:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #1b2330;
  --muted: #5b6575;
  --border: #e3e6eb;
  --accent: #1f5fbf;
  --accent-hover: #184c99;
  --accent-text: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #11151c;
    --surface: #1a2029;
    --text: #e8ebf0;
    --muted: #a0a9b8;
    --border: #2b3340;
    --accent: #5b9bff;
    --accent-hover: #7fb1ff;
    --accent-text: #0b1220;
  }
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--accent); }

.wrap {
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding: 0 16px;
}

header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.brand {
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.01em;
  color: var(--text);
  text-decoration: none;
}

main { flex: 1; padding: 64px 0; }

h1 {
  font-size: clamp(1.8rem, 5vw, 2.4rem);
  line-height: 1.2;
  margin: 0 0 16px;
}

.lead { color: var(--muted); font-size: 1.1rem; margin: 0 0 32px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 16px;
}

.card h2 { margin: 0 0 8px; font-size: 1.25rem; }
.card p { margin: 0 0 16px; color: var(--muted); }

ul.features { margin: 0 0 24px; padding-left: 20px; color: var(--muted); }
ul.features li { margin-bottom: 6px; }

.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-text);
  text-decoration: none;
  font-weight: 600;
  padding: 10px 22px;
  border-radius: 8px;
}

.btn:hover, .btn:focus-visible { background: var(--accent-hover); }

.btn-link { font-weight: 600; text-decoration: none; }
.btn-link:hover { text-decoration: underline; }

footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
  padding: 20px 0;
}