/* ==========================================================================
   Herdegenbau GmbH – Stylesheet
   Mobile First / reines CSS, keine Build-Tools
   ========================================================================== */

:root {
  --color-primary: #2c1b6b;   /* Dunkelblau/Violett aus dem Logo */
  --color-secondary: #5b8aa6; /* Petrolblau aus dem Logo-Dach */
  --color-text: #232323;
  --color-text-light: #5a5a5a;
  --color-bg: #ffffff;
  --color-bg-alt: #f4f6f8;
  --color-border: #e2e5e9;
  --max-width: 1100px;
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", Arial, Helvetica, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

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

a {
  color: var(--color-secondary);
  text-decoration: none;
}

a:hover,
a:focus {
  text-decoration: underline;
}

h1, h2, h3 {
  margin: 0 0 0.6em;
  line-height: 1.25;
  color: var(--color-primary);
}

p {
  margin: 0 0 1em;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ==========================================================================
   Header / Navigation
   ========================================================================== */

.site-header {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  padding-top: 0.75rem;
  padding-bottom: 0.75rem;
  position: relative;
}

.logo-link {
  display: inline-block;
}

.logo {
  height: 68px;
  width: auto;
}

/* Checkbox-basiertes Mobile-Menü (ohne JavaScript) */
.nav-toggle {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.nav-toggle-label {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 28px;
  height: 20px;
  cursor: pointer;
}

.nav-toggle-label span,
.nav-toggle-label::before,
.nav-toggle-label::after {
  content: "";
  display: block;
  height: 3px;
  border-radius: 2px;
  background: var(--color-primary);
}

.main-nav {
  flex-basis: 100%;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.nav-toggle:checked ~ .main-nav {
  max-height: 300px;
}

.main-nav ul {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
}

.main-nav li + li {
  margin-top: 0.5rem;
}

.main-nav a {
  display: block;
  color: var(--color-text);
  font-weight: 600;
  padding: 0.4rem 0;
}

.main-nav a:hover,
.main-nav a:focus {
  color: var(--color-secondary);
  text-decoration: none;
}

/* ==========================================================================
   Hero
   ========================================================================== */

.hero {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #fff;
  padding: 3.5rem 0;
  text-align: center;
}

.hero-inner {
  max-width: 700px;
}

.hero h1 {
  color: #fff;
  font-size: 1.8rem;
}

.hero p {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.92);
}

.btn {
  display: inline-block;
  margin-top: 0.5rem;
  padding: 0.85rem 1.75rem;
  background: #fff;
  color: var(--color-primary);
  font-weight: 700;
  border-radius: var(--radius);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover,
.btn:focus {
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

/* ==========================================================================
   Features
   ========================================================================== */

.features {
  padding: 3rem 0;
}

.features h2 {
  text-align: center;
  font-size: 1.6rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

.feature-card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.75rem;
  text-align: center;
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  margin-bottom: 1rem;
  border-radius: 50%;
  background: rgba(91, 138, 166, 0.12);
  color: var(--color-secondary);
}

.feature-icon svg {
  width: 32px;
  height: 32px;
}

.feature-card h3 {
  font-size: 1.15rem;
}

.feature-card p {
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ==========================================================================
   About
   ========================================================================== */

.about {
  background: var(--color-bg-alt);
  padding: 3rem 0;
}

.about h2 {
  text-align: center;
  font-size: 1.6rem;
}

.about p {
  max-width: 750px;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
  color: var(--color-text-light);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  background: var(--color-primary);
  color: rgba(255, 255, 255, 0.9);
  padding: 2.5rem 0 1.25rem;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.site-footer h2 {
  color: #fff;
  font-size: 1.1rem;
}

.site-footer address {
  font-style: normal;
}

.site-footer a {
  color: #fff;
}

.copyright {
  margin: 2rem 0 0;
  text-align: center;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.65);
}

/* ==========================================================================
   Breakpoints
   ========================================================================== */

@media (min-width: 640px) {
  .hero h1 {
    font-size: 2.2rem;
  }

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .header-inner {
    flex-wrap: nowrap;
  }

  .nav-toggle-label {
    display: none;
  }

  .main-nav {
    flex-basis: auto;
    max-height: none;
    overflow: visible;
  }

  .main-nav ul {
    display: flex;
    gap: 2rem;
    margin: 0;
  }

  .main-nav li + li {
    margin-top: 0;
  }

  .hero {
    padding: 5rem 0;
  }

  .hero h1 {
    font-size: 2.6rem;
  }

  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer-inner {
    grid-template-columns: repeat(2, 1fr);
  }
}