html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: 'Lato', Arial, sans-serif;
    overflow-y: auto;
    box-sizing: border-box;
    background-color: #f7f7f5;
    scroll-behavior: smooth;
    color: #2d3748;
}

*, *::before, *::after {
    box-sizing: inherit;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 50px 20px 60px;
    margin-top: 110px;
}

.portfolio {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Heading Container */
.heading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    margin-bottom: 36px;
}

.portfolio h2 {
    font-family: 'Merriweather', serif;
    font-size: 2.2em;
    margin-bottom: 0;
    color: #003366;
    font-weight: 700;
    text-align: center;
    letter-spacing: 0.2px;
}

/* Animated Separation Line */
.separation-line {
    width: 56px;
    height: 3px;
    background-color: #b8983a;
    margin: 20px auto 0;
    display: block;
    transform: scaleX(0);
    transform-origin: center;
    transition: transform 0.9s ease-in-out;
}

.separation-line.animate {
    transform: scaleX(1);
}

@keyframes line-grow {
    0%   { transform: scaleX(0); }
    100% { transform: scaleX(1); }
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.portfolio-item {
    position: relative;
    overflow: hidden;
    border-radius: 2px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
    height: 210px;
    cursor: pointer;
}

.portfolio-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.portfolio-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: filter 0.3s ease;
}

.portfolio-item:hover img {
    filter: blur(3px) brightness(0.85);
}

.portfolio-item .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: flex-start;
    padding: 16px;
    background: linear-gradient(to top, rgba(0, 25, 60, 0.88) 0%, rgba(0, 25, 60, 0.2) 60%, transparent 100%);
    color: white;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.portfolio-item:hover .overlay {
    opacity: 1;
}

.portfolio-item .overlay h3 {
    font-family: 'Merriweather', serif;
    font-size: 1em;
    margin-bottom: 4px;
    font-weight: 700;
    text-align: left;
    text-shadow: 0 1px 3px rgba(0,0,0,0.5);
}

.portfolio-item .overlay p {
    font-size: 0.82em;
    margin: 0;
    text-align: left;
    color: rgba(255,255,255,0.82);
    letter-spacing: 0.3px;
}

@media (max-width: 1024px) {
    .portfolio-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    main {
        margin-top: 100px;
        padding: 36px 16px 48px;
    }

    .portfolio h2 {
        font-size: 1.8em;
    }

    .portfolio-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    .portfolio-item {
        height: 180px;
    }
}

@media (max-width: 480px) {
    .portfolio-grid {
        grid-template-columns: 1fr;
    }

    .portfolio-item {
        height: 220px;
    }
}

/* Fullscreen Image Viewer */
.image-viewer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  z-index: 1000;
}

.image-viewer.active {
  opacity: 1;
  visibility: visible;
}

.image-viewer img {
  max-width: 90%;
  max-height: 90%;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

.image-viewer .close-btn,
.image-viewer .prev-btn,
.image-viewer .next-btn {
  position: absolute;
  background: none;
  border: none;
  color: white;
  font-size: 2rem;
  cursor: pointer;
  z-index: 1001;
  display: block;
}

.image-viewer .prev-btn {
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
}

.image-viewer .next-btn {
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
}

.image-viewer .prev-btn[style*="display: none"],
.image-viewer .next-btn[style*="display: none"] {
  display: none !important;
}

.image-viewer .close-btn {
  top: 20px;
  right: 20px;
  background: none;
  border: none;
  color: white;
  font-size: 2rem;
  cursor: pointer;
  z-index: 1001;
}

.image-viewer .close-btn:hover,
.image-viewer .prev-btn:hover,
.image-viewer .next-btn:hover {
  color: #ccc;
}