.page-about {
  --about-line: rgba(46, 70, 97, .30);
  --about-line-soft: rgba(46, 70, 97, .16);
  --about-paper-line: rgba(16, 24, 32, .10);
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

.page-about .wrap {
  min-width: 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background-image: repeating-linear-gradient(0deg, rgba(16, 24, 32, .035) 0 1px, transparent 1px 36px);
  border-bottom: 1px solid var(--about-paper-line);
  padding-bottom: clamp(28px, 5vw, 56px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(22px, 4vw, 42px);
  padding-top: clamp(22px, 4vw, 46px);
  align-items: start;
}

.page-about .about-hero__copy {
  min-width: 0;
}

.page-about .about-hero__copy h1 {
  margin: 10px 0 0;
  font-size: clamp(32px, 6.2vw, 62px);
  line-height: 1.12;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-hero__lead {
  margin: 18px 0 0;
  max-width: 34em;
  font-size: clamp(16px, 1.4vw, 18px);
  line-height: 1.78;
  color: var(--text);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 20px;
  margin-top: 26px;
}

.page-about .about-more {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 3px;
  color: var(--ink);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid var(--amber);
  transition: color .2s ease, gap .2s ease;
}

.page-about .about-more:hover,
.page-about .about-more:focus-visible {
  color: var(--amber);
  gap: 14px;
}

.page-about .about-board {
  min-width: 0;
  padding: 18px 18px 6px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  box-shadow: var(--shadow-panel);
  color: var(--paper);
}

.page-about .about-board__cap {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--amber-soft);
}

.page-about .about-board__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-board__list li {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding: 12px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-board__list li:first-child {
  border-top: 0;
}

.page-about .about-board__num {
  font-size: 20px;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: .02em;
}

.page-about .about-board__txt {
  font-size: 14px;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .about-hero__figure {
  margin: clamp(24px, 4vw, 40px) 0 0;
}

.page-about .media__inner {
  overflow: hidden;
  border: 1px solid var(--about-line);
  background: var(--mist);
}

.page-about .media__inner img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--slate);
}

/* ---------- 目录带 ---------- */
.page-about .about-index {
  background: var(--ink);
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
}

.page-about .about-index__cap {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: .10em;
  color: var(--amber-soft);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
}

.page-about .about-index__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  color: var(--mist);
  font-size: 14px;
  text-decoration: none;
  transition: border-color .2s ease, color .2s ease, background .2s ease;
}

.page-about .about-index__list a .mono {
  font-size: 11px;
  color: var(--amber);
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  border-color: var(--amber);
  background: rgba(201, 147, 58, .10);
  color: var(--paper);
}

/* ---------- 区块通用 ---------- */
.page-about .section {
  padding: clamp(42px, 6vw, 78px) 0;
}

.page-about .about-head {
  max-width: 46em;
  margin-bottom: clamp(24px, 3.4vw, 38px);
}

.page-about .about-head h2 {
  margin: 10px 0 0;
  font-size: clamp(25px, 3.4vw, 38px);
  line-height: 1.22;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-head__lead,
.page-about .about-head > p:not(.eyebrow) {
  margin: 14px 0 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text);
}

/* ---------- 版本沿革 ---------- */
.page-about .about-timeline {
  background: var(--paper);
}

.page-about .stage-track {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--about-line);
}

.page-about .stage {
  position: relative;
  padding-left: 18px;
}

.page-about .stage + .stage {
  margin-top: 6px;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 20px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 3px var(--paper);
}

.page-about .stage:nth-child(2)::before {
  background: var(--slate);
}

.page-about .stage:nth-child(3)::before {
  background: var(--sage);
}

.page-about .stage:nth-child(4)::before {
  background: var(--cinnabar);
}

.page-about .stage summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 12px;
  padding: 12px 0;
  list-style: none;
  cursor: pointer;
  border-bottom: 1px dashed var(--about-line-soft);
}

.page-about .stage summary::-webkit-details-marker {
  display: none;
}

.page-about .stage summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--slate);
}

.page-about .stage[open] summary::after {
  content: "−";
  color: var(--amber);
}

.page-about .stage__year {
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--slate);
}

.page-about .stage__name {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .stage__body {
  padding: 12px 0 18px;
}

.page-about .stage__body p {
  margin: 0;
  max-width: 44em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .stage__facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 14px 0 0;
  padding: 0;
}

.page-about .stage__facts li {
  padding: 5px 10px;
  font-size: 12px;
  letter-spacing: .03em;
  color: var(--ink);
  background: rgba(201, 147, 58, .14);
  border: 1px solid rgba(201, 147, 58, .38);
}

.page-about .about-timeline__figure {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

/* ---------- 编号与索引（深色带） ---------- */
.page-about .about-numbering {
  background: var(--ink);
  color: var(--paper);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-head--deep h2 {
  color: var(--paper);
}

.page-about .about-head--deep p:not(.eyebrow) {
  color: var(--mist);
}

.page-about .term-band {
  display: grid;
  gap: 12px;
}

.page-about .term {
  padding: 18px 16px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--line);
  transition: border-color .2s ease, background .2s ease;
}

.page-about .term:hover {
  border-color: var(--amber);
  border-top-color: var(--amber);
  background: #172c42;
}

.page-about .term__no {
  margin: 0;
  font-size: 12px;
  letter-spacing: .10em;
  color: var(--amber);
}

.page-about .term__name {
  margin: 8px 0 0;
  font-size: 20px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .term__desc {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .term__eg {
  margin: 14px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--line-soft);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--amber-soft);
}

.page-about .code-example {
  display: grid;
  gap: 6px;
  margin: 18px 0 0;
  padding: 18px 16px;
  background: rgba(201, 147, 58, .10);
  border: 1px solid rgba(201, 147, 58, .45);
  border-left: 3px solid var(--amber);
}

.page-about .code-example__code {
  margin: 0;
  font-size: clamp(28px, 6vw, 44px);
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--amber-soft);
}

.page-about .code-example__read {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .cat-list {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  border-top: 1px solid var(--line);
}

.page-about .cat-list__item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 4px 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
  transition: background .2s ease, padding-left .2s ease;
}

.page-about .cat-list__item:hover {
  background: rgba(244, 241, 233, .04);
  padding-left: 6px;
}

.page-about .cat-list__no {
  grid-row: span 2;
  margin: 0;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--sage);
}

.page-about .cat-list__name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .cat-list__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-numbering__figure {
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  max-width: 640px;
}

.page-about .about-numbering__figure .media__inner {
  border-color: var(--line);
  background: var(--panel);
}

.page-about .about-numbering__figure .media__caption {
  color: var(--slate);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  background: var(--paper);
}

.page-about .team-list {
  border-top: 1px solid var(--about-paper-line);
}

.page-about .team-item {
  border-bottom: 1px solid var(--about-paper-line);
}

.page-about .team-item summary {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) auto;
  gap: 4px 12px;
  align-items: baseline;
  padding: 16px 0;
  list-style: none;
  cursor: pointer;
}

.page-about .team-item summary::-webkit-details-marker {
  display: none;
}

.page-about .team-item__num {
  grid-row: span 2;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--amber);
}

.page-about .team-item__name {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .team-item__hint {
  grid-column: 2;
  font-size: 13px;
  line-height: 1.6;
  color: var(--slate);
}

.page-about .team-item__count {
  grid-row: 1;
  grid-column: 3;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--ink);
  padding: 3px 8px;
  border: 1px solid var(--about-line);
}

.page-about .team-item[open] .team-item__name {
  color: var(--amber);
}

.page-about .team-item__body {
  padding: 0 0 18px 46px;
}

.page-about .team-item__body p {
  margin: 0;
  max-width: 42em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text);
  border-left: 2px solid var(--amber);
  padding-left: 14px;
}

/* ---------- 服务对象 ---------- */
.page-about .about-audience {
  background: var(--mist);
  border-top: 1px solid var(--about-line-soft);
  border-bottom: 1px solid var(--about-line-soft);
}

.page-about .scene-list {
  display: grid;
  gap: 16px;
}

.page-about .scene {
  padding: 20px 18px 18px;
  background: var(--paper);
  border: 1px solid var(--about-line);
  box-shadow: var(--shadow-paper);
}

.page-about .scene__no {
  margin: 0;
  font-size: 12px;
  letter-spacing: .10em;
  color: var(--cinnabar);
}

.page-about .scene__title {
  margin: 8px 0 0;
  font-size: 19px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .scene p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text);
}

.page-about .scene__go {
  margin-top: 16px !important;
  padding-top: 12px;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .scene__go a {
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid var(--amber);
  padding-bottom: 2px;
  transition: color .2s ease;
}

.page-about .scene__go a:hover,
.page-about .scene__go a:focus-visible {
  color: var(--amber);
}

/* ---------- 维护节奏 ---------- */
.page-about .about-cadence {
  background: var(--paper);
}

.page-about .about-cadence__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-cadence__main h2 {
  margin: 10px 0 0;
  font-size: clamp(25px, 3.4vw, 36px);
  line-height: 1.24;
  font-weight: 800;
  color: var(--ink);
}

.page-about .about-cadence__main > p {
  margin: 14px 0 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .cadence-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  margin: 24px 0 0;
  background: var(--about-line-soft);
  border: 1px solid var(--about-line-soft);
}

.page-about .cadence-stats__item {
  background: var(--paper);
  padding: 14px 14px 16px;
}

.page-about .cadence-stats dt {
  font-size: 13px;
  line-height: 1.5;
  color: var(--slate);
}

.page-about .cadence-stats dd {
  margin: 8px 0 0;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ink);
}

.page-about .cadence-steps {
  padding: 20px 18px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--sage);
  color: var(--paper);
  align-self: start;
}

.page-about .cadence-steps__title {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .cadence-steps__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  counter-reset: none;
}

.page-about .cadence-steps__list li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 10px;
  padding: 10px 0;
  border-top: 1px solid var(--line-soft);
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .cadence-steps__list li .mono {
  font-size: 12px;
  color: var(--amber);
}

.page-about .cadence-steps__note {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
  font-size: 12.5px;
  line-height: 2.1;
  color: var(--slate);
}

.page-about .cadence-steps__note .tag {
  margin-left: 6px;
  margin-right: 4px;
}

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  background: var(--ink-deep);
  border-top: 2px solid var(--amber);
  padding: clamp(34px, 5vw, 58px) 0;
}

.page-about .about-cta__inner {
  display: grid;
  gap: 22px;
  align-items: center;
}

.page-about .about-cta__text h2 {
  margin: 10px 0 0;
  font-size: clamp(23px, 3.2vw, 34px);
  line-height: 1.26;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-cta__text p:not(.eyebrow) {
  margin: 12px 0 0;
  max-width: 42em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

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

  .page-about .term-band .term:last-child {
    grid-column: span 2;
  }

  .page-about .scene-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .scene:last-child {
    grid-column: span 2;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, .85fr);
  }

  .page-about .term-band {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .term-band .term:last-child {
    grid-column: auto;
  }

  .page-about .code-example {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: 20px;
  }

  .page-about .scene-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .scene:last-child {
    grid-column: auto;
  }

  .page-about .scene:nth-child(2) {
    margin-top: 28px;
  }

  .page-about .about-cadence__grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, .8fr);
    align-items: start;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 32px;
  }

  .page-about .stage summary {
    flex-wrap: nowrap;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}