/* ===== VARIABLES & RESET ===== */
:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --bg: #f8fafc;
  --surface: #ffffff;
  --text: #0f172a;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 2px rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --radius: 12px;
  --font-main: system-ui, -apple-system, sans-serif;
  --transition: 0.2s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-main);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-hover); }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ===== HEADER & NAV ===== */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  letter-spacing: -0.02em;
}
.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}
.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  position: relative;
}
.nav-links a.active,
.nav-links a:hover {
  color: var(--primary);
}
.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}
.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  transition: var(--transition);
}

/* ===== MAIN CONTENT ===== */
.content {
  flex: 1;
  max-width: 1100px;
  margin: 2rem auto;
  padding: 0 1.5rem;
  width: 100%;
}
.page-title {
  font-size: clamp(2rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 1rem;
  letter-spacing: -0.03em;
}
.page-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
  max-width: 600px;
}
.grid {
  display: grid;
  gap: 1.5rem;
  margin-bottom: 2rem;
}
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.card h3 {
  margin-bottom: 0.5rem;
  font-size: 1.25rem;
}
.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}
.btn {
  display: inline-block;
  background: var(--primary);
  color: white;
  padding: 0.6rem 1rem;
  border-radius: 8px;
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: background var(--transition);
}
.btn:hover { background: var(--primary-hover); color: white; }

/* ===== FOOTER ===== */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 2rem 1.5rem;
  margin-top: auto;
}
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1.5rem;
}
.footer-col h4 {
  font-size: 1rem;
  margin-bottom: 0.75rem;
}
.footer-col ul li { margin-bottom: 0.4rem; }
.footer-col a { color: var(--text-muted); font-size: 0.9rem; }
.footer-bottom {
  max-width: 1100px;
  margin: 1.5rem auto 0;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .hamburger { display: block; }
  .nav-links {
    position: fixed;
    top: 64px;
    left: 0;
    width: 100%;
    background: var(--surface);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1.25rem;
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  .nav-links a.active::after { display: none; }
}