/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #fafafa;
  --color-text: #1a1a1a;
  --color-muted: #777;
  --color-accent: #333;
  --color-border: #e0e0e0;
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --max-width: 1200px;
  --nav-height: 64px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  font-size: 16px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  width: 100%;
  object-fit: cover;
}

/* Navigation */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-size: 0.9rem;
  color: var(--color-muted);
  letter-spacing: 0.03em;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
}

/* Page wrapper */
main {
  margin-top: var(--nav-height);
  flex: 1;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

/* Hero */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 6rem 2rem 4rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 300;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 1.2rem;
}

.hero p {
  font-size: 1.1rem;
  color: var(--color-muted);
  max-width: 480px;
  margin-bottom: 2.5rem;
}

/* Photo gallery grid */
.gallery-section {
  padding: 4rem 0;
}

.gallery-section h1 {
  color: var(--color-muted);
  margin-bottom: 1rem;
  font-size: 1.2rem;
  font-weight: 400;
  text-align: center;
}

.gallery-filters {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 2rem;
}

.filter-btn {
  background: none;
  border: 1px solid var(--color-border);
  padding: 0.4rem 1.1rem;
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--color-muted);
}

.filter-btn:hover,
.filter-btn.active {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.photo-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
}

.photo-item {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--color-border);
  cursor: pointer;
}

.photo-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.4s ease, opacity 0.3s;
}

.photo-item:hover img {
  transform: scale(1.02);
}

.photo-item a {
  position: relative;
  display: block;
  height: 100%;
}

.photo-item a::after {
  content: attr(data-title);
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 1.5rem 0.75rem 0.6rem;
  background: linear-gradient(transparent, rgba(0, 0, 0, 0.65));
  color: #fff;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  opacity: 0;
  transition: opacity 0.2s;
}

.photo-item:hover a::after {
  opacity: 1;
}

.photo-item.hidden {
  display: none;
}

/* About / content pages */
.about-section,
.content-section {
  max-width: 720px;
  margin: 0 auto;
  padding: 5rem 2rem;
}

.about-section h1,
.content-section h1 {
  font-size: 2.5rem;
  font-weight: 300;
  letter-spacing: -0.01em;
  margin-bottom: 2rem;
}

.about-section p,
.content-section p {
  color: var(--color-muted);
  margin-bottom: 1.4rem;
  font-size: 1.05rem;
  line-height: 1.8;
}

.about-section p:first-of-type,
.content-section p:first-of-type {
  font-size: 1.2rem;
  color: var(--color-text);
}

/* Footer */
footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-muted);
  letter-spacing: 0.05em;
}

/* Responsive */
@media (max-width: 768px) {
  nav {
    padding: 0 1.2rem;
  }

  .nav-links {
    gap: 1.2rem;
  }

  .photo-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .container {
    padding: 0 1.2rem;
  }
}

@media (max-width: 600px) {
  .photo-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 480px) {
  .photo-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}