:root {
  --primary-color: #4361ee;
  --secondary-color: #3f37c9;
  --accent-color: #4cc9f0;
  --light-color: #f8f9fa;
  --dark-color: #212529;
  --success-color: #4bb543;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2rem;
}

.container {
  max-width: 800px;
  width: 100%;
  background: white;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  padding: 2.5rem;
  animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

h1 {
  color: var(--primary-color);
  text-align: center;
  margin-bottom: 1.5rem;
  font-weight: 600;
}

.upload-area {
  border: 2px dashed var(--primary-color);
  border-radius: 10px;
  padding: 2rem;
  text-align: center;
  margin-bottom: 1.5rem;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.upload-area:hover {
  border-color: var(--secondary-color);
  transform: translateY(-3px);
}

.upload-area.active {
  background-color: rgba(67, 97, 238, 0.05);
}

.file-input {
  display: none;
}

.file-label {
  display: block;
  cursor: pointer;
  padding: 1rem;
}

.file-label i {
  font-size: 3rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
  display: block;
}

.file-label h3 {
  color: var(--dark-color);
  margin-bottom: 0.5rem;
}

.file-label p {
  color: #6c757d;
  font-size: 0.9rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

select {
  width: 100%;
  padding: 0.8rem 1rem;
  border: 1px solid #ced4da;
  border-radius: 8px;
  font-size: 1rem;
  color: var(--dark-color);
  background-color: white;
  transition: all 0.3s;
}

select:focus {
  border-color: var(--primary-color);
  outline: none;
  box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

.btn {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 0.8rem 1.5rem;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s;
  width: 100%;
  font-weight: 500;
}

.btn:hover {
  background-color: var(--secondary-color);
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.supported {
  text-align: center;
  margin-top: 1.5rem;
  color: #6c757d;
  font-size: 0.9rem;
  animation: fadeIn 1s ease-out;
}

.progress-bar {
  width: 0;
  height: 4px;
  background-color: var(--accent-color);
  position: absolute;
  bottom: 0;
  left: 0;
  transition: width 0.3s ease;
}

/* Loading animation */
.loading {
  display: none;
  text-align: center;
  margin: 1rem 0;
}

.spinner {
  width: 40px;
  height: 40px;
  margin: 0 auto;
  border: 4px solid rgba(0, 0, 0, 0.1);
  border-radius: 50%;
  border-top-color: var(--primary-color);
  animation: spin 1s ease-in-out infinite;
}

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

.success-message {
  display: none;
  text-align: center;
  color: var(--success-color);
  margin: 1rem 0;
  animation: fadeIn 0.5s ease-out;
}