/* Global Reset & Base */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --secondary: #64748b;
  --text: #1e293b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --radius: 0.5rem;
}

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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--primary-dark);
}

ul {
  list-style: none;
}

/* Utilities */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background: var(--primary);
  color: white;
  border-radius: var(--radius);
  font-weight: 600;
  text-align: center;
  transition: background 0.2s ease, transform 0.1s ease;
}

.btn:hover {
  background: var(--primary-dark);
  color: white;
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--bg-alt);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--border);
  color: var(--text);
}

/* Header & Nav */
header {
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  z-index: 100;
}

nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  color: var(--secondary);
  font-weight: 500;
}

.nav-links a:hover {
  color: var(--primary);
}

/* Sections */
section {
  padding: 4rem 0;
}

.bg-alt {
  background-color: var(--bg-alt);
}

h1, h2, h3 {
  line-height: 1.2;
  margin-bottom: 1rem;
}

h1 {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.025em;
}

h2 {
  font-size: 2rem;
  font-weight: 700;
}

h3 {
  font-size: 1.5rem;
  font-weight: 600;
}

p {
  margin-bottom: 1.5rem;
}

/* Cards */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.card {
  background: white;
  padding: 1.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

/* Forms */
.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

input, textarea, select {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 1rem;
}

input:focus, textarea:focus {
  outline: 2px solid var(--primary);
  outline-offset: -1px;
}

/* Footer */
footer {
  background: var(--text);
  color: var(--bg-alt);
  padding: 4rem 0 2rem;
}

footer a {
  color: #cad1d9;
}

footer a:hover {
  color: white;
}

footer .grid {
  gap: 3rem;
  margin-bottom: 3rem;
}

footer h3 {
  color: white;
  margin-bottom: 1.5rem;
}

.copyright {
  text-align: center;
  border-top: 1px solid #334155;
  padding-top: 2rem;
  color: #94a3b8;
  font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  
  .nav-links {
    display: none; /* simple mobile hide for now, usually would add hamburger */
  }
}