html,
body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  font-size: 14px;
  background-color: #ececec;
  color: #333;
  margin: 0;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.wrapper {
  width: 90%;
  max-width: 600px;
  padding: 30px 20px;
  min-height: 400px;
  background-color: #fff;
  border: 1px solid #ffffff;
  outline: 1px solid #909399;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  box-sizing: border-box;
}

h1 {
  margin-top: 0;
  margin-bottom: 20px;
  text-align: center;
  font-size: 22px;
  font-weight: 600;
  color: #333;
}

label {
  font-weight: 600;
  color: #3a3a3a;
  display: inline-block;
  margin-bottom: 4px;
}

button {
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  color: #222;
  background: linear-gradient(to bottom, #f0f0f0, #dcdcdc);
  border: 1px solid #a8a8a8;
  border-radius: 5px;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7),
    0 2px 2px rgba(0, 0, 0, 0.2);
  transition: background 0.3s ease, box-shadow 0.3s ease;
  user-select: none;
  margin-left: 8px;
  margin-right: 10px;
  height: 36px;
  font-size: 12px;
  box-sizing: border-box;
}

button:hover {
  background: linear-gradient(to bottom, #e0e0e0, #c8c8c8);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9),
    0 3px 4px rgba(0, 0, 0, 0.3);
}

button:active {
  background: linear-gradient(to bottom, #c8c8c8, #a8a8a8);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.4);
}

input[type="file"] {
  font-family: inherit;
  font-size: 14px;
  padding: 6px 8px;
  height: 36px;
  box-sizing: border-box;
  border: 1px solid #bbb;
  border-radius: 4px;
  background-color: #fff;
  cursor: pointer;
}

#generatedUrl a {
  color: #3399ff;
  text-decoration: underline;
}

pre {
  background-color: #f5f5f5;
  color: #333;
  border: 1px solid #bbb;
  padding: 10px;
  max-height: 300px;
  overflow-y: auto;
  white-space: pre-wrap;
  word-break: break-all;
  margin-top: 10px;
}

hr {
  border: none;
  border-top: 1px solid #ccc;
  margin: 20px 0;
}

.file-controls {
  display: flex;
  align-items: center;
  margin-bottom: 10px;
}