:root {
  color-scheme: dark;
  --bg: #0a0e17;
  --panel: #0f1522;
  --panel-2: #0c111b;
  --line: #1e2739;
  --text: #e8edf6;
  --muted: #9aa7bb;
  --brand: #72a7ff;
  --flame: #ff9d61;
  --good: #6ee7b7;
  --max: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background:
    radial-gradient(900px 520px at 50% -160px, rgba(79, 141, 255, .22), transparent 70%),
    var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
}
a { color: var(--brand); text-underline-offset: 3px; }
a:hover { color: #a9c9ff; }
img { max-width: 100%; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(30, 39, 57, .9);
  background: rgba(10, 14, 23, .88);
  backdrop-filter: blur(14px);
}
.nav {
  width: min(var(--max), calc(100% - 32px));
  min-height: 64px;
  margin: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.brand { display: flex; align-items: center; gap: 10px; color: #fff; font-weight: 800; text-decoration: none; }
.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  background: linear-gradient(135deg, #4f8dff, #ff8a3d);
}
.nav-links { display: flex; flex-wrap: wrap; align-items: center; gap: 20px; font-size: 14px; }
.nav-links a { color: var(--muted); text-decoration: none; }
.nav-links a:hover { color: #fff; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 12px;
  background: linear-gradient(100deg, #4f8dff, #ff8a3d);
  color: #fff;
  font-weight: 800;
  text-decoration: none;
}
.button:hover { color: #fff; filter: brightness(1.08); }

.wrap { width: min(var(--max), calc(100% - 32px)); margin: auto; }
.article { width: min(820px, 100%); margin: auto; }
.hero { padding: 72px 0 48px; }
.eyebrow { color: var(--brand); font-weight: 800; font-size: 14px; letter-spacing: .04em; }
.breadcrumb { margin-bottom: 22px; color: #75839a; font-size: 14px; }
.breadcrumb a { color: #98a6bc; }
h1, h2, h3 { color: #fff; line-height: 1.25; letter-spacing: -.02em; }
h1 { margin: 14px 0 20px; font-size: clamp(38px, 7vw, 64px); }
h2 { margin: 56px 0 16px; font-size: clamp(27px, 4.5vw, 38px); scroll-margin-top: 90px; }
h3 { margin: 32px 0 10px; font-size: 21px; scroll-margin-top: 90px; }
p { margin: 0 0 18px; color: #bdc7d6; }
.lead { max-width: 760px; color: #cdd7e5; font-size: 19px; }
.meta { display: flex; flex-wrap: wrap; gap: 10px 18px; margin-top: 22px; color: #7f8da2; font-size: 14px; }
.tag { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; padding: 4px 10px; color: #aebbd0; font-size: 13px; }
.answer {
  margin: 24px 0;
  padding: 20px 22px;
  border-left: 4px solid var(--brand);
  border-radius: 0 14px 14px 0;
  background: linear-gradient(135deg, rgba(79, 141, 255, .14), rgba(15, 21, 34, .92));
}
.answer p:last-child { margin-bottom: 0; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.card {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
}
.card h3 { margin-top: 0; }
.card p:last-child { margin-bottom: 0; }
.steps { margin: 24px 0; padding: 0; list-style: none; counter-reset: steps; }
.steps li {
  position: relative;
  margin: 0 0 14px;
  padding: 20px 20px 20px 62px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel);
  color: #bdc7d6;
}
.steps li::before {
  counter-increment: steps;
  content: counter(steps);
  position: absolute;
  left: 18px;
  top: 18px;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: #24406d;
  color: #fff;
  font-weight: 800;
}
.table-wrap { overflow-x: auto; margin: 24px 0; border: 1px solid var(--line); border-radius: 14px; }
table { width: 100%; min-width: 660px; border-collapse: collapse; background: var(--panel-2); }
th, td { padding: 14px 16px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: var(--panel); color: #fff; }
td { color: #b8c3d3; }
tr:last-child td { border-bottom: 0; }
ul, ol { color: #bdc7d6; }
li { margin: 8px 0; }
.checklist { padding-left: 0; list-style: none; }
.checklist li::before { content: "✓"; margin-right: 10px; color: var(--good); font-weight: 800; }
.author {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  align-items: start;
  margin-top: 52px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--panel);
}
.author-mark { width: 46px; height: 46px; display: grid; place-items: center; border-radius: 14px; background: linear-gradient(135deg, #4f8dff, #ff8a3d); font-weight: 900; }
.author strong { color: #fff; }
.author p { margin: 4px 0 0; font-size: 14px; }
.cta { margin: 56px 0 20px; padding: 30px; border: 1px solid #2a4775; border-radius: 20px; background: linear-gradient(135deg, #13213a, #171623); text-align: center; }
.cta h2 { margin: 0 0 12px; }
.cta p { max-width: 620px; margin: 0 auto 20px; }
.related { margin: 48px 0; }
.related a { text-decoration: none; }
.site-footer { margin-top: 70px; padding: 34px 0; border-top: 1px solid var(--line); color: #77859a; font-size: 13px; }
.footer-row { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 14px; }
.footer-links a { color: #91a0b5; }

@media (max-width: 760px) {
  .nav { align-items: flex-start; padding: 14px 0; }
  .nav-links { display: none; }
  .grid { grid-template-columns: 1fr; }
  .hero { padding-top: 50px; }
  .author { grid-template-columns: 1fr; }
}

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