/* foundation.css — 基础重置与设计变量 */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body,
h1,
h2,
h3,
h4,
p,
figure,
blockquote,
ul,
ol,
dl,
dd {
  margin: 0;
}

ul,
ol {
  padding: 0;
  list-style: none;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

:root {
  --brand: #1f8fdc;
  --brand-dark: #1574b8;
  --brand-soft: #eaf5fd;
  --ink: #17202a;
  --ink-soft: #5b6672;
  --line: #e5e7eb;
  --surface: #ffffff;
  --surface-alt: #f6f8fb;
  --footer-bg: #101a24;
  --footer-ink: #c9d3dd;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --shell: 1200px;
  --shadow-sm: 0 1px 2px rgba(16, 26, 36, 0.06);
  --shadow-md: 0 12px 32px rgba(16, 26, 36, 0.08);
  --font: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

body {
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--ink);
  background: var(--surface);
  -webkit-font-smoothing: antialiased;
}

.container {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: 24px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  padding: 10px 16px;
  background: var(--brand);
  color: #fff;
  border-radius: var(--radius-sm);
  z-index: 999;
}

.skip-link:focus {
  left: 16px;
  top: 12px;
}

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}