/* ==========================================================================
   base.css — 设计变量 / 重置 / 排版
   无锡顺康科技有限公司 · 企业官网模板
   ========================================================================== */

:root {
  /* 主色：工业深海军蓝 */
  --navy-900: #08192a;
  --navy-800: #0d2438;
  --navy-700: #14324b;
  --navy-600: #1d4462;

  /* 中性色 */
  --steel-700: #354d61;
  --steel-600: #4a6276;
  --steel-500: #6b8296;
  --steel-300: #a8b7c3;
  --steel-200: #cdd7de;

  --paper: #f4f6f8;
  --surface: #ffffff;
  --surface-2: #eef2f5;
  --line: #dfe5ea;
  --line-strong: #c6d0d8;

  /* 强调色：工业橙 */
  --accent: #c2622b;
  --accent-dark: #a04f20;
  --accent-soft: #f8ece3;

  --ink: #0d1c29;
  --ink-2: #3a4f60;
  --ink-3: #6b8296;

  --focus: #1d6fa5;

  --shadow-sm: 0 1px 2px rgba(8, 25, 42, .06);
  --shadow-md: 0 12px 28px -16px rgba(8, 25, 42, .35);
  --shadow-lg: 0 24px 48px -28px rgba(8, 25, 42, .45);

  --container: 1240px;
  --header-h: 72px;
  --topbar-h: 36px;
  --radius: 4px;
  --radius-lg: 8px;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", Roboto, Arial, sans-serif;
  --font-num: "DIN Alternate", "Bahnschrift", "Segoe UI", Roboto, Arial, sans-serif;
}

*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; }
li { list-style: none; }
img, svg, video { display: block; max-width: 100%; }
img { height: auto; }

a {
  color: var(--navy-700);
  text-decoration: none;
  transition: color .16s ease;
}
a:hover { color: var(--accent); }

button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -.01em;
  color: var(--ink);
  text-wrap: balance;
}
h1 { font-size: clamp(1.9rem, 1.2rem + 2.4vw, 3rem); }
h2 { font-size: clamp(1.45rem, 1.15rem + 1.2vw, 2rem); }
h3 { font-size: clamp(1.1rem, 1rem + .45vw, 1.28rem); }
h4 { font-size: 1rem; }

p { text-wrap: pretty; }
strong { font-weight: 700; }

::selection { background: var(--accent); color: #fff; }

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

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

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -80px;
  left: 16px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--accent);
  color: #fff;
  font-size: .88rem;
}
.skip-link:focus { top: 0; color: #fff; }

/* 章节标题 */
.section { padding: 80px 0; }
.section--tight { padding: 56px 0; }
.section--paper { background: var(--surface-2); }

.section-head { margin-bottom: 40px; }
.section-head--row {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
}
.section-head__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-num);
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}
.section-head__eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--accent);
}
.section-head h2 { max-width: 720px; }
.section-head p {
  margin-top: 12px;
  max-width: 680px;
  color: var(--ink-3);
  font-size: .95rem;
  line-height: 1.85;
}

.lead { font-size: 1rem; line-height: 1.9; color: var(--ink-2); }
.muted { color: var(--ink-3); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    transition-duration: .001ms !important;
  }
}