.page-about {
  --about-measure: 30em;
  --about-gap: clamp(56px, 9vw, 128px);
  background: var(--paper);
  color: var(--indigo);
  font-family: var(--font-body);
  padding-bottom: clamp(48px, 8vw, 104px);
}

.page-about a {
  color: inherit;
}

.page-about .breadcrumb {
  padding: clamp(18px, 2.4vw, 30px) 0 0;
}

/* ---------- 首屏 ---------- */

.page-about .about-open {
  position: relative;
  overflow: hidden;
  padding: clamp(32px, 5vw, 60px) 0 clamp(48px, 7vw, 96px);
  isolation: isolate;
}

.page-about .about-open__shard {
  position: absolute;
  z-index: 0;
  top: -14%;
  right: -18%;
  width: min(64vw, 720px);
  height: min(50vw, 540px);
  background: linear-gradient(158deg, var(--indigo) 0%, var(--glass) 100%);
  transform: rotate(-8deg);
  border-radius: 6px;
  opacity: .96;
}

.page-about .about-open__shard--deep {
  top: 46%;
  right: -30%;
  width: min(50vw, 560px);
  height: min(28vw, 300px);
  background: var(--ink-deep);
  opacity: .9;
}

.page-about .about-open__inner {
  position: relative;
  z-index: 1;
  max-width: 1020px;
}

.page-about .about-open__eyebrow {
  margin: 0 0 clamp(18px, 2.6vw, 32px);
  font-size: var(--step-meta);
  letter-spacing: .14em;
  color: var(--amber);
  text-transform: none;
}

.page-about .about-open__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.1rem, 6.2vw, 4.6rem);
  line-height: 1.05;
  letter-spacing: -.015em;
  max-width: 12em;
}

.page-about .about-open__lede {
  margin: clamp(24px, 3.4vw, 40px) 0 0;
  max-width: var(--about-measure);
  font-size: clamp(1rem, 1.35vw, 1.125rem);
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .about-open__facts {
  list-style: none;
  margin: clamp(32px, 4.5vw, 56px) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 14px clamp(24px, 3.4vw, 52px);
  border-top: 1px solid var(--rule);
  padding-top: clamp(18px, 2.4vw, 26px);
}

.page-about .about-open__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-open__num {
  font-size: clamp(1.375rem, 2.4vw, 1.875rem);
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--amber);
  line-height: 1;
}

.page-about .about-open__cap {
  font-family: var(--font-display);
  font-size: var(--step-meta);
  letter-spacing: .04em;
  color: var(--gray-brown);
}

/* ---------- 通用章节标题组 ---------- */

.page-about .about-start__num,
.page-about .about-stages__num,
.page-about .about-team__num,
.page-about .about-cadence__num,
.page-about .about-land__num,
.page-about .about-brief__num {
  margin: 0 0 10px;
  font-size: var(--step-meta);
  letter-spacing: .16em;
  color: var(--amber);
}

.page-about .about-start__title,
.page-about .about-stages__title,
.page-about .about-team__title,
.page-about .about-cadence__title,
.page-about .about-land__title,
.page-about .about-brief__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 3.2vw, 2.5rem);
  line-height: 1.24;
  letter-spacing: -.01em;
}

.page-about .about-start__rule {
  display: block;
  width: 18%;
  max-width: 108px;
  height: 3px;
  margin-top: 20px;
  background: var(--amber);
}

/* ---------- 01 起点 ---------- */

.page-about .about-start {
  padding-top: var(--about-gap);
}

.page-about .about-start__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 56px);
}

.page-about .about-start__body p {
  margin: 0 0 1.15em;
  max-width: var(--about-measure);
  font-size: var(--step-body);
  line-height: 1.9;
}

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

.page-about .about-start__points {
  list-style: none;
  margin: 0 0 1.4em;
  padding: 0;
  max-width: var(--about-measure);
  border-top: 1px solid var(--rule);
}

.page-about .about-start__points li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--gray-brown);
}

.page-about .about-start__points .tag {
  flex: none;
  margin-top: 2px;
}

/* ---------- 02 三段路 ---------- */

.page-about .about-stages {
  padding-top: var(--about-gap);
}

.page-about .about-stages__lead,
.page-about .about-team__lead,
.page-about .about-land__lead,
.page-about .about-brief__lead {
  margin: 18px 0 0;
  max-width: var(--about-measure);
  font-size: var(--step-body);
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .stage-track {
  position: relative;
  height: clamp(190px, 20vw, 240px);
  margin: clamp(28px, 4vw, 48px) 0 clamp(24px, 3vw, 40px);
}

.page-about .stage-track__line {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
}

.page-about .stage-track__line polyline {
  fill: none;
  stroke: var(--rule);
  stroke-width: 1.5;
  stroke-linejoin: round;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}

.page-about .stage-node {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  transform: translate(-50%, -50%);
  text-decoration: none;
  text-align: center;
}

.page-about .stage-node--a { left: 6%; top: 82%; }
.page-about .stage-node--b { left: 50%; top: 57%; }
.page-about .stage-node--c { left: 92%; top: 28%; }

.page-about .stage-node__dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--amber-light);
  border: 2px solid var(--amber);
  transition: background var(--dur-mid) var(--ease), transform var(--dur-mid) var(--ease);
}

.page-about .stage-node:hover .stage-node__dot,
.page-about .stage-node:focus-visible .stage-node__dot {
  background: var(--amber);
  transform: scale(1.25);
}

.page-about .stage-node__num {
  font-size: clamp(1.125rem, 1.9vw, 1.5rem);
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--indigo);
  line-height: 1;
}

.page-about .stage-node__name {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--step-meta);
  letter-spacing: .06em;
  color: var(--gray-brown);
}

.page-about .stage-details {
  display: grid;
  gap: 0;
}

.page-about .stage-detail {
  padding: clamp(22px, 3vw, 34px) 0;
  border-top: 1px solid var(--rule);
  scroll-margin-top: 140px;
}

.page-about .stage-detail:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .stage-detail__index {
  margin: 0 0 8px;
  font-size: var(--step-meta);
  letter-spacing: .14em;
  color: var(--celadon);
}

.page-about .stage-detail__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.125rem, 1.9vw, 1.375rem);
  line-height: 1.4;
}

.page-about .stage-detail p {
  margin: 0;
  max-width: var(--about-measure);
  font-size: var(--step-body);
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .about-stages__figure {
  margin: clamp(36px, 5vw, 64px) 0 0;
}

.page-about .about-stages__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: var(--glass);
  border-radius: var(--radius);
}

.page-about .about-stages__caption {
  margin-top: 12px;
  font-family: var(--font-display);
  font-size: var(--step-meta);
  letter-spacing: .04em;
  color: var(--gray-brown);
}

/* ---------- 引文区 ---------- */

.page-about .about-quote {
  position: relative;
  margin: clamp(56px, 9vw, 128px) 0;
  padding: clamp(64px, 10vw, 140px) 0;
  overflow: hidden;
  background: linear-gradient(178deg, rgba(200, 145, 47, .07) 0%, rgba(78, 140, 122, .05) 100%);
}

.page-about .about-quote__contour {
  position: absolute;
  inset: -25% -10%;
  background-image: repeating-radial-gradient(ellipse at 26% 86%, transparent 0 36px, rgba(27, 42, 74, .07) 36px 37px);
  pointer-events: none;
}

.page-about .about-quote__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-quote__mark {
  display: block;
  width: 18%;
  max-width: 120px;
  height: 3px;
  background: var(--amber);
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-quote__text {
  margin: 0;
  max-width: 22em;
  font-family: var(--font-body);
  font-size: clamp(1.25rem, 2.6vw, 1.9rem);
  line-height: 1.72;
  color: var(--indigo);
}

.page-about .about-quote__more {
  margin-top: clamp(24px, 3vw, 36px);
  max-width: var(--about-measure);
}

.page-about .about-quote__more summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--step-meta);
  letter-spacing: .1em;
  color: var(--celadon);
  padding: 6px 0;
}

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

.page-about .about-quote__more summary::before {
  content: "+";
  font-size: 1rem;
  line-height: 1;
  color: var(--amber);
}

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

.page-about .about-quote__more p {
  margin: 12px 0 0;
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--gray-brown);
}

/* ---------- 03 谁在维护 ---------- */

.page-about .about-team {
  padding-top: 0;
}

.page-about .role-list {
  list-style: none;
  margin: clamp(32px, 4.5vw, 56px) 0 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.page-about .role-list__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: clamp(20px, 2.6vw, 30px) 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .role-list__num {
  font-size: clamp(2rem, 3.4vw, 3rem);
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--amber);
  line-height: 1;
}

.page-about .role-list__role {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: .02em;
}

.page-about .role-list__desc {
  margin: 0;
  max-width: var(--about-measure);
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--gray-brown);
}

/* ---------- 04 每周与每月 ---------- */

.page-about .about-cadence {
  padding-top: var(--about-gap);
}

.page-about .about-cadence__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(32px, 5vw, 64px);
}

.page-about .about-cadence__body > p {
  margin: 18px 0 0;
  max-width: var(--about-measure);
  font-size: var(--step-body);
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .cadence-list {
  margin-top: clamp(28px, 3.6vw, 44px);
}

.page-about .cadence-list__row {
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-top: 1px solid var(--rule);
}

.page-about .cadence-list__row:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .cadence-list__row h3 {
  position: relative;
  margin: 0 0 10px;
  padding-left: 18px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.5;
}

.page-about .cadence-list__row h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--celadon);
}

.page-about .cadence-list__row p {
  margin: 0;
  max-width: var(--about-measure);
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .about-cadence__stamp {
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 14px 18px;
  border-left: 3px solid var(--amber);
  background: rgba(200, 145, 47, .08);
  display: inline-block;
}

.page-about .about-cadence__stamp .mono {
  font-size: var(--step-meta);
  letter-spacing: .1em;
  color: var(--indigo);
}

.page-about .about-cadence__figure {
  margin: 0;
  align-self: start;
}

.page-about .about-cadence__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  background: var(--glass);
  border-radius: var(--radius);
  box-shadow: var(--shadow-plate);
}

.page-about .about-cadence__figure .media-frame__caption {
  margin-top: 14px;
  font-family: var(--font-display);
  font-size: var(--step-meta);
  letter-spacing: .04em;
  line-height: 1.7;
  color: var(--gray-brown);
}

/* ---------- 05 视觉里的山 ---------- */

.page-about .about-land {
  padding-top: var(--about-gap);
}

.page-about .about-land__figure {
  position: relative;
  margin: clamp(28px, 4vw, 48px) 0 clamp(28px, 4vw, 48px);
  overflow: hidden;
  background: var(--ink-deep);
}

.page-about .about-land__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  opacity: .88;
  filter: saturate(.72) contrast(.96);
}

.page-about .about-land__body p {
  margin: 0 0 1.15em;
  max-width: var(--about-measure);
  font-size: var(--step-body);
  line-height: 1.9;
}

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

.page-about .about-land__body a {
  color: var(--indigo);
  text-decoration: none;
  background-image: linear-gradient(var(--amber), var(--amber));
  background-repeat: no-repeat;
  background-size: 0% 1px;
  background-position: 0 100%;
  transition: background-size var(--dur-fast) var(--ease);
  padding-bottom: 2px;
}

.page-about .about-land__body a:hover,
.page-about .about-land__body a:focus-visible {
  background-size: 100% 1px;
}

.page-about .about-land__body .tag {
  vertical-align: middle;
  margin: 0 4px;
}

/* ---------- 06 速查筛选 ---------- */

.page-about .about-brief {
  padding-top: var(--about-gap);
}

.page-about .about-brief__filter {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: clamp(24px, 3vw, 36px);
}

.page-about .about-brief__filter .filter-chip {
  appearance: none;
  border: 1px solid var(--rule);
  background: transparent;
  color: var(--indigo);
  font-family: var(--font-display);
  font-size: 0.875rem;
  letter-spacing: .06em;
  padding: 8px 16px;
  border-radius: 999px;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}

.page-about .about-brief__filter .filter-chip:hover {
  border-color: var(--amber);
}

.page-about .about-brief__filter .filter-chip[aria-pressed="true"] {
  background: var(--amber-light);
  border-color: var(--amber);
  color: var(--ink-deep);
}

.page-about .about-brief__filter .filter-status {
  font-family: var(--font-mono);
  font-size: var(--step-meta);
  letter-spacing: .06em;
  color: var(--gray-brown);
  margin-left: auto;
}

.page-about .brief-list {
  list-style: none;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0;
}

.page-about .brief-list__item {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px) 0 clamp(18px, 2.4vw, 26px) 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .brief-list__item:first-child {
  border-top: 1px solid var(--rule);
}

.page-about .brief-list__item .tag {
  display: inline-block;
  margin-bottom: 10px;
}

.page-about .brief-list__q {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.55;
}

.page-about .brief-list__a {
  margin: 0;
  max-width: var(--about-measure);
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .brief-list__item.is-hidden {
  display: none;
}

/* ---------- 联系方式 ---------- */

.page-about .about-reach {
  padding-top: var(--about-gap);
}

.page-about .about-reach__panel {
  border-top: 3px solid var(--amber);
  padding-top: clamp(26px, 3.4vw, 44px);
}

.page-about .about-reach__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  line-height: 1.28;
}

.page-about .about-reach__lead {
  margin: 18px 0 0;
  max-width: var(--about-measure);
  font-size: var(--step-body);
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .reach-list {
  margin: clamp(28px, 3.6vw, 44px) 0 0;
  border-top: 1px solid var(--rule);
}

.page-about .reach-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.page-about .reach-row__label {
  font-family: var(--font-display);
  font-size: var(--step-meta);
  letter-spacing: .1em;
  color: var(--celadon);
}

.page-about .reach-row__value {
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--indigo);
  word-break: break-word;
}

.page-about .reach-row__value .mono {
  font-size: 0.9375rem;
  letter-spacing: .06em;
}

.page-about .reach-row__copy {
  appearance: none;
  border: 1px solid var(--rule);
  background: transparent;
  color: var(--gray-brown);
  font-family: var(--font-display);
  font-size: 0.8125rem;
  letter-spacing: .06em;
  padding: 5px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}

.page-about .reach-row__copy:hover {
  border-color: var(--amber);
  color: var(--indigo);
}

.page-about .about-reach__note {
  margin: 24px 0 0;
  max-width: var(--about-measure);
  font-size: var(--step-meta);
  line-height: 1.9;
  color: var(--gray-brown);
}

.page-about .about-reach__actions {
  margin-top: clamp(24px, 3vw, 36px);
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

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

/* ---------- 响应式 ---------- */

@media (min-width: 760px) {
  .page-about .role-list__item {
    grid-template-columns: 5rem 8rem minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }

  .page-about .reach-row {
    grid-template-columns: 8rem minmax(0, 1fr);
    gap: 12px 24px;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .about-start__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(32px, 5vw, 72px);
  }

  .page-about .about-start__aside {
    position: sticky;
    top: 140px;
    align-self: start;
  }

  .page-about .stage-detail {
    display: grid;
    grid-template-columns: 8rem minmax(0, 1fr);
    gap: 0 32px;
    align-items: start;
  }

  .page-about .stage-detail__index {
    margin: 6px 0 0;
  }

  .page-about .stage-detail__title {
    grid-column: 2;
  }

  .page-about .stage-detail > p {
    grid-column: 2;
  }
}

@media (min-width: 960px) {
  .page-about .about-cadence__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }

  .page-about .about-cadence__figure {
    margin-top: clamp(48px, 6vw, 88px);
  }
}

@media (max-width: 719px) {
  .page-about .about-open__shard {
    top: -8%;
    right: -34%;
    width: 78vw;
    height: 52vw;
  }

  .page-about .about-open__shard--deep {
    display: none;
  }

  .page-about .stage-track {
    height: auto;
    display: grid;
    gap: 2px;
    margin-top: 24px;
  }

  .page-about .stage-track__line {
    display: none;
  }

  .page-about .stage-node {
    position: static;
    transform: none;
    flex-direction: row;
    justify-content: flex-start;
    align-items: center;
    gap: 12px;
    text-align: left;
    padding: 14px 0 14px 20px;
    border-left: 1px solid var(--rule);
  }

  .page-about .stage-node__dot {
    flex: none;
  }

  .page-about .stage-node__num {
    min-width: 3ch;
  }

  .page-about .brief-list__item {
    padding-left: 0;
  }

  .page-about .about-brief__filter .filter-status {
    margin-left: 0;
    flex-basis: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-node__dot,
  .page-about .about-land__body a,
  .page-about .about-brief__filter .filter-chip,
  .page-about .reach-row__copy {
    transition: none;
  }
}