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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  transition: background var(--transition), color var(--transition);
  display: flex; flex-direction: column; min-height: 100vh;
}
main { flex: 1; }

a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-light); }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* Header */
header {
  position: sticky; top: 0; z-index: 100;
  height: var(--header-h);
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  background: rgba(255,255,255,.85);
  transition: background var(--transition), border-color var(--transition);
}
[data-theme="dark"] header {
  background: rgba(13,27,42,.9);
}
.header-inner {
  display: grid; grid-template-columns: 1fr auto 1fr; align-items: center;
  height: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
}
.logo { justify-self: start; }
nav { justify-self: center; }
.controls { justify-self: end; }
.logo {
  font-family: var(--font-serif);
  font-size: 1.4rem; font-weight: 700;
  color: var(--accent-dark);
  letter-spacing: -.5px;
}
.logo span { color: var(--accent); }

nav { display: flex; align-items: center; gap: 8px; }
nav a {
  padding: 6px 14px; border-radius: var(--radius-sm);
  font-size: .9rem; font-weight: 500;
  color: var(--text-secondary);
  transition: background var(--transition), color var(--transition);
}
nav a:hover, nav a.active { background: var(--nav-hover); color: var(--accent); }

/* Controls */
.controls {
  display: flex; align-items: center; gap: 8px;
}
.controls button {
  width: 36px; height: 36px; border-radius: 50%; border: 1px solid var(--border);
  background: transparent; color: var(--text-secondary);
  font-size: 1rem; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.controls button:hover {
  background: var(--nav-hover); color: var(--accent); border-color: var(--accent-light);
}

/* Hero */
.hero {
  background: var(--hero-bg);
  padding: 80px 0 64px;
  text-align: center;
  transition: background var(--transition);
}
.hero h1 {
  font-family: var(--font-serif);
  font-size: 2.6rem; font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}
.hero p {
  font-size: 1.1rem; color: var(--text-secondary);
  max-width: 640px; margin: 0 auto 32px;
}

/* Sections */
section { padding: 56px 0; }
.section-title {
  font-family: var(--font-serif);
  font-size: 1.6rem; font-weight: 700;
  margin-bottom: 32px;
  color: var(--text-primary);
  display: flex; align-items: center; gap: 12px;
}
.section-title::after {
  content: ''; flex: 1; height: 1px;
  background: var(--border);
}

/* Grids */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
  gap: 24px;
}

/* Footer */
footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 40px 0 24px;
  margin-top: 40px;
}
footer .container {
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 16px;
}
footer a { color: var(--accent-light); }
footer a:hover { color: #fff; }

/* Responsive */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.8rem; }
  .hero p { font-size: 1rem; }
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .header-inner { grid-template-columns: auto 1fr auto; gap: 8px; padding: 0 12px; }
  nav { gap: 4px; }
  nav a { padding: 4px 8px; font-size: .78rem; }
  .logo { font-size: 1.1rem; }
}