.page-contact {
  --co-pad: clamp(52px, 7vw, 96px);
  --co-track-1: var(--brand);
  --co-track-2: var(--warm);
  --co-track-3: var(--neon);
  --co-track-4: var(--cool);
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-contact section[id] {
  scroll-margin-top: 104px;
}

/* ---------- 面包屑 ---------- */
.page-contact .co-crumb-bar {
  background: var(--ink-soft);
  border-bottom: 1px solid var(--line);
}
.page-contact .co-crumb-bar .shell {
  padding-top: 14px;
  padding-bottom: 14px;
}
.page-contact .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--cool);
}
.page-contact .breadcrumb a {
  color: var(--cool);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.page-contact .breadcrumb a:hover {
  color: var(--paper);
  border-bottom-color: var(--brand);
}
.page-contact .breadcrumb [aria-current="page"] {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-contact .co-masthead {
  position: relative;
  padding: 42px 0 56px;
  background:
    radial-gradient(880px 400px at 10% -12%, rgba(255, 61, 24, .24), transparent 62%),
    radial-gradient(700px 360px at 92% -6%, rgba(37, 242, 210, .13), transparent 60%),
    var(--ink);
  border-bottom: 1px solid var(--line);
}
.page-contact .co-masthead-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}
.page-contact .co-masthead-copy h1 {
  margin: 14px 0 18px;
  font-size: clamp(30px, 7.4vw, 58px);
  line-height: 1.02;
  font-weight: 900;
  letter-spacing: -.02em;
}
.page-contact .co-lede {
  max-width: 60ch;
  margin: 0;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--cool);
}
.page-contact .co-masthead-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-contact .co-masthead-side {
  padding: 18px 20px 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  background: var(--glass);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}
.page-contact .co-side-title {
  margin: 0 0 12px;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cool);
}
.page-contact .co-toc {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.page-contact .toc-link {
  display: block;
  padding: 9px 12px;
  border-left: 2px solid transparent;
  border-radius: 0 10px 10px 0;
  font-size: 14px;
  color: var(--cool);
  text-decoration: none;
  transition: color .2s var(--ease), background .2s var(--ease), border-color .2s var(--ease);
}
.page-contact .toc-link:hover {
  color: var(--paper);
  background: rgba(255, 255, 255, .05);
}
.page-contact .toc-link[aria-current] {
  color: var(--neon);
  border-left-color: var(--neon);
  background: rgba(37, 242, 210, .07);
}

/* ---------- 通用区块头部 ---------- */
.page-contact .co-section-head {
  max-width: 780px;
  margin-bottom: 34px;
}
.page-contact .co-section-head h2 {
  margin: 12px 0 14px;
  font-size: clamp(23px, 4.4vw, 38px);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -.015em;
}
.page-contact .co-section-note {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--cool);
}

/* ---------- 01 合作方向 ---------- */
.page-contact .co-tracks {
  padding: var(--co-pad) 0;
  background: var(--ink);
}
.page-contact .co-track-media {
  position: relative;
  margin: 0 0 26px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line);
}
.page-contact .co-track-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  filter: saturate(.9) brightness(.78);
}
.page-contact .co-track-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(11, 13, 16, .1) 34%, rgba(11, 13, 16, .9) 100%);
  pointer-events: none;
}

.page-contact .co-track-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.page-contact .co-track {
  position: relative;
  padding: 28px 22px 32px;
  background: linear-gradient(180deg, rgba(15, 42, 35, .6), var(--ink-soft));
}
.page-contact .co-track::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 7px;
  background: linear-gradient(90deg, var(--co-tone), transparent 94%);
  clip-path: polygon(0 0, 100% 0, 100% 46%, 0 100%);
}
.page-contact .co-track:nth-child(1) { --co-tone: var(--co-track-1); }
.page-contact .co-track:nth-child(2) { --co-tone: var(--co-track-2); }
.page-contact .co-track:nth-child(3) { --co-tone: var(--co-track-3); }
.page-contact .co-track:nth-child(4) { --co-tone: var(--co-track-4); }

.page-contact .co-track-num {
  display: inline-block;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--co-tone);
}
.page-contact .co-track h3 {
  margin: 12px 0 10px;
  font-size: 19px;
  line-height: 1.3;
  font-weight: 800;
}
.page-contact .co-track-fit {
  margin: 0 0 16px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--cool);
}
.page-contact .co-track-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.page-contact .co-track-list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(243, 240, 234, .9);
}
.page-contact .co-track-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--co-tone);
}

/* ---------- 02 对接节奏 ---------- */
.page-contact .co-flow {
  padding: var(--co-pad) 0;
  background: var(--ink-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.page-contact .co-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}
.page-contact .co-step {
  position: relative;
  padding-top: 26px;
}
.page-contact .co-step::before {
  content: "";
  position: absolute;
  top: 4px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--line);
}
.page-contact .co-step::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--neon);
  box-shadow: 0 0 0 4px rgba(37, 242, 210, .14);
}
.page-contact .co-step-num {
  display: block;
  font-family: var(--font-num);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}
.page-contact .co-step h3 {
  margin: 10px 0 8px;
  font-size: 17px;
  font-weight: 800;
}
.page-contact .co-step-time {
  display: inline-block;
  margin: 0 0 12px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(255, 197, 61, .4);
  background: rgba(255, 197, 61, .1);
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--alert);
}
.page-contact .co-step-body {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--cool);
}

/* ---------- 03 支持内容 ---------- */
.page-contact .co-support {
  padding: var(--co-pad) 0;
  background: var(--ink);
}
.page-contact .co-support-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-contact .co-support-card {
  padding: 24px 22px 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(15, 42, 35, .72), var(--ink-soft));
  transition: transform .25s var(--ease), border-color .25s var(--ease);
}
.page-contact .co-support-card:hover {
  transform: translateY(-3px);
  border-color: rgba(37, 242, 210, .35);
}
.page-contact .co-support-card h3 {
  margin: 0 0 10px;
  font-size: 16.5px;
  font-weight: 800;
  color: var(--paper);
}
.page-contact .co-support-card h3::before {
  content: "";
  display: inline-block;
  width: 18px;
  height: 3px;
  margin-right: 10px;
  vertical-align: middle;
  background: var(--brand);
}
.page-contact .co-support-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--cool);
}

/* ---------- 04 城市邀请赛 ---------- */
.page-contact .co-invite {
  padding: var(--co-pad) 0;
  background:
    linear-gradient(200deg, rgba(255, 61, 24, .14), transparent 55%),
    var(--green);
  border-top: 1px solid var(--line);
}
.page-contact .co-invite-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}
.page-contact .co-invite-copy h2 {
  margin: 12px 0 16px;
  font-size: clamp(23px, 4.4vw, 38px);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -.015em;
}
.page-contact .co-invite-copy p {
  margin: 0 0 14px;
  max-width: 56ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(243, 240, 234, .82);
}
.page-contact .co-invite-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}
.page-contact .co-invite-figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line-soft);
}
.page-contact .co-invite-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(.85) brightness(.82);
}

/* ---------- 05 联络方式 ---------- */
.page-contact .co-contact {
  padding: var(--co-pad) 0;
  background: linear-gradient(180deg, var(--ink) 0%, rgba(15, 42, 35, .9) 100%);
}
.page-contact .co-contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-contact .co-contact-card {
  padding: 24px 22px 26px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  background: var(--glass);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
}
.page-contact .co-contact-label {
  margin: 0 0 12px;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cool);
}
.page-contact .co-contact-value {
  margin: 0 0 12px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
  word-break: break-word;
}
.page-contact .co-contact-value--mail {
  font-family: var(--font-num);
  font-size: 16px;
  color: var(--neon);
}
.page-contact .co-contact-value--addr {
  font-size: 16px;
  line-height: 1.7;
}
.page-contact .co-contact-hint {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--cool);
}
.page-contact .co-contact-note {
  margin: 22px 0 0;
  padding: 16px 18px;
  border-left: 3px solid var(--alert);
  background: rgba(255, 197, 61, .07);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(243, 240, 234, .86);
}
.page-contact .co-contact-fine {
  margin: 14px 0 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--cool);
}
.page-contact .co-contact-fine a {
  color: var(--neon);
  text-decoration: none;
  border-bottom: 1px solid rgba(37, 242, 210, .45);
}
.page-contact .co-contact-fine a:hover {
  border-bottom-color: var(--neon);
}

/* ---------- 06 常见问题 ---------- */
.page-contact .co-faq {
  padding: var(--co-pad) 0 calc(var(--co-pad) + 20px);
  background: var(--ink);
  border-top: 1px solid var(--line);
}
.page-contact .co-faq-list {
  border-top: 1px solid var(--line);
}
.page-contact .co-faq-item {
  border-bottom: 1px solid var(--line);
}
.page-contact .co-faq-item summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 20px 2px;
  cursor: pointer;
  list-style: none;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.6;
  color: var(--paper);
}
.page-contact .co-faq-item summary::-webkit-details-marker {
  display: none;
}
.page-contact .co-faq-item summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-num);
  font-size: 20px;
  line-height: 1.2;
  color: var(--brand);
}
.page-contact .co-faq-item[open] summary::after {
  content: "–";
}
.page-contact .co-faq-item[open] summary {
  color: var(--neon);
}
.page-contact .co-faq-item p {
  margin: 0;
  padding: 0 2px 22px;
  max-width: 78ch;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--cool);
}
.page-contact .co-faq-item p a {
  color: var(--neon);
  text-decoration: none;
  border-bottom: 1px solid rgba(37, 242, 210, .45);
}

/* ---------- 返回顶部 ---------- */
.page-contact .to-top {
  position: fixed;
  right: 18px;
  bottom: 22px;
  z-index: 30;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-soft);
  border-radius: 50%;
  background: var(--glass);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  color: var(--paper);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity .25s var(--ease), transform .25s var(--ease), color .2s var(--ease);
}
.page-contact .to-top[data-visible="true"] {
  opacity: 1;
  pointer-events: auto;
  transform: none;
}
.page-contact .to-top:hover {
  color: var(--brand);
}

/* ---------- 动效 ---------- */
.page-contact [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}
.page-contact [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

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

@media (min-width: 860px) {
  .page-contact .co-track-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-contact .co-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 30px 28px;
  }
}

@media (min-width: 960px) {
  .page-contact .co-masthead {
    padding: 56px 0 72px;
  }
  .page-contact .co-masthead-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
    align-items: end;
  }
  .page-contact .co-invite-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 46px;
    align-items: center;
  }
  .page-contact .co-contact-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-contact .co-track-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-contact .co-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-contact .co-support-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-contact [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .page-contact .co-support-card,
  .page-contact .to-top {
    transition: none;
  }
  .page-contact .co-support-card:hover {
    transform: none;
  }
}
</main>