Global Reset & Mobile-First Design
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background-color: #f5f7fa;
  color: #1e293b;
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  background: linear-gradient(135deg, #0f3b5e, #1a5f7a);
  color: white;
  padding: 1.5rem 1rem;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

header h1 {
  font-size: 1.8rem;
  margin-bottom: 0.25rem;
  font-weight: 600;
}

.subtitle {
  font-size: 1rem;
  opacity: 0.9;
}

/* Navigation */
.main-nav {
  display: flex;
  justify-content: space-around;
  background: white;
  padding: 0.5rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-decoration: none;
  color: #64748b;
  font-size: 0.8rem;
  padding: 0.5rem;
  border-radius: 12px;
  transition: all 0.2s;
  flex: 1;
  max-width: 120px;
}

.nav-card .icon {
  font-size: 1.5rem;
  margin-bottom: 0.2rem;
}

.nav-card.active {
  background: #e0f2fe;
  color: #0369a1;
  font-weight: 500;
}

/* Main Container */
.container {
  flex: 1;
  padding: 1.5rem 1rem;
  max-width: 800px;
  margin: 0 auto;
  width: 100%;
}

/* Cards */
.tool-card, .feature-card, .info-box  {
  background: white;
  border-radius: 20px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  border: 1px solid #e2e8f0;
}

.feature-card h3 {
  color: #0f3b5e;
  margin-bottom: 0.75rem;
}

.btn {
  display: inline-block;
  background: #1a5f7a;
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 40px;
  font-size: 1rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s;
  border: 1px solid transparent;
  margin-top: 1rem;
}

.btn-primary {
  background: #0f3b5e;
  width: 100%;
}

.btn:hover {
  background: #0e4a6b;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* File Input Styling */
.file-input-wrapper {
  position: relative;
  margin-bottom: 1.5rem;
}

.file-input-wrapper input[type="file"] {
  position: absolute;
  left: -9999px;
}

.file-label {
  display: block;
  background: #f1f5f9;
  border: 2px dashed #94a3b8;
  border-radius: 16px;
  padding: 1rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  color: #475569;
  font-weight: 500;
  word-break: break-all;
}

.file-label:hover {
  border-color: #1a5f7a;
  background: #e0f2fe;
}

/* Size options (radio) */
.size-options {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
  justify-content: center;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  background: #f8fafc;
  padding: 0.5rem 1rem;
  border-radius: 30px;
  border: 1px solid #cbd5e1;
  cursor: pointer;
}

/* Tabs */
.tool-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.tab-btn {
  flex: 1;
  background: #e2e8f0;
  border: none;
  padding: 0.75rem;
  border-radius: 40px;
  font-weight: 600;
  color: #334155;
  cursor: pointer;
  transition: all 0.2s;
}

.tab-btn.active {
  background: #1a5f7a;
  color: white;
}

/* .tab-content {
  display: none;
} */

.tab-content.active {
  display: block;
}

/* Loading Spinner */
.loading {
  text-align: center;
  padding: 1.5rem;
}

.spinner {
  width: 40px;
  height: 40px;
  margin: 0 auto 1rem;
  border: 4px solid #e2e8f0;
  border-top-color: #1a5f7a;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.hidden {
  display: none !important;
}

.error-message {
  background: #fee2e2;
  color: #b91c1c;
  padding: 0.75rem;
  border-radius: 12px;
  margin-top: 1rem;
  border-left: 4px solid #dc2626;
}

.success-message {
  background: #dcfce7;
  color: #166534;
  padding: 0.75rem;
  border-radius: 12px;
  margin-top: 1rem;
  border-left: 4px solid #16a34a;
}

.info-box {
  background: #f0f9ff;
  border-left: 6px solid #1a5f7a;
}

.info-box h3 {
  margin-bottom: 0.75rem;
  color: #0f3b5e;
}

.info-box ul, .info-box p {
  margin-left: 1.2rem;
  color: #334155;
}

footer {
  text-align: center;
  padding: 1.5rem;
  color: #64748b;
  background: white;
  border-top: 1px solid #e2e8f0;
  margin-top: auto;
}

/* Hero */
.hero {
  text-align: center;
  margin-bottom: 2rem;
}

.hero h2 {
  font-size: 1.8rem;
  color: #0f3b5e;
  margin-bottom: 0.5rem;
}

.features-grid {
  display: grid;
  gap: 1.5rem;
}

/* Trust Badge / Privacy Disclaimer */
.trust-badge {
  margin-top: 1.2rem;
  padding: 0.8rem 1rem;
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  border-radius: 12px;
  color: #166534;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.95rem;
}

.shield-icon {
  font-size: 1.3rem;
}

.trust-badge strong {
  color: #14532d;
}

/* Footer Styles */
footer {
  text-align: center;
  padding: 1.5rem 1rem;
  color: #64748b;
  background: white;
  border-top: 1px solid #e2e8f0;
  margin-top: auto;
}

footer .privacy-note {
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: #64748b;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.3rem;
}

footer .privacy-note span {
  font-size: 1rem;
}

/* Mobile adjustments */
@media (max-width: 480px) {
  header h1 {
    font-size: 1.5rem;
  }
  .main-nav {
    padding: 0.25rem;
  }
  .nav-card {
    padding: 0.25rem;
  }
}

/* Custom CSS - Works with Bootstrap */

/* Custom Color Variables */
:root {
  --primary-dark: #0f3b5e;
  --primary: #1a5f7a;
  --primary-light: #2980b9;
}

/* Custom Background Gradient */
.bg-gradient-primary {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
}

/* Text Colors */
.text-primary-dark {
  color: var(--primary-dark);
}

/* Opacity Utilities */
.opacity-90 {
  opacity: 0.9;
}

/* Feature Icon Styling */
.feature-icon {
  width: 70px;
  height: 70px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* Card Hover Effects */
.card {
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.1) !important;
}

/* Button Styling */
.btn {
  border-radius: 50px;
  padding: 0.6rem 1.5rem;
  font-weight: 500;
  transition: all 0.2s;
}

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

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

/* File Upload Area */
.file-upload-area {
  border: 2px dashed #dee2e6;
  border-radius: 1rem;
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
}

.file-upload-area:hover {
  border-color: var(--primary);
  background-color: rgba(26, 95, 122, 0.05);
}

/* Loading Spinner */
.spinner-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

/* Trust Badge */
.trust-badge {
  background: #d1fae5;
  border: 1px solid #6ee7b7;
  color: #065f46;
}

/* Footer Styling */
footer {
  background: white;
  border-top: 1px solid #e5e7eb;
  padding: 1.5rem 0;
  margin-top: auto;
}

footer .privacy-note {
  color: #6b7280;
  font-size: 0.875rem;
}

/* Mobile Responsiveness */
@media (max-width: 576px) {
  .nav-link {
    padding: 0.5rem !important;
  }
  
  .nav-link span {
    font-size: 0.7rem;
  }
  
  .feature-icon {
    width: 60px;
    height: 60px;
  }
  
  h1 {
    font-size: 1.8rem !important;
  }
}

/* Form Styling */
.form-container {
  max-width: 500px;
  margin: 0 auto;
}

.size-option-card {
  border: 2px solid #e5e7eb;
  border-radius: 12px;
  padding: 1rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
}

.size-option-card:hover,
.size-option-card.selected {
  border-color: var(--primary);
  background: rgba(26, 95, 122, 0.05);
}

/* Tab Styling */
.nav-tabs .nav-link {
  border: none;
  color: #6b7280;
  font-weight: 500;
  padding: 0.75rem 1.5rem;
}

.nav-tabs .nav-link.active {
  color: var(--primary);
  border-bottom: 3px solid var(--primary);
  background: transparent;
}

/* Alert Customization */
.alert-success {
  background: #d1fae5;
  border-color: #6ee7b7;
  color: #065f46;
}

.alert-danger {
  background: #fee2e2;
  border-color: #fca5a5;
  color: #991b1b;
}

/* File Upload Area */
.file-upload-area {
  border: 2px dashed #dee2e6;
  border-radius: 1rem;
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  background: #f8f9fa;
}

.file-upload-area:hover {
  border-color: var(--primary);
  background: rgba(26, 95, 122, 0.05);
}

.file-upload-area.border-primary {
  border-color: var(--primary) !important;
}

/* Hide default file input */
.file-input-wrapper input[type="file"] {
  position: absolute;
  left: -9999px;
}

.file-input-wrapper label {
  cursor: pointer;
}

/* Button Check Styles (for size options) */
.btn-check:checked + .btn-outline-primary {
  background: var(--primary);
  color: white;
}

.btn-outline-primary {
  color: var(--primary);
  border-color: var(--primary);
}

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

/* Loading Spinner */
.spinner-border {
  width: 3rem;
  height: 3rem;
}

/* Alert Styling */
.alert {
  border-radius: 12px;
  border: none;
}

.alert-danger {
  background: #fee2e2;
  color: #991b1b;
}

.alert-success {
  background: #d1fae5;
  color: #065f46;
}

/* Tab Pills Customization */
.nav-pills .nav-link {
  color: var(--primary);
  border-radius: 50px;
  padding: 0.75rem 1.5rem;
  font-weight: 500;
  transition: all 0.2s;
}

.nav-pills .nav-link.active {
  background: var(--primary);
  color: white;
}

.nav-pills .nav-link:not(.active):hover {
  background: rgba(26, 95, 122, 0.1);
}

/* File Upload Area Enhancement */
.file-upload-area {
  border: 2px dashed #dee2e6;
  border-radius: 1rem;
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  background: #f8f9fa;
}

.file-upload-area:hover {
  border-color: var(--primary);
  background: rgba(26, 95, 122, 0.03);
}

.file-upload-area.border-primary {
  border-color: var(--primary) !important;
}