:root {
  --bg: #14151a;
  --panel: #1c1e26;
  --border: #2c2f3a;
  --text: #e8e9ed;
  --muted: #8b8fa3;
  --accent: #7dd3a8;
}

* {
  box-sizing: border-box;
}

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

body {
  display: flex;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

/* ---- Sidebar ---- */
/* Deliberately pure black/white/grey (no accent color) with a pixel-art
   arcade font, styled like a Game Boy menu: a ">" cursor marks the
   hovered/focused item instead of a color change. */

.sidebar {
  --px-white: #fff;
  --px-black: #000;
  --px-grey: #8a8a8a;
  width: 280px;
  flex-shrink: 0;
  background: var(--px-black);
  color: var(--px-white);
  border-right: 4px solid var(--px-white);
  padding: 28px 20px;
  display: flex;
  flex-direction: column;
  gap: 30px;
  font-family: "Press Start 2P", "Courier New", monospace;
}

.sidebar-header h1 {
  font-size: 0.85rem;
  font-weight: normal;
  line-height: 1.6;
  margin: 0 0 10px;
  text-transform: uppercase;
}

.sidebar-header p {
  margin: 0;
  color: var(--px-grey);
  font-size: 0.6rem;
  line-height: 1.6;
}

.nav-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.nav-links a {
  display: block;
  padding: 10px 10px 10px 22px;
  position: relative;
  color: var(--px-white);
  text-decoration: none;
  text-transform: uppercase;
  font-size: 0.65rem;
  line-height: 1.4;
  border: 2px solid transparent;
}

.nav-links a::before {
  content: ">";
  position: absolute;
  left: 4px;
  opacity: 0;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  border-color: var(--px-white);
  outline: none;
}

.nav-links a:hover::before,
.nav-links a:focus-visible::before {
  opacity: 1;
}

.sidebar-footer {
  margin-top: auto;
  font-size: 0.55rem;
  color: var(--px-grey);
  line-height: 1.8;
}

.sidebar-footer .hint {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 2px dashed var(--px-grey);
  color: var(--px-white);
}

/* ---- Stage ---- */

.stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 24px;
}

.screen-wrap {
  position: relative;
  border: 3px solid var(--border);
  border-radius: 10px;
  background: #000;
  line-height: 0;
}

#screen {
  width: 640px;
  height: 576px;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  display: block;
  border-radius: 7px;
}

.overlay {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 14px;
  padding: 24px;
  background: rgba(10, 11, 15, 0.82);
  color: var(--accent);
  font-family: "SF Mono", "Cascadia Code", Consolas, monospace;
  font-size: 0.95rem;
  line-height: normal;
  border-radius: 7px;
}

.overlay.visible {
  display: flex;
}

.overlay-section {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.overlay-row {
  display: flex;
  justify-content: space-between;
  gap: 24px;
}

.overlay-row span:first-child {
  color: var(--muted);
}

.overlay-toggle {
  position: absolute;
  bottom: 10px;
  right: 10px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.5);
  color: var(--muted);
  cursor: pointer;
  font-size: 0.9rem;
  line-height: 1;
}

.overlay-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.rom-status {
  color: var(--muted);
  font-size: 0.8rem;
  margin: 0;
}

@media (max-width: 760px) {
  body {
    flex-direction: column;
  }
  .sidebar {
    width: 100%;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    padding: 16px;
    border-right: none;
    border-bottom: 4px solid var(--px-white);
  }
  .sidebar-footer {
    display: none;
  }
  #screen {
    width: min(90vw, 480px);
    height: calc(min(90vw, 480px) * 0.9);
  }
}