/* 西缈科技 · 紧固件
   Palette: 石墨 ink, 冷灰纸 paper, 锌灰 zinc (secondary), 黄铜 brass (accent, used sparingly), 钢蓝 steel (links)
   Type: Newsreader (display, Latin) + Noto Serif SC (display, CJK); IBM Plex Sans (text) + Noto Sans SC (CJK text) */

:root {
  --ink: #1C2126;
  --paper: #EDEFEA;
  --zinc: #5E6670;
  --body-2: #33393F;
  --rule: #C7CCC6;
  --brass: #9A7430;
  --steel: #2D5470;
  --display: "Newsreader", "Noto Serif SC", "Songti SC", serif;
  --text: "IBM Plex Sans", "Noto Sans SC", system-ui, sans-serif;
  --max: 1120px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.7 var(--text);
}

a { color: var(--steel); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--brass); }
:focus-visible { outline: 2px solid var(--brass); outline-offset: 3px; }

.skip { position: absolute; left: -999px; }
.skip:focus { left: 12px; top: 12px; background: var(--ink); color: var(--paper); padding: 8px 12px; z-index: 9; }

/* Header: wordmark on the left, plain text nav, one hairline below */
.top {
  display: flex; justify-content: space-between; align-items: center;
  max-width: var(--max); margin: 0 auto; padding: 22px 24px;
  border-bottom: 1px solid var(--rule);
}
.mark { font: 500 20px/1 var(--display); color: var(--ink); text-decoration: none; }
.top nav { display: flex; gap: 24px; font-size: 15px; }
.top nav a { color: var(--ink); text-decoration: none; }
.top nav a:hover { color: var(--brass); }

main { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* Hero: headline left, engineering drawing right */
.hero {
  display: grid; grid-template-columns: 1.25fr 1fr; gap: 56px; align-items: center;
  padding: 80px 0 72px; border-bottom: 1px solid var(--rule);
}
h1 {
  font: 500 clamp(40px, 5.6vw, 76px)/1.06 var(--display);
  letter-spacing: -0.01em; margin: 0 0 24px; max-width: 15ch;
  text-wrap: balance;
}
.lede { font-size: 19px; max-width: 34em; color: var(--body-2); margin: 0 0 32px; }

.drawing { width: 100%; height: auto; color: var(--ink); max-width: 360px; justify-self: end; }
.drawing text { font: 500 14px var(--text); fill: var(--zinc); }

.btn {
  display: inline-block; padding: 12px 22px; margin: 0 12px 12px 0;
  background: var(--ink); color: var(--paper); text-decoration: none; font-weight: 500;
}
.btn:hover { background: var(--steel); color: var(--paper); }
.btn.ghost { background: transparent; color: var(--ink); box-shadow: inset 0 0 0 1px var(--ink); }
.btn.ghost:hover { background: transparent; color: var(--brass); box-shadow: inset 0 0 0 1px var(--brass); }

section { padding: 72px 0; border-bottom: 1px solid var(--rule); }
section:last-of-type { border-bottom: 0; }
h2 {
  font: 500 clamp(28px, 3.4vw, 40px)/1.2 var(--display);
  margin: 0 0 8px; max-width: 24ch;
  text-wrap: balance;
}

/* Spec table: structure carries the information */
.spec { width: 100%; border-collapse: collapse; font-size: 16px; margin-top: 28px; }
.spec th, .spec td { text-align: left; padding: 16px 16px 16px 0; border-top: 1px solid var(--rule); vertical-align: top; }
.spec thead th { font-weight: 500; color: var(--zinc); font-size: 14px; border-top: 0; border-bottom: 1px solid var(--ink); }
.spec tbody th { font-weight: 500; width: 34%; }

/* Process: a true sequence, so numbering is used */
.steps {
  list-style: none; padding: 0; margin: 28px 0 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px;
}
.steps li { border-top: 2px solid var(--ink); padding-top: 16px; }
.steps h3 { font: 500 22px/1.3 var(--display); margin: 0 0 8px; }
.steps p { margin: 0; color: var(--body-2); }

/* News */
.news-list { list-style: none; padding: 0; margin: 28px 0 0; }
.news-list li { padding: 22px 0; border-top: 1px solid var(--rule); }
.news-list li:last-child { border-bottom: 1px solid var(--rule); }
.meta { font-size: 14px; color: var(--zinc); margin: 0 0 6px; }
.news-list h3 { font: 500 22px/1.35 var(--display); margin: 0 0 8px; }
.news-list h3 a { color: var(--ink); text-decoration: none; }
.news-list h3 a:hover { color: var(--brass); }
.news-list p { margin: 0; max-width: 40em; color: var(--body-2); }
.more { margin: 20px 0 0; }

/* FAQ */
.faq details { border-top: 1px solid var(--rule); padding: 18px 0; }
.faq details:last-of-type { border-bottom: 1px solid var(--rule); }
.faq summary { cursor: pointer; font-weight: 500; font-size: 18px; }
.faq p { margin: 12px 0 0; max-width: 42em; color: var(--body-2); }

/* Contact */
.contact { display: grid; grid-template-columns: 1.3fr 1fr; gap: 56px; }
.contact p { margin: 0 0 12px; }

/* Footer */
.foot {
  max-width: var(--max); margin: 0 auto; padding: 48px 24px 56px;
  font-size: 14px; color: var(--zinc); border-top: 1px solid var(--rule);
}
.foot p { margin: 0 0 10px; }
.foot-name { font-weight: 500; color: var(--ink); }
.foot .net a { margin-right: 16px; }
.fine { font-size: 13px; margin-top: 20px !important; }

/* Article pages */
.crumbs { font-size: 14px; color: var(--zinc); margin: 40px 0 24px; }
.crumbs a { color: var(--zinc); }
.index { padding-bottom: 80px; border-bottom: 0; }
.index h1 { font-size: clamp(36px, 4.8vw, 56px); max-width: none; }
.article { max-width: 42em; padding: 0 0 80px; }
.article h1 { font-size: clamp(32px, 4.4vw, 52px); max-width: none; }
.article p { margin: 0 0 1.2em; }

@media (max-width: 820px) {
  .hero, .contact { grid-template-columns: 1fr; gap: 36px; }
  .hero { padding: 48px 0; }
  .drawing { justify-self: start; max-width: 260px; }
  .steps { grid-template-columns: 1fr; gap: 24px; }
  .top nav { gap: 14px; font-size: 14px; }
  section { padding: 52px 0; }
  .spec thead { display: none; }
  .spec tbody th { width: auto; }
  .spec, .spec tbody, .spec tr, .spec th, .spec td { display: block; width: 100%; }
  .spec tr { border-top: 1px solid var(--rule); padding: 14px 0; }
  .spec th, .spec td { border: 0; padding: 2px 0; }
  .spec td::before { content: attr(data-label) "："; color: var(--zinc); font-size: 14px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}