body {
  font-family: sans-serif;
  margin: 0;
  padding: 0;
  display: flex; 
  flex-direction: column; 
  min-height: 100vh;
}

header {
  background: #333;
  color: #fff;
  padding: 1rem;
}

header a {
  color: #fff;
  text-decoration: none;
}

main {
  flex: 1;
  padding: 1rem;
  max-width: 600px;
  margin: auto;
}

.btn {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  background: #007bff;
  color: #fff;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

.btn:hover {
  background: #0056b3;
}

.file-drop-area {
  border: 2px dashed #ccc;
  padding: 2rem;
  text-align: center;
  position: relative;
  cursor: pointer;
}

.file-drop-area.highlight {
  border-color: #007bff;
}

.file-drop-area.disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.file-input {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  opacity: 0;
  cursor: pointer;
}

.upload-status {
  margin: 1rem 0;
  font-style: italic;
  color: #555;
}

.hidden {
  display: none;
}

.file-content {
  max-height: 60vh;
  overflow-y: auto;
  background: #f9f9f9;
  padding: 1rem;
  border: 1px solid #ddd;
  border-radius: 4px;
}

.flashes {
  list-style: none;
  padding: 0;
}

.flash {
  padding: 0.5rem;
  margin-bottom: 0.5rem;
  border-radius: 4px;
}

.flash.danger {
  background: #f8d7da;
  color: #721c24;
}

.error-box {
  padding: 1rem;
  background: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
  border-radius: 4px;
  margin: 1rem 0;
}