.page-about {
  --about-rail: 200px;
  --about-hi: #163D33;
  --about-row-hi: #0D211B;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(28px, 5vw, 56px) 0 clamp(32px, 5vw, 56px);
  border-bottom: 1px solid var(--rule);
  background:
    linear-gradient(180deg, rgba(0, 232, 200, .05) 0%, rgba(0, 232, 200, 0) 46%),
    var(--ink);
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(20px, 3vw, 36px);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .breadcrumb a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-hero-lead h1 {
  margin: 12px 0 22px;
  font-size: clamp(34px, 7vw, 88px);
  line-height: 1.04;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .kicker {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .24em;
  color: var(--cyan);
  margin: 0;
  text-transform: uppercase;
}

.page-about .about-lede {
  max-width: 36em;
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.9;
  color: rgba(243, 238, 226, .86);
  margin: 0;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero-side {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  padding-top: 18px;
  border-top: 1px solid var(--rule);
}

.page-about .about-side-note {
  max-width: 24em;
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
  margin: 0;
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(28px, 4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: var(--ink);
}

.page-about .about-fact-num {
  font-family: var(--mono);
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
  transition: color .18s var(--ease), transform .18s var(--ease);
}

.page-about .about-fact-label {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--muted);
}

.page-about .about-fact:hover .about-fact-num {
  color: var(--flame);
  transform: translateY(-2px);
}

/* ---------- 通栏主图 ---------- */
.page-about .about-banner {
  position: relative;
  margin: 0;
  background: var(--pit);
  border-bottom: 1px solid var(--rule);
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  opacity: .78;
}

.page-about .about-banner::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(11, 31, 26, .08) 0%, rgba(6, 18, 15, .88) 100%);
}

.page-about .about-banner .img-cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1;
  margin: 0;
  padding: 16px var(--pad-x) 18px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cyan-soft);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding: clamp(44px, 6vw, 88px) 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .about-chapter-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

.page-about .about-chapter-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

.page-about .about-rail-num {
  font-family: var(--mono);
  font-size: 44px;
  line-height: 1;
  letter-spacing: -0.03em;
  color: rgba(0, 232, 200, .26);
  transition: color .18s var(--ease);
}

.page-about .about-rail-name {
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--muted);
}

.page-about .about-chapter:hover .about-rail-num {
  color: rgba(0, 232, 200, .6);
}

.page-about .about-chapter-body {
  min-width: 0;
}

.page-about .about-chapter-title {
  margin: 0 0 20px;
  font-size: clamp(24px, 3.4vw, 42px);
  line-height: 1.22;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-chapter-body p {
  max-width: 40em;
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.9;
  color: rgba(243, 238, 226, .8);
}

.page-about .about-chapter-body a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 232, 200, .35);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-chapter-body a:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

.page-about .about-points {
  list-style: none;
  margin: 26px 0 22px;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .about-points li {
  padding: 16px 18px;
  background: var(--ink);
  font-size: 15px;
  line-height: 1.85;
  color: rgba(243, 238, 226, .8);
  transition: background .18s var(--ease);
}

.page-about .about-points li:hover {
  background: var(--about-row-hi);
}

.page-about .about-points strong {
  margin-right: 6px;
  color: var(--cyan);
  font-weight: 700;
}

.page-about .about-crosslink {
  color: var(--muted) !important;
  font-size: 14px !important;
  letter-spacing: .02em;
}

/* ---------- 角色分工 ---------- */
.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 26px;
}

.page-about .about-role {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 22px 26px;
  background: var(--panel);
  border: 1px solid var(--rule);
  transition: border-color .18s var(--ease), background .18s var(--ease);
}

.page-about .about-role:hover {
  border-color: var(--cyan);
  background: var(--about-hi);
}

.page-about .about-role-count {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--amber);
}

.page-about .about-role h3 {
  margin: 0;
  font-size: 22px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-role p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(243, 238, 226, .78);
}

.page-about .about-role .about-role-scope {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid var(--rule);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--muted);
}

/* ---------- 三步校对 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-flow-step {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 0 0;
  border-top: 1px solid var(--rule);
  transition: border-color .18s var(--ease);
}

.page-about .about-flow-step::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 42px;
  height: 2px;
  background: var(--cyan);
  transition: width .18s var(--ease);
}

.page-about .about-flow-step:hover {
  border-top-color: var(--cyan);
}

.page-about .about-flow-step:hover::before {
  width: 96px;
}

.page-about .about-flow-tag {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .about-flow-title {
  margin: 0;
  font-size: 20px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-flow-step p {
  margin: 0;
  max-width: 30em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(243, 238, 226, .78);
}

.page-about .about-flow-checks {
  list-style: none;
  margin: 4px 0 0;
  padding: 12px 0 0;
  display: grid;
  gap: 9px;
  border-top: 1px solid var(--rule);
}

.page-about .about-flow-checks li {
  position: relative;
  padding-left: 16px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-flow-checks li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 5px;
  background: var(--rule);
  transition: background .18s var(--ease);
}

.page-about .about-flow-step:hover .about-flow-checks li::before {
  background: var(--cyan-soft);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: 32px 0 26px;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--rule);
  filter: saturate(.85) contrast(1.04);
}

.page-about .about-figure .img-cap {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

/* ---------- 更新节奏时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .about-tl-item {
  position: relative;
  margin-left: 5px;
  padding: 0 0 30px 30px;
  border-left: 1px solid var(--rule);
}

.page-about .about-tl-item:last-child {
  padding-bottom: 0;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 5px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px var(--ink);
  transition: background .18s var(--ease), transform .18s var(--ease);
}

.page-about .about-tl-item:hover::before {
  background: var(--flame);
  transform: scale(1.3);
}

.page-about .about-tl-when {
  display: block;
  margin-bottom: 7px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--amber);
}

.page-about .about-timeline .about-tl-item h3 {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-timeline .about-tl-item p {
  margin: 0;
  max-width: 38em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(243, 238, 226, .78);
}

/* ---------- 版本口径 ---------- */
.page-about .about-versions {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 28px;
}

.page-about .about-version {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 24px 22px 22px;
  background: var(--panel);
  border: 1px solid var(--rule);
  transition: border-color .18s var(--ease), background .18s var(--ease);
}

.page-about .about-version--stable {
  border-top: 3px solid var(--amber);
}

.page-about .about-version--full {
  border-top: 3px solid var(--cyan);
}

.page-about .about-version:hover {
  border-color: var(--cyan);
  background: var(--about-hi);
}

.page-about .about-version h3 {
  margin: 0;
  font-size: 20px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-version > p {
  margin: 0;
  max-width: 32em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(243, 238, 226, .78);
}

.page-about .about-version .about-version-scope {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px dashed var(--rule);
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: .01em;
  color: var(--cyan-soft);
  word-break: break-word;
}

.page-about .about-version .copy-btn {
  align-self: flex-start;
}

/* ---------- 复制按钮 ---------- */
.page-about .copy-btn {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 0;
  padding: 7px 14px;
  cursor: pointer;
  transition: color .18s var(--ease), border-color .18s var(--ease), background .18s var(--ease);
}

.page-about .copy-btn:hover {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- 联系与备案 ---------- */
.page-about .about-contact {
  position: relative;
  padding: clamp(44px, 6vw, 76px) 0 clamp(48px, 7vw, 90px);
  background: var(--pit);
}

.page-about .about-contact::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 6px;
  background: var(--flame);
}

.page-about .about-contact-title {
  margin: 0 0 26px;
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .about-contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  padding: 16px 18px;
  background: var(--pit);
  transition: background .18s var(--ease);
}

.page-about .about-contact-row:hover {
  background: var(--about-row-hi);
}

.page-about .contact-key {
  flex: 0 0 108px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--muted);
}

.page-about .contact-val {
  flex: 1 1 200px;
  min-width: 0;
  font-family: var(--mono);
  font-size: 15px;
  line-height: 1.6;
  color: var(--cyan-soft);
  word-break: break-all;
}

.page-about .about-contact-row .copy-btn {
  margin-left: auto;
}

.page-about .about-contact-note {
  margin: 26px 0 0;
  max-width: 64em;
  font-size: 13px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-contact-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 232, 200, .35);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-contact-note a:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .about-versions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
    align-items: end;
  }

  .page-about .about-hero-side {
    min-height: 190px;
    padding: 4px 0 4px 26px;
    border-top: 0;
    border-left: 1px solid var(--rule);
  }

  .page-about .about-chapter-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-chapter-rail {
    position: sticky;
    top: 96px;
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 4px 0 4px 18px;
    border-bottom: 0;
    border-left: 1px solid var(--rule);
  }

  .page-about .about-rail-num {
    font-size: 68px;
  }

  .page-about .about-figure--wide {
    width: 62%;
    margin-left: auto;
  }

  .page-about .about-figure--archive {
    max-width: 520px;
    margin-right: auto;
  }
}

@media (min-width: 960px) {
  .page-about .about-roles {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-role:nth-child(1) {
    grid-column: 1 / span 5;
  }

  .page-about .about-role:nth-child(2) {
    grid-column: 6 / span 4;
    margin-top: 48px;
  }

  .page-about .about-role:nth-child(3) {
    grid-column: 3 / span 8;
    margin-top: -8px;
  }
}

@media (max-width: 520px) {
  .page-about .about-contact-row {
    align-items: flex-start;
  }

  .page-about .contact-key {
    flex: 0 0 100%;
  }

  .page-about .about-contact-row .copy-btn {
    margin-left: 0;
  }

  .page-about .about-banner .img-cap {
    position: static;
    background: var(--pit);
  }
}