* {
  box-sizing: border-box;
}

:root {
  --bg: #0f172a;
  --surface: rgba(30, 41, 59, 0.72);
  --surface-hover: #1e293b;

  --border: #334155;
  --border-hover: #64748b;

  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;

  --blue: #3b82f6;
  --blue-hover: #60a5fa;
  --green: #22c55e;
  --amber: #f59e0b;

  --code-bg: #111827;
}

html {
  color-scheme: dark;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-secondary);
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  line-height: 1.6;
}

.container {
  width: min(900px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0 72px;
}

header {
  margin-bottom: 32px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--blue);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2 {
  color: var(--text-primary);
  font-weight: 600;
}

h1 {
  margin: 0;
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  line-height: 1.1;
}

h2 {
  margin-top: 0;
}

.lead {
  max-width: 720px;
  color: var(--text-muted);
  font-size: 1.1rem;
}

.card {
  margin-bottom: 20px;
  padding: 24px;

  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;

  transition:
    background-color 200ms ease-out,
    border-color 200ms ease-out,
    transform 300ms ease-out,
    box-shadow 300ms ease-out;
}

.card:hover {
  background: var(--surface-hover);
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
}

.platform-picker {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 18px;
}

.platform-button,
.copy-button {
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
  font-weight: 500;
  cursor: pointer;

  transition:
    background-color 200ms ease-out,
    border-color 200ms ease-out,
    transform 100ms ease-out,
    box-shadow 200ms ease-out;
}

.platform-button {
  padding: 10px 16px;
  background: #334155;
  color: var(--text-primary);

  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.platform-button:hover {
  background: #475569;
  border-color: var(--border-hover);
}

.platform-button.active {
  background: var(--blue);
  border-color: var(--blue);
  color: #f8fafc;

  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.2),
    0 0 10px rgba(59, 130, 246, 0.3);
}

.platform-button:active,
.copy-button:active {
  transform: scale(0.98);
  box-shadow:
    inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

.platform-button:focus-visible,
.copy-button:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}

.code-block {
  position: relative;
  margin: 16px 0;
  padding: 18px 85px 18px 18px;

  overflow-x: auto;

  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 10px;

  color: #dbeafe;
}

.code-block pre {
  margin: 0;
  white-space: pre-wrap;
}

.code-block code,
.response code {
  font-family:
    Consolas,
    "Liberation Mono",
    monospace;
}

.copy-button {
  position: absolute;
  top: 10px;
  right: 10px;

  padding: 7px 11px;

  background: #334155;
  color: var(--text-primary);

  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.copy-button:hover {
  background: #475569;
  border-color: var(--border-hover);
}

.response {
  padding: 18px;
  overflow-x: auto;

  background: #111827;
  color: #cbd5e1;

  border: 1px solid var(--border);
  border-radius: 10px;
}

.note {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.note strong {
  color: var(--text-secondary);
}

.concepts {
  display: grid;
  grid-template-columns: minmax(90px, 140px) 1fr;
  gap: 12px 20px;
}

.concepts dt {
  color: var(--green);
  font-weight: 600;
}

.concepts dd {
  margin: 0;
  color: var(--text-secondary);
}

.warning {
  background: rgba(245, 158, 11, 0.08);
  border-color: rgba(245, 158, 11, 0.45);
}

.warning:hover {
  background: rgba(245, 158, 11, 0.12);
  border-color: var(--amber);
}

.warning h2 {
  color: #fbbf24;
}

@media (max-width: 600px) {
  .container {
    width: min(100% - 20px, 900px);
    padding-top: 24px;
  }

  .card {
    padding: 18px;
  }

  .concepts {
    grid-template-columns: 1fr;
    gap: 2px;
  }

  .concepts dd {
    margin-bottom: 12px;
  }

  .platform-picker {
    flex-direction: column;
  }

  .platform-button {
    width: 100%;
    text-align: left;
  }
}