/* Tool Shelf - Main Stylesheet */

/* ============================================
   CSS Variables & Design System
   ============================================ */
:root {
  /* Colors - Modern Palette */
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #818cf8;
  --secondary-color: #ec4899;
  --accent-color: #14b8a6;

  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-tertiary: #94a3b8;

  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Fira Code', 'Courier New', monospace;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
}

/* ============================================
   Reset & Base Styles
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   Typography
   ============================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.5rem;
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* ============================================
   Layout Components
   ============================================ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.container-narrow {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* Header */
.site-header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-lg) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  background-color: rgba(255, 255, 255, 0.9);
}

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

.site-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.site-logo:hover {
  color: var(--primary-dark);
}

/* Language Switcher */
.language-switcher {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

.lang-btn {
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border-color);
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition-fast);
  color: var(--text-secondary);
}

.lang-btn:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
  transform: translateY(-1px);
}

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

/* Main Content */
.main-content {
  min-height: calc(100vh - 200px);
  padding: var(--spacing-2xl) 0;
}

/* Footer */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
  margin-top: var(--spacing-2xl);
}

.footer-content {
  text-align: center;
  color: var(--text-tertiary);
  font-size: 0.875rem;
}

/* ============================================
   Card Components
   ============================================ */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.card {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  transform: scaleX(0);
  transition: transform var(--transition-base);
}

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

.card:hover::before {
  transform: scaleX(1);
}

.card-icon {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
  display: inline-block;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.card-description {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
}

/* ============================================
   Form Elements
   ============================================ */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
  color: var(--text-primary);
  font-size: 0.9375rem;
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--spacing-md);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: all var(--transition-fast);
  background: var(--bg-primary);
  color: var(--text-primary);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
  font-family: var(--font-mono);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-sans);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
  box-shadow: var(--shadow-md);
}

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

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

.btn-secondary:hover {
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
}

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

.btn-success:hover {
  background: #0f9488;
}

.btn-group {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

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

.mt-1 {
  margin-top: var(--spacing-sm);
}

.mt-2 {
  margin-top: var(--spacing-md);
}

.mt-3 {
  margin-top: var(--spacing-lg);
}

.mt-4 {
  margin-top: var(--spacing-xl);
}

.mb-1 {
  margin-bottom: var(--spacing-sm);
}

.mb-2 {
  margin-bottom: var(--spacing-md);
}

.mb-3 {
  margin-bottom: var(--spacing-lg);
}

.mb-4 {
  margin-bottom: var(--spacing-xl);
}

.result-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  margin-top: var(--spacing-lg);
}

.result-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: var(--spacing-sm);
}

.alert {
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-lg);
  border-left: 4px solid;
}

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

.alert-success {
  background: #d1fae5;
  border-color: var(--accent-color);
  color: #065f46;
}

.alert-warning {
  background: #fef3c7;
  border-color: #f59e0b;
  color: #92400e;
}

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



/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  html {
    font-size: 14px;
  }

  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.5rem;
  }

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

  .header-content {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .language-switcher {
    flex-wrap: wrap;
    justify-content: center;
  }

  .btn-group {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}

/* ============================================
   Loading Animation
   ============================================ */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(99, 102, 241, 0.3);
  border-radius: 50%;
  border-top-color: var(--primary-color);
  animation: spin 1s linear infinite;
}

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

/* ============================================
   Animations
   ============================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn var(--transition-base) ease-out;
}
/* Related Tools Section */
.related-tools-section {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.related-tools-section h3 {
    margin-bottom: var(--spacing-md);
    font-size: 1.2rem;
    color: var(--text-secondary);
}

.related-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
}

.related-btn {
    display: inline-block;
    padding: 8px 16px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.2s;
}

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