.container {
  position: relative;
  margin: 20px auto;
  padding: 20px;
  border-radius: 16px;
  font-family: 'Poppins', sans-serif;
  text-align: center;
  max-width: 900px;
  background: #121212; /* Ultra-dark background */
  color: #e0e0e0; /* Soft white text for readability */
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.3);
  z-index: 1;
}

/* Dark gradient border (deep blue + teal green) */
.container::before {
  content: '';
  position: absolute;
  top: -4px;
  left: -4px;
  right: -4px;
  bottom: -4px;
  z-index: -1;
  border-radius: 20px;
  background: linear-gradient(135deg, #003366, #005544); /* Dark blue to dark green */
}

.container h1 {
  font-size: 40px;
  font-weight: 800;
  color: #222;
  background: linear-gradient(90deg, #0d6efd, #20c997);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
  margin-bottom: 30px;
  letter-spacing: 1.5px;
  text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
  padding: 10px 0;
  border-bottom: 3px solid #0d6efd;
  display: inline-block;
}

/* File input styling */
input[type="file"] {
  display: block;
  width: 100%;
  padding: 12px;
  border: 1px solid #ccc;
  border-radius: 8px;
  background: #f9f9f9;
  font-size: 16px;
  margin-top: 10px;
  transition: all 0.3s ease;
  cursor: pointer;
}

input[type="file"]:hover {
  border-color: #6a5acd;
  background: #fff;
}

input[type="file"]::file-selector-button {
  background: linear-gradient(135deg, #6a5acd, #00bcd4);
  color: #fff;
  border: none;
  padding: 10px 18px;
  border-radius: 8px;
  margin-right: 15px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.3s ease;
}

input[type="file"]::file-selector-button:hover {
  background: linear-gradient(135deg, #00bcd4, #6a5acd);
}

/* Progress bar styles */
.progress-bar {
  width: 100%;
  background-color: #e0e0e0;
  height: 12px;
  margin-top: 20px;
  border-radius: 10px;
  overflow: hidden;
  display: none;
}

.progress-bar span {
  display: block;
  height: 100%;
  background-color: #007bff;
  width: 0%;
  transition: width 0.2s ease;
}

/* Loading text styling */
.loading {
  text-align: center;
  margin-top: 10px;
  color: #007bff;
  font-size: 18px;
  display: none;
}

/* Textarea styling */
textarea {
  margin-top: 20px;
  width: 100%;
  padding: 12px;
  font-size: 16px;
  border: 1px solid #ccc;
  border-radius: 8px;
  background: #f9f9f9;
  height: 200px;
  resize: vertical;
}

/* Copy Button styling */
.second-button {
  margin-top: 20px;
  margin-bottom: 10px;
  padding: 12px 20px;
  background: #007bff;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
}

.download-button {
  margin-top: 20px;
}

.second-button:hover {
  background: #0056b3;
}

/* Message after copy */
#copyMessage {
  margin-top: 10px;
  font-size: 16px;
}

/* Download button styling */
.download-button {
  margin-top: 25px;
  background: linear-gradient(135deg, #6a5acd, #00bcd4);
  color: #fff;
  border: none;
  padding: 14px 28px;
  border-radius: 50px;
  font-size: 16px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 5px 15px rgba(106, 90, 205, 0.3);
  display: inline-block;
  text-decoration: none;
}

.download-button:hover {
  background: linear-gradient(135deg, #00bcd4, #6a5acd);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.header-section {
  margin: 30px auto;
  background: #ffffff;
  padding: 40px;
  border-radius: 16px;
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.08);
  text-align: center;
  font-family: 'Poppins', sans-serif;
}

.header-section h1 {
  font-size: 30px;
  font-weight: 800;
  color: #222;
  background: linear-gradient(90deg, #0d6efd, #20c997);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
  margin-bottom: 30px;
  letter-spacing: 1.5px;
  text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
  padding: 10px 0;
  border-bottom: 3px solid #0d6efd;
  display: inline-block;
}

.header-section p {
  font-size: 18px;
  line-height: 1.8;
  text-align: left;
  margin-bottom: 16px;
  letter-spacing: 0.3px;
  word-spacing: 1px;
  font-weight: 400;
  font-family: "Segoe UI", Roboto, sans-serif;
}