:root {
  --ink: #14181d;
  --muted: #5b6570;
  --line: #d9dee4;
  --bg: #fbfcfd;
  --accent: #0b5fa5;
  --soft: #f1f4f7;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.65 -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
main { max-width: 60rem; margin: 0 auto; padding: 2.2rem 1.25rem 5rem; }
h1 { font-size: 1.7rem; line-height: 1.25; margin: 0 0 .35rem; letter-spacing: -.01em; }
h2 { font-size: 1.2rem; margin: 2.6rem 0 .7rem; padding-bottom: .35rem; border-bottom: 1px solid var(--line); }
h3 { font-size: 1.03rem; margin: 1.9rem 0 .5rem; }
p, li { color: var(--ink); }
a { color: var(--accent); }
.zh { color: var(--muted); font-size: .88em; font-weight: 400; }
.hs { color: var(--muted); font-size: .82em; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.small { font-size: .88rem; }
.small.terms { color: var(--muted); }

/* 顶栏 */
.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  max-width: 60rem; margin: 0 auto; padding: .9rem 1.25rem;
  border-bottom: 1px solid var(--line); background: #fff;
}
.brand { font-weight: 700; text-decoration: none; color: var(--ink); }
.topbar nav a { margin-left: 1rem; font-size: .9rem; text-decoration: none; }
.topbar nav a:hover { text-decoration: underline; }

/* 面包屑 */
.crumbs { font-size: .85rem; color: var(--muted); margin: 0 0 1rem; }
.crumbs a { text-decoration: none; }
.crumbs a:hover { text-decoration: underline; }

.sub { color: var(--muted); font-size: .9rem; margin: 0 0 1.6rem; }
.lead { font-size: 1.06rem; }

code, .mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .92em; white-space: nowrap; }

/* 表格 */
table { width: 100%; border-collapse: collapse; margin: .8rem 0 1rem; font-size: .93rem; }
th, td { text-align: left; padding: .5rem .6rem; border-bottom: 1px solid var(--line); vertical-align: top; }
th { background: var(--soft); font-weight: 600; white-space: nowrap; }
tbody tr:hover { background: #f6f9fb; }

/* 规格表（dl） */
dl.spec { margin: 1.2rem 0 1.6rem; display: grid; grid-template-columns: 15rem 1fr; gap: .1rem 1rem; }
dl.spec dt { color: var(--muted); font-size: .9rem; padding: .35rem 0; border-bottom: 1px solid var(--line); }
dl.spec dd { margin: 0; padding: .35rem 0; border-bottom: 1px solid var(--line); }

/* 列表 */
ol, ul { padding-left: 1.3rem; }
ul.tick { list-style: none; padding-left: 0; }
ul.tick li { padding: .3rem 0; border-bottom: 1px dashed var(--line); }

/* 品类组卡片 */
.group { margin: 1.6rem 0 2.2rem; padding: 1rem 1.1rem; border: 1px solid var(--line); border-radius: 6px; background: #fff; }
.group h3 { margin-top: 0; }
ul.cards { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .8rem 1.2rem; }
ul.cards li { padding: .7rem .8rem; border: 1px solid var(--line); border-radius: 5px; background: #fff; }
ul.cards li a { font-weight: 600; text-decoration: none; }
ul.cards li a:hover { text-decoration: underline; }
ul.cards p { margin: .3rem 0 0; }

/* 表单 */
form { margin: 1rem 0; }
fieldset {
  border: 1px solid var(--line); border-radius: 6px; padding: 1rem 1.1rem 1.2rem; background: #fff;
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 1.2rem;
}
legend { padding: 0 .4rem; color: var(--muted); font-size: .9rem; }
label { display: block; margin: 0 0 .8rem; font-size: .9rem; color: var(--muted); }
label:has(textarea) { grid-column: 1 / -1; }
fieldset legend { grid-column: 1 / -1; }
input, textarea {
  display: block; width: 100%; margin-top: .25rem; padding: .5rem .6rem;
  border: 1px solid var(--line); border-radius: 4px; font: inherit; color: var(--ink); background: #fff;
}
input:focus, textarea:focus { outline: 2px solid var(--accent); outline-offset: 0; border-color: var(--accent); }
button {
  padding: .6rem 1.2rem; border: 0; border-radius: 4px; background: var(--accent); color: #fff;
  font: inherit; font-weight: 600; cursor: pointer;
}
.contact { color: var(--muted); font-size: .93rem; }

/* FAQ（GEO 用：问句式内容 + 明确答案） */
.faq { margin: 1rem 0 1.6rem; }
.qa { padding: .8rem 0; border-bottom: 1px solid var(--line); }
.qa h3 { margin: 0 0 .35rem; font-size: 1rem; color: var(--ink); }
.qa p { margin: 0; color: #2b333c; }
.qa:last-child { border-bottom: 0; }
select {
  display: block; width: 100%; margin-top: .25rem; padding: .5rem .6rem;
  border: 1px solid var(--line); border-radius: 4px; font: inherit; color: var(--ink); background: #fff;
}
select:focus { outline: 2px solid var(--accent); outline-offset: 0; border-color: var(--accent); }

footer { margin-top: 3.5rem; padding-top: 1rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }
.meta { margin-top: .5rem; }

@media (max-width: 720px) {
  table { font-size: .86rem; }
  th, td { padding: .4rem .35rem; }
  fieldset { grid-template-columns: 1fr; }
  ul.cards { grid-template-columns: 1fr; }
  dl.spec { grid-template-columns: 1fr; }
  dl.spec dt { border-bottom: 0; padding-bottom: 0; }
  .topbar { flex-direction: column; align-items: flex-start; gap: .3rem; }
  .topbar nav a { margin-left: 0; margin-right: 1rem; }
}