/* ========================
   Professional Grade CSS
   ======================== */

/* Base Styles */
:root {
  /* Color Palette */
  --background: hsl(0, 0%, 100%);
  --foreground: hsl(240, 10%, 3.9%);
  --primary: hsl(240, 5.9%, 10%);
  --primary-foreground: hsl(0, 0%, 98%);
  --secondary: hsl(240, 4.8%, 95.9%);
  --secondary-foreground: hsl(240, 5.9%, 10%);
  --muted: hsl(240, 4.8%, 95.9%);
  --muted-foreground: hsl(240, 3.8%, 46.1%);
  --accent: hsl(220, 85%, 56%);
  --accent-foreground: hsl(0, 0%, 100%);
  --destructive: hsl(0, 84.2%, 60.2%);
  --destructive-foreground: hsl(0, 0%, 98%);
  --border: hsl(240, 5.9%, 90%);
  --input: hsl(240, 5.9%, 90%);
  --ring: hsl(240, 5.9%, 10%);
  --radius: 0.75rem;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.15);
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  background-color: var(--background);
  color: var(--foreground);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  margin: 0;
  padding: 0;
}

/* Utility Classes */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
}

.rounded-xl { border-radius: var(--radius); }
.shadow { box-shadow: var(--shadow-md); }
.transition { transition: all 0.3s ease; }

/* Typography */
.text-sm { font-size: 0.875rem; }
.text-base { font-size: 1rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }
.text-2xl { font-size: 1.5rem; }
.text-3xl { font-size: 1.875rem; }
.text-4xl { font-size: 2.25rem; }
.text-5xl { font-size: 3rem; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

/* Flexbox */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }

/* Buttons */
.button {
  background-color: var(--primary);
  color: var(--primary-foreground);
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
}

.button:hover {
  background-color: var(--accent);
  box-shadow: var(--shadow-lg);
}

/* Links */
a {
  color: var(--accent);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  text-decoration: underline;
}

/* Cards */
.card {
  background-color: var(--background);
  border: 1px solid var(--border);
  padding: 1.5rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

/* Responsive Breakpoints */
@media (min-width: 768px) {
  .container {
    padding: 0 2rem;
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 4rem;
  }
}