:root {
  color-scheme: dark;
  --bg: #020a14;
  --surface: #07192b;
  --surface-2: #0a2238;
  --border: #123553;
  --text: #ffffff;
  --muted: #a6b5c7;
  --blue: #168bff;
  --danger: #ff686d;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 50% -10%, #07365b 0%, #020a14 38%, #01050c 100%);
  color: var(--text);
  font-family:
    Inter,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    Arial,
    sans-serif;
  line-height: 1.7;
}

a {
  color: #66b7ff;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: rgba(2, 10, 20, 0.92);
  backdrop-filter: blur(14px);
}

.header-inner {
  width: min(980px, calc(100% - 36px));
  margin: 0 auto;
  padding: 18px 0;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
}

.logo {
  color: white;
  text-decoration: none;
  font-size: 24px;
  font-weight: 900;
  letter-spacing: 3px;
}

.logo span {
  color: var(--blue);
}

nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
}

nav a:hover {
  color: white;
}

.container {
  width: min(900px, calc(100% - 36px));
  margin: 0 auto;
  padding: 52px 0 70px;
}

.hero {
  padding: 40px 0 26px;
}

.hero h1 {
  margin: 0;
  font-size: clamp(34px, 7vw, 56px);
  line-height: 1.1;
}

.hero p {
  max-width: 720px;
  color: var(--muted);
  font-size: 18px;
}

.card {
  background: rgba(7, 25, 43, 0.92);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 26px;
  margin: 18px 0;
}

h2 {
  margin-top: 42px;
  line-height: 1.25;
}

h3 {
  margin-top: 28px;
}

p,
li {
  color: var(--muted);
}

strong {
  color: white;
}

code {
  color: #9bd1ff;
}

.notice {
  border-left: 4px solid var(--blue);
  background: var(--surface);
  padding: 16px 18px;
  border-radius: 8px;
  margin: 24px 0;
}

.danger {
  border-left-color: var(--danger);
}

.button {
  display: inline-block;
  margin: 8px 6px 0 0;
  padding: 12px 20px;
  background: var(--blue);
  color: white;
  text-decoration: none;
  border-radius: 10px;
  font-weight: 700;
}

.secondary-button {
  background: var(--surface-2);
  border: 1px solid var(--border);
}

footer {
  border-top: 1px solid var(--border);
  color: #72869a;
  padding: 28px 18px;
  text-align: center;
  font-size: 14px;
}

@media (max-width: 700px) {
  .header-inner {
    display: block;
  }

  nav {
    margin-top: 12px;
  }

  .card {
    padding: 20px;
  }
}