.page-about {
  --spine: rgba(0, 229, 199, 0.34);
  --cut-lg: 18px;
  --sec-gap: clamp(46px, 8vw, 104px);
}

.page-about [id] {
  scroll-margin-top: 92px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding-block: clamp(20px, 4vw, 40px) clamp(32px, 6vw, 68px);
}

.page-about .about-hero__media {
  position: absolute;
  inset: 0;
  z-index: -1;
  overflow: hidden;
}

.page-about .about-hero__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 38%;
  opacity: 0.42;
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(88% 110% at 6% 0%, rgba(0, 229, 199, 0.18), transparent 58%),
    linear-gradient(180deg, rgba(8, 27, 47, 0.82) 0%, rgba(11, 59, 54, 0.9) 52%, var(--pine-deep) 100%);
}

.page-about .about-hero__inner {
  max-width: 860px;
  padding-top: clamp(18px, 3vw, 34px);
}

.page-about .about-hero .crumbs {
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(34px, 6.6vw, 62px);
  line-height: 1.06;
  letter-spacing: -0.012em;
  color: var(--text);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  max-width: 640px;
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 目录索引 ---------- */

.page-about .about-index {
  margin-top: clamp(32px, 5vw, 60px);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

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

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 15px 18px;
  background: rgba(8, 27, 47, 0.74);
  color: var(--text);
  text-decoration: none;
  font-size: 15px;
  transition: background 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  background: rgba(0, 229, 199, 0.1);
  color: var(--cyan);
}

.page-about .about-index__no {
  font-size: 13px;
  color: var(--cyan);
  letter-spacing: 0.06em;
}

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

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter {
  padding-block: var(--sec-gap);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-chapter--last {
  padding-bottom: clamp(52px, 9vw, 120px);
}

.page-about .section-band {
  margin-bottom: clamp(20px, 3.4vw, 34px);
}

.page-about .about-chapter__lead {
  margin: 0 0 clamp(26px, 4vw, 44px);
  max-width: var(--w-read);
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 52px);
  align-items: start;
}

.page-about .about-prose p {
  margin: 0 0 1.15em;
  font-size: 16px;
  line-height: 1.88;
  color: var(--text-dim);
}

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

.page-about .about-prose strong {
  color: var(--text);
  font-weight: 600;
}

/* ---------- 旁注事实表 ---------- */

.page-about .about-aside {
  border-left: 2px solid var(--cyan);
  padding-left: clamp(16px, 2.4vw, 22px);
}

.page-about .about-aside__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-mute);
  font-weight: 500;
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line-soft);
  font-size: 14px;
}

.page-about .about-facts__key {
  color: var(--text-mute);
  white-space: nowrap;
}

.page-about .about-facts__val {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
  text-align: right;
  min-width: 0;
}

/* ---------- 版本卡 ---------- */

.page-about .about-versions {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 3vw, 26px);
}

.page-about .about-version {
  position: relative;
  padding: clamp(22px, 3vw, 32px);
  background: linear-gradient(155deg, rgba(14, 42, 71, 0.94) 0%, rgba(11, 59, 54, 0.88) 100%);
  clip-path: polygon(0 0, calc(100% - var(--cut-lg)) 0, 100% var(--cut-lg), 100% 100%, 0 100%);
  border-left: 2px solid rgba(0, 229, 199, 0.5);
}

.page-about .about-version__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
}

.page-about .about-version__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-version__years {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-mute);
}

.page-about .about-version__title {
  margin: 0 0 16px;
  font-family: var(--font-head);
  font-size: clamp(20px, 2.6vw, 25px);
  font-weight: 800;
  line-height: 1.32;
  color: var(--text);
}

.page-about .about-version__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 11px;
}

.page-about .about-version__list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--text-dim);
}

.page-about .about-version__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 7px;
  height: 7px;
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

/* ---------- 图片容器 ---------- */

.page-about .about-figure {
  margin: clamp(28px, 4.6vw, 52px) 0 0;
}

.page-about .about-figure--tight {
  margin-top: 0;
}

.page-about .media-frame__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 时间轴 ---------- */

.page-about .about-axis {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 6px 0 6px 34px;
}

.page-about .about-axis::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(0, 229, 199, 0.35) 55%, rgba(0, 229, 199, 0.05) 100%);
}

.page-about .about-axis__node {
  position: relative;
  padding-bottom: clamp(28px, 4.6vw, 52px);
}

.page-about .about-axis__node:last-child {
  padding-bottom: 0;
}

.page-about .about-axis__node::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 10px;
  width: 11px;
  height: 11px;
  box-sizing: border-box;
  background: var(--ice-deep);
  border: 2px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .about-axis__year {
  display: block;
  font-size: clamp(20px, 3vw, 26px);
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--cyan);
  line-height: 1.2;
}

.page-about .about-axis__title {
  margin: 8px 0 10px;
  font-family: var(--font-head);
  font-size: clamp(19px, 2.4vw, 23px);
  font-weight: 800;
  line-height: 1.34;
  color: var(--text);
}

.page-about .about-axis__node p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 里程碑数字 ---------- */

.page-about .about-marks {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: clamp(32px, 5vw, 58px);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-mark {
  padding: 22px 20px 24px;
  background: linear-gradient(160deg, rgba(11, 59, 54, 0.92) 0%, rgba(8, 27, 47, 0.96) 100%);
}

.page-about .about-mark__num {
  display: block;
  font-size: clamp(30px, 4.6vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--text);
  letter-spacing: -0.02em;
}

.page-about .about-mark__unit {
  margin-left: 5px;
  font-size: 0.44em;
  font-weight: 500;
  letter-spacing: 0;
}

.page-about .about-mark__label {
  display: block;
  margin-top: 12px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--text-mute);
}

.page-about .about-mark--cyan .about-mark__num {
  color: var(--cyan);
}

.page-about .about-mark--gold .about-mark__num {
  color: var(--gold);
}

.page-about .about-mark--orange .about-mark__num {
  color: var(--orange);
}

.page-about .about-mark--silver .about-mark__num {
  color: var(--silver);
}

/* ---------- 协作网络 ---------- */

.page-about .about-network {
  margin-top: clamp(36px, 6vw, 72px);
}

.page-about .about-network__hub {
  position: relative;
  padding: 20px clamp(20px, 3vw, 28px);
  background: linear-gradient(118deg, var(--pine) 0%, var(--ice-blue) 100%);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.page-about .about-network__hub-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--cyan);
}

.page-about .about-network__hub-text {
  margin: 8px 0 0;
  font-family: var(--font-head);
  font-size: clamp(18px, 2.4vw, 22px);
  font-weight: 800;
  line-height: 1.35;
  color: var(--text);
}

.page-about .about-network__list {
  position: relative;
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 26px;
  display: grid;
  gap: 18px;
}

.page-about .about-network__list::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 4px;
  bottom: 4px;
  width: 1px;
  background: linear-gradient(180deg, var(--spine) 0%, rgba(0, 229, 199, 0.05) 100%);
}

.page-about .about-network__node {
  position: relative;
}

.page-about .about-network__node::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 12px;
  width: 9px;
  height: 9px;
  box-sizing: border-box;
  background: var(--ice-deep);
  border: 2px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .about-network__count {
  display: block;
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .about-network__unit {
  margin-left: 3px;
  font-size: 0.5em;
  font-weight: 500;
}

.page-about .about-network__node h3 {
  margin: 6px 0 6px;
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: var(--text);
}

.page-about .about-network__node p {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.72;
  color: var(--text-dim);
}

/* ---------- 未来方向 ---------- */

.page-about .about-plan {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-plan__item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: clamp(14px, 3vw, 28px);
  padding: clamp(20px, 3vw, 30px) 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-plan__no {
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--orange);
  padding-top: 4px;
}

.page-about .about-plan__body h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: clamp(18px, 2.3vw, 21px);
  font-weight: 800;
  line-height: 1.35;
  color: var(--text);
}

.page-about .about-plan__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 延伸入口 ---------- */

.page-about .about-links {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: clamp(32px, 5vw, 56px);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 18px 20px;
  background: rgba(8, 27, 47, 0.76);
  color: var(--text);
  text-decoration: none;
  font-size: 15px;
  transition: background 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  background: rgba(0, 229, 199, 0.1);
  color: var(--cyan);
}

.page-about .about-link__go {
  color: var(--cyan);
  font-size: 16px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 620px) {
  .page-about .about-index__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .about-versions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .about-split--team {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  }

  .page-about .about-figure--tight {
    margin-top: 0;
  }
}

@media (min-width: 1024px) {
  .page-about .about-index__list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

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

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

  .page-about .about-network__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(20px, 2.6vw, 34px);
    padding-left: 0;
    margin-top: clamp(28px, 3vw, 40px);
  }

  .page-about .about-network__list::before {
    left: 0;
    right: 0;
    top: -14px;
    bottom: auto;
    width: auto;
    height: 1px;
    background: linear-gradient(90deg, transparent 0%, var(--spine) 12%, var(--spine) 88%, transparent 100%);
  }

  .page-about .about-network__node::before {
    left: 4px;
    top: -21px;
  }

  .page-about .about-network__node {
    padding-top: 18px;
    border-top: 1px solid var(--line-soft);
  }
}

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