:root {
  color-scheme: light;
  --blue: #17649a;
  --blue-dark: #0f3858;
  --cream: #f7f1e7;
  --paper: #fffdf8;
  --ink: #142436;
  --muted: #647487;
  --line: #ded6ca;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--cream);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.72;
}

.shell {
  width: min(860px, calc(100% - 32px));
  margin: 0 auto;
  padding: 36px 0 64px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 24px;
}

.brand { display: flex; align-items: center; gap: 12px; }
.mark {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  background: var(--blue);
  color: white;
  font-weight: 800;
}
.brand strong { display: block; font-size: 18px; }
.brand span { display: block; color: var(--muted); font-size: 12px; }
nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 12px; }
a { color: var(--blue); }
nav a { font-size: 13px; font-weight: 700; text-decoration: none; }

main {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: clamp(24px, 5vw, 48px);
  box-shadow: 0 14px 40px rgba(20, 36, 54, .06);
}

h1 { margin: 0; font-size: clamp(28px, 6vw, 42px); line-height: 1.2; }
.lead { color: var(--muted); margin: 10px 0 28px; }
.meta {
  padding: 12px 14px;
  background: #eaf3f9;
  border-radius: 12px;
  color: var(--blue-dark);
  font-size: 13px;
}
h2 { margin: 34px 0 10px; font-size: 21px; color: var(--blue-dark); }
h3 { margin: 24px 0 8px; font-size: 17px; }
p, li { font-size: 15px; }
ul { padding-left: 22px; }
.language-block + .language-block {
  border-top: 1px solid var(--line);
  margin-top: 48px;
  padding-top: 48px;
}
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; margin-top: 24px; }
.card { border: 1px solid var(--line); border-radius: 16px; padding: 18px; background: white; }
.card h2 { margin-top: 0; }
.button {
  display: inline-block;
  margin-top: 12px;
  border-radius: 11px;
  background: var(--blue);
  color: white;
  font-weight: 700;
  padding: 10px 14px;
  text-decoration: none;
}
footer { color: var(--muted); font-size: 12px; text-align: center; margin-top: 24px; }

@media (max-width: 560px) {
  header { align-items: flex-start; flex-direction: column; }
  nav { justify-content: flex-start; }
  .shell { width: min(100% - 20px, 860px); padding-top: 20px; }
  main { border-radius: 18px; }
}