:root {
  --page-bg: #f5f7fb;
  --surface: #ffffff;
  --ink: #162033;
  --muted: #657084;
  --brand: #1976d2;
  --line: #e4e9f2;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: linear-gradient(180deg, #eef5f3 0%, var(--page-bg) 34%, #ffffff 100%);
  color: var(--ink);
  font-family: Georgia, 'Times New Roman', serif;
  line-height: 1.68;
}

.container {
  width: min(960px, calc(100% - 32px));
  margin: 0 auto;
  padding: 42px 0 64px;
}

header {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-bottom: 26px;
}

.logo {
  display: inline-grid;
  width: 56px;
  height: 56px;
  place-items: center;
  border-radius: 8px;
  background: var(--brand);
  color: #fff;
  font: 700 18px/1 system-ui, sans-serif;
  letter-spacing: .06em;
}

h1,
h2 {
  line-height: 1.2;
  margin: 0;
}

h1 {
  font-size: clamp(30px, 5vw, 40px);
  font-weight: 700;
}

h2 {
  margin-top: 28px;
  margin-bottom: 10px;
  color: #173f39;
  font-size: 24px;
}

.meta {
  margin-top: 8px;
  color: var(--muted);
  font-family: system-ui, sans-serif;
  font-size: 14px;
}

.card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  padding: clamp(22px, 4vw, 42px);
  box-shadow: 0 18px 45px rgba(22, 32, 51, .08);
}

p {
  margin: 0 0 14px;
}

ul {
  margin: 10px 0 18px;
  padding-left: 24px;
}

li {
  margin: 7px 0;
}

code {
  border-radius: 4px;
  background: #eef3f1;
  color: #0b544b;
  font-family: Consolas, Monaco, monospace;
  padding: 2px 5px;
}

hr {
  margin: 24px 0;
  border: 0;
  border-top: 1px solid var(--line);
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 20px, 960px);
    padding-top: 24px;
  }

  header {
    align-items: flex-start;
  }

  .logo {
    width: 44px;
    height: 44px;
    font-size: 14px;
  }

  .card {
    padding: 20px;
  }
}