.page-about {
  --story-line: rgba(201, 160, 99, .16);
  --story-line-strong: rgba(201, 160, 99, .32);
  --story-num-strong: #C9A063;
  --story-num-dark: #A87A3E;
  --story-timeline-line: rgba(20, 33, 61, .18);
  position: relative;
  background: var(--jb-bg);
  color: var(--jb-text-ink);
  font-family: var(--jb-font-body);
  line-height: 1.6;
  overflow-x: clip;
}

.page-about a {
  color: var(--jb-gold-dark);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(168, 122, 62, .45);
  transition: color .2s ease, text-decoration-color .2s ease;
}

.page-about a:hover,
.page-about a:focus-visible {
  color: var(--jb-red);
  text-decoration-color: rgba(154, 27, 30, .6);
}

/* ========== Hero ========== */
.page-about-hero {
  position: relative;
  padding: clamp(2rem, 5vw, 4.5rem) 0 clamp(1.5rem, 4vw, 3rem);
  background-image:
    linear-gradient(var(--story-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--story-line) 1px, transparent 1px);
  background-size: 26px 26px;
  border-bottom: 1px solid var(--story-line-strong);
}

.page-about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: min(36vw, 260px);
  height: 6px;
  background: linear-gradient(90deg, transparent, var(--jb-gold));
  opacity: .7;
}

.page-about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  margin-top: clamp(1.5rem, 4vw, 2.75rem);
}

.page-about-hero__title {
  margin: 0;
  font-family: var(--jb-font-head);
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: .01em;
  color: var(--jb-text-ink);
}

.page-about-hero__subtitle {
  margin: .75rem 0 0;
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  color: var(--jb-gold-dark);
  font-weight: 600;
  letter-spacing: .06em;
}

.page-about-hero__quote {
  margin: 2rem 0 0;
  padding: 0;
  border: 0;
  max-width: 620px;
}

.page-about-hero__quote p {
  margin: 0;
  font-family: var(--jb-font-head);
  font-size: clamp(1.1rem, 2vw, 1.45rem);
  line-height: 1.55;
  color: var(--jb-text-muted);
}

.page-about-hero__quote-line {
  display: block;
  width: 58px;
  height: 2px;
  background: var(--jb-gold);
  margin-bottom: 1rem;
}

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

/* ========== 通用章节标题 ========== */
.page-about .section-heading {
  margin-bottom: clamp(1.75rem, 4vw, 3rem);
}

.page-about .section-heading__index {
  font-family: var(--jb-font-head);
  font-size: 1.6rem;
  color: var(--jb-gold);
  display: block;
  line-height: 1;
}

.page-about .section-heading__kicker {
  display: block;
  margin-top: .35rem;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .28em;
  color: var(--jb-text-muted);
}

.page-about .section-heading__title {
  margin: .6rem 0 0;
  font-family: var(--jb-font-head);
  font-size: clamp(1.8rem, 3.4vw, 2.6rem);
  line-height: 1.2;
}

.page-about .section-heading__desc {
  margin: .6rem 0 0;
  max-width: 560px;
  color: var(--jb-text-muted);
  font-size: .95rem;
}

/* ========== 通用图注 ========== */
.page-about-figure {
  position: relative;
  margin: 0;
  border-radius: 6px;
  overflow: hidden;
  background: var(--jb-surface);
  box-shadow: var(--jb-shadow);
}

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

.page-about-figure figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(20, 33, 61, .82);
  color: var(--jb-on-dark);
  font-size: .78rem;
  line-height: 1.4;
  padding: .5rem .75rem;
  backdrop-filter: blur(2px);
}

/* ========== 品牌起源 ========== */
.page-about-origin {
  padding-top: clamp(2.5rem, 5vw, 4rem);
  padding-bottom: clamp(2rem, 4vw, 3.5rem);
}

.page-about-origin__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.25rem, 3vw, 2.5rem);
  align-items: start;
}

.page-about-origin__body p {
  margin: 0 0 1rem;
  font-size: .98rem;
  color: var(--jb-text-ink);
}

.page-about-origin__note {
  padding-left: 1rem;
  border-left: 3px solid var(--jb-gold);
  color: var(--jb-text-muted) !important;
  font-style: italic;
}

/* ========== 时间线容器 ========== */
.page-about-timeline-wrap {
  padding-top: clamp(2.5rem, 5vw, 4rem);
  padding-bottom: clamp(2rem, 4vw, 3.5rem);
  background:
    linear-gradient(rgba(247, 242, 232, .85), rgba(247, 242, 232, .85)),
    linear-gradient(45deg, var(--story-line) 25%, transparent 25%, transparent 75%, var(--story-line) 75%),
    linear-gradient(45deg, var(--story-line) 25%, transparent 25%, transparent 75%, var(--story-line) 75%);
  background-size: auto, 18px 18px, 18px 18px;
  background-position: auto, 0 0, 9px 9px;
  border-top: 1px solid var(--story-line-strong);
  border-bottom: 1px solid var(--story-line-strong);
}

.page-about-timeline {
  position: relative;
  margin-top: 0;
}

.page-about-timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 22px;
  width: 2px;
  background: linear-gradient(180deg, var(--jb-gold), var(--jb-blue) 82%);
  opacity: .5;
  border-radius: 2px;
}

.page-about-timeline__item {
  position: relative;
  padding-left: 68px;
  margin-bottom: clamp(1.5rem, 3vw, 2.25rem);
}

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

.page-about-timeline__marker {
  position: absolute;
  left: 0;
  top: .25rem;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--jb-surface);
  border: 1px solid var(--jb-gold);
  box-shadow: 0 0 0 4px rgba(201, 160, 99, .14);
  z-index: 1;
}

.page-about-timeline__marker-num {
  font-family: var(--jb-font-head);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--story-num-dark);
}

.page-about-timeline__card {
  background: var(--jb-surface);
  border-radius: 6px;
  border-left: 3px solid var(--jb-gold);
  padding: clamp(1rem, 2.2vw, 1.5rem) clamp(1rem, 2.4vw, 1.75rem);
  box-shadow: 0 1px 4px rgba(20, 33, 61, .07), 0 6px 18px rgba(20, 33, 61, .05);
  transition: opacity .35s ease, transform .35s ease, box-shadow .35s ease;
}

.page-about-timeline__item:not(.is-active) .page-about-timeline__card {
  opacity: .82;
}

.page-about-timeline__item.is-active .page-about-timeline__card {
  opacity: 1;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(20, 33, 61, .12), 0 2px 6px rgba(20, 33, 61, .08);
}

.page-about-timeline__card-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem .75rem;
  margin-bottom: .6rem;
}

.page-about-timeline__tag {
  display: inline-block;
  padding: .18rem .6rem;
  background: rgba(201, 160, 99, .15);
  color: var(--story-num-dark);
  border: 1px solid rgba(201, 160, 99, .35);
  border-radius: 3px;
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .08em;
}

.page-about-timeline__stage {
  font-size: .76rem;
  color: var(--jb-text-muted);
  letter-spacing: .12em;
}

.page-about-timeline__title {
  margin: 0 0 .5rem;
  font-family: var(--jb-font-head);
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  line-height: 1.35;
}

.page-about-timeline__summary {
  margin: 0;
  font-size: .92rem;
  color: var(--jb-text-muted);
}

.page-about-timeline__detail {
  margin-top: .8rem;
  padding-top: .65rem;
  border-top: 1px dashed rgba(168, 122, 62, .4);
}

.page-about-timeline__detail summary {
  cursor: pointer;
  list-style: none;
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  font-weight: 600;
  font-size: .84rem;
  color: var(--story-num-dark);
  transition: color .2s ease;
}

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

.page-about-timeline__detail summary::before {
  content: "+";
  font-family: var(--jb-font-body);
  font-size: .9rem;
  font-weight: 700;
  line-height: 1;
}

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

.page-about-timeline__detail summary:hover,
.page-about-timeline__detail summary:focus-visible {
  color: var(--jb-red);
  outline: none;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about-timeline__detail p {
  margin: .65rem 0 0;
  font-size: .88rem;
  color: var(--jb-text-muted);
  max-width: 560px;
}

/* ========== 档案规模速览 ========== */
.page-about-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.25rem, 3vw, 2rem);
  padding-top: clamp(2.5rem, 5vw, 4rem);
  padding-bottom: clamp(2rem, 4vw, 3.5rem);
  align-items: stretch;
}

.page-about-stats__chart,
.page-about-stats__chart .page-about-figure {
  height: 100%;
}

.page-about-stats__board {
  background: var(--jb-blue);
  color: var(--jb-on-dark);
  border-radius: 6px;
  padding: clamp(1.25rem, 2.4vw, 1.75rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
  box-shadow: var(--jb-shadow);
  border-top: 3px solid var(--jb-gold);
}

.page-about-stats__heading {
  margin: 0 0 1rem;
  font-family: var(--jb-font-head);
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  color: var(--jb-on-dark);
}

.page-about-stats__list {
  margin: 0;
  display: grid;
  gap: .35rem;
}

.page-about-stats__row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: .5rem 0;
  border-bottom: 1px solid rgba(240, 230, 210, .16);
}

.page-about-stats__row dt {
  color: rgba(240, 230, 210, .72);
  font-size: .86rem;
}

.page-about-stats__row dd {
  margin: 0;
  font-weight: 700;
  font-size: .94rem;
  color: var(--jb-on-dark);
  text-align: right;
}

.page-about-stats__note {
  margin: 1rem 0 0;
  font-size: .78rem;
  color: rgba(240, 230, 210, .6);
  line-height: 1.5;
}

/* ========== 信息透明承诺 ========== */
.page-about-pledge {
  background: var(--jb-blue);
  padding: clamp(2.5rem, 5vw, 4.5rem) 0;
  border-top: 3px solid var(--jb-gold);
  border-bottom: 3px solid var(--jb-gold);
}

.page-about-pledge .section-heading__index {
  color: var(--jb-gold);
}

.page-about-pledge .section-heading__kicker {
  color: rgba(240, 230, 210, .66);
}

.page-about-pledge .section-heading__title {
  color: var(--jb-on-dark);
}

.page-about-pledge .section-heading__desc {
  color: rgba(240, 230, 210, .7);
}

.page-about-pledge__body {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.25rem);
}

.page-about-figure--pledge {
  max-width: min(400px, 100%);
  margin: 0 auto;
}

.page-about-pledge__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.page-about-pledge__card {
  position: relative;
  background: rgba(247, 242, 232, .06);
  border: 1px solid rgba(201, 160, 99, .3);
  border-left: 3px solid var(--jb-gold);
  border-radius: 6px;
  padding: 1.4rem 1.25rem 1.25rem;
  transition: background .3s ease, transform .3s ease;
}

.page-about-pledge__card:hover {
  background: rgba(247, 242, 232, .1);
  transform: translateY(-2px);
}

.page-about-pledge__num {
  display: block;
  font-family: var(--jb-font-head);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--jb-gold);
  line-height: 1;
  margin-bottom: .75rem;
}

.page-about-pledge__title {
  margin: 0 0 .5rem;
  font-family: var(--jb-font-head);
  font-size: 1.2rem;
  color: var(--jb-on-dark);
}

.page-about-pledge__card p {
  margin: 0;
  font-size: .88rem;
  line-height: 1.65;
  color: rgba(240, 230, 210, .78);
}

/* ========== 品牌宣言 ========== */
.page-about-manifesto {
  padding-top: clamp(3rem, 6vw, 5rem);
  padding-bottom: clamp(1.5rem, 3vw, 2.5rem);
  text-align: center;
}

.page-about-manifesto__quote {
  margin: 0 auto;
  max-width: 700px;
  border: 0;
  padding: 0;
}

.page-about-manifesto__quote::before,
.page-about-manifesto__quote::after {
  content: "";
  display: block;
  width: 52px;
  height: 2px;
  background: var(--jb-gold);
  margin: 1.1rem auto;
}

.page-about-manifesto__quote p {
  margin: 0;
  font-family: var(--jb-font-head);
  font-size: clamp(1.4rem, 3vw, 2.1rem);
  line-height: 1.45;
  color: var(--jb-text-ink);
}

.page-about-manifesto__sub {
  margin: 1.25rem 0 0;
  font-size: .86rem;
  letter-spacing: .22em;
  color: var(--jb-text-muted);
}

/* ========== 继续浏览引导 ========== */
.page-about-guide {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  padding-top: clamp(1.5rem, 3vw, 2.5rem);
  padding-bottom: clamp(2rem, 4vw, 3.5rem);
}

.page-about-guide__link {
  position: relative;
  display: block;
  min-height: 132px;
  text-decoration: none;
  background: var(--jb-surface);
  border: 1px solid rgba(201, 160, 99, .35);
  border-radius: 6px;
  padding: 1.1rem 1.1rem 1.1rem 1.25rem;
  overflow: hidden;
  transition: border-color .25s ease, box-shadow .25s ease, transform .25s ease;
}

.page-about-guide__link::after {
  content: "→";
  position: absolute;
  right: .9rem;
  top: .85rem;
  font-size: 1rem;
  color: var(--jb-gold);
  transition: color .25s ease, transform .25s ease;
}

.page-about-guide__link:hover,
.page-about-guide__link:focus-visible {
  border-color: var(--jb-gold);
  box-shadow: 0 6px 22px rgba(20, 33, 61, .1);
  transform: translateY(-2px);
  outline: none;
}

.page-about-guide__link:hover::after,
.page-about-guide__link:focus-visible::after {
  color: var(--jb-red);
  transform: translateX(3px);
}

.page-about-guide__index {
  display: block;
  font-family: var(--jb-font-head);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--story-num-strong);
  margin-bottom: .5rem;
}

.page-about-guide__label {
  display: block;
  font-family: var(--jb-font-head);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--jb-text-ink);
  margin-bottom: .35rem;
}

.page-about-guide__desc {
  display: block;
  font-size: .8rem;
  line-height: 1.5;
  color: var(--jb-text-muted);
  max-width: 220px;
  padding-right: 1.5rem;
}

/* ========== 平板与桌面响应 ========== */
@media (min-width: 640px) {
  .page-about-hero__grid {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: start;
    gap: 2.5rem;
  }

  .page-about-hero__index {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    padding-top: .6rem;
    min-width: 110px;
  }

  .page-about-hero__index-number {
    font-family: var(--jb-font-head);
    font-size: 2.6rem;
    font-weight: 700;
    color: var(--jb-gold);
    line-height: 1;
  }

  .page-about-hero__index-label {
    font-size: .68rem;
    font-weight: 700;
    letter-spacing: .24em;
    color: var(--jb-text-muted);
    margin-top: .5rem;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    transform-origin: center;
  }

  .page-about-hook__quote {
    max-width: 620px;
  }

  .page-about-origin__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
  }

  .page-about-stats {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  }

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

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

  .page-about-guide__link {
    min-height: 150px;
  }

  .page-about-figure figcaption {
    opacity: 0;
    transform: translateY(6px);
    transition: opacity .25s ease, transform .25s ease;
  }

  .page-about-figure:hover figcaption,
  .page-about-figure:focus-within figcaption {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (min-width: 900px) {
  .page-about-origin {
    padding-top: clamp(3rem, 5.5vw, 4.5rem);
    padding-bottom: clamp(2.5rem, 5vw, 4rem);
  }

  .page-about-timeline {
    margin-left: clamp(0rem, 4vw, 3rem);
  }

  .page-about-timeline__item {
    padding-left: 96px;
  }

  .page-about-timeline__marker {
    width: 60px;
    height: 60px;
  }

  .page-about-timeline__marker-num {
    font-size: 1.35rem;
  }

  .page-about-timeline::before {
    left: 29px;
  }

  .page-about-timeline__card {
    max-width: 680px;
  }

  .page-about-stats__note {
    font-size: .8rem;
  }
}