/*
 * Lider Metal - Referanslar Sayfası Stilleri
 * Hakkimizda.css ile uyumlu tasarım
 * Responsive grid layout for reference logos
 */

/* ============================================
   References Section (Ana Konteyner)
   ============================================ */

.references-section {
  position: relative;
  padding: 10px 0 120px;
  z-index: 2;
  margin-bottom: 6rem;
  width: 100%;
}

/* ============================================
   References Grid - Temel Yapı
   ============================================ */

.references-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 35px;
  max-width: 1200px;
  margin: 0 auto;
}

/* ============================================
   Reference Item - Logo Container
   ============================================ */

.reference-item {
  background: #f8f8f8;
  padding: 40px 30px;
  border-radius: 20px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  opacity: 0;
  transform: translateY(30px);
  min-height: 160px;
  position: relative;
  overflow: hidden;
}

.reference-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(49, 80, 142, 0.03) 0%, rgba(44, 68, 117, 0.05) 100%);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 0;
  border-radius: 20px;
}

.reference-item:hover::before {
  opacity: 1;
}

.reference-item:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 12px 24px rgba(49, 80, 142, 0.18);
}

/* Logo Container */
.reference-logo-container {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 1;
}

/* Logo Image */
.reference-logo {
  max-width: 100%;
  height: auto;
  max-height: 80px;
  object-fit: contain;
  filter: grayscale(100%);
  opacity: 0.7;
  transition: all 0.4s ease;
}

.reference-item:hover .reference-logo {
  filter: grayscale(0%);
  opacity: 1;
  transform: scale(1.05);
}

/* ============================================
   RESPONSIVE - EKSIKSIZ
   ============================================ */

/* Large Desktop - 1400px ve üstü */
@media (min-width: 1400px) {
  .references-grid {
    max-width: 1320px;
    gap: 40px;
  }
  
  .reference-item {
    padding: 45px 35px;
    min-height: 180px;
  }
  
  .reference-logo {
    max-height: 90px;
  }
}

/* Desktop - 992px - 1399px → 4 sütun */
@media (min-width: 992px) and (max-width: 1399px) {
  .references-grid {
    gap: 30px;
  }
  
  .reference-item {
    padding: 38px 28px;
    min-height: 160px;
  }
}

/* Tablet: 768px - 991px → 3 sütun */
@media (max-width: 991px) {
  .references-section {
    padding: 70px 0 100px;
  }
  
  .references-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    max-width: 900px;
  }
  
  .reference-item {
    padding: 35px 25px;
    min-height: 150px;
  }
  
  .reference-logo {
    max-height: 75px;
  }
}

/* Tablet Small: 576px - 767px → 2 sütun */
@media (max-width: 767px) {
  .references-section {
    padding: 60px 0 90px;
  }
  
  .references-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    max-width: 600px;
  }
  
  .reference-item {
    padding: 32px 22px;
    min-height: 140px;
    border-radius: 16px;
  }
  
  .reference-logo {
    max-height: 70px;
  }
}

/* Mobile: ≤ 575px → 2 sütun (küçük ekranlara optimize) */
@media (max-width: 575px) {
  .references-section {
    padding: 50px 0 80px;
  }
  
  .references-grid {
    gap: 20px;
    max-width: 100%;
  }
  
  .reference-item {
    padding: 28px 18px;
    min-height: 120px;
    border-radius: 14px;
  }
  
  .reference-logo {
    max-height: 60px;
  }
}

/* Very Small Mobile: ≤ 400px → 1 sütun (çok küçük ekranlar için) */
@media (max-width: 400px) {
  .references-grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }
  
  .reference-item {
    padding: 30px 20px;
    min-height: 130px;
  }
  
  .reference-logo {
    max-height: 70px;
  }
}

/* ============================================
   Accessibility & Print
   ============================================ */

/* Focus states for keyboard navigation */
.reference-item:focus-within {
  outline: 2px solid #31508E;
  outline-offset: 4px;
}

/* Print optimization */
@media print {
  .references-section {
    padding: 40px 0;
  }
  
  .references-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }
  
  .reference-item {
    box-shadow: none;
    border: 1px solid #ddd;
    page-break-inside: avoid;
  }
  
  .reference-logo {
    filter: grayscale(100%);
  }
}

/* ============================================
   Loading State (Optional)
   ============================================ */

.reference-item.loading {
  background: linear-gradient(
    90deg,
    #f0f0f0 25%,
    #e0e0e0 50%,
    #f0f0f0 75%
  );
  background-size: 200% 100%;
  animation: loading-shimmer 1.5s infinite;
}

@keyframes loading-shimmer {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}