.page-about {
  --about-card: rgba(11, 43, 34, .78);
  --about-cut: 22px;
  background: var(--by-ink);
  color: var(--by-white);
  font-family: var(--by-font);
  overflow-x: hidden;
}

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

.page-about .by-h2 {
  letter-spacing: -.01em;
}

/* ===== 封面 ===== */
.page-about .about-cover {
  position: relative;
  isolation: isolate;
  padding: clamp(24px, 5vw, 54px) 0 clamp(40px, 7vw, 80px);
  background:
    radial-gradient(120% 100% at 8% -20%, rgba(57, 242, 208, .22), transparent 56%),
    radial-gradient(90% 80% at 96% 0%, rgba(255, 138, 61, .16), transparent 62%),
    linear-gradient(180deg, #08251c 0%, var(--by-ink) 78%);
}

.page-about .about-cover::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: .55;
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, .035) 0 1px, transparent 1px 5px),
    repeating-linear-gradient(90deg, rgba(57, 242, 208, .06) 0 1px, transparent 1px 130px);
}

.page-about .about-cover .by-wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-cover .by-breadcrumb {
  color: rgba(255, 255, 255, .58);
}

.page-about .about-cover .by-breadcrumb a {
  color: var(--by-cyan);
  text-decoration: none;
}

.page-about .about-cover__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 48px);
  margin-top: clamp(20px, 4vw, 34px);
}

.page-about .about-cover h1 {
  margin: 14px 0 0;
  font-family: var(--by-display);
  font-weight: 800;
  font-size: clamp(30px, 7vw, 64px);
  line-height: 1.06;
  letter-spacing: -.02em;
  text-wrap: balance;
}

.page-about .about-cover__intro {
  max-width: 44ch;
  margin-top: 16px;
  color: rgba(255, 255, 255, .82);
}

.page-about .about-cover__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* 目录卡 */
.page-about .about-index {
  padding: 20px 20px 18px;
  background: linear-gradient(155deg, rgba(31, 92, 74, .55), rgba(11, 43, 34, .94));
  border: 1px solid var(--by-line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-index__title {
  margin: 0;
  font-family: var(--by-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--by-cyan-soft);
}

.page-about .about-index__list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
}

.page-about .about-index__list a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 9px 0;
  color: rgba(255, 255, 255, .84);
  font-size: 15px;
  text-decoration: none;
  border-bottom: 1px dashed var(--by-line-soft);
  transition: color .2s var(--by-ease), transform .2s var(--by-ease);
}

.page-about .about-index__list li:last-child a {
  border-bottom: 0;
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--by-cyan);
  transform: translateX(3px);
}

.page-about .about-index__num {
  font-family: var(--by-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--by-cyan);
}

.page-about .about-index__note {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--by-line-soft);
  font-size: 13px;
  line-height: 1.65;
  color: rgba(255, 255, 255, .56);
}

/* 首屏数据条 */
.page-about .about-cover__stats {
  list-style: none;
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 5vw, 46px) 0 0;
  padding: 0;
  background: var(--by-line-soft);
  border-top: 1px solid var(--by-line);
  border-bottom: 1px solid var(--by-line);
}

.page-about .about-cover__stats > li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  background: rgba(7, 26, 20, .6);
}

.page-about .about-cover__statnum {
  font-family: var(--by-mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--by-cyan);
  letter-spacing: .02em;
}

.page-about .about-cover__statlab {
  font-size: 13px;
  color: rgba(255, 255, 255, .62);
}

/* ===== 通用章节留白 ===== */
.page-about .about-origin,
.page-about .about-team,
.page-about .about-flow,
.page-about .about-scenes,
.page-about .about-contact {
  padding-block: clamp(48px, 8vw, 96px);
  position: relative;
}

/* ===== 01 品牌起点 ===== */
.page-about .about-origin__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 52px);
  align-items: start;
}

.page-about .about-origin__text p {
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 255, 255, .78);
}

.page-about .about-origin__text p:first-of-type {
  color: rgba(255, 255, 255, .9);
}

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

.page-about .about-origin__figure img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%);
  border: 1px solid var(--by-line);
  filter: saturate(.92) brightness(.94);
}

.page-about .about-origin__figure .by-figure__caption {
  margin-top: 12px;
  font-family: var(--by-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .02em;
  color: rgba(255, 255, 255, .5);
}

/* ===== 02 内容团队 ===== */
.page-about .about-team {
  background: linear-gradient(180deg, rgba(31, 92, 74, .26), rgba(7, 26, 20, .55));
  border-top: 1px solid var(--by-line-soft);
  border-bottom: 1px solid var(--by-line-soft);
}

.page-about .about-team__head .by-lead {
  max-width: 58ch;
  margin-top: 12px;
  color: rgba(255, 255, 255, .74);
}

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 38px);
  margin-top: clamp(26px, 4vw, 40px);
}

.page-about .about-team__lanes {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--by-line-soft);
  border: 1px solid var(--by-line-soft);
}

.page-about .about-lane {
  position: relative;
  padding: 22px 20px 26px;
  background: var(--by-panel);
}

.page-about .about-lane__num {
  margin: 0;
  font-family: var(--by-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--by-amber);
}

.page-about .about-lane__title {
  margin: 10px 0 8px;
  font-size: 19px;
  font-weight: 700;
  color: var(--by-white);
}

.page-about .about-lane__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(255, 255, 255, .7);
}

.page-about .about-facts {
  padding: 22px 20px 24px;
  background: rgba(7, 26, 20, .68);
  border: 1px solid var(--by-line);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}

.page-about .about-facts__title {
  margin: 0 0 6px;
  font-family: var(--by-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--by-cyan-soft);
}

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

.page-about .about-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--by-line-soft);
}

.page-about .about-facts__row:last-child {
  border-bottom: 0;
}

.page-about .about-facts__row dt {
  font-size: 14px;
  color: rgba(255, 255, 255, .66);
}

.page-about .about-facts__row dd {
  margin: 0;
  font-family: var(--by-mono);
  font-size: 16px;
  font-weight: 700;
  color: var(--by-cyan);
}

.page-about .about-facts__link {
  display: inline-block;
  margin-top: 16px;
  font-size: 14px;
  color: var(--by-amber);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 196, 107, .5);
  padding-bottom: 2px;
}

.page-about .about-facts__link:hover,
.page-about .about-facts__link:focus-visible {
  color: var(--by-cyan);
  border-bottom-color: var(--by-cyan);
}

/* ===== 03 维护流程 ===== */
.page-about .about-flow__head .by-lead {
  max-width: 52ch;
  margin-top: 12px;
  color: rgba(255, 255, 255, .72);
}

.page-about .about-flow__steps {
  list-style: none;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--by-line-soft);
  border: 1px solid var(--by-line-soft);
}

.page-about .about-flow__step {
  position: relative;
  padding: 24px 20px 24px;
  background: var(--by-panel);
}

.page-about .about-flow__step::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  background: linear-gradient(90deg, var(--by-cyan), rgba(57, 242, 208, 0));
}

.page-about .about-flow__num {
  font-family: var(--by-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--by-cyan);
}

.page-about .about-flow__step h3 {
  margin: 10px 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--by-white);
}

.page-about .about-flow__step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(255, 255, 255, .7);
}

/* ===== 04 发展历程（浅底） ===== */
.page-about .about-timeline {
  background: var(--by-paper);
  color: var(--by-slate);
  clip-path: polygon(0 28px, 100% 0, 100% calc(100% - 28px), 0 100%);
  padding-block: clamp(72px, 9vw, 112px);
}

.page-about .about-timeline .by-eyebrow {
  color: var(--by-moss);
}

.page-about .about-timeline .by-h2 {
  color: var(--by-ink);
}

.page-about .about-timeline__lead {
  margin: 14px 0 0;
  max-width: 54ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--by-slate);
}

.page-about .about-timeline__figure {
  margin: clamp(26px, 4vw, 40px) 0 0;
}

.page-about .about-timeline__figure img {
  width: 100%;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  border: 1px solid rgba(7, 26, 20, .14);
  filter: saturate(.85);
}

.page-about .about-timeline__figure .by-figure__caption {
  margin-top: 12px;
  font-family: var(--by-mono);
  font-size: 12px;
  line-height: 1.6;
  color: rgba(63, 84, 77, .82);
}

.page-about .about-timeline__list {
  list-style: none;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
  margin-left: 6px;
}

.page-about .about-timeline__node {
  position: relative;
  padding-left: 24px;
  border-left: 1px solid rgba(31, 92, 74, .3);
}

.page-about .about-timeline__node::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 24px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--by-paper);
  border: 2px solid var(--by-moss);
  box-sizing: border-box;
}

.page-about .about-timeline__node[open]::before {
  background: var(--by-cyan);
  border-color: var(--by-moss);
}

.page-about .about-timeline__summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 15px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-timeline__summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--by-mono);
  font-size: 15px;
  color: var(--by-moss);
}

.page-about .about-timeline__node[open] .about-timeline__summary::after {
  content: "－";
  color: var(--by-orange);
}

.page-about .about-timeline__summary:hover .about-timeline__title,
.page-about .about-timeline__summary:focus-visible .about-timeline__title {
  color: var(--by-moss);
}

.page-about .about-timeline__year {
  flex: 0 0 auto;
  font-family: var(--by-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--by-moss);
}

.page-about .about-timeline__title {
  font-size: 17px;
  font-weight: 700;
  color: var(--by-ink);
  transition: color .2s var(--by-ease);
}

.page-about .about-timeline__body {
  max-width: 62ch;
  padding: 0 0 18px;
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--by-slate);
}

/* ===== 05 看球场景 ===== */
.page-about .about-scenes {
  background:
    radial-gradient(90% 80% at 100% 0%, rgba(255, 138, 61, .13), transparent 60%),
    var(--by-ink);
}

.page-about .about-scenes__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 48px);
  align-items: start;
}

.page-about .about-scenes__lead {
  margin: 14px 0 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 255, 255, .76);
}

.page-about .about-scenes__list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-scenes__item {
  display: grid;
  gap: 6px;
  padding: 14px 16px;
  background: rgba(11, 43, 34, .74);
  border-left: 2px solid var(--by-orange);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  font-size: 15px;
  line-height: 1.72;
  color: rgba(255, 255, 255, .82);
}

.page-about .about-scenes__time {
  font-family: var(--by-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--by-amber);
}

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

.page-about .about-scenes__figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 24px 100%, 0 calc(100% - 24px));
  border: 1px solid var(--by-line);
  filter: saturate(.9) brightness(.92);
}

.page-about .about-scenes__figure .by-figure__caption {
  margin-top: 12px;
  font-family: var(--by-mono);
  font-size: 12px;
  line-height: 1.6;
  color: rgba(255, 255, 255, .5);
}

/* ===== 06 反馈与联系 ===== */
.page-about .about-contact {
  background: linear-gradient(180deg, rgba(31, 92, 74, .32), rgba(7, 26, 20, .94));
  border-top: 1px solid var(--by-line);
}

.page-about .about-contact__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 44px);
  align-items: start;
}

.page-about .about-contact__text p {
  margin: 14px 0 0;
  max-width: 48ch;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 255, 255, .78);
}

.page-about .about-contact__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-contact__card {
  padding: 24px 20px;
  background: var(--about-card);
  border: 1px solid var(--by-line);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}

.page-about .about-contact__cardtitle {
  margin: 0 0 8px;
  font-family: var(--by-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--by-cyan-soft);
}

.page-about .about-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 12px;
  padding: 12px 0;
  border-bottom: 1px dashed var(--by-line-soft);
}

.page-about .about-contact__label {
  flex: 0 0 auto;
  font-family: var(--by-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: rgba(255, 255, 255, .45);
}

.page-about .about-contact__value {
  font-size: 15px;
  line-height: 1.7;
  color: rgba(255, 255, 255, .86);
  word-break: break-word;
}

.page-about .about-contact__note {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(255, 255, 255, .56);
}

.page-about .about-copy {
  appearance: none;
  padding: 0 0 2px;
  border: 0;
  border-bottom: 1px solid rgba(57, 242, 208, .45);
  background: none;
  font-family: var(--by-mono);
  font-size: 15px;
  letter-spacing: .01em;
  color: var(--by-cyan);
  cursor: pointer;
  word-break: break-word;
  text-align: left;
}

.page-about .about-copy:hover,
.page-about .about-copy:focus-visible {
  color: var(--by-cyan-soft);
  border-bottom-color: var(--by-cyan-soft);
}

/* ===== 响应式 ===== */
@media (min-width: 720px) {
  .page-about .about-cover__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-cover__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
  }

  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 58fr) minmax(0, 42fr);
  }

  .page-about .about-scenes__grid {
    grid-template-columns: minmax(0, 56fr) minmax(0, 44fr);
  }

  .page-about .about-contact__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
}

@media (min-width: 960px) {
  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  }

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

@media (min-width: 1080px) {
  .page-about .about-flow__steps {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__list a,
  .page-about .about-timeline__title {
    transition: none;
  }

  .page-about .about-index__list a:hover,
  .page-about .about-index__list a:focus-visible {
    transform: none;
  }
}
<<<END>>>