:root {
  --primary-color: #007bff;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --warning-color: #ffc107;
  --info-color: #17a2b8;
  --light-color: #f8f9fa;
  --dark-color: #343a40;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  padding: 0;
  margin: 0;
}

.container {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  margin-top: 2rem;
  margin-bottom: 2rem;
  backdrop-filter: blur(10px);
}

.header-section {
  background: linear-gradient(135deg, var(--primary-color), var(--info-color));
  color: white;
  padding: 2rem 0;
  border-radius: 15px 15px 0 0;
  text-align: center;
}

.header-section h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.header-section p {
  font-size: 1.1rem;
  opacity: 0.9;
  margin: 0;
}

.main-content {
  padding: 2rem;
}

.card {
  border: none;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  margin-bottom: 2rem;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.card-header {
  background: linear-gradient(135deg, var(--light-color), #e9ecef);
  border-bottom: 2px solid var(--primary-color);
  border-radius: 12px 12px 0 0 !important;
  padding: 1.25rem;
}

.card-header h3 {
  margin: 0;
  color: var(--dark-color);
  font-weight: 600;
}

.card-body {
  padding: 2rem;
}

.btn {
  border-radius: 8px;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  transition: all 0.3s ease;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--info-color));
  color: white;
  box-shadow: 0 4px 15px rgba(0, 123, 255, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #0056b3, #138496);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 123, 255, 0.4);
}

.btn-success {
  background: linear-gradient(135deg, var(--success-color), #20c997);
  color: white;
  box-shadow: 0 4px 15px rgba(40, 167, 69, 0.3);
}

.btn-success:hover {
  background: linear-gradient(135deg, #1e7e34, #1a9f7c);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(40, 167, 69, 0.4);
}

.form-control {
  border-radius: 8px;
  border: 2px solid #e9ecef;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  transition: all 0.3s ease;
}

.form-control:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.form-label {
  font-weight: 600;
  color: var(--dark-color);
  margin-bottom: 0.5rem;
}

.alert {
  border-radius: 10px;
  border: none;
  padding: 1.25rem;
  margin: 1.5rem 0;
  font-weight: 500;
}

.alert-success {
  background: linear-gradient(135deg, rgba(40, 167, 69, 0.1), rgba(32, 201, 151, 0.1));
  color: var(--success-color);
  border-left: 4px solid var(--success-color);
}

.alert-danger {
  background: linear-gradient(135deg, rgba(220, 53, 69, 0.1), rgba(229, 62, 62, 0.1));
  color: var(--danger-color);
  border-left: 4px solid var(--danger-color);
}

.format-example {
  background: linear-gradient(135deg, #f8f9fa, #e9ecef);
  border: 1px solid #dee2e6;
  border-radius: 10px;
  padding: 1.5rem;
  margin: 1rem 0;
  border-left: 4px solid var(--info-color);
}

.format-example pre {
  background: var(--dark-color);
  color: #f8f9fa;
  padding: 1rem;
  border-radius: 8px;
  font-size: 0.85rem;
  line-height: 1.4;
  overflow-x: auto;
  margin: 0;
}

.accordion-button {
  font-weight: 600;
  color: var(--dark-color);
  background: linear-gradient(135deg, var(--light-color), #e9ecef);
  border: none;
  border-radius: 10px !important;
}

.accordion-button:focus {
  box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.accordion-button:not(.collapsed) {
  background: linear-gradient(135deg, var(--primary-color), var(--info-color));
  color: white;
}

.accordion-item {
  border: none;
  margin-bottom: 0.5rem;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.accordion-body {
  background: white;
  padding: 1.5rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.feature-card {
  background: white;
  padding: 1.5rem;
  border-radius: 10px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  text-align: center;
  transition: transform 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
}

.feature-icon {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--dark-color);
  margin-bottom: 0.5rem;
}

.feature-description {
  color: #6c757d;
  font-size: 0.95rem;
}

.upload-zone {
  border: 2px dashed var(--primary-color);
  border-radius: 10px;
  padding: 2rem;
  text-align: center;
  background: rgba(0, 123, 255, 0.05);
  transition: all 0.3s ease;
  margin: 1rem 0;
}

.upload-zone:hover {
  background: rgba(0, 123, 255, 0.1);
  border-color: var(--info-color);
}

.upload-icon {
  font-size: 3rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.progress {
  height: 8px;
  border-radius: 10px;
  background: #e9ecef;
  overflow: hidden;
}

.progress-bar {
  background: linear-gradient(90deg, var(--primary-color), var(--info-color));
  border-radius: 10px;
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    margin: 1rem;
    border-radius: 10px;
  }

  .header-section {
    padding: 1.5rem 0;
    border-radius: 10px 10px 0 0;
  }

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

  .main-content {
    padding: 1rem;
  }

  .card-body {
    padding: 1.5rem;
  }

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

/* Animation */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.6s ease-out;
}

/* Icons */
.fas,
.far {
  margin-right: 0.5rem;
}

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: #f1f1f1;
  border-radius: 10px;
}

::-webkit-scrollbar-thumb {
  background: var(--primary-color);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--info-color);
}

/* Step List */
.step-list {
  margin: 0;
  padding: 0;
}

.step-item {
  display: flex;
  align-items: flex-start;
  margin-bottom: 1.5rem;
  padding: 1rem;
  background: rgba(0, 123, 255, 0.05);
  border-radius: 10px;
  border-left: 4px solid var(--primary-color);
  transition: all 0.3s ease;
}

.step-item:hover {
  background: rgba(0, 123, 255, 0.1);
  transform: translateX(5px);
}

.step-number {
  flex-shrink: 0;
  width: 35px;
  height: 35px;
  background: linear-gradient(135deg, var(--primary-color), var(--info-color));
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  margin-right: 1rem;
  box-shadow: 0 4px 10px rgba(0, 123, 255, 0.3);
}

.step-content {
  flex: 1;
}

.step-content strong {
  color: var(--dark-color);
  font-size: 1.1rem;
}

.step-content small {
  display: block;
  margin-top: 0.25rem;
  line-height: 1.4;
}