:root {
  color-scheme: light;
  --blue: #0b67c2;
  --blue-dark: #084c91;
  --ink: #17202a;
  --muted: #5d6b7a;
  --line: #d9e2ec;
  --surface: #ffffff;
  --background: #f4f7fb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--background);
  color: var(--ink);
  font-family: Arial, "Helvetica Neue", sans-serif;
  line-height: 1.65;
}

a {
  color: var(--blue);
}

.site-header {
  background: linear-gradient(135deg, var(--blue-dark), var(--blue));
  color: #fff;
}

.header-inner,
.content,
.footer-inner {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
}

.header-inner {
  padding: 36px 0 28px;
}

.brand {
  display: flex;
  gap: 16px;
  align-items: center;
}

.brand-mark {
  display: grid;
  width: 70px;
  height: 70px;
  place-items: center;
  border: 2px solid rgba(255, 255, 255, .7);
  border-radius: 18px;
  background: rgba(255, 255, 255, .12);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.05;
  text-align: center;
}

h1 {
  margin: 0;
  font-size: clamp(28px, 5vw, 42px);
}

.tagline {
  margin: 6px 0 0;
  color: #e9f3ff;
}

nav {
  display: flex;
  gap: 18px;
  margin-top: 24px;
  flex-wrap: wrap;
}

nav a {
  color: #fff;
  font-weight: 700;
  text-decoration: none;
}

.content {
  padding: 32px 0 48px;
}

.card {
  margin-bottom: 20px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
  box-shadow: 0 8px 28px rgba(25, 50, 80, .06);
}

h2 {
  margin-top: 0;
  color: var(--blue-dark);
}

h3 {
  margin-bottom: 6px;
}

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

.notice {
  border-left: 4px solid var(--blue);
  background: #edf6ff;
}

.button {
  display: inline-block;
  padding: 10px 15px;
  border-radius: 9px;
  background: var(--blue);
  color: #fff;
  font-weight: 700;
  text-decoration: none;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #fff;
  color: var(--muted);
}

.footer-inner {
  padding: 22px 0;
  font-size: 14px;
}

code {
  padding: 2px 5px;
  border-radius: 5px;
  background: #edf2f7;
}