/* K1 · 经典双栏门户 · Signal */
:root {
  --c-blue: #2c6bed;
  --c-blue-deep: #1a4fbf;
  --c-ink: #0f1728;
  --c-muted: #5b657a;
  --c-line: rgba(15, 23, 40, 0.1);
  --c-surface: #f3f6fb;
  --c-white: #fff;
  --font-d: "Outfit", "Segoe UI", sans-serif;
  --font-b: "DM Sans", "Segoe UI", sans-serif;
  --max: 1120px;
  --r: 14px;
  --shadow: 0 12px 28px rgba(15, 23, 40, 0.08);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
.z372a8body {
  margin: 0;
  font-family: var(--font-b);
  color: var(--c-ink);
  background:
    radial-gradient(1000px 420px at 8% -8%, rgba(44, 107, 237, 0.1), transparent 55%),
    linear-gradient(180deg, #eef3fb 0%, #f8fafc 40%, #fff 100%);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
.z372a8container { width: min(100% - 2rem, var(--max)); margin-inline: auto; }

.z372a8header {
  position: sticky; top: 0; z-index: 100; height: 72px;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.9);
  border-bottom: 1px solid var(--c-line);
}
.z372a8header_inner { height: 100%; display: flex; align-items: center; gap: 0.75rem; }
.z372a8logo { display: inline-flex; align-items: center; gap: 0.55rem; font-family: var(--font-d); font-weight: 700; }
.z372a8logo_mark {
  width: 28px; height: 28px; border-radius: 8px;
  background: linear-gradient(135deg, var(--c-blue), #14b8a6);
}
.z372a8nav { margin-left: auto; }
.z372a8nav_list { display: flex; gap: 0.35rem; list-style: none; margin: 0; padding: 0; }
.z372a8nav_link {
  display: block; padding: 0.45rem 0.7rem; border-radius: 8px;
  font-size: 0.92rem; color: var(--c-muted); font-weight: 500;
}
.z372a8nav_link:hover, .z372a8nav_link.is-active { color: var(--c-blue); background: rgba(44, 107, 237, 0.08); }
.z372a8nav_toggle {
  display: none; width: 42px; height: 42px; border: 1px solid var(--c-line);
  border-radius: 10px; background: var(--c-white); cursor: pointer; margin-left: auto;
  flex-direction: column; justify-content: center; align-items: center; gap: 5px;
}
.z372a8nav_toggle span { width: 18px; height: 2px; background: var(--c-ink); }

.z372a8btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 0.65rem 1.15rem; border-radius: 10px; font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent; transition: 0.2s ease; cursor: pointer;
}
.z372a8btn_primary { background: var(--c-blue); color: #fff; }
.z372a8btn_primary:hover { background: var(--c-blue-deep); }
.z372a8btn_secondary { background: var(--c-white); border-color: var(--c-line); color: var(--c-ink); }
.z372a8btn_secondary:hover { border-color: var(--c-blue); color: var(--c-blue); }
.z372a8btn_ghost { background: transparent; border-color: rgba(15, 23, 40, 0.18); }
.z372a8btn_ghost:hover { border-color: var(--c-blue); color: var(--c-blue); }
.z372a8btn_lg { padding: 0.85rem 1.4rem; font-size: 1rem; }
.z372a8header_cta { margin-left: 0.5rem; }

.z372a8ad { padding: 0.75rem 0; }
.z372a8ad_top { background: rgba(255, 255, 255, 0.5); }

.z372a8hero { padding: 3.5rem 0 2.5rem; }
.z372a8hero_grid {
  display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 2.5rem; align-items: center;
}
.z372a8hero_brand {
  margin: 0 0 0.6rem; font-family: var(--font-d); font-weight: 700;
  color: var(--c-blue); letter-spacing: 0.04em; text-transform: uppercase; font-size: 0.85rem;
}
.z372a8hero_title {
  margin: 0 0 1rem; font-family: var(--font-d); font-size: clamp(2rem, 4vw, 3.1rem);
  line-height: 1.15; letter-spacing: -0.02em;
}
.z372a8hero_desc { margin: 0 0 1.5rem; color: var(--c-muted); font-size: 1.05rem; max-width: 36rem; }
.z372a8hero_actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-bottom: 1.5rem; }
.z372a8hero_trust {
  display: flex; flex-wrap: wrap; gap: 0.6rem 1.2rem; list-style: none; margin: 0; padding: 0;
  color: var(--c-muted); font-size: 0.9rem;
}
.z372a8hero_trust li { position: relative; padding-left: 1rem; }
.z372a8hero_trust li::before {
  content: ""; position: absolute; left: 0; top: 0.45em; width: 6px; height: 6px;
  border-radius: 50%; background: var(--c-blue);
}
.z372a8hero_visual {
  border-radius: 20px; overflow: hidden; background: var(--c-surface);
  box-shadow: var(--shadow); border: 1px solid var(--c-line);
}
.z372a8hero_img { width: 100%; aspect-ratio: 4/3; object-fit: cover; }

.z372a8section { padding: 4rem 0; }
.z372a8sec_head { margin-bottom: 2rem; max-width: 40rem; }
.z372a8sec_title {
  margin: 0 0 0.65rem; font-family: var(--font-d); font-size: clamp(1.6rem, 3vw, 2.1rem);
  letter-spacing: -0.02em;
}
.z372a8sec_desc { margin: 0; color: var(--c-muted); }

.z372a8dl_grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.z372a8dl_card {
  background: var(--c-white); border: 1px solid var(--c-line); border-radius: var(--r);
  padding: 1.5rem; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 0.75rem;
}
.z372a8dl_card h3 { margin: 0; font-family: var(--font-d); font-size: 1.15rem; }
.z372a8dl_card p { margin: 0; color: var(--c-muted); flex: 1; }
.z372a8dl_icon {
  width: 42px; height: 42px; border-radius: 10px; display: grid; place-items: center;
  background: rgba(44, 107, 237, 0.12); color: var(--c-blue); font-family: var(--font-d); font-weight: 700;
}

.z372a8official { background: var(--c-surface); }
.z372a8official_row { display: grid; grid-template-columns: 1.3fr 0.7fr; gap: 2rem; align-items: center; }
.z372a8checklist { margin: 1.25rem 0 1.5rem; padding: 0; list-style: none; }
.z372a8checklist li {
  position: relative; padding: 0.4rem 0 0.4rem 1.4rem; color: var(--c-muted);
}
.z372a8checklist li::before {
  content: ""; position: absolute; left: 0; top: 0.85em; width: 8px; height: 8px;
  border-radius: 2px; background: var(--c-blue);
}
.z372a8official_panel {
  background: linear-gradient(160deg, #1a4fbf, #2c6bed); color: #fff;
  border-radius: 18px; padding: 2rem; box-shadow: var(--shadow);
}
.z372a8panel_label { margin: 0; opacity: 0.8; font-size: 0.85rem; }
.z372a8panel_url { margin: 0.4rem 0 0.8rem; font-family: var(--font-d); font-size: 1.8rem; font-weight: 700; }
.z372a8panel_note { margin: 0; opacity: 0.85; font-size: 0.92rem; }

.z372a8feat_grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.z372a8feat_card {
  background: var(--c-white); border: 1px solid var(--c-line); border-radius: var(--r); padding: 1.35rem;
}
.z372a8feat_card h3 { margin: 0 0 0.5rem; font-family: var(--font-d); font-size: 1.05rem; }
.z372a8feat_card p { margin: 0; color: var(--c-muted); font-size: 0.95rem; }

.z372a8guide { background: var(--c-surface); }
.z372a8steps {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem;
  list-style: none; margin: 0; padding: 0;
}
.z372a8steps li {
  background: var(--c-white); border-radius: var(--r); padding: 1.5rem; border: 1px solid var(--c-line);
}
.z372a8step_num {
  display: block; font-family: var(--font-d); font-weight: 800; color: var(--c-blue);
  font-size: 1.4rem; margin-bottom: 0.5rem;
}
.z372a8steps h3 { margin: 0 0 0.45rem; font-family: var(--font-d); font-size: 1.1rem; }
.z372a8steps p { margin: 0; color: var(--c-muted); }

.z372a8faq_wrap { max-width: 760px; }
.z372a8faq_list { display: grid; gap: 0.75rem; }
.z372a8faq_item {
  background: var(--c-white); border: 1px solid var(--c-line); border-radius: 12px; padding: 0.2rem 1rem 0.2rem;
}
.z372a8faq_item summary {
  cursor: pointer; font-weight: 600; padding: 0.9rem 0; list-style: none;
}
.z372a8faq_item summary::-webkit-details-marker { display: none; }
.z372a8faq_item p { margin: 0 0 1rem; color: var(--c-muted); }
.z372a8text_link { color: var(--c-blue); text-decoration: underline; }

.z372a8cta { padding: 3.5rem 0 4.5rem; }
.z372a8cta_inner {
  text-align: center; background: linear-gradient(135deg, #1a4fbf, #2c6bed);
  color: #fff; border-radius: 20px; padding: 2.75rem 1.5rem; box-shadow: var(--shadow);
}
.z372a8cta_inner h2 { margin: 0 0 0.6rem; font-family: var(--font-d); font-size: clamp(1.6rem, 3vw, 2.2rem); }
.z372a8cta_inner p { margin: 0 0 1.4rem; opacity: 0.92; }
.z372a8cta_actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 0.75rem; }
.z372a8cta .z372a8btn_primary { background: #fff; color: var(--c-blue-deep); }
.z372a8cta .z372a8btn_ghost { border-color: rgba(255, 255, 255, 0.45); color: #fff; }

.z372a8footer {
  background: #0f1728; color: rgba(255, 255, 255, 0.82); padding: 3rem 0 2rem;
}
.z372a8footer_inner { display: grid; gap: 1.25rem; }
.z372a8footer_brand { display: inline-flex; align-items: center; gap: 0.55rem; font-family: var(--font-d); font-weight: 700; color: #fff; }
.z372a8footer_note { margin: 0; max-width: 42rem; }
.z372a8flink_title { margin: 0 0 0.5rem; color: #fff; font-weight: 600; }
.z372a8flink_list { display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; list-style: none; margin: 0; padding: 0; }
.z372a8footer_nav { display: flex; flex-wrap: wrap; gap: 0.75rem 1.25rem; }
.z372a8footer_link { color: rgba(255, 255, 255, 0.78); }
.z372a8footer_link:hover { color: #fff; }
.z372a8powered { font-size: 0.88rem; opacity: 0.75; }
.z372a8powered a { color: #fff; }

@media (max-width: 960px) {
  .z372a8hero_grid,
  .z372a8official_row,
  .z372a8feat_grid,
  .z372a8dl_grid,
  .z372a8steps { grid-template-columns: 1fr 1fr; }
  .z372a8feat_grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .z372a8header_cta { display: none; }
  .z372a8nav_toggle { display: inline-flex; }
  .z372a8nav {
    position: absolute; left: 0; right: 0; top: 72px;
    background: #fff; border-bottom: 1px solid var(--c-line);
    display: none; padding: 0.75rem 1rem 1rem;
  }
  .z372a8nav.is-open { display: block; }
  .z372a8nav_list { flex-direction: column; }
  .z372a8hero_grid,
  .z372a8official_row,
  .z372a8feat_grid,
  .z372a8dl_grid,
  .z372a8steps { grid-template-columns: 1fr; }
  .z372a8hero { padding-top: 2rem; }
}