:root {
  --ciena-red: #C71C2C;
  --ciena-green: #55AF89;
  --ciena-orange: #F47F0C;
  --ciena-purple: #800A68;
  --ciena-blue: #294CC4;
  --ciena-light-grey: #E4E5E6;
  --ciena-dark-grey: #343642;
  --ciena-dark-blue: #282A36;
  --ciena-black: #1C1E2A;
}

html,
body {
  background: var(--ciena-light-grey);
  color: var(--ciena-dark-grey);
}

/* Sidebar */
.wy-nav-side {
  background: var(--ciena-dark-blue);
}

.wy-side-nav-search {
  background: var(--ciena-black);
  color: #ffffff;
  border-bottom: 2px solid var(--ciena-red);
}

.wy-side-nav-search a,
.wy-side-nav-search a:hover {
  color: #ffffff;
}

.wy-side-nav-search input[type="text"] {
  border: 1px solid var(--ciena-blue);
  box-shadow: none;
}

.wy-menu-vertical a {
  color: var(--ciena-light-grey);
}

.wy-menu-vertical a:hover {
  background: var(--ciena-purple);
  color: #ffffff;
}

.wy-menu-vertical li.current > a {
  background: var(--ciena-red);
  color: #ffffff;
}

.wy-menu-vertical li.current > a:hover {
  background: var(--ciena-red);
}

/* Top nav (mobile) */
.wy-nav-top {
  background: var(--ciena-black);
  border-bottom: 2px solid var(--ciena-red);
}

.wy-nav-top a,
.wy-nav-top a:hover {
  color: #ffffff;
}

/* Content */
.wy-nav-content {
  background: var(--ciena-light-grey);
}

.wy-nav-content a {
  color: var(--ciena-blue);
}

.wy-nav-content a:hover {
  color: var(--ciena-red);
}

h1,
h2,
h3,
h4,
h5,
h6 {
  color: var(--ciena-black);
}

/* Code blocks */
.rst-content pre code,
.rst-content code {
  border: 1px solid #d0d2d3;
}

/* Admonitions */
.rst-content .admonition {
  border-left: 4px solid var(--ciena-orange);
}

.rst-content .admonition-title {
  background: var(--ciena-orange);
  color: #ffffff;
}

/* Tables */
.rst-content table thead th {
  background: var(--ciena-dark-grey);
  color: #ffffff;
}

.rst-content table tbody tr:nth-child(odd) {
  background: #f0f1f2;
}

/* Let the content column fill the space up to the sidebar so topology
   diagrams can use the full available width. Prose is re-capped below. */
.wy-nav-content {
  max-width: none;
}

/* Keep body text, code, and tables at a comfortable reading measure even
   though the column is now full width — but exempt the paragraphs that only
   hold a topology SVG so those can break out to full width. */
.rst-content .section > *:not(:has(> img[src$=".svg"])) {
  max-width: 1100px;
}

/* Topology SVGs span the full content width (responsive via their viewBox),
   with a ceiling so they don't balloon on ultra-wide monitors. */
.rst-content img[src$=".svg"] {
  display: block;
  width: 100%;
  max-width: 1600px;
  height: auto;
}

/* Click-to-zoom lightbox (see assets/js/lightbox.js). Diagrams get a zoom
   cursor; clicking opens a full-viewport overlay with the SVG scaled to fit. */
.rst-content img[src$=".svg"].zoomable {
  cursor: zoom-in;
}

.topo-lightbox {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1000;
  align-items: center;
  justify-content: center;
  padding: 2.5vh 2.5vw;
  background: var(--ciena-black); /* fully opaque — not see-through */
  cursor: zoom-out;
}

.topo-lightbox.open {
  display: flex;
}

/* Higher specificity than the global SVG rule above, so it wins and the
   enlarged image fits the viewport instead of spanning full width.
   The diagram SVGs are transparent with dark-grey ink meant for a light
   page, so give the enlarged image a solid white card — otherwise the ink
   washes out against the dark backdrop and the diagram looks see-through. */
.topo-lightbox img {
  box-sizing: border-box;
  width: auto;
  height: auto;
  max-width: 95vw;
  max-height: 95vh;
  padding: 1.5rem;
  background: #ffffff;
  border-radius: 4px;
}

body.lightbox-open {
  overflow: hidden;
}