* {
  box-sizing: border-box;
}

body {
  margin: 0;
  height: 100vh;
  font-family: "Segoe UI", sans-serif;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.app {
  width: 360px;
  padding: 25px;
  border-radius: 20px;
  background: rgba(255,255,255,0.08);
  backdrop-filter: blur(12px);
  text-align: center;
  box-shadow: 0 20px 40px rgba(0,0,0,0.4);
}

h1 {
  margin: 0;
}

.sub {
  font-size: 14px;
  opacity: 0.8;
  margin-bottom: 15px;
}

#reader {
  width: 100%;
  border-radius: 15px;
  overflow: hidden;
  border: 2px solid rgba(255,255,255,0.3);
}

.upload-btn {
  display: inline-block;
  margin-top: 15px;
  padding: 10px 18px;
  background: #00c6ff;
  color: black;
  border-radius: 25px;
  cursor: pointer;
  font-weight: 600;
}

.upload-btn:hover {
  background: #00a3d9;
}

#status {
  margin-top: 12px;
  font-size: 13px;
  opacity: 0.85;
}