body {
  margin: 0;
  padding: 0;
  background: #fff;
  font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
  font-size: 17px;
  color: #000;
  min-height: 100vh;
}

.center-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.card {
  background: #fff;
  border-radius: 18px;
  box-shadow: 0 8px 32px 0 rgba(0,0,0,0.15);
  padding: 2.5em 2em 1.5em 2em;
  max-width: 520px;
  width: 96vw;
  margin: 40px 0;
  text-align: center;
}

h1 {
  font-size: 2em;
  font-weight: bold;
  margin: 0 0 0.7em 0;
  line-height: 1.2;
}

.node-uri-label {
  font-weight: bold;
  margin-bottom: 0.2em;
  display: block;
}

.node-uri-input {
  width: 100%;
  max-width: 100%;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
  font-size: 1em;
  padding: 0.3em 0.5em;
  margin: 0.3em 0 1.2em 0;
  border: 1px solid #aaa;
  border-radius: 4px;
  background: #f8f8f8;
  text-align: left;
  overflow-x: auto;
  box-sizing: border-box;
  display: block;
}

.qr-section {
  margin: 1.2em 0 1.5em 0;
}

.qr-section img {
  display: block;
  margin: 0 auto;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  width: 285px;
  height: 285px;
  max-width: 90vw;
}

.info-section {
  margin: 1.5em 0 1em 0;
  font-size: 1em;
}

.info-section a {
  color: #2a0dab;
  text-decoration: underline;
  display: block;
  margin: 0.2em 0;
  word-break: break-all;
}

.footer {
  margin-top: 1.5em;
  font-size: 1em;
}

@media (max-width: 600px) {
  .card {
    padding: 1em 0.3em;
    max-width: 99vw;
  }
  .qr-section img {
    width: 98vw;
    height: auto;
    max-width: 98vw;
  }
  .node-uri-input {
    font-size: 0.95em;
  }
}