.page-about {
  display: block;
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 36px 0 28px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-crumb {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--steel);
  display: flex;
  gap: 10px;
  align-items: center;
  margin-bottom: 30px;
}

.page-about .about-crumb a {
  color: var(--ice);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .18s var(--ease);
}

.page-about .about-crumb a:hover {
  border-bottom-color: var(--ice);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 22px;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 7.2vw, 62px);
  line-height: 1.08;
  letter-spacing: -.015em;
  color: var(--white);
}

.page-about .about-hero__title em {
  font-style: normal;
  color: var(--lime);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 44ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 56px 0 40px;
  }
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    gap: 60px;
    align-items: end;
  }
  .page-about .about-hero__lede {
    text-align: left;
    padding-bottom: 6px;
  }
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding: clamp(46px, 8vw, 86px) 0;
  border-bottom: 1px solid var(--line);
}

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

.page-about .about-chapter__num {
  display: none;
}

.page-about .about-h2 {
  margin: 10px 0 22px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(23px, 3.6vw, 37px);
  line-height: 1.22;
  letter-spacing: -.005em;
  color: var(--white);
}

@media (min-width: 900px) {
  .page-about .about-chapter {
    padding-left: 64px;
  }
  .page-about .about-chapter__num {
    display: block;
    position: absolute;
    left: 4px;
    top: 6px;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-family: var(--font-data);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .34em;
    color: var(--steel);
    opacity: .85;
  }
}

/* ---------- 正文段落 ---------- */
.page-about .about-p {
  margin: 0 0 18px;
  max-width: 42ch;
  font-size: 15px;
  line-height: 1.88;
  color: var(--text);
}

.page-about .about-p--wide {
  max-width: 62ch;
  margin-top: 30px;
  padding-left: 16px;
  border-left: 2px solid var(--lime);
  color: var(--white);
}

/* ---------- 图片容器 ---------- */
.page-about .about-figure {
  position: relative;
  margin: 0 0 28px;
  overflow: hidden;
  background: var(--ink-2);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--tall {
  aspect-ratio: 4 / 5;
  margin-bottom: 0;
}

.page-about .about-figure img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  display: block;
  filter: saturate(.92) contrast(1.06);
}

/* ---------- 品牌起点 ---------- */
.page-about .about-origin {
  display: grid;
  gap: 30px;
}

@media (min-width: 900px) {
  .page-about .about-origin {
    grid-template-columns: minmax(0, 1.28fr) minmax(0, .72fr);
    gap: 52px;
    align-items: start;
  }
}

/* ---------- 可展开补充说明 ---------- */
.page-about .about-aside {
  margin: 26px 0 0;
  padding: 4px 0 4px 16px;
  border-left: 2px solid var(--ice);
}

.page-about .about-aside summary {
  list-style: none;
  cursor: pointer;
  font-family: var(--font-data);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--ice);
}

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

.page-about .about-aside summary::after {
  content: " ＋";
  color: var(--steel);
}

.page-about .about-aside[open] summary::after {
  content: " －";
}

.page-about .about-aside p {
  margin: 12px 0 0;
  max-width: 42ch;
  font-size: 14px;
  line-height: 1.82;
  color: var(--text-dim);
}

/* ---------- 团队与分工 ---------- */
.page-about .about-team {
  display: grid;
  gap: 32px;
}

@media (min-width: 900px) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: 56px;
    align-items: start;
  }
}

.page-about .about-bars {
  display: grid;
  gap: 20px;
  padding: 22px 20px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 0 100%);
}

.page-about .about-bar__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-dim);
  margin-bottom: 9px;
}

.page-about .about-bar__head b {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--lime);
}

.page-about .about-bar__track {
  display: block;
  height: 6px;
  background: var(--ink);
  border: 1px solid var(--line-soft);
  overflow: hidden;
}

.page-about .about-bar__fill {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--ice), var(--lime));
}

.page-about .about-bar__fill--a { width: 45%; }
.page-about .about-bar__fill--b { width: 30%; }
.page-about .about-bar__fill--c { width: 25%; }

/* ---------- 数据从哪里来 ---------- */
.page-about .about-data {
  display: grid;
  gap: 28px;
}

@media (min-width: 900px) {
  .page-about .about-data {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    gap: 52px;
    align-items: start;
  }
  .page-about .about-data .about-figure {
    margin-bottom: 0;
  }
}

/* ---------- 暖纸色阅读区 ---------- */
.page-about .about-paper {
  margin: clamp(40px, 7vw, 74px) 0;
  padding: clamp(36px, 5vw, 62px) clamp(24px, 4vw, 54px);
  background: var(--paper);
  color: var(--ink);
  clip-path: polygon(0 24px, 100% 0, 100% calc(100% - 24px), 0 100%);
}

.page-about .about-paper h2 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(22px, 3.3vw, 34px);
  line-height: 1.22;
  color: var(--ink);
}

.page-about .about-paper__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .about-paper__list li {
  border-top: 2px solid var(--ink);
  padding-top: 14px;
}

.page-about .about-paper__list strong {
  display: block;
  margin-bottom: 7px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-paper__list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--teal-deep);
}

@media (min-width: 760px) {
  .page-about .about-paper__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }
}

/* ---------- 时间线 ---------- */
.page-about .about-line {
  padding: clamp(46px, 8vw, 86px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-line__wrap {
  display: grid;
  gap: 26px;
  margin-top: 34px;
}

.page-about .about-line__toc {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: none;
}

.page-about .about-line__toc::-webkit-scrollbar {
  display: none;
}

.page-about .about-line__year {
  flex: 0 0 auto;
  padding: 7px 13px;
  font-family: var(--font-data);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--steel);
  text-decoration: none;
  border: 1px solid var(--line-soft);
  transition: color .18s var(--ease), background-color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-line__year:hover,
.page-about .about-line__year:focus-visible {
  color: var(--ink);
  background: var(--ice);
  border-color: var(--ice);
}

.page-about .about-line__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .about-node {
  padding: 24px 22px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-left: 2px solid var(--line-soft);
  scroll-margin-top: calc(var(--bar-h) + 26px);
  transition: border-color .2s var(--ease), background-color .2s var(--ease);
}

.page-about .about-node:target {
  border-left-color: var(--lime);
  background: var(--teal-deep);
}

.page-about .about-node__head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.page-about .about-node__yr {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 27px;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--ice);
}

.page-about .about-node h3 {
  margin: 0 0 9px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--white);
}

.page-about .about-node p {
  margin: 0;
  max-width: 46ch;
  font-size: 14.5px;
  line-height: 1.86;
  color: var(--text-dim);
}

@media (min-width: 900px) {
  .page-about .about-line__wrap {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 56px;
    margin-top: 42px;
  }
  .page-about .about-line__toc {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    overflow: visible;
    position: sticky;
    top: calc(var(--bar-h) + 28px);
    align-self: start;
    padding-bottom: 0;
  }
  .page-about .about-line__year {
    position: relative;
    border: none;
    border-left: 1px solid var(--line);
    padding: 15px 0 15px 20px;
    font-size: 14px;
  }
  .page-about .about-line__year::before {
    content: "";
    position: absolute;
    left: -4px;
    top: 50%;
    width: 7px;
    height: 7px;
    margin-top: -3.5px;
    background: var(--line-soft);
    transform: rotate(45deg);
    transition: background-color .2s var(--ease);
  }
  .page-about .about-line__year:hover {
    background: none;
    color: var(--ice);
    border-color: var(--ice);
  }
  .page-about .about-line__year:hover::before {
    background: var(--lime);
  }
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  list-style: none;
  margin: 6px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-next li {
  border-bottom: 1px solid var(--line);
}

.page-about .about-next a {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 4px 14px;
  align-items: baseline;
  padding: 18px 4px;
  text-decoration: none;
  color: var(--text);
  transition: background-color .18s var(--ease), padding-left .18s var(--ease);
}

.page-about .about-next a:hover,
.page-about .about-next a:focus-visible {
  background: var(--ink-2);
  padding-left: 14px;
}

.page-about .about-next__idx {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--steel);
}

.page-about .about-next__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: -.005em;
  color: var(--white);
}

.page-about .about-next__desc {
  grid-column: 2;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--text-dim);
}

@media (min-width: 800px) {
  .page-about .about-next a {
    grid-template-columns: 56px 170px minmax(0, 1fr);
    gap: 0 20px;
    padding: 20px 4px;
  }
  .page-about .about-next__desc {
    grid-column: auto;
  }
}

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

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}