/* ================= 商务合作 /cooperation/ ================= */
.page-contact {
  --co-pad-card: clamp(1.25rem, 2.4vw, 1.75rem);
  --co-sec-gap: clamp(3rem, 7vw, 5.5rem);
  --co-tone: var(--c-cyan);
  background: var(--c-ink);
  color: var(--c-paper);
  overflow-x: clip;
}

.page-contact h1,
.page-contact h2,
.page-contact h3 {
  font-family: var(--f-head);
  letter-spacing: -0.02em;
  line-height: 1.18;
  color: var(--c-paper);
  margin: 0;
}

.page-contact .co-eyebrow {
  color: var(--c-cyan);
}

.page-contact .co-link {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line-cyan);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-contact .co-link:hover,
.page-contact .co-link:focus-visible {
  color: var(--c-paper);
  border-bottom-color: var(--c-amber);
}

.page-contact .btn-quiet {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.15rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: transparent;
  color: var(--c-paper);
  font-size: var(--fs-15);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-contact .btn-quiet:hover,
.page-contact .btn-quiet:focus-visible {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
}

/* ---------- 首屏 ---------- */
.page-contact .co-hero {
  position: relative;
  padding-top: calc(var(--shell-offset) + clamp(1.25rem, 4vw, 3rem));
  padding-bottom: clamp(2.5rem, 6vw, 4.5rem);
  overflow: hidden;
  background:
    radial-gradient(115% 85% at 92% -12%, rgba(0, 229, 255, 0.13), transparent 62%),
    linear-gradient(180deg, var(--c-ink) 0%, var(--c-ink) 48%, var(--c-ink-2) 100%);
}

.page-contact .co-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(138, 106, 60, 0.16) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(138, 106, 60, 0.16) 1px, transparent 1px);
  background-size: 96px 96px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 74%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 74%);
  pointer-events: none;
}

.page-contact .co-hero .container {
  position: relative;
  z-index: 1;
}

.page-contact .co-hero .breadcrumb {
  margin-bottom: clamp(1.25rem, 4vw, 2.25rem);
}

.page-contact .co-hero-grid {
  display: grid;
  gap: clamp(2rem, 5vw, 3rem);
  grid-template-columns: minmax(0, 1fr);
}

.page-contact .co-hero-main h1 {
  font-size: var(--fs-64);
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-top: 0.7rem;
  max-width: 16em;
}

.page-contact .co-lead {
  margin: 1.35rem 0 0;
  max-width: 40em;
  color: var(--c-mist);
  font-size: var(--fs-17);
  line-height: 1.78;
}

.page-contact .co-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: clamp(1.5rem, 3vw, 2.25rem);
}

.page-contact .co-hero-aside {
  align-self: start;
  padding: var(--co-pad-card);
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--c-cyan);
  background: rgba(18, 48, 68, 0.42);
}

.page-contact .co-facts {
  list-style: none;
  margin: 0.9rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

.page-contact .co-facts li {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  font-size: var(--fs-15);
  line-height: 1.6;
  color: var(--c-paper);
}

.page-contact .co-facts b {
  flex: none;
  font-size: var(--fs-20);
  font-weight: 500;
  line-height: 1;
  color: var(--c-cyan);
}

.page-contact .co-aside-note {
  margin: 1.25rem 0 0;
  color: var(--c-mist);
  font-size: var(--fs-13);
  line-height: 1.72;
}

/* ---------- 区块通用 ---------- */
.page-contact .co-directions,
.page-contact .co-flow,
.page-contact .co-contact,
.page-contact .co-mail,
.page-contact .co-faq-sec {
  padding: var(--co-sec-gap) 0;
}

.page-contact .co-directions { background: var(--c-ink-2); }
.page-contact .co-flow { background: var(--c-ink); }
.page-contact .co-contact { background: linear-gradient(180deg, var(--c-ink-2) 0%, var(--c-slate) 100%); }
.page-contact .co-mail { background: var(--c-ink); }
.page-contact .co-faq-sec { background: var(--c-ink-2); }

.page-contact .co-sec-head {
  display: grid;
  gap: 0.9rem;
  grid-template-columns: minmax(0, 1fr);
  margin-bottom: clamp(1.75rem, 4vw, 3rem);
}

.page-contact .co-sec-head h2,
.page-contact .co-mail-intro h2 {
  font-size: var(--fs-40);
  margin-top: 0.55rem;
}

.page-contact .co-sec-sub {
  margin: 0;
  color: var(--c-mist);
  font-size: var(--fs-17);
  line-height: 1.75;
  max-width: 36em;
}

/* ---------- 合作方向 ---------- */
.page-contact .co-dir-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: minmax(0, 1fr);
}

.page-contact .co-dir {
  --co-tone: var(--c-cyan);
  position: relative;
  display: flex;
  flex-direction: column;
  padding: var(--co-pad-card);
  border: 1px solid var(--line-soft);
  border-top: 2px solid var(--co-tone);
  background: linear-gradient(180deg, rgba(18, 48, 68, 0.55) 0%, rgba(6, 26, 43, 0.28) 100%);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-contact .co-dir[data-tone="cyan"] { --co-tone: var(--c-cyan); }
.page-contact .co-dir[data-tone="mint"] { --co-tone: var(--c-mint); }
.page-contact .co-dir[data-tone="amber"] { --co-tone: var(--c-amber); }
.page-contact .co-dir[data-tone="indigo"] { --co-tone: #A99BFF; }

.page-contact .co-dir:hover,
.page-contact .co-dir:focus-within {
  border-color: var(--co-tone);
  border-top-color: var(--co-tone);
  background: linear-gradient(180deg, rgba(18, 48, 68, 0.82) 0%, rgba(6, 26, 43, 0.42) 100%);
}

.page-contact .co-dir-no {
  margin: 0;
  font-size: var(--fs-13);
  letter-spacing: 0.16em;
  color: var(--co-tone);
}

.page-contact .co-dir-title {
  font-size: var(--fs-20);
  margin-top: 0.7rem;
}

.page-contact .co-dir-row {
  margin: 0.65rem 0 0;
  font-size: var(--fs-15);
  line-height: 1.72;
  color: var(--c-paper);
}

.page-contact .co-label {
  display: inline-block;
  margin-right: 0.5rem;
  padding: 0.05rem 0.42rem;
  border: 1px solid currentColor;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--co-tone);
  vertical-align: 0.06em;
}

.page-contact .co-dir-more {
  margin: 0.9rem 0 0;
  padding-top: 0.9rem;
  border-top: 1px dashed var(--line-soft);
  color: var(--c-mist);
  font-size: var(--fs-15);
  line-height: 1.72;
}

/* ---------- 合作流程 ---------- */
.page-contact .co-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 2.25rem;
  grid-template-columns: minmax(0, 1fr);
}

.page-contact .co-step {
  position: relative;
  padding-top: 3.5rem;
}

.page-contact .co-step-dot {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 1;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-cyan);
  border-radius: 50%;
  background: var(--c-ink);
  color: var(--c-cyan);
  font-size: var(--fs-13);
  letter-spacing: 0.04em;
}

.page-contact .co-step-title {
  font-size: var(--fs-20);
}

.page-contact .co-step-desc {
  margin: 0.55rem 0 0;
  color: var(--c-mist);
  font-size: var(--fs-15);
  line-height: 1.74;
}

.page-contact .co-step-list {
  list-style: none;
  margin: 0.85rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.42rem;
}

.page-contact .co-step-list li {
  position: relative;
  padding-left: 1rem;
  color: var(--c-paper);
  font-size: var(--fs-15);
  line-height: 1.6;
}

.page-contact .co-step-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 7px;
  height: 1px;
  background: var(--c-copper);
}

/* ---------- 联系渠道 ---------- */
.page-contact .co-channels {
  display: grid;
  gap: 1rem;
  grid-template-columns: minmax(0, 1fr);
}

.page-contact .co-channel {
  display: grid;
  gap: 0.6rem;
  padding: clamp(1.5rem, 3.2vw, 2.25rem);
  border: 1px solid var(--line-soft);
  background: rgba(6, 26, 43, 0.5);
}

.page-contact .co-channel-label {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-mist);
}

.page-contact .co-channel-value {
  margin: 0;
  color: var(--c-paper);
  font-size: clamp(1.05rem, 2.6vw, 1.6rem);
  line-height: 1.4;
  letter-spacing: 0.01em;
  overflow-wrap: anywhere;
}

.page-contact .co-channel--mail {
  border-left: 2px solid var(--c-cyan);
  background: rgba(18, 48, 68, 0.6);
}

.page-contact .co-channel--mail .co-channel-value {
  color: var(--c-cyan);
  font-size: clamp(1.1rem, 3.4vw, 2.3rem);
}

.page-contact .co-channel-value.co-addr {
  font-size: clamp(1rem, 1.7vw, 1.2rem);
  line-height: 1.6;
}

.page-contact .co-channel-note {
  margin: 0;
  color: var(--c-mist);
  font-size: var(--fs-15);
  line-height: 1.72;
  max-width: 42em;
}

.page-contact .co-plate {
  margin: clamp(2rem, 5vw, 3.25rem) 0 0;
}

/* ---------- 来信要点 ---------- */
.page-contact .co-mail-grid {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
  grid-template-columns: minmax(0, 1fr);
}

.page-contact .co-mail-intro p {
  margin: 1rem 0 0;
  color: var(--c-mist);
  font-size: var(--fs-17);
  line-height: 1.78;
  max-width: 34em;
}

.page-contact .co-mail-intro .btn {
  margin-top: 1.6rem;
}

.page-contact .co-checklist {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-contact .co-checklist li {
  border-bottom: 1px solid var(--line-soft);
}

.page-contact .co-check {
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  padding: 0.9rem 0.25rem;
  cursor: pointer;
  font-size: var(--fs-17);
  line-height: 1.6;
  color: var(--c-paper);
}

.page-contact .co-check input {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: 0;
  opacity: 0;
}

.page-contact .co-check-box {
  flex: none;
  width: 18px;
  height: 18px;
  margin-top: 0.28em;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  background: var(--c-ink);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-contact .co-check input:checked + .co-check-box {
  border-color: var(--c-amber);
  background: rgba(255, 179, 0, 0.14);
}

.page-contact .co-check input:checked + .co-check-box::after {
  content: "";
  width: 9px;
  height: 5px;
  border-left: 2px solid var(--c-amber);
  border-bottom: 2px solid var(--c-amber);
  transform: rotate(-45deg) translateY(-1px);
}

.page-contact .co-check input:focus-visible + .co-check-box {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
}

/* ---------- 常见问题 ---------- */
.page-contact .co-faq {
  border-top: 1px solid var(--line-soft);
  max-width: 62rem;
}

.page-contact .co-faq details {
  border-bottom: 1px solid var(--line-soft);
}

.page-contact .co-faq summary {
  position: relative;
  padding: 1.15rem 2.6rem 1.15rem 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--f-head);
  font-size: var(--fs-17);
  letter-spacing: -0.01em;
  color: var(--c-paper);
  transition: color var(--dur) var(--ease);
}

.page-contact .co-faq summary::-webkit-details-marker { display: none; }

.page-contact .co-faq summary::after {
  content: "＋";
  position: absolute;
  right: 0.2rem;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--f-mono);
  font-size: var(--fs-15);
  color: var(--c-cyan);
}

.page-contact .co-faq details[open] summary::after { content: "－"; }

.page-contact .co-faq summary:hover,
.page-contact .co-faq summary:focus-visible {
  color: var(--c-cyan);
}

.page-contact .co-faq details > p {
  margin: 0 0 1.35rem;
  padding-right: 2.6rem;
  color: var(--c-mist);
  font-size: var(--fs-15);
  line-height: 1.8;
  max-width: 48em;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-contact .co-dir-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .page-contact .co-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 2.5rem 1.75rem;
  }
}

@media (min-width: 720px) {
  .page-contact .co-channels { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-contact .co-channel--mail { grid-column: 1 / -1; }
}

@media (min-width: 900px) {
  .page-contact .co-sec-head {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    align-items: end;
    gap: 1rem 2.5rem;
  }

  .page-contact .co-sec-sub { padding-bottom: 0.3rem; }

  .page-contact .co-mail-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-contact .co-hero-grid {
    grid-template-columns: minmax(0, 1.62fr) minmax(0, 1fr);
    align-items: end;
    gap: 3.5rem;
  }
}

@media (min-width: 1024px) {
  .page-contact .co-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.75rem;
  }

  .page-contact .co-steps::before {
    content: "";
    position: absolute;
    top: 21px;
    left: 22px;
    right: 22px;
    height: 1px;
    background: linear-gradient(90deg, rgba(0, 229, 255, 0.55), rgba(138, 106, 60, 0.45) 58%, rgba(138, 106, 60, 0.08));
    pointer-events: none;
  }
}

@media (min-width: 1100px) {
  .page-contact .co-dir-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

@media (min-width: 1100px) and (hover: hover) {
  .page-contact .co-dir-more {
    max-height: 0;
    margin-top: 0;
    padding-top: 0;
    border-top-color: transparent;
    opacity: 0;
    overflow: hidden;
    transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease);
  }

  .page-contact .co-dir:hover .co-dir-more,
  .page-contact .co-dir:focus-within .co-dir-more {
    max-height: 14rem;
    margin-top: 0.9rem;
    padding-top: 0.9rem;
    border-top-color: var(--line-soft);
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-contact .co-dir,
  .page-contact .co-dir-more,
  .page-contact .co-link,
  .page-contact .btn-quiet,
  .page-contact .co-check-box,
  .page-contact .co-faq summary {
    transition: none;
  }
}