/* ==========================================================================
   1. GLOBAL STYLES & BASE
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
}

body {
  font-family: 'Helvetica', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: #333;
}

h1, h2, h3, h4 {
  color: #003366;
}

h1 { font-size: 2.5em; margin-bottom: 20px; }
h2 { font-size: 2em; margin-bottom: 15px; }
h3 { font-size: 1.75em; margin-bottom: 10px; }

/* ==========================================================================
   2. HEADER & NAVIGATION
   ========================================================================== */
header {
  background-color: #f8f9fa;
  box-shadow: 0 6px 15px rgba(0, 0, 0, 0.1);
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.logo img {
  max-height: 60px;
}

nav {
  position: relative;
  z-index: 9999;
}

.main-nav {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.main-nav li {
  position: relative;
}

.main-nav li a {
  text-decoration: none;
  color: #003366;
  padding: 10px 15px;
  font-weight: bold;
  transition: background-color 0.3s ease, color 0.3s ease;
}

.main-nav li a:hover {
  background-color: #009fe4;
  color: white;
}

/* Dropdown Submenu */
.main-nav li:hover .submenu {
  display: block;
}

.submenu {
  display: none;
  position: absolute;
  top: 120%;
  left: 0;
  z-index: 999;
  min-width: max-content;
  width: 100%;
  padding: 0;
  background: #ffffff;
  background-image: linear-gradient(to bottom, #ffffff, #f0f0f0);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
  border-radius: 8px;
}

.submenu li {
  display: block;
}

.submenu li a {
  padding: 12px 20px;
  display: block;
  text-align: left;
  color: #003366;
  white-space: nowrap;
}

.submenu li a:hover {
  background-color: #009fe4;
  color: white;
}

/* Chevron Animations */
.fas.fa-chevron-down {
  display: inline-block;
  vertical-align: middle;
  transition: transform 0.3s ease;
  transform-origin: center;
}

li:hover > a .fa-chevron-down {
  transform: rotate(180deg);
  vertical-align: text-top;
}

/* ==========================================================================
   3. ENDLOS-KARUSSELL (REFERENZEN)
   ========================================================================== */
.slider-wrapper {
  position: relative;
  max-width: 100%;
  margin-top: 32px;
  overflow: hidden;
}

.projects-slider {
  display: flex;
  gap: 24px;
  width: 100%;
  will-change: transform;
  padding: 12px 0;
  transition: transform 0.5s cubic-bezier(0.25, 1, 0.5, 1);
}

.project-item {
  margin: 0;
  flex: 0 0 calc(25% - 18px);
  overflow: hidden;
  border-radius: 12px;
  background-color: #f9f9f9;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  cursor: pointer;
  transition: box-shadow 0.4s ease;
}

.project-item img {
  width: 100%;
  height: 380px;
  object-fit: cover;
  display: block;
  transition: transform 0.5s cubic-bezier(0.25, 1, 0.5, 1);
}

.project-item:hover img {
  transform: scale(1.05);
}

.slider-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: #fff;
  color: #333;
  border: none;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  transition: background 0.2s, color 0.2s;
}

.slider-arrow:hover { background: #003366; color: #fff; }
.slider-arrow.prev { left: 10px; }
.slider-arrow.next { right: 10px; }

/* ==========================================================================
   4. LIGHTBOX (POPUP)
   ========================================================================== */
.lightbox {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 10000;
  background-color: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(8px);
  justify-content: center;
  align-items: center;
}

.lightbox.active { display: flex; }

.lightbox-content {
  position: relative;
  max-width: 90%;
  max-height: 85%;
  text-align: center;
}

.lightbox-content img {
  max-width: 100%;
  max-height: 85vh;
  object-fit: contain;
  border-radius: 8px;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

#lightbox-caption {
  color: #fff;
  margin-top: 14px;
  font-size: 1rem;
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  border: none;
  font-size: 2.5rem;
  line-height: 1;
  padding: 5px 15px;
  cursor: pointer;
  border-radius: 50px;
  transition: background 0.2s;
  z-index: 10001;
}

.lightbox-close:hover { background: rgba(255, 255, 255, 0.25); }

/* ==========================================================================
   5. FAQ SECTION (ACCORDION)
   ========================================================================== */
.faq-section {
  padding: 60px 16px;
  background: #0f172a;
}

.faq-accordion {
  max-width: 800px;
  margin: 30px auto 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: #1e293b;
  border: 1px solid #334155;
  border-radius: 8px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item summary {
  padding: 18px 20px;
  font-size: 16px;
  font-weight: 600;
  color: #f8fafc;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: '＋';
  font-size: 18px;
  color: #007bff;
  transition: transform 0.3s ease;
}

.faq-item[open] summary::after { content: '－'; }
.faq-item summary:focus { outline: none; }

.faq-content {
  padding: 0 20px 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.faq-content p {
  font-size: 14px;
  line-height: 1.6;
  color: #94a3b8;
  margin: 12px 0 0 0;
}

/* ==========================================================================
   6. RESPONSIVE LAYOUTS (GLOBAL & COMPONENTS)
   ========================================================================== */
@media (max-width: 1024px) {
  .project-item { flex: 0 0 calc(33.333% - 16px); }
}

@media (max-width: 768px) {
  .project-item { flex: 0 0 calc(50% - 12px); }
  .slider-arrow { display: none; }

  h1 { font-size: 28px; line-height: 1.2; margin-bottom: 15px; }
  h2 { font-size: 24px; margin-bottom: 12px; }
  h3 { font-size: 20px; }
  p { font-size: 16px; line-height: 1.5; }
}

@media (max-width: 480px) {
  .project-item { flex: 0 0 100%; }
}