:root {
  --bg: #f4f4f4;        /* slate-900 */
  --panel: #f4f4f4;     /* gray-900 */
  --text: #060708;      /* gray-200 */
  --muted: #005eff;     /* gray-400 */
  --accent: #fa7260;    /* blue-400 */
  --border: #f4f4f4;    /* gray-800 */
  --card: #f4f4f4;      /* deep */
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; padding: 0; }

body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  background: linear-gradient(180deg, var(--bg), #f4f4f4 50%, #f4f4f4 100%);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

header {
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(6px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.wrap {
  max-width: 900px;
  margin: 0 auto;
  padding: 1.25rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: .75rem;
  font-weight: 700;
  letter-spacing: .2px;
}

.brand .logo {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: radial-gradient(circle at 30% 30%, #7dd3fc, #60a5fa 40%, #3b82f6 70%, #1d4ed8);
  box-shadow: 0 4px 16px rgba(59,130,246,.35), inset 0 0 24px rgba(255,255,255,.08);
}

h1 {
  font-size: clamp(1.6rem, 2.4vw, 2.2rem);
  margin: 1.2rem 0 .5rem;
}

.muted {
  color: var(--muted);
  font-size: .95rem;
}

main { padding-bottom: 4rem; }

section.card {
  background: linear-gradient(180deg, #f4f4f4 0%, #f4f4f4 100%);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.25rem;
  margin: 1rem 0;
  box-shadow: 0 10px 30px rgba(0,0,0,.35);
}

section.card h2 {
  font-size: 1.2rem;
  margin: .2rem 0 .6rem;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

ul { padding-left: 1.1rem; }

code.placeholder {
  background: #0f172a;
  padding: .15rem .35rem;
  border-radius: 6px;
  border: 1px dashed #22304a;
  color: #93c5fd;
  font-size: .92em;
}

footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  padding: 1.25rem 0 2rem;
}