* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Open Sans', sans-serif;
  background: black;
  color: #eee;
  line-height: 1.6;
}

header {
  background: #1f1f1f;
  padding: 15px 50px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: 0 2px 5px rgba(0,0,0,0.8);
}

.logo-section {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: #4caf50;
}

.logo-section img.logo {
  height: 50px;
  margin-right: 12px;
}

.logo-section h1 {
  font-weight: 700;
  letter-spacing: 3px;
  font-size: 1.6rem;
}

nav ul.nav-links {
  list-style: none;
  display: flex;
  gap: 25px;
}

nav ul.nav-links li a {
  color: #eee;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: color 0.3s ease;
}

nav ul.nav-links li a:hover,
nav ul.nav-links li a:focus {
  color: #4caf50;
  outline: none;
}

.gallery-title {
  text-align: center;
  font-size: 20px;
  font-weight: 800;
  color: #4caf50; /* vibrant green */
  letter-spacing: 4px;
  margin: 40px 0 30px;
  text-transform: uppercase;
  font-family: 'Open Sans', sans-serif;
  padding-bottom: 10px;
}

/* Decorative underline */
.gallery-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: #4caf50;
  margin: 8px auto 0;
  border-radius: 2px;
  box-shadow: 0 0 8px #4caf50aa;
}

.showcase-subtitle {
  text-align: center;
  color: #a5d6a7; 
  font-size: 1rem;
  font-weight: 600;
  font-family: 'Open Sans', sans-serif;
  margin-top: -30px; 
  margin-bottom: 23px;
  letter-spacing: 1px;
  font-style: italic;
}
section.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 10px;
  max-width: 1200px;
  margin: 2px auto 4px auto;
}

section.gallery img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 8px;
  transition: transform 0.3s ease;
  cursor: pointer;
}

section.gallery img:hover {
  transform: scale(1.05);
}

.item1  { grid-column: span 2; grid-row: span 2; }
.item2  { grid-column: span 1; grid-row: span 1; }
.item3  { grid-column: span 1; grid-row: span 2; }
.item4  { grid-column: span 2; grid-row: span 1; }
.item5  { grid-column: span 1; grid-row: span 1; }
.item6  { grid-column: span 1; grid-row: span 1; }
.item7  { grid-column: span 2; grid-row: span 2; }
.item8  { grid-column: span 1; grid-row: span 1; }
.item9  { grid-column: span 1; grid-row: span 1; }
.item10 { grid-column: span 1; grid-row: span 2; }
.item11 { grid-column: span 2; grid-row: span 1; }
.item12 { grid-column: span 1; grid-row: span 1; }
.item13 { grid-column: span 1; grid-row: span 1; }
.item14 { grid-column: span 2; grid-row: span 2; }
.item15 { grid-column: span 1; grid-row: span 1; }

@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.lightbox {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100vw; height: 100vh;
  background: rgba(0, 0, 0, 0.9);
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.lightbox img {
  max-width: 90%;
  max-height: 90%;
  border-radius: 8px;
}

.lightbox-close {
  position: fixed;
  top: 20px; right: 30px;
  font-size: 3rem;
  color: #4caf50;
  cursor: pointer;
  user-select: none;
  transition: color 0.3s ease;
  z-index: 1100;
}

.lightbox-close:hover {
  color: white;
}

footer {
  background: #1f1f1f;
  color: #777;
  text-align: center;
  padding: 20px 10px;
  font-size: 0.9rem;
  letter-spacing: 1px;
  border-top: 1px solid #333;
}

@media (max-width: 900px) {
  section.gallery {
    grid-template-columns: repeat(3, 1fr);
    grid-auto-rows: 100px;
  }
}

@media (max-width: 600px) {
  nav ul.nav-links {
    flex-direction: column;
    gap: 15px;
  }
  section.gallery {
    grid-template-columns: repeat(2, 1fr);
    grid-auto-rows: 90px;
  }
}