:root {
  --page-pad: 40px;
  --left-pad: 280px;
  --sidebar-gap: 24px;
  --preview-height: 260px;

  /* ── Design tokens ── */
  --accent:         #e53935;
  --border:         rgba(255, 255, 255, 0.15);
  --text-secondary: rgba(255, 255, 255, 0.85);
  --text-tertiary:  rgba(255, 255, 255, 0.55);

  /* ── Typography ── */
  --font-body: 'IBM Plex Sans', sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  min-width: calc(var(--left-pad) + 400px);
}

body {
  background: #000000;
  overflow: hidden;
  font-family: var(--font-body);
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--page-pad) var(--page-pad) var(--page-pad) calc(var(--left-pad) + var(--sidebar-gap));
}

.hidden {
  display: none !important;
}

/* ── Light Mode ── */
html.light {
  --border:         rgba(0, 0, 0, 0.12);
  --text-secondary: rgba(0, 0, 0, 0.80);
  --text-tertiary:  rgba(0, 0, 0, 0.50);
}

html.light body {
  background: #ffffff;
  color: #111;
}

/* ── Responsive ── */
@media (max-width: 1200px) {
  :root {
    --page-pad: 30px;
    --preview-height: 320px;
  }
}

@media (max-width: 1024px) {
  :root {
    --page-pad: 24px;
    --preview-height: 260px;
  }
}

@media (max-width: 768px) {
  :root {
    --page-pad: 16px;
    --preview-height: 200px;
  }
}

@media (max-width: 480px) {
  :root {
    --page-pad: 10px;
    --preview-height: 150px;
  }
}