body {
  font-family: Arial, sans-serif;
  background: #f0f2f5;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  min-height: 100vh;
}

.card {
  background: #fff;
  padding: 25px;
  margin: 40px 10px;
  max-width: 420px;
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

h1 {
  margin-top: 0;
  font-size: 24px;
  text-align: center;
}

.muted {
  color: #555;
  font-size: 14px;
  text-align: center;
  margin-bottom: 20px;
}

.file-label {
  display: block;
  background: #007bff;
  color: white;
  padding: 12px;
  text-align: center;
  border-radius: 8px;
  cursor: pointer;
  margin-bottom: 15px;
  font-weight: bold;
}

.file-label input {
  display: none;
}

.controls {
  display: flex;
  justify-content: space-between;
  margin-bottom: 20px;
}

button {
  padding: 10px 14px;
  font-size: 15px;
  font-weight: bold;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

#convertBtn {
  background: #28a745;
  color: white;
}

#convertBtn:disabled {
  background: #9acfab;
}

#downloadBtn {
  background: #ff5722;
  color: white;
}

.progress {
  width: 100%;
  background: #ddd;
  border-radius: 8px;
  overflow: hidden;
  position: relative;
  margin-bottom: 15px;
}

.bar {
  height: 14px;
  background: #007bff;
  width: 0%;
}

.progressText {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  font-size: 12px;
  color: #fff;
}

.note {
  font-size: 13px;
  color: #444;
  text-align: center;
  margin-bottom: 20px;
}

.ad-placeholder {
  width: 100%;
  height: 100px;
  background: #f9f9f9;
  border: 1px dashed #ccc;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #777;
  margin-bottom: 25px;
}

footer {
  text-align: center;
  font-size: 13px;
  color: #444;
}