:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --card-bg: #fafafa;
  --border: #e5e5e5;
  --accent: #2563eb;
  --max-width: 960px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111112;
    --fg: #f2f2f2;
    --muted: #a3a3a3;
    --card-bg: #1a1a1c;
    --border: #2a2a2c;
    --accent: #6ea8fe;
  }
}

:root[data-theme="dark"] {
  --bg: #111112;
  --fg: #f2f2f2;
  --muted: #a3a3a3;
  --card-bg: #1a1a1c;
  --border: #2a2a2c;
  --accent: #6ea8fe;
}

:root[data-theme="light"] {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --card-bg: #fafafa;
  --border: #e5e5e5;
  --accent: #2563eb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.site-header {
  padding: 4rem 0 2rem;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.site-header h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: 600;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--card-bg);
  color: var(--fg);
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.theme-toggle .icon-moon {
  display: none;
}

:root[data-theme="dark"] .theme-toggle .icon-sun {
  display: none;
}

:root[data-theme="dark"] .theme-toggle .icon-moon {
  display: block;
}

.project-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  padding: 1rem 0 4rem;
}

@media (min-width: 640px) {
  .project-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .project-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s ease, transform 0.5s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.card.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

.card-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
  background: var(--border);
}

.card-body {
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex: 1;
}

.card-title {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 600;
}

.card-description {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  flex: 1;
}

.card-link {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
}

.card-link:hover {
  text-decoration: underline;
}