/* Utility Tools Website - Main Stylesheet */

:root {
  --primary-color: #3b82f6;
  --primary-dark: #2563eb;
  --secondary-color: #10b981;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --border-color: #e5e7eb;
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

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

/* Header & Navigation */
header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  align-items: center;
}

.nav-links a {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}

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

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 4rem 2rem;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.hero p {
  font-size: 1.25rem;
  margin-bottom: 2rem;
  opacity: 0.9;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.card {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 2rem;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
  color: inherit;
  display: block;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card h3 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
  font-size: 1.5rem;
}

.card p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

/* Tool Container */
.tool-container {
  max-width: 900px;
  margin: 2rem auto;
  padding: 2rem;
  background: var(--bg-primary);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

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

.tool-header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.tool-header p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Upload Area */
.upload-area {
  border: 2px dashed var(--border-color);
  border-radius: 8px;
  padding: 3rem;
  text-align: center;
  background: var(--bg-secondary);
  cursor: pointer;
  transition: all 0.3s;
  margin-bottom: 2rem;
}

.upload-area:hover {
  border-color: var(--primary-color);
  background: #f3f4f6;
}

.upload-area.dragover {
  border-color: var(--primary-color);
  background: #eff6ff;
}

.upload-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
  text-decoration: none;
}

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

.btn:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

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

.btn-secondary:hover {
  background: #4b5563;
}

.btn-secondary:focus {
  outline: 2px solid var(--text-secondary);
  outline-offset: 2px;
}

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

.btn-success:hover {
  background: #059669;
}

.btn-success:focus {
  outline: 2px solid var(--secondary-color);
  outline-offset: 2px;
}

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

.btn:disabled:focus {
  outline: none;
}

/* Alerts */
.alert {
  padding: 1rem;
  border-radius: 6px;
  margin-bottom: 1rem;
}

.alert-success {
  background: #d1fae5;
  color: #065f46;
  border: 1px solid #10b981;
}

.alert-error {
  background: #fee2e2;
  color: #991b1b;
  border: 1px solid #ef4444;
}

.alert-info {
  background: #dbeafe;
  color: #1e40af;
  border: 1px solid #3b82f6;
}

/* Footer */
footer {
  background: var(--text-primary);
  color: white;
  padding: 3rem 2rem;
  margin-top: 4rem;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.footer-section h3 {
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: 0.5rem;
}

.footer-section a {
  color: #d1d5db;
  text-decoration: none;
  transition: color 0.2s;
}

.footer-section a:hover {
  color: white;
}

.footer-bottom {
  text-align: center;
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid #374151;
  color: #9ca3af;
}

/* Content Sections */
.content-section {
  margin: 3rem 0;
}

.content-section h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.content-section h3 {
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.content-section p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.content-section ul {
  margin-left: 2rem;
  margin-bottom: 1rem;
}

.content-section li {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

/* FAQ Section */
.faq-section {
  margin: 3rem 0;
}

.faq-item {
  margin-bottom: 1.5rem;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 1.5rem;
}

.faq-question {
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.faq-answer {
  color: var(--text-secondary);
  line-height: 1.8;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 1rem;
    box-shadow: var(--shadow-lg);
  }

  .nav-links.active {
    display: flex;
  }

  .mobile-menu-toggle {
    display: block;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .tool-header h1 {
    font-size: 2rem;
  }

  .container {
    padding: 0 1rem;
  }
}

/* Loading Spinner */
.spinner {
  border: 3px solid #f3f3f3;
  border-top: 3px solid var(--primary-color);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  animation: spin 1s linear infinite;
  margin: 0 auto;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Code Block */
.code-block {
  background: #1f2937;
  color: #f9fafb;
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  margin: 1rem 0;
}

/* Utility Classes */
.text-center {
  text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.hidden {
  display: none;
}

/* Screen Reader Only - Accessibility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Form Input Focus States - Accessibility */
input[type="text"],
input[type="file"],
textarea,
select {
  outline: none;
}

input[type="text"]:focus,
textarea:focus,
select:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
  border-color: var(--primary-color);
}

a:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
  border-radius: 2px;
}