.page-about {
  --about-lead-gap: clamp(2.25rem, 6vw, 4rem);
  --about-tickline: var(--hairline-soft);
  color: var(--paper);
  font-family: var(--sans);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: 1.25rem 0;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 2rem;
  padding-block: 1rem 0;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 0.85rem;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.85rem, 6.2vw, 3.2rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  font-weight: 900;
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 0 0 1.5rem;
  max-width: 48ch;
  font-size: clamp(0.98rem, 2.2vw, 1.1rem);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-hero__tags {
  margin: 0 0 1.75rem;
}

.page-about .about-cover {
  margin: 0;
}

.page-about .about-cover img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--hairline);
  border-radius: var(--r-card);
  object-fit: cover;
}

.page-about .about-hero__visual {
  background: var(--ink-800);
  border: 1px solid var(--hairline);
  border-radius: var(--r-card);
  padding: 1rem 1rem 0.6rem;
}

.page-about .about-dial__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--about-tickline);
  color: var(--mist);
  font-size: 0.74rem;
}

.page-about .about-dial__pulse {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: var(--signal);
  animation: about-pulse 2.2s var(--ease) 1;
}

@keyframes about-pulse {
  0% { box-shadow: 0 0 0 0 rgba(255, 106, 42, 0.55); }
  70% { box-shadow: 0 0 0 10px rgba(255, 106, 42, 0); }
  100% { box-shadow: 0 0 0 0 rgba(255, 106, 42, 0); }
}

.page-about .about-dial__svg {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 0.6rem;
}

.page-about .dial-axis {
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .dial-ticks line {
  stroke: var(--about-tickline);
  stroke-width: 1;
}

.page-about .dial-nodes circle {
  fill: var(--ink-800);
  stroke: var(--cyan);
  stroke-width: 1.5;
}

.page-about .dial-nodes .is-current {
  fill: var(--signal);
  stroke: var(--signal);
}

.page-about .dial-year {
  fill: var(--paper);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.04em;
}

.page-about .dial-desc {
  fill: var(--mist);
  font-family: var(--sans);
  font-size: 10px;
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding-block: var(--about-lead-gap) 0;
}

.page-about .about-chapter__head {
  position: relative;
  padding-bottom: 0.9rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--about-tickline);
}

.page-about .about-chapter__head::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 64px;
  height: 2px;
  background: var(--signal);
}

.page-about .about-chapter__code {
  display: block;
  margin-bottom: 0.45rem;
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  color: var(--signal);
}

.page-about .about-chapter__title {
  margin: 0 0 0.4rem;
  font-size: clamp(1.28rem, 4.2vw, 1.95rem);
  line-height: 1.28;
  letter-spacing: -0.01em;
  font-weight: 800;
}

.page-about .about-chapter__kicker {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-chapter__intro {
  margin: 0 0 1.25rem;
  max-width: 60ch;
  font-size: 0.96rem;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 叙述 + 侧注 ---------- */
.page-about .about-split {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-prose p {
  margin: 0 0 1.1rem;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--mist);
}

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

.page-about .about-aside {
  align-self: start;
  padding: 1.15rem 1.15rem 1.25rem;
  border-radius: var(--r-card);
  background: var(--ink-800);
}

.page-about .about-aside__list {
  margin: 0.8rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.55rem;
}

.page-about .about-aside__list li {
  position: relative;
  padding-left: 1.1rem;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-aside__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 0.5rem;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 分类标签面板 ---------- */
.page-about .cat-map {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.75rem;
}

.page-about .cat-map__item {
  position: relative;
  padding: 1rem 1rem 1.1rem 1.25rem;
  background: var(--ink-800);
  border: 1px solid var(--about-tickline);
  border-radius: var(--r-card);
  transition: transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .cat-map__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1rem;
  bottom: 1rem;
  width: 2px;
  background: var(--line);
  transition: background-color var(--dur) var(--ease);
}

.page-about .cat-map__item:hover,
.page-about .cat-map__item:focus-within {
  transform: translateY(-2px);
  border-color: rgba(47, 224, 207, 0.45);
  background: var(--ink-700);
}

.page-about .cat-map__item:hover::before,
.page-about .cat-map__item:focus-within::before {
  background: var(--cyan);
}

.page-about .cat-map__code {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .cat-map__name {
  margin: 0 0 0.4rem;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .cat-map__desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.68;
  color: var(--mist);
}

/* ---------- 三道工序 ---------- */
.page-about .about-check {
  margin-top: 1.5rem;
  padding: 1.15rem;
  border: 1px dashed var(--line);
  border-radius: var(--r-card);
}

.page-about .about-check__list {
  margin: 0.85rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.9rem;
}

.page-about .about-check__list li {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--mist);
  padding-top: 0.7rem;
  border-top: 2px solid var(--ink-700);
}

.page-about .about-check__num {
  display: inline-block;
  margin-right: 0.5rem;
  font-size: 0.72rem;
  color: var(--signal);
  letter-spacing: 0.08em;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  margin-top: 0.5rem;
}

.page-about .timeline__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.5rem;
}

.page-about .timeline__node {
  position: relative;
  padding-left: 1.15rem;
  border-left: 2px solid var(--about-tickline);
}

.page-about .timeline__node::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 0.95rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--line);
  transition: background-color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.page-about .timeline__node[open]::before {
  background: var(--signal);
  border-color: var(--signal);
}

.page-about .timeline__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.35rem 0.85rem;
  padding: 0.55rem 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .timeline__summary::after {
  content: "展开 +";
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .timeline__node[open] .timeline__summary::after {
  content: "收起 −";
}

.page-about .timeline__summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: var(--r-sm);
}

.page-about .timeline__year {
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  color: var(--signal);
}

.page-about .timeline__name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .timeline__body {
  padding-bottom: 0.85rem;
}

.page-about .timeline__body p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--mist);
  max-width: 62ch;
}

/* ---------- 图片区 ---------- */
.page-about .about-figure {
  margin: 1.75rem 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--about-tickline);
  border-radius: var(--r-card);
  object-fit: cover;
}

.page-about .about-figure figcaption {
  margin-top: 0.6rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .about-split--team {
  gap: 1.5rem;
}

.page-about .about-team__roles {
  display: grid;
}

.page-about .role {
  padding: 1rem 0;
  border-bottom: 1px solid var(--about-tickline);
}

.page-about .role:first-child {
  border-top: 1px solid var(--about-tickline);
}

.page-about .role__code {
  margin: 0 0 0.3rem;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .role__title {
  margin: 0 0 0.4rem;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .role__desc {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--mist);
  max-width: 54ch;
}

.page-about .about-team__rhythm {
  align-self: start;
  padding: 1.15rem;
  border-radius: var(--r-card);
  background: var(--ink-800);
  border: 1px solid var(--about-tickline);
}

.page-about .rhythm {
  margin: 0.85rem 0 0;
  display: grid;
  gap: 0.9rem;
}

.page-about .rhythm__row {
  padding-left: 0.85rem;
  border-left: 1px solid var(--hairline);
}

.page-about .rhythm__row dt {
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--signal);
  margin-bottom: 0.2rem;
}

.page-about .rhythm__row dd {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.68;
  color: var(--mist);
}

/* ---------- 覆盖与合作 ---------- */
.page-about .coverage {
  display: grid;
  gap: 0.9rem;
}

.page-about .coverage__item {
  padding: 1.25rem;
  background: var(--ink-800);
  border: 1px solid var(--about-tickline);
  border-radius: var(--r-card);
}

.page-about .coverage__num {
  margin: 0;
  font-size: clamp(2rem, 7vw, 2.6rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .coverage__label {
  margin: 0.4rem 0 0.6rem;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .coverage__desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .eco {
  display: block;
  width: 100%;
  max-width: 560px;
  height: auto;
  margin: 1.5rem auto 0;
}

.page-about .eco__lines line {
  stroke: var(--hairline);
  stroke-width: 1;
}

.page-about .eco__nodes circle {
  fill: var(--ink-700);
  stroke: var(--cyan);
  stroke-width: 1.2;
}

.page-about .eco__nodes .is-hub {
  fill: var(--signal);
  stroke: var(--signal);
}

.page-about .eco__note {
  margin: 0.4rem 0 0;
  text-align: center;
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  color: var(--mist);
}

/* ---------- 守则清单 ---------- */
.page-about .principles {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .principles__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.9rem;
  padding: 0.95rem 0;
  border-top: 1px solid var(--about-tickline);
  align-items: start;
}

.page-about .principles__item:last-child {
  border-bottom: 1px solid var(--about-tickline);
}

.page-about .principles__mark {
  padding-top: 0.2rem;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .principles__text {
  margin: 0;
  font-size: 0.925rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 去向 ---------- */
.page-about .about-next {
  margin-top: var(--about-lead-gap);
  padding-block: clamp(1.75rem, 5vw, 2.75rem);
  background: var(--ink-800);
  border-top: 1px solid var(--hairline);
}

.page-about .about-next__grid {
  display: grid;
  gap: 1.25rem;
}

.page-about .about-next h2 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.2rem, 3.6vw, 1.6rem);
  line-height: 1.3;
  font-weight: 800;
}

.page-about .about-next__lead {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--mist);
  max-width: 36ch;
}

.page-about .about-next__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.5rem;
}

.page-about .about-next__list a {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.35rem 1rem;
  padding: 0.8rem 1rem;
  font-size: 0.9rem;
  color: var(--paper);
  text-decoration: none;
  background: var(--ink-700);
  border: 1px solid var(--about-tickline);
  border-radius: var(--r-sm);
  transition: border-color var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.page-about .about-next__list a:hover,
.page-about .about-next__list a:focus-visible {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .about-next__list a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .link-path {
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--cyan);
  white-space: nowrap;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .cat-map {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-check__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.1rem;
  }

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

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    gap: 3rem;
    align-items: start;
    padding-block: 1.5rem 0;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 2.5rem;
    align-items: start;
  }

  .page-about .about-split--team {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  }

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

  .page-about .about-chapter__head {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    column-gap: 1.1rem;
    align-items: baseline;
  }

  .page-about .about-chapter__code {
    grid-row: 1 / 3;
    margin-bottom: 0;
    padding-top: 0.2rem;
  }

  .page-about .about-next__grid {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    gap: 2.5rem;
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-dial__pulse {
    animation: none;
  }

  .page-about .cat-map__item,
  .page-about .about-next__list a,
  .page-about .timeline__node::before,
  .page-about .cat-map__item::before {
    transition: none;
  }

  .page-about .cat-map__item:hover,
  .page-about .cat-map__item:focus-within,
  .page-about .about-next__list a:hover,
  .page-about .about-next__list a:focus-visible {
    transform: none;
  }
}