.page-about {
  --about-gap: clamp(64px, 8vw, 118px);
}

.page-about .about-wrap {
  padding-top: clamp(16px, 3vw, 30px);
  padding-bottom: clamp(56px, 7vw, 96px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 30px;
  padding: clamp(18px, 3vw, 34px) 0 clamp(36px, 5vw, 62px);
  border-bottom: 1px solid var(--fb-line);
}

.page-about .about-hero__title {
  margin: 12px 0 16px;
  font-size: clamp(30px, 5.2vw, 56px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  font-weight: 800;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 36em;
  color: var(--fb-paper);
  opacity: 0.9;
}

.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-index__link {
  display: inline-block;
  padding: 5px 11px;
  border: 1px solid var(--fb-line);
  border-radius: 999px;
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--fb-muted);
  text-decoration: none;
  transition: color var(--fb-dur) var(--fb-ease), border-color var(--fb-dur) var(--fb-ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--fb-neon);
  border-color: var(--fb-neon);
}

.page-about .about-hero__side {
  display: grid;
  grid-template-columns: 20px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  min-width: 0;
}

.page-about .about-hero__vnote {
  color: var(--fb-muted);
  letter-spacing: 0.14em;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  background: var(--fb-line);
  min-width: 0;
}

.page-about .about-stats li {
  background: var(--fb-moss);
  padding: 14px 13px;
  min-width: 0;
}

.page-about .about-stats__num {
  display: block;
  font-size: 22px;
  line-height: 1.1;
  color: var(--fb-neon);
}

.page-about .about-stats__label {
  display: block;
  margin-top: 6px;
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--fb-muted);
}

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

.page-about .about-sec__head {
  display: grid;
  grid-template-columns: 22px minmax(0, 1fr);
  gap: 14px;
  margin-bottom: clamp(22px, 3vw, 38px);
}

.page-about .about-sec__vnote {
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--fb-clay);
}

.page-about .about-sec__title {
  margin: 0 0 10px;
  font-size: clamp(23px, 3.5vw, 38px);
  line-height: 1.16;
  letter-spacing: -0.01em;
}

.page-about .about-sec__sub {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--fb-muted);
  max-width: 42em;
}

/* ---------- 01 出发点 ---------- */
.page-about .about-stance {
  display: grid;
  gap: 26px;
  min-width: 0;
}

.page-about .about-stance__body p {
  margin: 0 0 15px;
  max-width: 36em;
  line-height: 1.75;
  color: var(--fb-paper);
  opacity: 0.9;
}

.page-about .about-points {
  display: grid;
  gap: 12px;
  min-width: 0;
}

.page-about .about-point {
  padding: 14px 16px;
  background: var(--fb-glass);
  border-left: 2px solid var(--fb-clay);
}

.page-about .about-point__label {
  margin: 0 0 6px;
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--fb-neon);
}

.page-about .about-point__t {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--fb-paper);
}

.page-about .about-point__d {
  margin: 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--fb-muted);
}

/* ---------- 02 历程 ---------- */
.page-about .about-timeline {
  position: relative;
  overflow: hidden;
  padding: clamp(22px, 3vw, 32px) clamp(14px, 3vw, 30px) clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--fb-line);
  border-bottom: 1px solid var(--fb-line);
  background: linear-gradient(165deg, rgba(180, 100, 60, 0.2), rgba(15, 42, 34, 0.1) 46%, rgba(11, 18, 16, 0.9));
}

.page-about .about-timeline__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.22;
  filter: saturate(0.55);
  pointer-events: none;
}

.page-about .about-timeline__list {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0 0 0 22px;
  list-style: none;
}

.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--fb-clay), var(--fb-line));
}

.page-about .about-node {
  position: relative;
  min-width: 0;
}

.page-about .about-node__sum {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) 18px;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  cursor: pointer;
  list-style: none;
  background: rgba(11, 18, 16, 0.55);
  border: 1px solid var(--fb-line);
  transition: border-color var(--fb-dur) var(--fb-ease), background var(--fb-dur) var(--fb-ease);
}

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

.page-about .about-node__sum:hover,
.page-about .about-node__sum:focus-visible {
  border-color: var(--fb-neon);
}

.page-about .about-node__sum::after {
  content: "+";
  grid-column: 3;
  font-family: var(--fb-mono);
  font-size: 14px;
  color: var(--fb-muted);
  text-align: center;
}

.page-about .about-node__d[open] > .about-node__sum {
  border-color: var(--fb-neon);
  background: rgba(21, 56, 45, 0.85);
}

.page-about .about-node__d[open] > .about-node__sum::after {
  content: "−";
  color: var(--fb-neon);
}

.page-about .about-node__dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--fb-neon);
  box-shadow: 0 0 0 4px rgba(200, 241, 53, 0.12);
}

.page-about .about-node__year {
  grid-column: 2;
  font-size: 20px;
  line-height: 1;
  color: var(--fb-paper);
}

.page-about .about-node__t {
  grid-column: 2;
  grid-row: 2;
  font-size: 13px;
  color: var(--fb-muted);
  letter-spacing: 0.02em;
}

.page-about .about-node__sum {
  grid-template-areas:
    "dot year icon"
    "dot title icon";
}

.page-about .about-node__dot { grid-area: dot; }
.page-about .about-node__year { grid-area: year; }
.page-about .about-node__t { grid-area: title; }
.page-about .about-node__sum::after { grid-area: icon; }

.page-about .about-node__body {
  padding: 12px 12px 4px 14px;
  border-left: 1px solid var(--fb-line);
  margin-left: 4px;
}

.page-about .about-node__body p {
  margin: 0 0 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--fb-paper);
  opacity: 0.88;
}

.page-about .about-node__meta {
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--fb-clay);
  opacity: 1;
}

.page-about .about-timeline__note {
  position: relative;
  z-index: 1;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding-top: 16px;
  border-top: 1px solid rgba(46, 74, 68, 0.8);
  font-size: 13px;
  line-height: 1.75;
  color: var(--fb-muted);
  max-width: 62em;
}

/* ---------- 03 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 26px;
  min-width: 0;
}

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

.page-about .about-boards {
  display: grid;
  gap: 14px;
  padding-bottom: 22px;
  min-width: 0;
}

.page-about .about-board {
  padding: 16px 16px 18px;
  background: var(--fb-card);
  border: 1px solid var(--fb-line);
  border-top: 2px solid var(--fb-clay);
  min-width: 0;
}

.page-about .about-board__role {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  margin: 0 0 10px;
  font-size: 15px;
  font-weight: 700;
  color: var(--fb-paper);
  letter-spacing: 0.01em;
}

.page-about .about-board__count {
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--fb-neon);
}

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

.page-about .about-board__list li {
  position: relative;
  padding-left: 14px;
  margin-bottom: 7px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--fb-muted);
}

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

.page-about .about-board__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 1px;
  background: var(--fb-clay);
}

/* ---------- 04 方法 ---------- */
.page-about .about-review {
  display: grid;
  gap: 26px;
  min-width: 0;
}

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

.page-about .about-flowline {
  display: block;
  width: 100%;
  height: 22px;
  margin-bottom: 10px;
}

.page-about .about-flowline__rail {
  fill: none;
  stroke: var(--fb-line);
  stroke-width: 1;
}

.page-about .about-flowline__head {
  fill: none;
  stroke: var(--fb-neon);
  stroke-width: 1.4;
}

.page-about .about-flow {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-step {
  padding: 13px 14px 14px;
  background: var(--fb-moss);
  border: 1px solid var(--fb-line);
  transition: border-color var(--fb-dur) var(--fb-ease), background var(--fb-dur) var(--fb-ease);
  min-width: 0;
}

.page-about .about-step:hover,
.page-about .about-step:focus-within {
  border-color: var(--fb-neon);
  background: var(--fb-card);
}

.page-about .about-step__idx {
  margin: 0 0 4px;
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--fb-muted);
  transition: color var(--fb-dur) var(--fb-ease);
}

.page-about .about-step:hover .about-step__idx,
.page-about .about-step:focus-within .about-step__idx {
  color: var(--fb-neon);
}

.page-about .about-step__t {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--fb-paper);
}

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

.page-about .about-step__list li {
  font-size: 12px;
  line-height: 1.6;
  color: var(--fb-muted);
  padding: 3px 0;
  border-top: 1px dashed rgba(46, 74, 68, 0.7);
}

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

.page-about .about-review__note {
  margin: 16px 0 0;
  color: var(--fb-muted);
  font-size: 12px;
  line-height: 1.7;
}

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

/* ---------- 05 适合谁 ---------- */
.page-about .about-audience {
  display: grid;
  gap: 14px;
  min-width: 0;
}

.page-about .about-aud {
  padding: 16px 16px 18px;
  background: linear-gradient(150deg, rgba(21, 56, 45, 0.95), rgba(15, 42, 34, 0.6));
  border: 1px solid var(--fb-line);
  min-width: 0;
}

.page-about .about-aud__tag {
  margin: 0 0 8px;
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--fb-clay);
}

.page-about .about-aud__who {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--fb-paper);
}

.page-about .about-aud__use {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--fb-muted);
}

/* ---------- 联系收束 ---------- */
.page-about .about-contact {
  display: grid;
  gap: 24px;
  margin-top: var(--about-gap);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--fb-line);
  background: linear-gradient(130deg, rgba(21, 56, 45, 0.92), rgba(11, 18, 16, 0.7));
  min-width: 0;
}

.page-about .about-contact__title {
  margin: 10px 0 12px;
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1.2;
  color: var(--fb-paper);
}

.page-about .about-contact__text {
  margin: 0;
  max-width: 34em;
  font-size: 14px;
  line-height: 1.75;
  color: var(--fb-muted);
}

.page-about .about-contact__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.page-about .about-contact__card {
  padding: 16px;
  border: 1px solid var(--fb-line);
  background: var(--fb-glass);
  min-width: 0;
}

.page-about .about-contact__key {
  margin: 0 0 6px;
  font-family: var(--fb-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--fb-muted);
}

.page-about .about-copy {
  display: block;
  width: 100%;
  margin: 0 0 14px;
  padding: 10px 12px;
  text-align: left;
  font-family: var(--fb-mono);
  font-size: 14px;
  color: var(--fb-neon);
  background: rgba(11, 18, 16, 0.6);
  border: 1px solid var(--fb-line);
  cursor: pointer;
  transition: border-color var(--fb-dur) var(--fb-ease);
}

.page-about .about-copy:hover,
.page-about .about-copy:focus-visible {
  border-color: var(--fb-neon);
}

.page-about .about-copy[data-copied] {
  color: var(--fb-paper);
  border-color: var(--fb-clay);
}

.page-about .about-contact__hint {
  margin: 0;
  font-size: 12px;
  line-height: 1.7;
  color: var(--fb-muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-boards {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-board:nth-child(even) {
    margin-top: 24px;
  }

  .page-about .about-flow {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-audience {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-aud:nth-child(even) {
    margin-top: 18px;
  }

  .page-about .about-contact__card {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0 18px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.9fr);
    gap: 48px;
    align-items: end;
  }

  .page-about .about-stance {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-review {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-contact {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.8fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-contact__card {
    grid-template-columns: 1fr;
  }

  .page-about .about-audience {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 16px 18px;
  }

  .page-about .about-aud:nth-child(even) {
    margin-top: 0;
  }

  .page-about .about-aud:nth-child(2),
  .page-about .about-aud:nth-child(4) {
    margin-top: 28px;
  }
}

@media (min-width: 860px) {
  .page-about .about-timeline__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
    padding-left: 0;
    padding-top: 8px;
  }

  .page-about .about-timeline__list::before {
    left: 0;
    right: 0;
    top: 16px;
    bottom: auto;
    width: auto;
    height: 1px;
    background: linear-gradient(90deg, var(--fb-clay), var(--fb-line));
  }

  .page-about .about-node__dot {
    margin-top: 2px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-node__sum,
  .page-about .about-step,
  .page-about .about-step__idx,
  .page-about .about-copy {
    transition: none;
  }
}