* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 16px;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f4f6f8;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Main card */
.container {
  background: white;
  padding: 24px;
  border-radius: 12px;
  width: 100%;
  max-width: 420px;
  text-align: center;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

/* Title */
.container h1 {
  font-size: 1.4rem;
  margin-bottom: 20px;
}

/* File input */
input[type="file"] {
  width: 100%;
  margin-bottom: 16px;
  font-size: 0.95rem;
}

/* Button */
button {
  width: 100%;
  padding: 14px;
  font-size: 1rem;
  font-weight: 600;
  background: #2563eb;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

button:hover {
  background: #1e40af;
}

button:active {
  transform: scale(0.98);
}

/* Status */
#status {
  margin-top: 16px;
  font-size: 0.9rem;
  color: #16a34a;
}

/* Native ad spacing */
.ad-container {
  margin-top: 30px;
  width: 100%;
  max-width: 420px;
}

/* Desktop polish */
@media (min-width: 768px) {
  .container h1 {
    font-size: 1.6rem;
  }
}