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

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background-color: #ffffff;
  color: #1a1a1a;
  line-height: 1.6;
  overflow-x: hidden;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  font-size: 1.5rem;
  font-weight: 600;
  color: #1a1a1a;
}

.nav {
  display: flex;
  gap: 2rem;
  flex: 1;
  justify-content: center;
}

.nav-link {
  text-decoration: none;
  color: #666;
  font-weight: 400;
  transition: color 0.3s ease;
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: #1a1a1a;
}

/* Main Content */
.upload-main {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 6rem 2rem 2rem;
  text-align: center;
  background-image: none;
}

.upload-container {
  max-width: 600px;
  width: 100%;
  text-align: center;
}

.back-btn-container {
  margin-bottom: 2rem;
  /* Updated to center the button */
  text-align: center;
  width: 100%;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  text-decoration: none;
  background-color: transparent;
  color: #6c757d;
  border: none;
  /* Updated padding to match the button size */
  padding: 0.75rem 1.5rem; 
  font-weight: 500;
  transition: all 0.3s ease;
  border-radius: 50px;
}

.back-btn:hover {
  /* Updated hover color to a darker shade of the button color */
  background-color: #c4ae36;
  color: #1a1a1a;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.upload-title {
  font-size: 2.5rem;
  font-weight: 300;
  margin-bottom: 0.5rem;
  color: #1a1a1a;
}

.upload-subtitle {
  color: #666;
  margin-bottom: 3rem;
  font-size: 1.1rem;
}

.upload-area {
  border: 2px dashed #d0d0d0;
  border-radius: 16px;
  padding: 3rem 2rem;
  margin-bottom: 2rem;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.upload-area:hover {
  border-color: #1a1a1a;
  background: #fafafa;
}

.upload-area.dragover {
  border-color: #1a1a1a;
  background: #f0f0f0;
}

.upload-icon-container {
  background-color: #f3f4f6;
  padding: 1rem;
  border-radius: 50%;
  width: 4rem;
  height: 4rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.upload-icon {
  width: 2rem;
  height: 2rem;
  color: #6b7280;
}

.upload-primary {
  font-size: 1.2rem;
  font-weight: 500;
  color: #1a1a1a;
  margin-bottom: 0.5rem;
}

.upload-secondary {
  color: #666;
  font-size: 0.9rem;
}

.browse-btn {
  background: none;
  border: 1px solid #d1d5db;
  color: #4b5563;
  padding: 0.75rem 2rem;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-top: 1rem;
}

.browse-btn:hover {
  background: #f3f4f6;
}

.file-input {
  display: none;
}

.file-info {
  background: #f8f8f8;
  border-radius: 12px;
  padding: 1rem;
  margin-bottom: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.file-name {
  font-weight: 500;
  color: #1a1a1a;
}

.file-size {
  color: #666;
  font-size: 0.9rem;
}

.remove-file {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: #999;
  padding: 0.25rem;
}

.analyze-btn {
  background: #1a1a1a;
  color: white;
  border: none;
  padding: 1rem 2rem;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  width: 100%;
}

.analyze-btn:hover:not(:disabled) {
  background: #333;
  transform: translateY(-1px);
}

.analyze-btn:disabled {
  background: #ccc;
  cursor: not-allowed;
}

.security-note {
  font-size: 0.8rem;
  color: #666;
  margin-top: 1rem;
}

@media (max-width: 768px) {
  .header {
    padding: 1rem;
    flex-direction: column;
    gap: 1rem;
  }
  
  .nav {
    gap: 1rem;
  }
  
  .upload-main {
    padding: 8rem 1rem 2rem;
  }
}