/* ==========================================================================
   Layout: container, sections, header, navigation, footer
   ========================================================================== */

.container {
  width: 100%;
  max-width: calc(var(--container) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: calc(var(--container-narrow) + var(--gutter) * 2); }

.section { padding-block: var(--section-y); position: relative; }
.section--tight { padding-block: clamp(2.5rem, 5vw, 4.5rem); }
.section--flush-top { padding-top: 0; }
/* Two consecutive sections on the same background share one gap. */
.section:not(.section--sunken, .section--energy) + .section:not(.section--sunken, .section--energy) { padding-top: 0; }
.section--sunken + .section--sunken { padding-top: 0; }
.section--sunken { background: var(--bg-sunken); }

/* Energy system section: light by default, navy in dark mode. */
.section--energy {
  border-block: 1px solid var(--border);
  background:
    radial-gradient(45% 55% at 88% 0%, rgb(179 222 44 / .16), transparent 70%),
    radial-gradient(40% 50% at 0% 100%, rgb(27 81 139 / .07), transparent 70%),
    radial-gradient(circle at 1px 1px, var(--grid-dot) 1px, transparent 1.6px) 0 0 / 26px 26px,
    var(--bg);
}
:root[data-theme="dark"] .section--energy {
  background:
    radial-gradient(60% 50% at 85% 0%, rgb(199 236 80 / .1), transparent 70%),
    radial-gradient(50% 60% at 0% 100%, rgb(27 81 139 / .35), transparent 70%),
    var(--navy-bg);
}

/* --------------------------------------------------------------- Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  transition: background-color var(--dur-2), box-shadow var(--dur-2), border-color var(--dur-2);
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled,
.site-header.has-open-menu {
  background: var(--header-bg);
  -webkit-backdrop-filter: saturate(1.5) blur(16px);
  backdrop-filter: saturate(1.5) blur(16px);
  border-bottom-color: var(--border);
}
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .site-header.is-scrolled, .site-header.has-open-menu { background: var(--bg); }
}

.site-header__inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(.75rem, 2vw, 2rem);
  min-height: var(--header-h);
}

.brand { display: inline-flex; align-items: center; flex-shrink: 0; border-radius: var(--radius-sm); }
.brand__img { height: 42px; width: auto; }
.brand__img--dark { display: none; }
:root[data-theme="dark"] .brand__img--light,
.site-footer .brand__img--light,
.contact-card--navy .brand__img--light { display: none; }
:root[data-theme="dark"] .brand__img--dark,
.site-footer .brand__img--dark,
.contact-card--navy .brand__img--dark { display: block; }

.primary-nav { display: none; margin-inline: auto; }
.primary-nav__list { display: flex; align-items: center; gap: .15rem; }
.primary-nav__item { display: flex; align-items: center; }

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: .55rem .85rem;
  border-radius: var(--radius-pill);
  color: var(--text-2);
  font-size: var(--fs-sm);
  font-weight: 600;
  text-decoration: none;
  transition: color var(--dur-1), background-color var(--dur-1);
}
.nav-link:hover { color: var(--text); background: var(--surface-2); }
.nav-link[aria-current="page"] { color: var(--text); }
.nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 50%; bottom: .18rem;
  width: 5px; height: 5px;
  margin-left: -2.5px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.has-mega .nav-link { padding-right: .2rem; }

.nav-link__toggle {
  display: inline-grid;
  place-items: center;
  width: 30px; height: 30px;
  margin-left: .05rem;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--text-2);
  transition: background-color var(--dur-1), transform var(--dur-2) var(--ease-out);
}
.nav-link__toggle:hover { background: var(--surface-2); color: var(--text); }
.nav-link__toggle .icon { width: 16px; height: 16px; transition: transform var(--dur-2) var(--ease-out); }
.nav-link__toggle[aria-expanded="true"] .icon { transform: rotate(180deg); }

/* Mega menu */
.mega {
  position: absolute;
  top: calc(100% - 6px);
  left: 50%;
  width: min(980px, calc(100vw - var(--gutter) * 2));
  translate: -50% 0;
  padding-top: 10px;
  opacity: 0;
  transform: translateY(-6px);
  transition: opacity var(--dur-2) var(--ease-out), transform var(--dur-2) var(--ease-out);
}
.mega.is-open { opacity: 1; transform: none; }
.mega__inner {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: .75rem;
  padding: .75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-lg);
}
.mega__grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .15rem; }
.mega__link {
  display: flex;
  align-items: flex-start;
  gap: .85rem;
  padding: .7rem .8rem;
  border-radius: var(--radius);
  color: var(--text);
  text-decoration: none;
  transition: background-color var(--dur-1);
}
.mega__link:hover, .mega__link[aria-current="page"] { background: var(--surface-2); }
.mega__icon {
  display: grid; place-items: center;
  width: 40px; height: 40px;
  flex-shrink: 0;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent-text);
  transition: background-color var(--dur-1), color var(--dur-1);
}
.mega__link:hover .mega__icon { background: var(--accent); color: var(--accent-ink); }
.mega__text { display: grid; line-height: 1.3; min-width: 0; }
.mega__title { font-weight: 650; font-size: var(--fs-sm); }
.mega__desc { color: var(--text-3); font-size: var(--fs-xs); }
.mega__aside {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem;
  border-radius: var(--radius);
  background:
    radial-gradient(120% 80% at 100% 0%, rgb(199 236 80 / .22), transparent 60%),
    var(--navy-800);
  color: #eef3f9;
  --border-strong: rgb(255 255 255 / .28);
  --text: #eef3f9;
  --surface: rgb(255 255 255 / .08);
}
.mega__kicker { display: flex; align-items: center; gap: .5rem; font-weight: 700; margin: 0; }
.mega__kicker .icon { color: var(--lime-400); }
.mega__aside-text { color: #b6c5d7; font-size: var(--fs-sm); margin: 0; }

/* Header actions */
.site-header__actions { display: flex; align-items: center; gap: .5rem; margin-left: auto; }


.header-phone {
  display: none;
  align-items: center;
  gap: .45rem;
  padding: .5rem .75rem;
  border-radius: var(--radius-pill);
  color: var(--text-2);
  font-size: var(--fs-sm);
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
}
.header-phone:hover { color: var(--text); background: var(--surface-2); }
.header-phone .icon { color: var(--accent-text); }

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 44px; height: 44px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--surface);
  color: var(--text);
  transition: background-color var(--dur-1), border-color var(--dur-1), transform var(--dur-1);
}
.icon-btn:hover { border-color: var(--border-strong); background: var(--surface-2); }
.icon-btn:active { transform: scale(.95); }
.icon-btn .icon { width: 20px; height: 20px; }

.site-header__actions .site-header__cta { display: none; }

/* Theme switch (Hell / Dunkel) – a two-state switch, not a menu */
.theme-toggle {
  display: none;
  padding: 0;
  border: 0;
  border-radius: var(--radius-pill);
  background: none;
  color: inherit;
}
.js .theme-toggle { display: inline-flex; }
.theme-toggle__track {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  width: 72px;
  height: 40px;
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  background: var(--surface-2);
  transition: border-color var(--dur-1);
}
.theme-toggle:hover .theme-toggle__track { border-color: var(--border-strong); }
.theme-toggle__thumb {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--surface);
  box-shadow: 0 1px 3px hsl(var(--shadow-color) / .18), 0 0 0 1px var(--border);
  transition: transform var(--dur-3) var(--ease-out);
}
:root[data-theme="dark"] .theme-toggle__thumb { background: #1d3558; }
.theme-toggle[aria-checked="true"] .theme-toggle__thumb { transform: translateX(32px); }
.theme-toggle__icon {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  height: 32px;
  color: var(--text-3);
  transition: color var(--dur-2);
}
.theme-toggle__icon .icon { width: 17px; height: 17px; }
.theme-toggle[aria-checked="false"] .theme-toggle__icon--light,
.theme-toggle[aria-checked="true"] .theme-toggle__icon--dark { color: var(--accent-text); }

/* Hamburger */
.nav-toggle__bars { position: relative; display: block; width: 18px; height: 12px; }
.nav-toggle__bars span {
  position: absolute; left: 0;
  width: 100%; height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur-2) var(--ease-out), opacity var(--dur-1), width var(--dur-2);
}
.nav-toggle__bars span:nth-child(1) { top: 0; }
.nav-toggle__bars span:nth-child(2) { top: 5px; width: 70%; }
.nav-toggle__bars span:nth-child(3) { top: 10px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

@media (min-width: 640px) {
  .site-header__actions .site-header__cta { display: inline-flex; }
}
@media (min-width: 1080px) {
  .primary-nav { display: block; }
  .nav-toggle { display: none; }
  .site-header__actions { margin-left: 0; }
}
@media (min-width: 1320px) {
  .header-phone { display: inline-flex; }
}
@media (max-width: 420px) {
  .brand__img { height: 36px; }
  .site-header__actions { gap: .35rem; }
}

/* ------------------------------------------------------------ Mobile nav */

.mobile-nav { position: fixed; inset: 0; z-index: 100; }
.mobile-nav__backdrop {
  position: absolute; inset: 0;
  background: rgb(3 15 29 / .5);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  opacity: 0;
  transition: opacity var(--dur-3) var(--ease-out);
}
.mobile-nav__panel {
  position: absolute;
  inset: 0 0 0 auto;
  display: flex;
  flex-direction: column;
  width: min(440px, 100%);
  height: 100%;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 0 var(--gutter) max(1.5rem, env(safe-area-inset-bottom));
  background: var(--bg);
  box-shadow: var(--shadow-lg);
  transform: translateX(100%);
  transition: transform var(--dur-3) var(--ease-out);
}
.mobile-nav.is-open .mobile-nav__backdrop { opacity: 1; }
.mobile-nav.is-open .mobile-nav__panel { transform: none; }

.mobile-nav__top {
  position: sticky;
  top: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
  background: var(--bg);
}
.mobile-nav__list { display: grid; gap: .1rem; padding-block: .5rem 1.5rem; }
.mobile-nav__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: .7rem .25rem;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -.02em;
  text-decoration: none;
}
.mobile-nav__link[aria-current="page"] { color: var(--accent-text); }
.mobile-nav__services {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .35rem;
  padding: .75rem 0 .5rem;
}
.mobile-nav__services a {
  display: flex;
  align-items: center;
  gap: .55rem;
  min-height: 44px;
  padding: .55rem .65rem;
  border-radius: var(--radius-sm);
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-size: var(--fs-xs);
  font-weight: 600;
  line-height: 1.25;
  text-decoration: none;
}
.mobile-nav__services a[aria-current="page"] { border-color: var(--accent); color: var(--text); }
.mobile-nav__services .icon { width: 18px; height: 18px; color: var(--accent-text); }
.mobile-nav__footer { display: grid; gap: .6rem; margin-top: auto; }
.mobile-nav__meta { display: flex; align-items: center; justify-content: center; gap: .5rem; margin: .25rem 0 0; color: var(--text-3); font-size: var(--fs-sm); }

body.nav-open { overflow: hidden; }

/* ---------------------------------------------------------------- Footer */

.site-footer {
  position: relative;
  margin-top: auto;
  padding-bottom: max(2rem, env(safe-area-inset-bottom));
  background:
    radial-gradient(50% 40% at 100% 0%, rgb(199 236 80 / .07), transparent 70%),
    var(--navy-950);
  overflow: hidden;
}
.site-footer__line { width: 100%; height: 48px; margin-bottom: clamp(2rem, 4vw, 3.5rem); }
.site-footer__grid {
  display: grid;
  gap: 2.5rem 2rem;
  grid-template-columns: 1fr;
}
.site-footer__logo .brand__img { height: 48px; }
.site-footer__tagline { margin: .9rem 0 .35rem; font-weight: 700; color: var(--text); }
.site-footer__text { max-width: 38ch; color: var(--text-2); font-size: var(--fs-sm); margin-bottom: 1.25rem; }
.site-footer__heading {
  margin-bottom: 1rem;
  color: var(--text-3);
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.site-footer__col ul { display: grid; gap: .45rem; }
.site-footer__col a { color: var(--text-2); text-decoration: none; font-size: var(--fs-sm); }
.site-footer__col a:hover { color: var(--text); text-decoration: underline; text-decoration-color: var(--accent); }
.site-footer__contact { display: grid; gap: .8rem; font-size: var(--fs-sm); color: var(--text-2); }
.site-footer__contact p { display: flex; gap: .65rem; align-items: flex-start; margin: 0; }
.site-footer__contact .icon { margin-top: .15em; color: var(--accent-text); }
.site-footer__contact a { color: var(--text); text-decoration: none; font-weight: 600; }
.site-footer__contact a:hover { text-decoration: underline; }

.site-footer__slogan {
  margin: clamp(3rem, 7vw, 5.5rem) 0 clamp(1.5rem, 3vw, 2.5rem);
  font-family: var(--font-display);
  font-size: clamp(2.4rem, .6rem + 7.4vw, 7.4rem);
  font-weight: 800;
  line-height: .95;
  letter-spacing: -.045em;
  color: transparent;
  -webkit-text-stroke: 1.25px rgb(255 255 255 / .2);
  user-select: none;
  hyphens: none;
}
.site-footer__slogan span:last-child { color: var(--lime-400); -webkit-text-stroke: 0; }

.site-footer__bottom {
  display: grid;
  gap: 1rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--text-3);
  font-size: var(--fs-xs);
}
.site-footer__topics { margin: 0; letter-spacing: .02em; }
.site-footer__legal { display: flex; flex-wrap: wrap; align-items: center; gap: .75rem 1.5rem; }
.site-footer__legal p { margin: 0; }
.site-footer__legal ul { display: flex; flex-wrap: wrap; gap: .25rem 1.25rem; }
.site-footer__legal a { color: var(--text-2); text-decoration: none; }
.site-footer__legal a:hover { color: var(--text); text-decoration: underline; }
.to-top {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  margin-left: auto;
  padding: .45rem .8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  font-weight: 600;
}
.to-top .icon { transform: rotate(-45deg); width: 16px; height: 16px; }

@media (min-width: 720px) {
  .site-footer__grid { grid-template-columns: 1fr 1fr; }
}
@media (min-width: 1040px) {
  .site-footer__grid { grid-template-columns: 1.5fr .9fr .9fr 1.1fr; }
  .site-footer__bottom { grid-template-columns: 1fr auto; align-items: center; }
}

/* Without JavaScript the toggles cannot work: hide them and rely on plain
   links (the "Leistungen" link and the complete footer navigation). */
html:not(.js) .nav-toggle,
html:not(.js) .nav-link__toggle { display: none; }