:root {
  --ink: #14181f;
  --muted: #5d6573;
  --line: #e4e7ee;
  --bg: #f4f6f8;
  --paper: #ffffff;
  --blue: #1d4ed8;
  --blue-deep: #1e3a8a;
  --soft: #e8eefc;
  --ok: #166534;
  --shadow: 0 16px 40px rgba(20, 24, 31, 0.06);
  --header: 72px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--font);
  line-height: 1.65;
}
img { max-width: 100%; }
a { color: inherit; }
code {
  font-family: Consolas, "Cascadia Mono", monospace;
  font-size: 0.92em;
  background: #eef1f6;
  padding: 0.1em 0.35em;
  border-radius: 4px;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}
.wrap { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.narrow { width: min(820px, calc(100% - 40px)); }
.kicker {
  margin: 0 0 8px;
  color: var(--blue);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  height: var(--header);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(12px);
}
.site-header.is-stuck { border-bottom-color: var(--line); }
.header-inner {
  width: min(1120px, calc(100% - 40px));
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
}
.brand-mark {
  width: 14px;
  height: 14px;
  border-radius: 4px;
  background: linear-gradient(135deg, #60a5fa, #1d4ed8);
  box-shadow: 0 0 0 4px #e8eefc;
}
.site-nav { display: flex; align-items: center; gap: 22px; }
.site-nav a { text-decoration: none; color: #3c4452; font-size: 0.95rem; }
.site-nav a:hover { color: var(--ink); }
.nav-cta {
  color: #fff !important;
  background: var(--ink);
  padding: 8px 14px;
  border-radius: 999px;
}
.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  padding: 10px;
}
.nav-toggle span {
  display: block;
  height: 2px;
  margin: 4px 0;
  background: var(--ink);
}

.hero {
  background:
    radial-gradient(620px 280px at 85% 0%, rgba(37, 99, 235, 0.18), transparent 70%),
    linear-gradient(180deg, #ffffff 0%, #f4f6f8 100%);
  padding: 48px 0 28px;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 40px;
  align-items: center;
}
.eyebrow { margin: 0 0 12px; color: var(--blue); font-weight: 700; }
.hero h1 {
  margin: 0;
  font-size: clamp(2.4rem, 5vw, 4.2rem);
  line-height: 1.08;
  letter-spacing: -0.04em;
}
.lede { max-width: 38rem; color: var(--muted); font-size: 1.08rem; }
.hero-actions { display: flex; gap: 12px; margin: 24px 0 28px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 600;
  border: 1px solid transparent;
}
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-deep); }
.btn-ghost, .btn-line { background: #fff; border-color: #d5dbe6; }
.btn-ghost:hover, .btn-line:hover { border-color: var(--blue); color: var(--blue); }
.hero-facts {
  display: flex;
  gap: 28px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.hero-facts strong, .hero-facts span { display: block; }
.hero-facts span { color: var(--muted); font-size: 0.88rem; }

.hero-photo { margin: 0; }
.hero-photo img {
  width: 100%;
  border-radius: 28px;
  box-shadow: 0 24px 50px rgba(16, 22, 34, 0.16);
}

.promise { padding-bottom: 10px; }
.promise-card {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 32px;
  background: var(--ink);
  color: #fff;
  border-radius: 24px;
  padding: 32px;
}
.promise-card .kicker { color: #93c5fd; }
.promise-card h2 { margin: 0; letter-spacing: -0.03em; }
.promise-card p { margin: 0; color: #c9d0dc; }

.section { padding: 72px 0; }
.section-alt { background: #fff; }
.section-head { max-width: 680px; margin-bottom: 28px; }
.section-head h2, .support-card h2 { margin: 0 0 8px; font-size: clamp(1.7rem, 3vw, 2.3rem); letter-spacing: -0.03em; }
.section-head p, .support-card p { margin: 0; color: var(--muted); }

.showcase {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 18px;
  align-items: stretch;
}
.showcase-photo,
.showcase-copy {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: var(--shadow);
}
.showcase-photo { margin: 0; overflow: hidden; }
.showcase-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.showcase-copy { padding: 22px 22px 8px; }
.showcase-copy h3 { margin: 8px 0 0; }
.card-tag { margin: 0; color: var(--blue); font-size: 0.82rem; font-weight: 700; }
.spec-list { margin: 14px 0 8px; }
.spec-list div {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 10px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
}
.spec-list dt { margin: 0; color: var(--muted); }
.spec-list dd { margin: 0; }

.debug-grid, .fw-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}
.debug-card, .fw-grid article {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 18px;
  box-shadow: var(--shadow);
}
.debug-card h3, .fw-grid h3 { margin: 6px 0; }

.port-legend {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
}
.port-legend li {
  display: flex;
  gap: 10px;
  align-items: center;
  background: var(--bg);
  border-radius: 14px;
  padding: 12px;
}
.port-legend b {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  flex: none;
}

.tabs { display: flex; gap: 8px; margin-bottom: 16px; }
.tab {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 999px;
  padding: 8px 16px;
  font: inherit;
  cursor: pointer;
}
.tab.is-active { background: var(--ink); color: #fff; border-color: var(--ink); }
.panel-lead { margin-top: 0; color: var(--muted); }
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.steps li {
  display: grid;
  grid-template-columns: 42px 1fr;
  column-gap: 12px;
  row-gap: 4px;
  align-items: start;
  background: var(--bg);
  border-radius: 16px;
  padding: 14px 16px;
}
.steps li::before {
  counter-increment: step;
  content: counter(step);
  grid-row: 1 / span 2;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: var(--soft);
  color: var(--blue);
  font-weight: 700;
}
.steps h3,
.steps p { grid-column: 2; }
.steps { counter-reset: step; }
.steps h3 { margin: 0 0 4px; font-size: 1rem; }
.steps p { margin: 0; color: var(--muted); }
.param-list { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 16px; padding: 0; }
.param-list li {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 8px 6px 12px;
}
.param-list button {
  border: 0;
  background: var(--soft);
  color: var(--blue);
  border-radius: 999px;
  padding: 4px 10px;
  font: inherit;
  cursor: pointer;
}
.param-list button.is-copied { color: var(--ok); }

.debug-grid { grid-template-columns: 1fr 1fr; }
.debug-card ul { margin: 0; padding-left: 18px; color: var(--muted); }
.callout {
  margin-top: 16px;
  background: #fff8ef;
  border: 1px solid #f3ddc2;
  border-radius: 18px;
  padding: 18px 20px;
}
.callout h3 { margin: 0 0 8px; }
.callout ol { margin: 0 0 8px; color: #5c4a36; }
.callout p { margin: 0; color: #6b5844; }

.section-alt .fw-grid article { background: var(--bg); }
.fw-grid article p { margin: 0; color: var(--muted); }
.ver { color: var(--ink) !important; font-weight: 700; margin-bottom: 6px !important; }

.faq details {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px 16px;
  margin-bottom: 8px;
}
.faq summary { cursor: pointer; font-weight: 700; }
.faq p { margin: 8px 0 0; color: var(--muted); }

.support-card {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: center;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 28px;
}
.support-actions { display: flex; flex-wrap: wrap; gap: 8px; justify-content: flex-end; }
.site-footer { padding: 10px 0 28px; color: var(--muted); }
.footer-inner { display: flex; justify-content: space-between; gap: 12px; }

@media (max-width: 980px) {
  .hero-grid, .promise-card, .fw-grid, .port-legend { grid-template-columns: 1fr 1fr; }
  .showcase { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .nav-toggle { display: block; }
  .site-nav {
    display: none;
    position: absolute;
    top: var(--header);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 8px 20px 16px;
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 10px 0; }
  .nav-cta { text-align: center; }
  .hero-grid, .promise-card, .showcase, .debug-grid, .fw-grid, .port-legend, .support-card {
    grid-template-columns: 1fr;
    display: grid;
  }
  .hero-facts, .footer-inner { flex-direction: column; gap: 12px; }
  .support-actions { justify-content: flex-start; }
}