/* ============================================================
   page-bangzhu-zhongxin.css — 帮助中心 · 纯净体验
   Layout: masthead band → sticky tabs → 2-col FAQ → bottom band
   ============================================================ */

/* ── Page shell ───────────────────────────────────────────── */

#page-bangzhu.hbz-page {
  padding-bottom: 0;
}

#page-bangzhu a.no-underline {
  text-decoration: none;
}

#page-bangzhu details > summary::-webkit-details-marker {
  display: none;
}

#page-bangzhu details > summary {
  list-style: none;
}

/* ── Masthead band ────────────────────────────────────────── */

.hbz-masthead {
  width: 100%;
  border-bottom: 1px solid rgba(226, 232, 240, 0.9);
  background: linear-gradient(
    105deg,
    rgba(255, 255, 255, 0.92) 0%,
    rgba(248, 250, 252, 0.88) 45%,
    rgba(239, 246, 255, 0.75) 100%
  );
  backdrop-filter: blur(12px);
}

.hbz-masthead__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  max-width: 72rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 2.75rem;
}

@media (min-width: 1024px) {
  .hbz-masthead__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 2.5rem;
    padding: 3rem 1.5rem 3.25rem;
  }
}

.hbz-masthead__kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0 0 0.75rem;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: #64748b;
}

.hbz-masthead__kicker-ico {
  width: 1rem;
  height: 1rem;
  color: #3b82f6;
}

.hbz-masthead__title {
  margin: 0 0 0.75rem;
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(1.875rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: #0f172a;
}

.hbz-masthead__desc {
  margin: 0 0 1.25rem;
  max-width: 34rem;
  font-size: 1.0625rem;
  font-weight: 300;
  line-height: 1.65;
  color: #64748b;
}

.hbz-masthead__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.8125rem;
  color: #64748b;
}

.hbz-masthead__meta li {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
}

.hbz-masthead__meta svg {
  width: 0.9375rem;
  height: 0.9375rem;
  color: #94a3b8;
}

/* Quick-action tiles (masthead right) */

.hbz-masthead__actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.625rem;
}

@media (min-width: 640px) {
  .hbz-masthead__actions {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.75rem;
  }
}

@media (min-width: 1024px) {
  .hbz-masthead__actions {
    width: max-content;
    min-width: 28rem;
  }
}

.hbz-masthead__tile {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.5rem;
  padding: 0.875rem 1rem;
  border-radius: 0.875rem;
  border: 1px solid rgba(226, 232, 240, 0.9);
  background: rgba(255, 255, 255, 0.82);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.hbz-masthead__tile:hover {
  border-color: rgba(147, 197, 253, 0.6);
  box-shadow: 0 4px 14px rgba(59, 130, 246, 0.1);
  transform: translateY(-1px);
}

.hbz-masthead__tile-ico {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: 0.5rem;
}

.hbz-masthead__tile-ico svg {
  width: 1.125rem;
  height: 1.125rem;
}

.hbz-masthead__tile-ico--blue {
  background: #eff6ff;
  color: #2563eb;
}

.hbz-masthead__tile-ico--indigo {
  background: #eef2ff;
  color: #4f46e5;
}

.hbz-masthead__tile-ico--emerald {
  background: #ecfdf5;
  color: #059669;
}

.hbz-masthead__tile-ico--violet {
  background: #f5f3ff;
  color: #7c3aed;
}

.hbz-masthead__tile-label {
  font-size: 0.875rem;
  font-weight: 700;
  color: #0f172a;
  line-height: 1.2;
}

.hbz-masthead__tile-hint {
  font-size: 0.6875rem;
  color: #94a3b8;
  line-height: 1.3;
}

/* ── Sticky topic tabs ────────────────────────────────────── */

.hbz-tabs-bar {
  position: sticky;
  top: var(--nav-height, 4rem);
  z-index: 30;
  width: 100%;
  border-bottom: 1px solid rgba(226, 232, 240, 0.95);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.hbz-tabs {
  display: flex;
  gap: 0.25rem;
  max-width: 72rem;
  margin: 0 auto;
  padding: 0.625rem 1.5rem;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.hbz-tabs::-webkit-scrollbar {
  display: none;
}

.hbz-tabs__link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
  padding: 0.5rem 1rem;
  border-radius: 9999px;
  font-size: 0.875rem;
  font-weight: 600;
  color: #475569;
  text-decoration: none;
  white-space: nowrap;
  border: 1px solid transparent;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.hbz-tabs__link svg {
  width: 1rem;
  height: 1rem;
  color: #94a3b8;
  flex-shrink: 0;
  transition: color 0.2s ease;
}

.hbz-tabs__link:hover {
  background: #f8fafc;
  color: #1d4ed8;
  border-color: rgba(226, 232, 240, 0.8);
}

.hbz-tabs__link:hover svg {
  color: #2563eb;
}

/* ── FAQ body ─────────────────────────────────────────────── */

.hbz-faq {
  max-width: 72rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 3rem;
}

.hbz-topic {
  scroll-margin-top: calc(var(--nav-height, 4rem) + 3.5rem);
  margin-bottom: 3rem;
}

.hbz-topic:last-child {
  margin-bottom: 0;
}

.hbz-topic__head {
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
}

.hbz-topic__title {
  margin: 0;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: #0f172a;
}

.hbz-topic__desc {
  margin: 0.375rem 0 0;
  font-size: 0.9375rem;
  color: #64748b;
}

.hbz-topic__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  align-items: start;
}

@media (min-width: 768px) {
  .hbz-topic__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.875rem;
  }
}

/* FAQ accordion cards */

.hbz-faq-item {
  border-radius: 1rem;
  border: 1px solid rgba(226, 232, 240, 0.9);
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(8px);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.04);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.hbz-faq-item:hover {
  border-color: rgba(203, 213, 225, 0.95);
}

.hbz-faq-item[open] {
  border-color: rgba(147, 197, 253, 0.55);
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.08);
}

.hbz-faq-item__summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.125rem 1.25rem;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9375rem;
  color: #1e293b;
  line-height: 1.45;
}

.hbz-faq-item__q {
  flex: 1;
  min-width: 0;
}

.hbz-faq-item__chev {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 0.125rem;
  transition: transform 0.25s ease;
}

.hbz-faq-item__chev svg {
  width: 1.125rem;
  height: 1.125rem;
  color: #94a3b8;
}

.hbz-faq-item[open] .hbz-faq-item__chev {
  transform: rotate(180deg);
}

.hbz-faq-item__body {
  padding: 0 1.25rem 1.125rem;
  font-size: 0.875rem;
  line-height: 1.65;
  color: #475569;
}

/* ── Full-width CTA band ──────────────────────────────────── */

.hbz-band {
  width: 100%;
  margin-top: 1rem;
  border-top: 1px solid rgba(191, 219, 254, 0.5);
  background: linear-gradient(
    90deg,
    #1e40af 0%,
    #2563eb 42%,
    #3b82f6 100%
  );
}

.hbz-band__inner {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 72rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

@media (min-width: 768px) {
  .hbz-band__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    padding: 2.75rem 1.5rem;
  }
}

.hbz-band__title {
  margin: 0 0 0.5rem;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: #fff;
}

.hbz-band__desc {
  margin: 0;
  max-width: 28rem;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: rgba(219, 234, 254, 0.92);
}

.hbz-band__actions {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  flex-shrink: 0;
}

@media (min-width: 480px) {
  .hbz-band__actions {
    flex-direction: row;
    align-items: center;
  }
}

.hbz-band__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: 0.625rem;
  font-size: 0.9375rem;
  font-weight: 600;
  white-space: nowrap;
  transition: background-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.hbz-band__btn svg {
  width: 1rem;
  height: 1rem;
}

.hbz-band__btn--primary {
  background: #fff;
  color: #1d4ed8;
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.15);
}

.hbz-band__btn--primary:hover {
  background: #f8fafc;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(15, 23, 42, 0.2);
}

.hbz-band__btn--ghost {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.28);
}

.hbz-band__btn--ghost:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* ── Reduced motion ───────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  .hbz-masthead__tile:hover,
  .hbz-band__btn--primary:hover {
    transform: none;
  }

  .hbz-faq-item__chev {
    transition: none;
  }
}