/* Base styles and theme customization */
:root {
  --color-primary: #4F46E5;
  --color-primary-dark: #4338CA;
  --color-primary-light: #6366F1;
  --color-secondary: #3B82F6;
  --color-accent: #818CF8;
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-danger: #EF4444;
  --color-text: #1E293B;
  --color-text-muted: #64748B;
  --color-bg: #FFFFFF;
  --color-bg-alt: #F8FAFC;
  --color-border: #E2E8F0;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  --radius: 0.5rem;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
}

/* Skip to main content link for accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary);
  color: white;
  padding: 8px 16px;
  text-decoration: none;
  z-index: 100;
  border-radius: 0 0 4px 0;
}

.skip-link:focus {
  top: 0;
}

/* Focus styles - highly visible for keyboard navigation */
*:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: 2px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

/* Ad slot container - responsive and clearly marked */
.ad-slot {
  min-height: 100px;
  background-color: var(--color-bg-alt);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  padding: 1rem;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin: 1.5rem 0;
}

.ad-slot::before {
  content: 'Advertisement';
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
  opacity: 0.6;
}

/* Sticky footer layout */
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1;
}

/* Button base styles */
button,
.btn {
  cursor: pointer;
  font-family: inherit;
  font-size: 1rem;
  border: none;
  border-radius: var(--radius);
  padding: 0.5rem 1rem;
  transition: all 0.2s ease;
  font-weight: 500;
}

button:disabled,
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-dark);
}

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

.btn-secondary:hover:not(:disabled) {
  background-color: #2563EB;
}

/* Input base styles */
input[type="text"],
input[type="number"],
input[type="email"],
input[type="url"],
input[type="password"],
input[type="range"],
select,
textarea {
  font-family: inherit;
  font-size: 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.5rem 0.75rem;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  width: 100%;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

/* Card component */
.card {
  background: white;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  padding: 1.5rem;
  transition: box-shadow 0.2s ease;
}

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

/* Copy button feedback */
.copy-btn {
  position: relative;
}

.copy-btn.copied::after {
  content: 'Copied!';
  position: absolute;
  top: -2rem;
  right: 0;
  background: var(--color-success);
  color: white;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  white-space: nowrap;
  animation: fadeInOut 2s ease;
}

@keyframes fadeInOut {
  0%, 100% { opacity: 0; transform: translateY(5px); }
  10%, 90% { opacity: 1; transform: translateY(0); }
}

/* Tool page layout */
.tool-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

.tool-header {
  margin-bottom: 2rem;
}

.tool-header h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text);
  margin: 0 0 0.5rem 0;
}

.tool-header p {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  margin: 0;
}

/* Grid layouts */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

.grid-3 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 640px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Alert/message boxes */
.alert {
  padding: 1rem;
  border-radius: var(--radius);
  margin: 1rem 0;
  border-left: 4px solid;
}

.alert-success {
  background-color: #D1FAE5;
  border-color: var(--color-success);
  color: #065F46;
}

.alert-warning {
  background-color: #FEF3C7;
  border-color: var(--color-warning);
  color: #92400E;
}

.alert-danger {
  background-color: #FEE2E2;
  border-color: var(--color-danger);
  color: #991B1B;
}

.alert-info {
  background-color: #DBEAFE;
  border-color: var(--color-secondary);
  color: #1E40AF;
}

/* Utility classes */
.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.hidden { display: none; }

/* Loading spinner */
.spinner {
  display: inline-block;
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Responsive utilities */
@media (max-width: 640px) {
  .tool-container {
    padding: 1rem;
  }

  .tool-header h1 {
    font-size: 1.5rem;
  }

  .tool-header p {
    font-size: 1rem;
  }
}

/* Print styles */
@media print {
  .ad-slot,
  nav,
  footer,
  button {
    display: none;
  }
}