  body::after { opacity: 0.025; }
}
@media (max-width: 480px) {
  nav ul a:not(.cta) { display: none; }
  .lp-hero .btn { width: 100%; }
}