:root {
  --header: #101828;
  --line: #263449;
  --text: #ffffff;
  --accent: #8de3dd;
}

* {
  box-sizing: border-box;
}

body {
  display: grid;
  grid-template-rows: auto 1fr;
  height: 100vh;
  margin: 0;
  overflow: hidden;
  background: #101828;
  color: var(--text);
  font-family: "Segoe UI", Arial, sans-serif;
}

.viewer-header {
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 58px;
  padding: 10px 18px;
  background: var(--header);
  border-bottom: 1px solid var(--line);
}

.back-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  padding: 8px 12px;
  border: 1px solid rgba(141, 227, 221, 0.55);
  border-radius: 8px;
  color: var(--accent);
  font-weight: 800;
  text-decoration: none;
}

.viewer-frame {
  min-height: 0;
}

iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  background: #ffffff;
}