:root {
  color-scheme: light;
  --bg: #f3f7fc;
  --panel: #ffffff;
  --text: #10233f;
  --muted: #4d6281;
  --primary: #1e4f96;
  --border: #d4e1f3;
  --chip: #e8f0fb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: linear-gradient(180deg, #eef5ff 0%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.55;
}

.container {
  width: min(960px, 94vw);
  margin: 24px auto 36px;
}

header {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.brand {
  font-weight: 700;
  color: var(--primary);
}

.nav-links {
  display: flex;
  gap: 8px;
  margin-left: auto;
}

.nav-links a,
.lang button {
  border: 1px solid var(--border);
  background: var(--chip);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 10px;
  font-size: 14px;
  text-decoration: none;
  cursor: pointer;
}

.lang {
  display: flex;
  gap: 8px;
}

.lang button.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

main {
  margin-top: 14px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
}

h1 {
  margin: 0 0 8px;
  font-size: 30px;
  line-height: 1.2;
}

.subtitle {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 14px;
}

section {
  margin-bottom: 20px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fbfdff;
}

h2 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 18px;
  color: var(--primary);
}

p {
  margin: 0;
  color: var(--text);
}

.footer {
  margin-top: 14px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

[data-lang] {
  display: none;
}

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