.page-about {
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

.page-about h2 {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(25px, 5.2vw, 34px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  margin: 0 0 18px;
  color: var(--ink);
}

.page-about h3 {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.3;
  margin: 0 0 10px;
  color: var(--ink);
}

.page-about p {
  font-size: 17px;
  line-height: 1.75;
  margin: 0 0 1em;
}

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

.page-about .about-link {
  color: var(--sky);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .about-link:hover {
  color: var(--clay);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(20px, 4vw, 40px) 0 clamp(24px, 4vw, 44px);
}

.page-about .about-hero__eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--clay);
  margin: 0 0 16px;
}

.page-about .about-hero h1 {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(33px, 8.4vw, 64px);
  line-height: 1.06;
  letter-spacing: -0.015em;
  margin: 0 0 20px;
  color: var(--ink);
}

.page-about .about-hero__accent {
  color: var(--clay);
  display: inline-block;
}

.page-about .about-hero__lede {
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink);
  max-width: 36em;
}

.page-about .about-hero__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero__facts {
  margin-top: 34px;
  padding: 20px 18px;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-1);
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
}

.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--rule);
}

.page-about .about-facts__num {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(26px, 6vw, 34px);
  line-height: 1;
  color: var(--clay);
  font-variant-numeric: tabular-nums;
}

.page-about .about-facts__label {
  font-size: 14px;
  line-height: 1.5;
  color: var(--moss);
}

.page-about .about-facts__note {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--rule);
  font-size: 14px;
  line-height: 1.65;
  color: var(--moss);
}

/* ---------- 工作台图 ---------- */
.page-about .about-bench {
  margin: 0;
  padding: 0 0 clamp(34px, 6vw, 68px);
}

.page-about .about-bench__media {
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-1);
}

.page-about .about-bench .media__caption {
  margin-top: 12px;
}

/* ---------- 起点 ---------- */
.page-about .about-origin {
  padding-top: clamp(28px, 5vw, 52px);
}

.page-about .about-origin__text {
  max-width: 40em;
}

.page-about .about-origin__aside {
  margin-top: 30px;
}

.page-about .about-origin__list {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--rule-strong);
}

.page-about .about-origin__row {
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .about-origin__row dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
  margin-bottom: 6px;
}

.page-about .about-origin__row dd {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
}

/* ---------- 团队 ---------- */
.page-about .about-team__lede {
  max-width: 42em;
  color: var(--ink);
}

.page-about .about-team__grid {
  margin-top: 30px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-team__card {
  position: relative;
  padding: 22px 20px 26px;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  transition: border-color var(--t) var(--ease), transform var(--t) var(--ease), box-shadow var(--t) var(--ease);
}

.page-about .about-team__card::after {
  content: "";
  position: absolute;
  right: 10px;
  bottom: 10px;
  width: 26px;
  height: 26px;
  border-right: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  transition: border-color var(--t) var(--ease);
}

.page-about .about-team__card:hover {
  transform: translateY(-2px);
  border-color: var(--clay);
  box-shadow: var(--shadow-1);
}

.page-about .about-team__card:hover::after {
  border-color: var(--clay);
}

.page-about .about-team__num {
  display: inline-block;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: 28px;
  line-height: 1;
  color: var(--clay);
  margin-bottom: 12px;
  font-variant-numeric: tabular-nums;
}

.page-about .about-team__out {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--rule-strong);
  font-size: 14px;
  line-height: 1.6;
  color: var(--moss);
}

/* ---------- 九步法 ---------- */
.page-about .about-method__lede {
  max-width: 42em;
}

.page-about .about-steps {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-step {
  position: relative;
  padding: 16px 16px 16px 20px;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  transition: border-color var(--t) var(--ease), transform var(--t) var(--ease);
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--gold);
  opacity: 0.4;
  transition: background-color var(--t) var(--ease), opacity var(--t) var(--ease);
}

.page-about .about-step:hover,
.page-about .about-step:focus-within {
  border-color: var(--clay);
  transform: translateY(-2px);
}

.page-about .about-step:hover::before,
.page-about .about-step:focus-within::before {
  background: var(--clay);
  opacity: 1;
}

.page-about .about-step__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .about-step__title {
  font-size: 17px;
  font-weight: 500;
  margin: 6px 0 0;
  font-family: var(--font-sans);
}

.page-about .about-step__out {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--moss);
  transition: color var(--t) var(--ease);
}

.page-about .about-step:hover .about-step__out,
.page-about .about-step:focus-within .about-step__out {
  color: var(--ink);
}

.page-about .about-method__fig {
  margin: 34px 0 0;
}

.page-about .about-method__media {
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-1);
}

.page-about .about-method__fig .media__caption {
  margin-top: 12px;
}

.page-about .about-structure {
  margin-top: 34px;
  padding: 22px 20px;
  background: var(--clay-soft);
  border-left: 3px solid var(--clay);
}

.page-about .about-structure__title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 21px;
  margin: 0 0 10px;
}

/* ---------- 时间线 ---------- */
.page-about .about-history__lede {
  max-width: 42em;
}

.page-about .about-timeline {
  position: relative;
  margin-top: 34px;
  padding-left: 30px;
  display: flex;
  flex-direction: column;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--pine);
  opacity: 0.45;
}

.page-about .about-phase {
  position: relative;
  padding-bottom: 30px;
}

.page-about .about-phase::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 5px;
  width: 15px;
  height: 15px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--gold);
  transition: background-color var(--t) var(--ease), border-color var(--t) var(--ease);
}

.page-about .about-phase:hover::before {
  border-color: var(--clay);
  background: var(--gold);
}

.page-about .about-phase__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--moss);
  margin: 0 0 8px;
}

.page-about .about-phase__body {
  padding: 18px 18px 20px;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  transition: border-color var(--t) var(--ease), transform var(--t) var(--ease);
}

.page-about .about-phase:hover .about-phase__body {
  border-color: var(--clay);
  transform: translateY(-2px);
}

.page-about .about-phase__title {
  font-size: 19px;
  margin: 0 0 10px;
}

.page-about .about-phase__fold {
  margin-top: 14px;
  border-top: 1px dashed var(--rule-strong);
}

.page-about .about-phase__fold summary {
  cursor: pointer;
  list-style: none;
  padding: 12px 0 4px;
  font-size: 14px;
  font-weight: 500;
  color: var(--clay);
}

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

.page-about .about-phase__fold summary::before {
  content: "＋";
  display: inline-block;
  width: 16px;
  color: var(--gold);
}

.page-about .about-phase__fold[open] summary::before {
  content: "－";
}

.page-about .about-phase__list {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
}

.page-about .about-phase__list li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--moss);
}

.page-about .about-phase__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 8px;
  height: 1px;
  background: var(--clay);
}

/* ---------- 协作 ---------- */
.page-about .about-partners__grid {
  margin-top: 26px;
}

.page-about .about-partners__text {
  max-width: 42em;
}

.page-about .about-partners__fig {
  margin: 28px 0 0;
}

.page-about .about-partners__media {
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-1);
}

.page-about .about-partners__fig .media__caption {
  margin-top: 12px;
}

.page-about .about-net-wrap {
  margin-top: 38px;
  padding: 24px 16px 12px;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  border-top: 3px solid var(--pine);
}

.page-about .about-net__title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 19px;
  margin: 0 0 8px;
}

.page-about .about-net {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-net__link {
  stroke: var(--pine);
  stroke-width: 1;
  stroke-dasharray: 5 6;
  opacity: 0.4;
}

.page-about .about-net__node circle {
  fill: var(--paper-raise);
  stroke: var(--rule-strong);
  stroke-width: 1;
  transition: stroke var(--t) var(--ease), fill var(--t) var(--ease), stroke-width var(--t) var(--ease);
}

.page-about .about-net__node text {
  font-family: var(--font-sans);
  pointer-events: none;
}

.page-about .about-net__num {
  font-size: 22px;
  font-weight: 700;
  fill: var(--clay);
}

.page-about .about-net__labeltext {
  font-size: 12px;
  fill: var(--moss);
}

.page-about .about-net__node:hover circle,
.page-about .about-net__node:focus circle {
  stroke: var(--clay);
  stroke-width: 2;
  fill: var(--clay-soft);
}

.page-about .about-net__node:hover .about-net__num,
.page-about .about-net__node:focus .about-net__num {
  fill: var(--flame);
}

.page-about .about-net__center circle {
  fill: var(--pine);
  stroke: var(--gold);
  stroke-width: 2;
}

.page-about .about-net__cname {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 900;
  fill: var(--paper);
}

.page-about .about-net__csub {
  font-size: 12px;
  fill: var(--sand);
}

.page-about .about-net__node:focus {
  outline: none;
}

/* ---------- 共建 ---------- */
.page-about .about-join__lede {
  max-width: 40em;
}

.page-about .about-join__grid {
  margin-top: 28px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-join__card {
  padding: 20px 18px;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--gold);
  transition: border-color var(--t) var(--ease), transform var(--t) var(--ease);
}

.page-about .about-join__card:hover {
  transform: translateY(-2px);
  border-color: var(--clay);
  border-left-color: var(--clay);
}

.page-about .about-join__card h3 {
  font-size: 19px;
  margin-bottom: 8px;
}

.page-about .about-join__card p {
  font-size: 15px;
  color: var(--moss);
}

.page-about .about-join__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
  padding-top: 22px;
  border-top: 1px solid var(--rule-strong);
}

/* ---------- 桌面 ---------- */
@media (min-width: 700px) {
  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-team__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-team__card:nth-child(2) {
    transform: translateY(18px);
  }

  .page-about .about-team__card:nth-child(2):hover {
    transform: translateY(16px);
  }

  .page-about .about-team__card:nth-child(4) {
    transform: translateY(18px);
  }

  .page-about .about-team__card:nth-child(4):hover {
    transform: translateY(16px);
  }

  .page-about .about-join__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__facts {
    margin-top: 0;
  }

  .page-about .about-origin__aside {
    margin-top: 0;
  }

  .page-about .about-partners__grid {
    display: grid;
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 48px;
    align-items: start;
  }

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

  .page-about .about-timeline {
    padding-left: 0;
  }

  .page-about .about-timeline::before {
    left: calc(50% - 0.5px);
  }

  .page-about .about-phase {
    width: calc(50% - 44px);
    padding-bottom: 38px;
  }

  .page-about .about-phase:nth-child(odd) {
    align-self: flex-start;
  }

  .page-about .about-phase:nth-child(even) {
    align-self: flex-end;
  }

  .page-about .about-phase:nth-child(odd)::before {
    left: auto;
    right: -44px;
    transform: translateX(50%);
  }

  .page-about .about-phase:nth-child(even)::before {
    left: -44px;
    transform: translateX(-50%);
  }

  .page-about .about-net-wrap {
    padding: 30px 40px 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-team__card,
  .page-about .about-step,
  .page-about .about-phase__body,
  .page-about .about-join__card {
    transition: none;
  }

  .page-about .about-team__card:hover,
  .page-about .about-step:hover,
  .page-about .about-step:focus-within,
  .page-about .about-phase:hover .about-phase__body,
  .page-about .about-join__card:hover {
    transform: none;
  }

  .page-about .about-team__card:nth-child(2),
  .page-about .about-team__card:nth-child(4) {
    transform: none;
  }
}
</main>