:root {
  --white:      #ffffff;
  --ink:        #171717;
  --gray-900:   #111827;
  --gray-700:   #374151;
  --gray-600:   #4b5563;
  --gray-500:   #6b7280;
  --gray-200:   #e5e7eb;
  --gray-100:   #f3f4f6;

  --blue-50:    #eff6ff;
  --blue-100:   #dbeafe;
  --blue-600:   #2563eb;
  --blue-700:   #1d4ed8;
  --purple-50:  #faf5ff;
  --purple-600: #9333ea;
  --green-50:   #f0fdf4;
  --green-700:  #15803d;

  --shadow-md:  0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg:  0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}

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

body {
  margin: 0;
  background: linear-gradient(to bottom right, var(--blue-50), var(--white) 45%, var(--purple-50));
  background-attachment: fixed;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blue-600); }

:focus-visible {
  outline: 3px solid var(--blue-600);
  outline-offset: 2px;
  border-radius: 0.375rem;
}

.wrap {
  max-width: 48rem;
  margin-inline: auto;
  padding: 2rem 1rem 4rem;
}

.back {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--blue-600);
  text-decoration: none;
  margin-bottom: 1.5rem;
}
.back:hover, .back:focus-visible { text-decoration: underline; }

.sheet {
  background: var(--white);
  border-radius: 0.75rem;
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.sheet-head {
  background: linear-gradient(to right, var(--blue-600), var(--purple-600));
  color: var(--white);
  padding: 2rem 1.75rem;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.sheet-head .emoji { font-size: 2rem; line-height: 1; flex-shrink: 0; }

.sheet-head h1 {
  font-size: clamp(1.5rem, 1.2rem + 1.4vw, 2rem);
  line-height: 1.2;
  font-weight: 700;
  margin: 0 0 0.35rem;
  text-wrap: balance;
}

.sheet-head .app {
  font-size: 0.9375rem;
  color: var(--blue-100);
  margin: 0;
}

.sheet-body { padding: 1.75rem; }

.sheet-body h2 {
  font-size: 1.1875rem;
  font-weight: 700;
  color: var(--gray-900);
  margin: 2rem 0 0.6rem;
}
.sheet-body h2:first-child { margin-top: 0; }

.sheet-body p { margin: 0 0 1rem; color: var(--gray-700); text-wrap: pretty; }
.sheet-body p:last-child { margin-bottom: 0; }

.updated {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--gray-600);
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  padding: 0.25rem 0.7rem;
  border-radius: 9999px;
  margin-bottom: 1.5rem;
}

.callout {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
  background: var(--green-50);
  border: 1px solid #bbf7d0;
  border-radius: 0.5rem;
  padding: 1rem 1.15rem;
  margin: 0 0 1.5rem;
}
.callout .ico { font-size: 1.25rem; line-height: 1.4; flex-shrink: 0; }
.callout p { margin: 0; color: var(--green-700); font-weight: 600; }

.contact {
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  border-radius: 0.5rem;
  padding: 1rem 1.15rem;
  margin-top: 1.5rem;
}
.contact p { margin: 0; color: var(--blue-700); }
.contact a { font-weight: 600; }

footer {
  text-align: center;
  padding: 2rem 1rem 3rem;
  color: var(--gray-500);
  font-size: 0.9375rem;
}
footer a { font-weight: 600; text-decoration: none; }
footer a:hover, footer a:focus-visible { text-decoration: underline; }

@media (prefers-reduced-motion: reduce) {
  * { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}