:root {
  --color-bg: #ffffff;
  --color-text: #111111;
  --color-muted: #666666;
  --color-border: #e0e0e0;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --header-height: 60px;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  background: var(--color-bg);
  color: var(--color-text);
}

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

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

/* ── Header ── */

header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  z-index: 100;
}

.site-title {
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

nav a {
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-muted);
  transition: color 0.2s;
}

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

.nav-social {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding-left: 1.5rem;
  border-left: 1px solid var(--color-border);
}

.nav-social a {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-muted);
  transition: color 0.2s;
}

.nav-social a:hover {
  color: var(--color-text);
}

/* ── Main ── */

main {
  padding-top: var(--header-height);
}

/* ── Logos Strip ── */

.logos-strip {
  padding: 2.5rem 2rem;
  border-bottom: 1px solid var(--color-border);
  overflow: hidden;
}

.logos-track {
  display: flex;
  align-items: center;
  gap: 3rem;
  flex-wrap: wrap;
  justify-content: center;
}

.logos-track img {
  width: auto;
  height: 28px;
  object-fit: contain;
  opacity: 0.6;
  filter: grayscale(100%);
  transition: opacity 0.2s, filter 0.2s;
}

.logos-track img:hover {
  opacity: 1;
  filter: grayscale(0%);
}

/* ── Project Grid ── */

.project-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}

.project-card {
  position: relative;
  aspect-ratio: 2 / 3;
  overflow: hidden;
  display: block;
}

.project-card img {
  transition: transform 0.4s ease;
}

.project-card:hover img {
  transform: scale(1.03);
}

.project-card-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0);
  display: flex;
  align-items: flex-end;
  padding: 1.25rem;
  transition: background 0.3s ease;
}

.project-card:hover .project-card-overlay {
  background: rgba(0, 0, 0, 0.55);
}

.project-card-title {
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.project-card:hover .project-card-title {
  opacity: 1;
  transform: translateY(0);
}

/* ── Footer ── */

footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--color-muted);
}

.footer-social {
  display: flex;
  gap: 1.5rem;
}

.footer-social a {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-muted);
  transition: color 0.2s;
}

.footer-social a:hover {
  color: var(--color-text);
}

/* ── Responsive ── */

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

@media (max-width: 768px) {
  header {
    padding: 0 1rem;
  }

  .site-title {
    font-size: 0.75rem;
  }

  nav {
    gap: 1rem;
  }

  nav a {
    font-size: 0.7rem;
  }

  .nav-social {
    display: none;
  }

  .logos-strip {
    padding: 1.5rem 1rem;
  }

  .logos-track {
    gap: 1.5rem;
  }

  .logos-track img {
    height: 20px;
  }

  .project-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  footer {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

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