:root {
  --ui-body: 14px;
  --ui-heading: 16px;
  --surface: #f0f0f3;
  --paper: #f8f8fa;
  --text: #343b46;
  --muted: #596473;
  --accent: #1c5fcb;
  --raised: 5px 5px 12px #d8dbe1, -5px -5px 12px #fff;
  color-scheme: light;
  font-family: Arial, "Microsoft YaHei", "微软雅黑", sans-serif;
  font-size: var(--ui-body);
  line-height: 1.8;
  color: var(--text);
  background: var(--surface);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 24px;
}

a {
  color: var(--accent);
  text-underline-offset: 3px;
  overflow-wrap: anywhere;
}

a:focus-visible {
  outline: 2px solid #4285f4;
  outline-offset: 4px;
}

.skip-link {
  position: absolute;
  left: 24px;
  top: -100px;
  padding: 8px 16px;
  background: var(--paper);
}

.skip-link:focus {
  top: 12px;
  z-index: 1;
}

.page {
  max-width: 880px;
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  font-size: 22px;
  font-weight: bold;
  text-decoration: none;
}

.brand-mark {
  display: flex;
  align-items: center;
  gap: 3px;
  width: 44px;
  height: 44px;
  padding: 11px;
  border-radius: 12px;
  box-shadow: var(--raised);
}

.brand-mark span {
  width: 4px;
  height: 19px;
  border-radius: 3px;
  background: #4285f4;
}

.brand-mark span:nth-child(2) {
  height: 25px;
  background: #ea4335;
}

.brand-mark span:nth-child(3) {
  height: 17px;
  background: #fbbc05;
}

.brand-mark span:nth-child(4) {
  height: 22px;
  background: #34a853;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 12px;
  border-radius: 12px;
  text-decoration: none;
}

nav a[aria-current="page"] {
  background: #e4ebf8;
  box-shadow:
    inset 2px 2px 5px #d7deea,
    inset -2px -2px 5px #fff;
}

main {
  padding: 28px;
  border-radius: 22px;
  background: var(--paper);
  box-shadow: var(--raised);
  overflow-wrap: anywhere;
}

h1,
h2,
h3 {
  font-size: var(--ui-heading);
  line-height: 1.5;
}

h1 {
  margin: 0 0 12px;
}

h2 {
  margin: 28px 0 10px;
}

p {
  margin: 10px 0;
}

code {
  font: inherit;
}

ul,
ol {
  padding-left: 24px;
}

li + li {
  margin-top: 8px;
}

.muted,
footer {
  color: var(--muted);
}

.contact-card {
  padding: 12px 16px;
  border: 1px solid #d7deea;
  border-radius: 10px;
  background: #e4ebf8;
}

.page-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  margin-top: 24px;
}

footer {
  padding: 24px 4px 8px;
}

footer p {
  margin: 0;
}

@media (max-width: 560px) {
  body {
    padding: 16px;
  }

  .site-header {
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 20px;
  }

  nav {
    width: 100%;
  }

  nav a {
    padding-inline: 10px;
  }

  main {
    padding: 20px;
    border-radius: 16px;
  }
}