:root {
  --page-bg: #f5f5f7;
  --page-text: #222222;

  --canvas-bg: #ffffff;
  --line-color: #111111;
  --cadmium-red: #d21f26;
  --cobalt-blue: #0047a8;

  --grid-line-width: 8px;
  --edge-strip-height: 26px;
}

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

body {
  margin: 0;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", system-ui, sans-serif;
  background-color: var(--page-bg);
  color: var(--page-text);
}

.site-header,
.site-footer {
  padding: 1.25rem 1rem;
  text-align: center;
}

.site-header {
  border-bottom: 1px solid #dddddf;
}

.site-footer {
  border-top: 1px solid #dddddf;
  font-size: 0.875rem;
  color: #555555;
}

.page-title {
  margin: 0 0 0.5rem;
  font-size: 1.4rem;
  font-weight: 600;
}

.page-subtitle {
  margin: 0;
  max-width: 40rem;
  margin-inline: auto;
  font-size: 0.95rem;
  color: #444444;
}

.site-main {
  flex: 1;
  display: flex;
}

.artwork-center {
  flex: 1;
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  overflow: auto;
}

.artwork-canvas {
  position: relative;
  width: 430px;
  height: 412px;
  background-color: var(--canvas-bg);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.16);
}

.herrera-grid {
  position: absolute;
  left: 15px;
  top: 6px;
  width: 400px;
  height: 400px;
  background-color: var(--line-color);
  padding: var(--grid-line-width);
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  gap: var(--grid-line-width);
}

.cell {
  position: relative;
  background-clip: padding-box;
}

.cell--red {
  background-color: var(--cadmium-red);
}

.cell--blue {
  background-color: var(--cobalt-blue);
}

.edge-strip {
  position: absolute;
  width: 120px;
  height: var(--edge-strip-height);
  background-color: var(--cadmium-red);
}
.edge-strip--top {
  top: 14px;
  left: 255px;
}
.edge-strip--bottom {
  bottom: 14px;
  left: 55px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}