:root {
  color-scheme: light;
  --page: #f8f5ea;
  --ink: #172026;
  --muted: #4b5563;
  --soft: #64748b;
  --green-950: #052e16;
  --green-900: #14532d;
  --green-800: #166534;
  --green-100: #bbdfb4;
  --green-panel: #e7f4df;
  --sky-panel: #f3f9ff;
  --sky-100: #cfe8ff;
  --sky-800: #075985;
  --white: #ffffff;
  --amber-50: #fff7d6;
  --amber-800: #92400e;
  --rose-50: #fff1f2;
  --rose-700: #be123c;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--page);
}

body {
  min-height: 100%;
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

button,
input {
  font: inherit;
}

button {
  min-height: 42px;
  border: 0;
  border-radius: 14px;
  background: var(--white);
  color: #1f2937;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 850;
  box-shadow: 0 3px 10px rgba(31, 41, 55, 0.08);
  transition:
    background 160ms ease,
    color 160ms ease,
    transform 160ms ease,
    box-shadow 160ms ease;
}

button:hover {
  transform: translateY(-1px);
  background: #f3f7ef;
  box-shadow: 0 6px 16px rgba(31, 41, 55, 0.1);
}

button:focus-visible,
input:focus-visible {
  outline: 3px solid rgba(34, 197, 94, 0.2);
  outline-offset: 3px;
}

.page-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 36px 0 40px;
}

.intro {
  max-width: 760px;
  margin-bottom: 22px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--green-800);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  color: var(--green-950);
  font-size: clamp(2.5rem, 6vw, 4.2rem);
  font-weight: 900;
  letter-spacing: 0;
  line-height: 0.98;
}

.lede {
  max-width: 680px;
  margin-top: 16px;
  color: var(--muted);
  font-size: clamp(1rem, 2vw, 1.12rem);
  line-height: 1.65;
}

.demo-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 18px;
  align-items: stretch;
}

.canvas-card,
.controls,
.explanation article {
  border: 1px solid var(--green-100);
  border-radius: 20px;
  box-shadow: 0 14px 34px rgba(47, 78, 58, 0.07);
}

.canvas-card {
  position: relative;
  overflow: hidden;
  min-height: 430px;
  border: 4px solid var(--white);
  background: var(--sky-panel);
}

canvas {
  display: block;
  width: 100%;
  min-height: 430px;
}

.canvas-status {
  position: absolute;
  top: 14px;
  left: 14px;
  border: 1px solid var(--sky-100);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.86);
  padding: 8px 12px;
  color: var(--sky-800);
  font-size: 0.78rem;
  font-weight: 900;
  box-shadow: 0 4px 14px rgba(14, 116, 144, 0.08);
  backdrop-filter: blur(12px);
}

.controls {
  padding: 16px;
  background: var(--green-panel);
}

.button-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
}

.controls > button {
  width: 100%;
  margin-top: 10px;
}

.primary-button {
  background: var(--green-800);
  color: var(--white);
}

.primary-button:hover {
  background: var(--green-900);
}

.active {
  background: var(--amber-50);
  color: var(--amber-800);
}

.danger-button {
  background: var(--rose-50);
  color: var(--rose-700);
}

.control-field {
  display: block;
  margin-top: 18px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.7);
  padding: 12px;
}

.control-field > span {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
  color: var(--green-800);
  font-size: 0.88rem;
  font-weight: 900;
}

output {
  color: var(--sky-800);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.8rem;
  font-weight: 800;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--green-800);
}

.keyboard-note {
  margin: 16px 0 0;
  border: 1px solid #d8ead1;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.72);
  padding: 12px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 650;
  line-height: 1.6;
}

.explanation {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 18px;
}

.explanation article {
  padding: 16px;
  background: rgba(255, 255, 255, 0.86);
}

.explanation h2 {
  color: #082f49;
  font-size: 0.94rem;
  font-weight: 900;
}

.explanation p {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.6;
}

@media (max-width: 920px) {
  .page-shell {
    width: min(100% - 24px, 760px);
    padding-top: 28px;
  }

  .demo-grid,
  .explanation {
    grid-template-columns: 1fr;
  }

  .controls {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .button-row,
  .control-field,
  .keyboard-note,
  .danger-button {
    grid-column: 1 / -1;
  }

  .controls > button {
    margin-top: 0;
  }
}

@media (max-width: 560px) {
  .page-shell {
    width: min(100% - 18px, 520px);
    padding-top: 22px;
  }

  .controls {
    grid-template-columns: 1fr;
  }

  .button-row {
    grid-template-columns: 1fr;
  }

  .canvas-card,
  canvas {
    min-height: 390px;
  }
}