:root {
  --sky: #50baf2;
  --sky-deep: #1267ae;
  --card: #fffdf6;
  --ink: #22303d;
  --muted: #5c6b7a;
  --accent: #e8452c;
  --rule: #dfe7ef;
  --link: #1f6fc2;
}

@media (prefers-color-scheme: dark) {
  :root {
    --sky: #0f3a5c;
    --sky-deep: #081f33;
    --card: #15212d;
    --ink: #eef3f7;
    --muted: #a9b7c4;
    --rule: #2a3a4a;
    --link: #7cc0ff;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: linear-gradient(180deg, var(--sky) 0%, var(--sky-deep) 100%) fixed;
  color: var(--ink);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

main {
  max-width: 720px;
  margin: 32px auto;
  padding: 0 16px;
}

.card {
  background: var(--card);
  border-radius: 20px;
  padding: 28px 28px 20px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}

header { text-align: center; color: #fff; margin-bottom: 20px; }
header .brand { font-weight: 900; font-size: 30px; letter-spacing: 0.5px; text-shadow: 0 3px 0 rgba(0, 0, 0, 0.25); }
header .brand span { color: #ffce45; }
header .tag { opacity: 0.9; font-weight: 600; }

h1 { font-size: 26px; margin: 0 0 4px; }
h2 { font-size: 19px; margin: 28px 0 6px; }
p, li { margin: 6px 0; }
ul { padding-left: 22px; }
a { color: var(--link); }
.meta { color: var(--muted); font-size: 15px; margin-bottom: 18px; }
.lead { font-weight: 600; }
.box { border: 1px solid var(--rule); border-radius: 14px; padding: 14px 18px; margin: 16px 0; }

footer { text-align: center; color: #fff; opacity: 0.85; font-size: 14px; margin: 20px 0 40px; }
footer a { color: #fff; }