* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, Arial, sans-serif;
  background: linear-gradient(135deg, #f9fafb, #eef2ff);
  color: #111827;
}

.header {
  text-align: center;
  padding: 30px 15px;
}

.subtitle {
  color: #4b5563;
}

.container {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

.content, .faq, .internal-link {
  margin-bottom: 30px;
}

ul {
  padding-left: 20px;
}

.tool {
  background: white;
  padding: 25px;
  border-radius: 16px;
  box-shadow: 0 10px 25px rgba(0,0,0,.08);
  margin-bottom: 30px;
  text-align: center;
}

input[type="file"] {
  margin-bottom: 15px;
}

.convert-btn {
  width: 100%;
  padding: 14px;
  border-radius: 999px;
  border: none;
  background: linear-gradient(135deg, #4f46e5, #6366f1);
  color: white;
  font-size: 16px;
  cursor: pointer;
}

.convert-btn:hover {
  opacity: 0.9;
}

.hint {
  font-size: 14px;
  color: #4b5563;
  margin-top: 10px;
}

.internal-link a {
  color: #4f46e5;
  font-weight: 600;
  text-decoration: none;
}

.internal-link a:hover {
  text-decoration: underline;
}

.ad {
  margin: 30px 0;
}

.privacy {
  text-align: center;
  font-size: 14px;
  color: #374151;
}

.footer {
  text-align: center;
  padding: 20px;
  color: #6b7280;
}