/* K4 · 应用商店产品页 · Signal */
:root {
  --blue: #3a76f0;
  --blue-deep: #2156d6;
  --ink: #111827;
  --muted: #6b7280;
  --line: #e5e7eb;
  --soft: #f3f4f6;
  --white: #ffffff;
  --font: "Plus Jakarta Sans", "Segoe UI", sans-serif;
  --max: 1080px;
  --r: 14px;
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
.zbd258body {
  margin: 0; font-family: var(--font); color: var(--ink);
  background: #fafbfc; line-height: 1.65; overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
.zbd258container { width: min(100% - 2rem, var(--max)); margin-inline: auto; }

.zbd258header {
  position: sticky; top: 0; z-index: 50; background: rgba(250, 251, 252, 0.92);
  border-bottom: 1px solid var(--line); backdrop-filter: blur(10px);
}
.zbd258navwrap { min-height: 68px; display: flex; align-items: center; gap: 0.75rem; }
.zbd258brand {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-weight: 800; font-size: 1.05rem;
}
.zbd258brand_mark {
  width: 26px; height: 26px; border-radius: 8px;
  background: linear-gradient(145deg, var(--blue), #22c55e);
}
.zbd258nav { margin-left: auto; display: flex; flex-wrap: wrap; gap: 0.85rem; font-size: 0.9rem; color: var(--muted); font-weight: 600; }
.zbd258nav a:hover { color: var(--blue); }
.zbd258header_btn { margin-left: 0.25rem; }
.zbd258burger {
  display: none; margin-left: auto; width: 40px; height: 40px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--white); cursor: pointer;
  position: relative;
}
.zbd258burger::before, .zbd258burger::after {
  content: ""; position: absolute; left: 10px; right: 10px; height: 2px; background: var(--ink);
}
.zbd258burger::before { top: 14px; }
.zbd258burger::after { bottom: 14px; }

.zbd258btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 0.7rem 1.15rem; border-radius: 12px; font-weight: 700; font-size: 0.95rem;
  border: 1px solid transparent;
}
.zbd258btn_blue { background: var(--blue); color: #fff; }
.zbd258btn_blue:hover { background: var(--blue-deep); }
.zbd258btn_soft { background: var(--soft); color: var(--ink); }
.zbd258btn_soft:hover { background: #e5e7eb; }
.zbd258btn_lg { padding: 0.9rem 1.35rem; }

.zbd258store_hero { padding: 3rem 0 2rem; }
.zbd258store_grid {
  display: grid; grid-template-columns: 0.95fr 1.05fr; gap: 2.5rem; align-items: center;
}
.zbd258device {
  background: var(--soft); border-radius: 24px; padding: 1.25rem; border: 1px solid var(--line);
}
.zbd258device img { width: 100%; border-radius: 16px; aspect-ratio: 4/3; object-fit: cover; }
.zbd258store_badge {
  display: inline-block; margin: 0 0 0.75rem; padding: 0.3rem 0.7rem;
  background: rgba(58, 118, 240, 0.1); color: var(--blue); border-radius: 8px;
  font-size: 0.8rem; font-weight: 700;
}
.zbd258store_copy h1 {
  margin: 0 0 0.9rem; font-size: clamp(1.9rem, 4vw, 2.8rem); line-height: 1.15; letter-spacing: -0.02em;
}
.zbd258store_desc { margin: 0 0 1.1rem; color: var(--muted); font-size: 1.05rem; }
.zbd258rating { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 1.4rem; }
.zbd258rating span {
  background: var(--white); border: 1px solid var(--line); border-radius: 8px;
  padding: 0.35rem 0.7rem; font-size: 0.85rem; font-weight: 600; color: var(--muted);
}
.zbd258store_actions { display: flex; flex-wrap: wrap; gap: 0.7rem; }

.zbd258ad { padding: 0.75rem 0; }
.zbd258sec { padding: 3.75rem 0; }
.zbd258sec_soft { background: var(--soft); }
.zbd258sec_head { margin-bottom: 1.75rem; max-width: 36rem; }
.zbd258sec_head h2, .zbd258dl_layout header h2 {
  margin: 0 0 0.5rem; font-size: clamp(1.5rem, 3vw, 2rem); letter-spacing: -0.02em;
}
.zbd258sec_head p, .zbd258dl_layout header p { margin: 0; color: var(--muted); }

.zbd258dl_layout { display: grid; gap: 1.5rem; max-width: 720px; }
.zbd258dl_stack { display: grid; gap: 0.75rem; }
.zbd258dl_row {
  display: grid; grid-template-columns: 7rem 1fr auto; gap: 1rem; align-items: center;
  background: var(--white); border: 1px solid var(--line); border-radius: var(--r);
  padding: 1.1rem 1.25rem; transition: 0.2s ease;
}
.zbd258dl_row:hover { border-color: var(--blue); box-shadow: 0 8px 20px rgba(58, 118, 240, 0.08); }
.zbd258dl_os { font-weight: 800; color: var(--blue); }
.zbd258dl_info { color: var(--muted); font-size: 0.95rem; }
.zbd258dl_go { font-weight: 700; color: var(--ink); }

.zbd258strip { background: var(--ink); color: #fff; padding: 1.35rem 0; }
.zbd258strip_row {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; text-align: center; font-size: 0.95rem;
}
.zbd258strip strong { display: block; margin-bottom: 0.2rem; font-size: 1.05rem; }

.zbd258feat6 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.zbd258feat6 article {
  background: var(--white); border: 1px solid var(--line); border-radius: var(--r); padding: 1.25rem;
}
.zbd258feat6 h3 { margin: 0 0 0.4rem; font-size: 1.05rem; }
.zbd258feat6 p { margin: 0; color: var(--muted); font-size: 0.94rem; }

.zbd258guide_box { max-width: 760px; }
.zbd258step {
  background: var(--white); border: 1px solid var(--line); border-radius: 12px;
  padding: 0.35rem 1.1rem; margin-bottom: 0.65rem;
}
.zbd258step summary {
  cursor: pointer; font-weight: 700; list-style: none; padding: 0.85rem 0;
  display: flex; align-items: center; gap: 0.75rem;
}
.zbd258step summary::-webkit-details-marker { display: none; }
.zbd258step summary span {
  width: 28px; height: 28px; border-radius: 8px; background: rgba(58, 118, 240, 0.12);
  color: var(--blue); display: grid; place-items: center; font-size: 0.85rem;
}
.zbd258step p { margin: 0 0 1rem 2.5rem; color: var(--muted); }

.zbd258official_card {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 1rem;
  background: linear-gradient(120deg, #2156d6, #3a76f0); color: #fff;
  border-radius: 18px; padding: 2rem;
}
.zbd258official_card h2 { margin: 0 0 0.4rem; }
.zbd258official_card p { margin: 0; opacity: 0.92; }
.zbd258official_card .zbd258btn_blue { background: #fff; color: var(--blue-deep); }

.zbd258faq_list { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.zbd258faq_list article {
  background: var(--white); border: 1px solid var(--line); border-radius: 12px; padding: 1.2rem;
}
.zbd258faq_list h3 { margin: 0 0 0.4rem; font-size: 1.02rem; }
.zbd258faq_list p { margin: 0; color: var(--muted); font-size: 0.94rem; }

.zbd258cta { padding: 3.5rem 0 4rem; text-align: center; }
.zbd258cta h2 { margin: 0 0 0.5rem; font-size: clamp(1.5rem, 3vw, 2rem); }
.zbd258cta p { margin: 0 0 1.25rem; color: var(--muted); }

.zbd258footer { background: #111827; color: rgba(255,255,255,0.78); padding: 2.75rem 0 2rem; }
.zbd258flink h3 { margin: 0 0 0.55rem; color: #fff; font-size: 1rem; }
.zbd258flink ul { list-style: none; margin: 0 0 1.25rem; padding: 0; display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; }
.zbd258foot_name { margin: 0.5rem 0; font-weight: 800; color: #fff; }
.zbd258foot_note { margin: 0 0 1rem; max-width: 40rem; }
.zbd258powered { font-size: 0.88rem; opacity: 0.75; }
.zbd258powered a { color: #fff; }

@media (max-width: 900px) {
  .zbd258store_grid, .zbd258feat6, .zbd258faq_list, .zbd258strip_row { grid-template-columns: 1fr 1fr; }
  .zbd258store_grid { grid-template-columns: 1fr; }
  .zbd258dl_row { grid-template-columns: 1fr; gap: 0.35rem; }
}
@media (max-width: 720px) {
  .zbd258header_btn { display: none; }
  .zbd258burger { display: inline-block; }
  .zbd258nav {
    display: none; position: absolute; left: 0; right: 0; top: 68px;
    background: #fff; border-bottom: 1px solid var(--line); padding: 0.85rem 1rem; flex-direction: column;
  }
  .zbd258nav.is-open { display: flex; }
  .zbd258navwrap { position: relative; }
  .zbd258feat6, .zbd258faq_list, .zbd258strip_row { grid-template-columns: 1fr; }
  .zbd258step p { margin-left: 0; }
}