.page-about {
  --about-sec-pad: clamp(44px, 7vw, 88px);
  --about-grid-line: rgba(44, 47, 55, 0.5);
  --about-rule: rgba(201, 162, 77, 0.28);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 4vw, 44px) 0 clamp(34px, 6vw, 72px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(120% 90% at 8% 0%, rgba(201, 162, 77, 0.11), transparent 58%),
    repeating-linear-gradient(90deg, var(--about-grid-line) 0 1px, transparent 1px 56px);
  opacity: 0.42;
}

.page-about .about-hero > .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(20px, 4vw, 40px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
  align-items: end;
}

.page-about .about-hero__title {
  margin: 10px 0 0;
  line-height: 1.06;
}

.page-about .about-hero__lede {
  margin-top: 18px;
  max-width: 46ch;
}

.page-about .about-hero__tags {
  margin-top: 22px;
}

.page-about .about-hero__media {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--charcoal);
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 正文布局 ---------- */
.page-about .about-body {
  position: relative;
  padding-bottom: clamp(48px, 8vw, 104px);
}

.page-about .about-layout {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
}

.page-about .about-rail {
  order: 2;
  border-top: 1px solid var(--line);
  padding-top: 18px;
}

.page-about .about-rail__label {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--gold);
  text-transform: uppercase;
}

.page-about .about-index {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px 16px;
}

.page-about .about-index .doc-index__link {
  display: block;
  padding: 7px 0 7px 12px;
  border-left: 2px solid transparent;
  color: var(--body-text);
  font-size: 15px;
  line-height: 1.5;
  text-decoration: none;
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-index .doc-index__link:hover,
.page-about .about-index .doc-index__link.is-active {
  color: var(--gold-light);
  border-left-color: var(--gold);
}

.page-about .about-rail__note {
  display: none;
  margin-top: 22px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.3em;
}

/* ---------- 通用章节 ---------- */
.page-about .about-flow {
  order: 1;
  min-width: 0;
}

.page-about .about-section {
  padding: var(--about-sec-pad) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-section--band {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(22, 24, 30, 0.9), rgba(12, 13, 16, 0.4)),
    repeating-linear-gradient(0deg, var(--about-grid-line) 0 1px, transparent 1px 62px);
  margin-inline: calc(-1 * clamp(0px, 2vw, 24px));
  padding-inline: clamp(0px, 2vw, 24px);
}

.page-about .about-section--paper {
  background: linear-gradient(180deg, rgba(244, 240, 230, 0.045), transparent 70%);
}

.page-about .about-section__intro {
  margin: 14px 0 0;
  max-width: 52ch;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.page-about .about-prose p {
  margin: 0 0 1.05em;
  color: var(--body-text);
  font-size: 17px;
  line-height: 1.9;
}

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

.page-about .about-prose a {
  color: var(--gold-light);
  text-decoration: none;
  border-bottom: 1px solid var(--about-rule);
  padding-bottom: 1px;
}

.page-about .about-prose a:hover {
  border-bottom-color: var(--gold-light);
}

/* ---------- 起点数据带 ---------- */
.page-about .about-strip {
  margin-top: clamp(26px, 4vw, 44px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-strip__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(16px, 3vw, 26px);
  background: var(--ink-deep);
}

.page-about .about-strip__num {
  font-family: var(--narrow);
  font-size: clamp(30px, 5vw, 46px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold-light);
}

.page-about .about-strip__unit {
  font-size: 0.5em;
  margin-left: 2px;
  color: var(--gold);
}

.page-about .about-strip__cap {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 版本演进 ---------- */
.page-about .about-filter {
  margin-top: 22px;
  flex-wrap: wrap;
}

.page-about .about-trail {
  display: block;
  width: 100%;
  height: 54px;
  margin: 20px 0 4px;
}

.page-about .about-track {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-node {
  position: relative;
  border: 1px solid var(--line);
  background: var(--charcoal);
  padding: clamp(20px, 3vw, 28px) clamp(18px, 3vw, 26px) clamp(18px, 3vw, 24px);
  transition: transform 220ms var(--ease), border-color 220ms var(--ease), box-shadow 220ms var(--ease);
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--gold);
  opacity: 0.5;
}

.page-about .about-node--key {
  border-color: rgba(201, 162, 77, 0.55);
  background: linear-gradient(160deg, rgba(201, 162, 77, 0.1), rgba(22, 24, 30, 0.98) 62%);
}

.page-about .about-node--key::before {
  opacity: 1;
}

.page-about .about-node:hover {
  transform: translateY(-4px);
  border-color: rgba(201, 162, 77, 0.6);
}

.page-about .about-node__num {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .about-node__title {
  margin: 10px 0 0;
  font-family: var(--narrow);
  font-size: clamp(21px, 3vw, 27px);
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-node__text {
  margin: 12px 0 0;
  color: var(--body-text);
  font-size: 15.5px;
  line-height: 1.85;
}

.page-about .about-node__result {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--cyan);
}

.page-about .about-node--key .about-node__result {
  color: var(--gold-light);
}

.page-about .about-more {
  margin: 24px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-more a {
  color: var(--gold-light);
  text-decoration: none;
  border-bottom: 1px solid var(--about-rule);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  margin-top: clamp(24px, 4vw, 40px);
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-team__flow {
  display: grid;
  gap: 16px;
  min-width: 0;
}

.page-about .about-role {
  padding: clamp(20px, 3vw, 26px);
}

.page-about .about-role__title {
  margin: 0;
  font-family: var(--narrow);
  font-size: clamp(20px, 2.6vw, 24px);
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-role__text {
  margin: 12px 0 0;
  color: var(--body-text);
  font-size: 15.5px;
  line-height: 1.85;
}

.page-about .paper--gold .about-role__title {
  color: var(--gold-light);
}

.page-about .paper--cyan .about-role__title {
  color: var(--cyan);
}

.page-about .about-role__meta {
  margin: 16px 0 0;
  font-size: 12.5px;
  letter-spacing: 0.05em;
  color: var(--muted);
}

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

.page-about .about-team__media img,
.page-about .about-rhythm__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 覆盖与节奏 ---------- */
.page-about .about-rhythm {
  margin-top: clamp(24px, 4vw, 40px);
  display: grid;
  gap: clamp(22px, 4vw, 40px);
  align-items: start;
}

.page-about .about-rhythm__lead {
  margin: 0 0 1em;
  color: var(--body-text);
  font-size: 16.5px;
  line-height: 1.9;
}

.page-about .about-rhythm__lead:last-of-type {
  margin-bottom: 0;
}

.page-about .about-rhythm__stamp {
  margin: 22px 0 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.page-about .about-rhythm__stamp-note {
  font-size: 12.5px;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.page-about .about-rhythm__media {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--ink-deep);
}

.page-about .about-cycles {
  list-style: none;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-cycle {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-cycle__k {
  font-size: 12.5px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .about-cycle__v {
  color: var(--body-text);
  font-size: 15.5px;
  line-height: 1.75;
}

/* ---------- 伙伴协作 ---------- */
.page-about .about-partner-grid {
  margin-top: clamp(24px, 4vw, 38px);
  display: grid;
  gap: 14px;
}

.page-about .about-partner-card {
  padding: 20px;
  border-left: 2px solid var(--cyan-deep);
}

.page-about .about-partner-card__k {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-partner-card__v {
  margin: 10px 0 0;
  color: var(--body-text);
  font-size: 15px;
  line-height: 1.8;
}

/* ---------- 长期维护 ---------- */
.page-about .about-next {
  margin-top: clamp(26px, 4vw, 42px);
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-next__item {
  display: grid;
  gap: 6px;
  padding: clamp(18px, 3vw, 24px);
  background: var(--ink-deep);
  text-decoration: none;
  transition: background 200ms var(--ease);
}

.page-about .about-next__item:hover {
  background: var(--charcoal);
}

.page-about .about-next__k {
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--gold);
}

.page-about .about-next__t {
  font-family: var(--narrow);
  font-size: clamp(18px, 2.4vw, 21px);
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-next__item:hover .about-next__t {
  color: var(--gold-light);
}

.page-about .about-next__d {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .about-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-track {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

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

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

  .page-about .about-cycle {
    grid-template-columns: 110px minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 6.5fr) minmax(0, 5.5fr);
  }

  .page-about .about-layout {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: clamp(40px, 5vw, 76px);
    align-items: start;
  }

  .page-about .about-rail {
    order: 1;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    border-top: 0;
    border-left: 1px solid var(--line);
    padding: 4px 0 4px 18px;
  }

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

  .page-about .about-rail__note {
    display: block;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    margin-top: 26px;
    margin-left: 2px;
    letter-spacing: 0.34em;
  }

  .page-about .about-flow {
    order: 2;
  }

  .page-about .about-section--band {
    margin-inline: calc(-1 * clamp(0px, 3vw, 34px));
    padding-inline: clamp(0px, 3vw, 34px);
  }

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

  .page-about .about-team {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.82fr);
  }

  .page-about .about-rhythm {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  }

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

  .page-about .about-next__item--last {
    background: linear-gradient(150deg, rgba(201, 162, 77, 0.12), var(--ink-deep) 70%);
  }
}

/* ---------- 大屏 ---------- */
@media (min-width: 1240px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-node,
  .page-about .about-next__item,
  .page-about .about-index .doc-index__link {
    transition: none;
  }
}