:root {
  --bg: #f5f5f5;
  --surface: #ffffff;
  --text: #222222;
  --muted: #666666;
  --border: #dddddd;
  --link: #0b57d0;

  --radius: 14px;

  --container: 960px;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behaviour: smooth;
}

body {
  margin: 0;

  background: var(--bg);
  color: var(--text);

  font-family:
    Arial,
    Helvetica,
    sans-serif;

  line-height: 1.7;
}

img {
  max-width: 100%;
  height: auto;
}

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

.container {
  width: min(var(--container), 92%);
  margin-inline: auto;
}

.site-header {
  background: var(--surface);

  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;

  align-items: center;
  justify-content: space-between;

  gap: 20px;

  padding: 18px 0;
}

.site-title a {
  color: var(--text);

  text-decoration: none;

  font-size: 1.6rem;
  font-weight: bold;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;

  gap: 14px;
}

.site-nav a {
  text-decoration: none;

  color: var(--muted);
}

.site-nav a:hover,
.site-nav a:focus {
  color: var(--text);
}

main {
  padding: 40px 0;
}

.content-card {
  background: var(--surface);

  border: 1px solid var(--border);
  border-radius: var(--radius);

  padding: 28px;
}

.site-footer {
  margin-top: 60px;

  background: var(--surface);

  border-top: 1px solid var(--border);
}

.footer-inner {
  padding: 24px 0;

  color: var(--muted);
}

@media (max-width: 700px) {

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

  .site-title a {
    font-size: 1.3rem;
  }

  .content-card {
    padding: 20px;
  }

}