:root {
  --bg: #f4f7fb;
  --card: #ffffff;
  --ink: #111827;
  --sub: #4b5563;
  --brand: #1d5acf;
  --border: #dbe4f4;
  --ok: #0f766e;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: radial-gradient(1200px 600px at 10% -10%, #deebff 0, transparent 60%),
    radial-gradient(900px 500px at 100% 0, #f0f7ff 0, transparent 58%),
    var(--bg);
  color: var(--ink);
  font-family: "SF Pro Text", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.62;
}

a {
  color: var(--brand);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 920px;
  margin: 0 auto;
  padding: 20px 16px 56px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.brand {
  display: flex;
  gap: 10px;
  align-items: center;
}

.logo {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, #0e4bbf, #63a0ff);
  box-shadow: 0 8px 22px rgba(29, 90, 207, 0.24);
}

.brand-title {
  margin: 0;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0.2px;
}

.brand-sub {
  margin: 0;
  color: var(--sub);
  font-size: 12px;
}

.lang-switch {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: #fff;
}

.lang-switch button {
  border: 0;
  background: transparent;
  padding: 7px 12px;
  font-size: 13px;
  color: var(--sub);
  cursor: pointer;
}

.lang-switch button.active {
  background: #edf3ff;
  color: #123884;
  font-weight: 700;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 22px;
  box-shadow: 0 8px 28px rgba(20, 40, 80, 0.06);
  margin-bottom: 16px;
}

.card h1,
.card h2,
.card h3 {
  margin: 0 0 10px;
  line-height: 1.3;
}

.card h1 {
  font-size: 28px;
  margin-bottom: 8px;
}

.card h2 {
  font-size: 20px;
  margin-top: 18px;
}

.card h3 {
  font-size: 16px;
  margin-top: 14px;
}

.muted {
  color: var(--sub);
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.link-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  background: #fcfdff;
}

.badge {
  display: inline-block;
  background: #e8f7f5;
  color: var(--ok);
  border: 1px solid #bae8e3;
  border-radius: 999px;
  font-size: 12px;
  padding: 4px 10px;
}

ul,
ol {
  margin: 8px 0 0;
  padding-left: 22px;
}

li + li {
  margin-top: 6px;
}

hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 20px 0;
}

.footer {
  color: var(--sub);
  font-size: 13px;
  margin-top: 12px;
}

[data-lang] {
  display: none;
}

[data-lang].active {
  display: block;
}

.inline-lang[data-lang].active {
  display: inline;
}

@media (max-width: 760px) {
  .grid {
    grid-template-columns: 1fr;
  }

  .card {
    padding: 18px;
  }

  .card h1 {
    font-size: 24px;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }
}