:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-soft: #f2f5f9;
  --surface-strong: #e9eef5;
  --text: #16202a;
  --muted: #5f6c7b;
  --line: #d9e1ea;
  --accent: #175cd3;
  --accent-strong: #1247a8;
  --accent-soft: rgba(23, 92, 211, 0.1);
  --warm: #f27a37;
  --success-soft: #edf8f3;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 18px 42px rgba(15, 23, 42, 0.08);
  --content-width: 1120px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: inherit;
}

img {
  display: block;
  max-width: 100%;
}

button,
.button-link {
  min-height: 44px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 11px 16px;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition:
    background 160ms ease,
    border-color 160ms ease,
    color 160ms ease,
    transform 160ms ease;
}

button:hover,
.button-link:hover {
  background: var(--accent-strong);
}

button:active,
.button-link:active {
  transform: translateY(1px);
}

.button-link.secondary,
button.secondary {
  background: var(--surface);
  color: var(--text);
  border-color: var(--line);
}

.button-link.secondary:hover,
button.secondary:hover {
  background: var(--surface-soft);
}

.site-shell {
  width: min(100%, var(--content-width));
  margin: 0 auto;
  padding: 20px 20px 48px;
}

.site-main {
  display: grid;
  gap: 24px;
}

code {
  border-radius: 6px;
  padding: 2px 6px;
  background: var(--surface-soft);
}

@media (max-width: 760px) {
  .site-shell {
    padding: 16px 16px 36px;
  }
}