.page-contact {
  --contact-rule: rgba(26, 31, 46, .14);
  --contact-rule-night: rgba(245, 240, 230, .16);
}

/* ---------- 页头 ---------- */
.page-contact .contact-head-grid {
  margin-top: 1.6rem;
  align-items: end;
  gap: 2rem 0;
}

.page-contact .contact-head h1 {
  margin: .55rem 0 0;
  max-width: 20ch;
}

.page-contact .contact-head .lede {
  margin-top: 1.1rem;
}

.page-contact .contact-head-side {
  display: flex;
  flex-direction: column;
  gap: .9rem;
  align-items: flex-start;
}

.page-contact .contact-head-side .muted {
  max-width: 42ch;
  font-size: 14px;
  line-height: 1.7;
}

/* ---------- 章节索引 ---------- */
.page-contact .chapter-index {
  background: var(--paper);
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
  padding: .95rem 0 1.05rem;
}

.page-contact .index-inner {
  display: flex;
  align-items: center;
  gap: .8rem 1.6rem;
  flex-wrap: wrap;
}

.page-contact .chapter-index-title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--ink-muted);
  white-space: nowrap;
}

.page-contact .chapter-index-list {
  display: flex;
  flex-wrap: nowrap;
  gap: .5rem;
  margin: 0;
  padding: 0 0 .2rem;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  max-width: 100%;
}

.page-contact .chapter-index-list::-webkit-scrollbar {
  display: none;
}

.page-contact .chapter-link {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  white-space: nowrap;
  padding: .5rem .95rem;
  border: 1px solid var(--hair);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  line-height: 1;
  color: var(--ink-muted);
  text-decoration: none;
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-contact .chapter-link .chapter-idx {
  font-weight: 700;
  color: var(--ice-ink);
}

.page-contact .chapter-link:hover {
  color: var(--ink);
  border-color: var(--ink-muted);
}

.page-contact .chapter-link[aria-current="true"] {
  color: var(--ink);
  border-color: var(--pulse-ink);
  background: rgba(53, 214, 164, .12);
}

/* ---------- 章节 01：偏左联系卡 ---------- */
.page-contact .contact-channels {
  gap: 2.4rem 0;
}

.page-contact .contact-card {
  position: relative;
  padding: clamp(1.4rem, 4vw, 2.1rem);
  border: 1px solid var(--hair);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, .62);
  box-shadow: none;
  overflow: hidden;
}

.page-contact .contact-card .chapter-num {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.6rem, 8vw, 3.6rem);
  line-height: .9;
  letter-spacing: -.04em;
  color: var(--hair);
  margin-bottom: .6rem;
}

.page-contact .contact-card .h-sub {
  margin: 0;
}

.page-contact .channel-list {
  margin: 1.3rem 0 0;
  display: grid;
}

.page-contact .channel {
  padding: .95rem 0;
  border-top: 1px solid var(--contact-rule);
}

.page-contact .channel:last-child {
  border-bottom: 1px solid var(--contact-rule);
}

.page-contact .channel dt {
  margin: 0;
}

.page-contact .channel-value {
  margin: .38rem 0 0;
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  overflow-wrap: anywhere;
}

.page-contact .channel-mail {
  font-family: var(--font-mono);
  font-size: clamp(15px, 4.2vw, 19px);
  letter-spacing: .06em;
  color: var(--ice-ink);
}

.page-contact .contact-card-note {
  margin: 1.15rem 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--ink-muted);
}

.page-contact .contact-intro h2 {
  margin-top: 0;
}

.page-contact .contact-intro p {
  max-width: 58ch;
  color: var(--ink);
}

.page-contact .contact-intro p + p {
  margin-top: 1.2em;
  padding-top: 1.2em;
  border-top: 1px solid var(--contact-rule);
}

/* ---------- 窄幅星空带 ---------- */
.page-contact .contact-band {
  padding-block: clamp(1.6rem, 5vw, 2.8rem);
}

.page-contact .band-figure {
  margin: 0;
}

.page-contact .band-frame {
  border: 1px solid var(--night-line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-night);
}

.page-contact .band-frame img {
  display: block;
  width: 100%;
  object-fit: cover;
}

.page-contact .contact-band .media-frame-caption {
  margin-top: .85rem;
  font-size: 13px;
  line-height: 1.65;
  color: var(--night-muted);
}

/* ---------- 章节 02：安全反馈 ---------- */
.page-contact .mail-rules {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
  display: grid;
}

.page-contact .mail-rules li {
  display: grid;
  grid-template-columns: 1fr;
  gap: .3rem;
  padding: 1rem 0;
  border-top: 1px solid var(--contact-rule);
}

.page-contact .mail-rules li:last-child {
  border-bottom: 1px solid var(--contact-rule);
}

.page-contact .rule-key {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .16em;
  color: var(--ice-ink);
}

.page-contact .rule-text {
  font-size: 17px;
  line-height: 1.7;
  color: var(--ink);
  max-width: 56ch;
}

.page-contact .note--alert {
  margin-top: 1.6rem;
  font-size: 15px;
  line-height: 1.7;
}

.page-contact .mail-figure {
  margin: 2rem 0 0;
}

.page-contact .mail-frame {
  border: 1px solid var(--hair);
  border-radius: var(--radius-md);
}

.page-contact .mail-frame img {
  display: block;
  width: 100%;
  object-fit: cover;
}

.page-contact .mail-figure .media-frame-caption {
  margin-top: .85rem;
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink-muted);
}

/* ---------- 章节 03：来信前自查 ---------- */
.page-contact .check-list {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
  display: grid;
}

.page-contact .check-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  padding: 1.35rem 0;
  border-top: 1px solid var(--contact-rule);
}

.page-contact .check-list li:last-child {
  border-bottom: 1px solid var(--contact-rule);
}

.page-contact .check-num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--gold-ink);
  padding-top: .3em;
}

.page-contact .check-body .h-sub {
  margin: 0 0 .45rem;
  font-size: 1.06rem;
}

.page-contact .check-body p {
  margin: 0;
  max-width: 54ch;
  font-size: 17px;
  line-height: 1.75;
}

.page-contact .check-body a {
  color: var(--ice-ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

/* ---------- 章节 04：备案信息（深色） ---------- */
.page-contact .registry-list {
  margin: 0;
  display: grid;
  border-top: 1px solid var(--contact-rule-night);
}

.page-contact .registry-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: .3rem;
  padding: .95rem 0;
  border-bottom: 1px solid var(--contact-rule-night);
}

.page-contact .registry-row dt {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .16em;
  color: var(--night-muted);
}

.page-contact .registry-value {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
  color: var(--night-text);
  overflow-wrap: anywhere;
}

.page-contact .registry-value.mono {
  font-family: var(--font-mono);
  letter-spacing: .06em;
  color: var(--ice);
}

.page-contact .registry-note {
  margin: 1.3rem 0 0;
  max-width: 54ch;
  font-size: 14px;
  line-height: 1.72;
}

/* ---------- 章节 05：处理边界 ---------- */
.page-contact .boundary-body p {
  margin: 0;
  max-width: 58ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--night-text);
}

.page-contact .boundary-body p + p {
  margin-top: 1.1em;
  padding-top: 1.1em;
  border-top: 1px solid var(--contact-rule-night);
}

.page-contact .boundary-body a {
  color: var(--ice);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.page-contact .boundary-links {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  margin-top: 1.7rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-contact .mail-rules li {
    grid-template-columns: 5rem 1fr;
    gap: 1.1rem;
  }

  .page-contact .registry-row {
    grid-template-columns: 7.5rem 1fr;
    gap: 1.2rem;
    align-items: baseline;
  }
}

@media (min-width: 1024px) {
  .page-contact .contact-head-grid {
    align-items: end;
  }

  .page-contact .contact-card {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }

  .page-contact .mail-figure {
    margin-top: 3.4rem;
  }
}

@media (max-width: 899px) {
  .page-contact .chapter-index-list {
    margin-inline: -4px;
    padding-inline: 4px;
  }

  .page-contact .contact-head h1 {
    max-width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-contact .chapter-link {
    transition: none;
  }
}
<<<END>>>