.page-about {
  --about-pad: clamp(2.75rem, 6.5vw, 5.5rem);
  --about-gap: clamp(1.5rem, 3.5vw, 2.75rem);
  --about-line: rgba(20, 32, 43, .16);
  --about-line-dark: rgba(244, 238, 226, .22);
  --about-rail: minmax(0, 4fr);
  --about-main: minmax(0, 8fr);
  background: var(--paper);
  color: var(--ink);
}

.page-about img {
  max-width: 100%;
  height: auto;
}

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

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: var(--about-rail) var(--about-main);
  }
}

.page-about .about-rail h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.15rem);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: .01em;
  margin: .5rem 0 .9rem;
}

.page-about .about-rail-note {
  margin: 0;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

@media (min-width: 900px) {
  .page-about .about-rail {
    border-right: 1px solid var(--about-line);
    padding-right: clamp(1.25rem, 2.5vw, 2rem);
  }
}

.page-about .about-body p {
  margin: 0 0 1.15rem;
  line-height: 1.8;
}

.page-about .about-body p:last-child {
  margin-bottom: 0;
}

.page-about .about-body a {
  color: var(--pitch);
  text-decoration: underline;
  text-underline-offset: .22em;
  text-decoration-thickness: 1px;
}

.page-about .about-body a:hover,
.page-about .about-body a:focus-visible {
  color: var(--pitch-deep);
  text-decoration-thickness: 2px;
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  position: relative;
  background: var(--stand-blue);
  color: var(--paper);
  border-bottom: 3px solid var(--night-ink);
  padding: clamp(1.25rem, 3vw, 2rem) 0 clamp(2.5rem, 6vw, 4.5rem);
  background-image: repeating-linear-gradient(90deg, rgba(244, 238, 226, .05) 0 1px, transparent 1px 88px);
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(1rem, 2.5vw, 1.75rem);
}

.page-about .about-hero .breadcrumb ol,
.page-about .about-hero .breadcrumb li,
.page-about .about-hero .breadcrumb a {
  color: var(--paper-dim);
}

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

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(2rem, 4vw, 3rem);
  align-items: end;
}

@media (min-width: 920px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  }
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 6.2vw, 4.1rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: .005em;
  margin: .6rem 0 1.1rem;
  color: var(--paper);
  max-width: 20em;
}

.page-about .about-hero-lead {
  margin: 0;
  max-width: 46em;
  font-size: clamp(1rem, 1.6vw, 1.1rem);
  line-height: 1.85;
  color: rgba(244, 238, 226, .86);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.6rem;
}

.page-about .about-board {
  border: 3px solid var(--amber);
  background: var(--night-ink);
  padding: clamp(1.1rem, 2.4vw, 1.5rem);
  box-shadow: var(--shadow-ink);
}

.page-about .about-board-title {
  font-family: var(--font-display);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .22em;
  color: var(--amber);
  margin: 0 0 .9rem;
}

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

.page-about .about-board-list li {
  display: grid;
  grid-template-columns: minmax(0, 7.5rem) minmax(0, 1fr);
  align-items: baseline;
  gap: .9rem;
  padding: .7rem 0;
  border-top: 1px solid var(--about-line-dark);
}

.page-about .about-board-list li:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-board-list .num {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3.2vw, 2rem);
  font-weight: 800;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .about-board-list span:last-child {
  font-size: .9rem;
  line-height: 1.55;
  color: rgba(244, 238, 226, .78);
}

/* ===== 分区背景 ===== */
.page-about .about-what {
  background: var(--paper);
}

.page-about .about-scope {
  background: var(--paper-dim);
}

.page-about .about-update {
  background: var(--paper);
}

.page-about .about-partners {
  background: var(--paper);
}

.page-about .about-team {
  background: var(--night-ink);
  color: var(--paper);
  --about-line: var(--about-line-dark);
}

.page-about .about-team .about-rail h2 {
  color: var(--paper);
}

.page-about .about-team .about-rail-note {
  color: rgba(244, 238, 226, .72);
}

.page-about .about-contact {
  background: var(--stand-blue);
  color: var(--paper);
  --about-line: var(--about-line-dark);
}

/* ===== 要点列表 ===== */
.page-about .about-points {
  list-style: none;
  counter-reset: pt;
  margin: clamp(1.75rem, 3vw, 2.5rem) 0 0;
  padding: 0;
  border-top: 3px solid var(--ink);
}

.page-about .about-points li {
  counter-increment: pt;
  position: relative;
  padding: 1.05rem 0 1.05rem clamp(3rem, 6vw, 3.6rem);
  border-bottom: 1px solid var(--about-line);
  font-size: .95rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

.page-about .about-points li::before {
  content: "0" counter(pt);
  position: absolute;
  left: 0;
  top: 1.05rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--pitch);
  font-variant-numeric: tabular-nums;
}

.page-about .about-points strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ink);
  margin-bottom: .2rem;
}

/* ===== 历程刻度带 ===== */
.page-about .about-track {
  background: var(--night-ink);
  color: var(--paper);
  --about-line: var(--about-line-dark);
  background-image: repeating-linear-gradient(90deg, rgba(244, 238, 226, .05) 0 1px, transparent 1px 96px);
}

.page-about .about-track-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.6vw, 2.6rem);
  font-weight: 800;
  line-height: 1.14;
  margin: .5rem 0 0;
  color: var(--paper);
}

.page-about .about-track-media {
  margin: clamp(1.5rem, 3vw, 2.25rem) 0 clamp(1.75rem, 3.5vw, 2.5rem);
  border: 3px solid rgba(244, 238, 226, .32);
  box-shadow: var(--shadow-ink);
  overflow: hidden;
}

.page-about .about-track-media img {
  display: block;
  width: 100%;
  aspect-ratio: 12 / 7;
  object-fit: cover;
}

.page-about .about-timeline {
  list-style: none;
  margin: clamp(1.25rem, 3vw, 2rem) 0 0;
  padding: 0;
  border-top: 3px solid var(--amber);
}

.page-about .about-node {
  position: relative;
  padding: 2rem 0 1.6rem 2.4rem;
  border-bottom: 1px solid var(--about-line);
  outline-offset: 6px;
}

.page-about .about-node:last-child {
  border-bottom: 0;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 2.35rem;
  width: 11px;
  height: 11px;
  background: var(--amber);
  box-shadow: 0 0 0 3px var(--night-ink);
}

.page-about .about-node::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--about-line);
}

.page-about .about-node-season {
  display: block;
  font-family: var(--font-display);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--amber);
  margin-bottom: .45rem;
}

.page-about .about-node h3 {
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2.2vw, 1.3rem);
  font-weight: 700;
  line-height: 1.32;
  margin: 0 0 .5rem;
  color: var(--paper);
}

.page-about .about-node p {
  margin: 0;
  max-width: 34em;
  font-size: .93rem;
  line-height: 1.75;
  color: rgba(244, 238, 226, .76);
}

.page-about .about-node .about-node-more {
  margin-top: .65rem;
  padding-left: .9rem;
  border-left: 2px solid var(--pitch);
  font-size: .87rem;
  line-height: 1.7;
  color: var(--amber);
  opacity: 1;
  max-height: 20rem;
  transition: opacity .16s ease, max-height .16s ease, margin-top .16s ease;
}

@media (min-width: 1024px) {
  .page-about .about-timeline {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0 clamp(1rem, 2vw, 1.75rem);
  }

  .page-about .about-node {
    border-bottom: 0;
    padding: 2.5rem 0 0;
  }

  .page-about .about-node::after {
    left: 0;
    top: -2.5rem;
    bottom: auto;
    width: 1px;
    height: calc(2.5rem + 12px);
  }

  .page-about .about-node::before {
    top: -2.5rem;
    left: 0;
  }

  .page-about .about-node p {
    max-width: none;
  }

  .page-about .about-node .about-node-more {
    opacity: 0;
    max-height: 0;
    margin-top: 0;
    overflow: hidden;
  }

  .page-about .about-node:hover .about-node-more,
  .page-about .about-node:focus .about-node-more,
  .page-about .about-node:focus-within .about-node-more {
    opacity: 1;
    max-height: 20rem;
    margin-top: .7rem;
  }
}

/* ===== 覆盖范围 ===== */
.page-about .about-scope-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.75rem, 4vw, 3rem);
}

@media (min-width: 900px) {
  .page-about .about-scope-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: start;
    gap: clamp(2rem, 4vw, 3.5rem);
  }
}

.page-about .about-scope-copy h2 {
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.4vw, 2.4rem);
  font-weight: 800;
  line-height: 1.15;
  margin: .5rem 0 1rem;
}

.page-about .about-scope-copy p {
  margin: 0 0 1.15rem;
  line-height: 1.8;
}

.page-about .about-scope-copy a {
  color: var(--pitch-deep);
  text-decoration: underline;
  text-underline-offset: .22em;
}

.page-about .about-scope-list {
  margin: clamp(1.5rem, 3vw, 2rem) 0;
  padding: 0;
  border-top: 3px solid var(--ink);
}

.page-about .about-scope-list > div {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .3rem;
  padding: 1.05rem 0;
  border-bottom: 1px solid var(--about-line);
}

@media (min-width: 640px) {
  .page-about .about-scope-list > div {
    grid-template-columns: minmax(0, 8rem) minmax(0, 1fr);
    gap: 1.25rem;
  }
}

.page-about .about-scope-list dt {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .03em;
  color: var(--pitch-deep);
}

.page-about .about-scope-list dd {
  margin: 0;
  font-size: .95rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

.page-about .about-scope-figure {
  margin: 0;
  border: 3px solid var(--ink);
  background: var(--paper);
  box-shadow: var(--shadow-hard);
}

.page-about .about-scope-figure img {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

.page-about .about-scope-figure figcaption {
  padding: .85rem 1rem;
  border-top: 1px solid var(--about-line);
  font-size: .84rem;
  line-height: 1.65;
  color: var(--ink-soft);
}

/* ===== 更新节奏 ===== */
.page-about .about-slots {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  margin: 1.75rem 0;
}

.page-about .about-slot {
  display: grid;
  grid-template-columns: minmax(0, 5rem) minmax(0, 1fr);
  gap: 1rem;
  align-items: baseline;
  padding: 1rem 0;
  border-top: 1px solid var(--about-line);
}

@media (min-width: 760px) {
  .page-about .about-slots {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 clamp(1rem, 2vw, 1.75rem);
  }

  .page-about .about-slot {
    grid-template-columns: minmax(0, 1fr);
    gap: .4rem;
    padding: .9rem 0 0;
    border-top: 3px solid var(--amber);
  }
}

.page-about .about-slot-time {
  font-family: var(--font-display);
  font-size: .95rem;
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--pitch);
}

.page-about .about-slot p {
  margin: 0;
  font-size: .92rem;
  line-height: 1.72;
  color: var(--ink-soft);
}

.page-about .about-metrics-intro {
  margin: 1.5rem 0 1rem;
}

.page-about .about-metrics-intro .num {
  font-family: var(--font-display);
  font-size: 1.9em;
  font-weight: 800;
  line-height: 1;
  color: var(--pitch-deep);
  font-variant-numeric: tabular-nums;
  vertical-align: -.08em;
  margin-right: .12em;
}

.page-about .about-metrics-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin: 0 0 1.5rem;
  padding: 0;
}

.page-about .about-metrics-tags li {
  padding: .38rem .8rem;
  border: 2px solid var(--pitch);
  font-size: .84rem;
  font-weight: 600;
  color: var(--pitch-deep);
  background: var(--paper);
}

/* ===== 团队 ===== */
.page-about .about-team-list {
  margin: 0;
  padding: 0;
  border-top: 3px solid var(--amber);
}

.page-about .about-team-list > div {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .5rem;
  padding: 1.35rem 0;
  border-bottom: 1px solid var(--about-line);
}

@media (min-width: 760px) {
  .page-about .about-team-list > div {
    grid-template-columns: minmax(0, 13rem) minmax(0, 1fr);
    gap: 1.5rem;
    align-items: start;
  }
}

.page-about .about-team-list dt {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: .6rem;
  font-family: var(--font-display);
}

.page-about .about-team-list .num {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3.5vw, 2.25rem);
  font-weight: 800;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .about-team-role {
  font-size: .95rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--paper);
}

.page-about .about-team-list dd {
  margin: 0;
  font-size: .94rem;
  line-height: 1.78;
  color: rgba(244, 238, 226, .78);
}

/* ===== 协作 ===== */
.page-about .about-partners-figure {
  margin: clamp(1.75rem, 4vw, 3rem) 0 0;
  border: 3px solid var(--ink);
  box-shadow: var(--shadow-hard);
  background: var(--paper);
}

.page-about .about-partners-figure img {
  display: block;
  width: 100%;
  aspect-ratio: 20 / 13;
  object-fit: cover;
}

.page-about .about-partners-figure figcaption {
  padding: .85rem 1rem;
  border-top: 1px solid var(--about-line);
  font-size: .84rem;
  line-height: 1.65;
  color: var(--ink-soft);
}

/* ===== 联系 ===== */
.page-about .about-contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.75rem, 4vw, 3rem);
}

@media (min-width: 900px) {
  .page-about .about-contact-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }
}

.page-about .about-contact-copy h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3.4vw, 2.3rem);
  font-weight: 800;
  line-height: 1.18;
  margin: .5rem 0 1rem;
  color: var(--paper);
}

.page-about .about-contact-copy p {
  margin: 0;
  max-width: 40em;
  line-height: 1.85;
  color: rgba(244, 238, 226, .82);
}

.page-about .about-contact-copy a {
  color: var(--amber);
  text-decoration: underline;
  text-underline-offset: .22em;
}

.page-about .about-contact-card {
  border: 3px solid var(--amber);
  background: var(--night-ink);
  padding: clamp(1.1rem, 2.4vw, 1.6rem);
  box-shadow: var(--shadow-ink);
}

.page-about .about-contact-list {
  margin: 0 0 1.4rem;
  padding: 0;
}

.page-about .about-contact-list > div {
  padding: .8rem 0;
  border-top: 1px solid var(--about-line-dark);
}

.page-about .about-contact-list > div:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-contact-list dt {
  font-family: var(--font-display);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--amber);
  margin-bottom: .3rem;
}

.page-about .about-contact-list dd {
  margin: 0;
  font-size: .95rem;
  line-height: 1.6;
  color: rgba(244, 238, 226, .9);
  overflow-wrap: anywhere;
}

.page-about .about-contact-value {
  font-weight: 700;
  letter-spacing: .02em;
}

.page-about .about-contact-value--mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .06em;
}

/* ===== 回到顶部 ===== */
.page-about .about-totop {
  position: fixed;
  right: 0;
  bottom: 20%;
  z-index: 20;
  writing-mode: vertical-rl;
  padding: .85rem .42rem;
  background: var(--stand-blue);
  color: var(--paper);
  border: 3px solid var(--night-ink);
  border-right: 0;
  font-family: var(--font-display);
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .2em;
  text-decoration: none;
  transition: background .16s ease, color .16s ease;
}

.page-about .about-totop:hover,
.page-about .about-totop:focus-visible {
  background: var(--amber);
  color: var(--night-ink);
}

@media (max-width: 640px) {
  .page-about .about-totop {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-node .about-node-more,
  .page-about .about-totop {
    transition: none;
  }
}