:root {
  --bg: #eef1f6;
  --surface: #ffffff;
  --text: #152033;
  --muted: #4e5c73;
  --line: #d5deea;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
}

body {
  font-family: "Inter", "Segoe UI", Roboto, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

.topbar {
  height: 64px;
  padding: 0 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.topbar h1 {
  margin: 0;
  font-size: 1.06rem;
  letter-spacing: 0.2px;
}

.actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.actions a {
  text-decoration: none;
  color: var(--muted);
  border: 1px solid var(--line);
  padding: 0.45rem 0.72rem;
  border-radius: 8px;
  font-size: 0.9rem;
  background: #fff;
}

.actions a:hover {
  color: var(--text);
  border-color: #c4d1e1;
}

.viewer-page {
  height: calc(100vh - 64px);
}

.viewer-page iframe {
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
  background: #fff;
}

@media (max-width: 720px) {
  .topbar {
    height: auto;
    align-items: flex-start;
    flex-direction: column;
    padding: 0.8rem;
  }

  .viewer-page {
    height: calc(100vh - 114px);
  }

  .actions {
    width: 100%;
    flex-wrap: wrap;
  }
}