/* Common styles */
:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #64748b;
  --background: #f8fafc;
  --surface: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --border-color: #e2e8f0;
  --success: #22c55e;
  --error: #ef4444;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--background);
  color: var(--text-primary);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: transparent;
  z-index: 100;
  padding: 0 40px;
}

.header .container {
  max-width: none;
  padding: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: white;
  text-decoration: none;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
}

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: opacity 0.2s;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
}

.nav a:hover,
.nav a.active {
  opacity: 0.8;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-primary:disabled {
  background: var(--secondary-color);
  cursor: not-allowed;
}

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

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

/* Footer */
.footer {
  background: #0a0a14;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 24px 0;
  text-align: center;
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.875rem;
}

/* Accessibility: visually hidden but accessible to screen readers */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}