.page-about {
  --about-rule: 1px solid var(--line);
  --about-rule-dash: 1px dashed var(--line);
  background: var(--ink);
  color: var(--white);
  overflow-x: clip;
}

.page-about .about-crumb {
  margin: 0;
  padding: 28px 0 0;
  list-style: none;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  padding-top: 40px;
  padding-bottom: 64px;
}

.page-about .about-hero__kicker {
  margin: 0 0 20px;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 0 0 24px;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(34px, 8vw, 76px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--white);
  max-width: 15ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-board {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: var(--about-rule);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-board__row {
  background: var(--navy);
  padding: 20px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .about-board__row dt {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .about-board__row dd {
  margin: 0;
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 6vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

/* ---------- 章节索引条 ---------- */
.page-about .about-index {
  position: sticky;
  top: 0;
  z-index: 30;
  padding: 10px 0;
  background: rgba(5, 11, 24, 0.94);
  border-top: var(--about-rule);
  border-bottom: var(--about-rule);
  backdrop-filter: blur(10px);
}

.page-about .about-index .index-strip {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

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

.page-about .about-index .index-strip__link {
  flex: 0 0 auto;
  font-size: 13px;
  white-space: nowrap;
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  padding: 72px 0;
  scroll-margin-top: 76px;
  border-bottom: var(--about-rule);
}

.page-about .about-sec--alt {
  background: var(--navy);
}

.page-about .about-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-bottom: 40px;
}

.page-about .about-head__no {
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .about-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(26px, 6vw, 52px);
  line-height: 1.14;
  letter-spacing: -0.015em;
  color: var(--white);
  max-width: 22ch;
}

.page-about .about-head__note {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
  max-width: 40ch;
}

.page-about .about-copy {
  max-width: 68ch;
}

.page-about .about-copy p {
  margin: 0 0 20px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--white);
}

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

.page-about .about-copy--tail {
  margin-top: 32px;
  padding-top: 24px;
  border-top: var(--about-rule-dash);
}

.page-about .about-copy--tail p {
  color: var(--mist);
}

/* ---------- 01 服务对象 ---------- */
.page-about .about-note-wrap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-note-sticky {
  align-self: start;
}

.page-about .note-block {
  padding: 16px 18px;
  border-left: 2px solid var(--cyan);
  background: rgba(52, 245, 208, 0.05);
  border-radius: 0 var(--r-card) var(--r-card) 0;
}

.page-about .note-block p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .note-block strong {
  color: var(--cyan);
  font-weight: 600;
}

/* ---------- 02 内容分层 ---------- */
.page-about .about-layers {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: var(--about-rule);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-layers__item {
  background: var(--ink);
  padding: 24px 20px 26px;
  transition: background var(--t-base) ease-out, transform var(--t-fast) ease-out;
}

.page-about .about-layers__idx {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 12px;
  border-radius: var(--r-pill);
  border: 1px solid var(--cyan);
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: 0.12em;
}

.page-about .about-layers__name {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -0.01em;
}

.page-about .about-layers__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-layers__item:hover,
.page-about .about-layers__item:focus-within {
  background: var(--stand);
}

/* ---------- 03 制作流程 ---------- */
.page-about .about-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-steps__item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  padding: 22px 0;
  border-top: var(--about-rule-dash);
}

.page-about .about-steps__item:last-child {
  border-bottom: var(--about-rule-dash);
}

.page-about .about-steps__no {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--orange);
}

.page-about .about-steps__name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 800;
  color: var(--white);
}

.page-about .about-steps__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-flow__side {
  display: grid;
  gap: 20px;
  align-content: start;
}

.page-about .about-flow__notes {
  display: grid;
  gap: 12px;
}

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

/* 步骤之间的虚线连接 */
.page-about .about-steps__item {
  position: relative;
}

.page-about .about-steps__item::before {
  content: "";
  position: absolute;
  left: 19px;
  top: 0;
  width: 2px;
  height: 100%;
  background: repeating-linear-gradient(180deg, var(--line) 0 6px, transparent 6px 12px);
  opacity: 0.9;
}

.page-about .about-steps__item:first-child::before {
  top: 22px;
}

.page-about .about-steps__item:last-child::before {
  height: 22px;
}

/* ---------- 04 时间线 ---------- */
.page-about .about-line {
  list-style: none;
  margin: 0;
  padding: 0 0 0 36px;
  position: relative;
}

.page-about .about-line::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--cyan-deep) 55%, var(--line) 100%);
}

.page-about .about-line__item {
  position: relative;
  padding-bottom: 40px;
}

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

.page-about .about-line__dot {
  position: absolute;
  left: -36px;
  top: 5px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid var(--cyan);
  background: var(--ink);
  box-sizing: border-box;
  transition: box-shadow var(--t-fast) ease-out, border-color var(--t-fast) ease-out;
}

.page-about .about-line__item--live .about-line__dot {
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 122, 47, 0.18);
}

.page-about .about-line__item:hover .about-line__dot,
.page-about .about-line__item:focus-within .about-line__dot {
  box-shadow: 0 0 0 5px rgba(52, 245, 208, 0.2);
}

.page-about .about-line__year {
  margin: 0 0 6px;
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-line__item--live .about-line__year {
  color: var(--orange);
}

.page-about .about-line__title {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -0.01em;
}

.page-about .about-line__text {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 05 团队 ---------- */
.page-about .about-team__figure {
  margin: 0 0 40px;
}

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--about-rule);
}

.page-about .about-roles__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 22px 0;
  border-bottom: var(--about-rule);
  transition: background var(--t-base) ease-out;
}

.page-about .about-roles__name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-roles__duty {
  font-size: 14px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 06 覆盖 ---------- */
.page-about .about-reach {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}

.page-about .about-stats {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: var(--about-rule);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-stats__item {
  background: var(--navy);
  padding: 22px 20px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}

.page-about .about-stats__num {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: clamp(30px, 8vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .about-stats__label {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--white);
}

.page-about .about-stats__label span {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--mist);
}

.page-about .about-partners {
  margin-top: 28px;
  padding: 20px 22px;
  border-radius: var(--r-card);
  background: linear-gradient(135deg, rgba(52, 245, 208, 0.1), rgba(12, 23, 48, 0) 62%);
  border: var(--about-rule);
}

.page-about .about-partners__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--mist);
}

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

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  padding: 64px 0 80px;
}

.page-about .about-cta__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: center;
  padding: 32px 24px;
  border-radius: var(--r-lg);
  border: 1px solid rgba(255, 122, 47, 0.35);
  background: linear-gradient(160deg, rgba(255, 122, 47, 0.12), rgba(12, 23, 48, 0.2) 70%);
}

.page-about .about-cta__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(24px, 6vw, 40px);
  line-height: 1.18;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 52ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 移动端优先之外的断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-head {
    grid-template-columns: 1fr;
    gap: 14px;
  }

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

  .page-about .about-stats__item {
    grid-template-columns: 160px 1fr;
    gap: 20px;
    align-items: baseline;
  }

  .page-about .about-stats__num {
    text-align: left;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: 7fr 5fr;
    gap: 64px;
    align-items: end;
    padding-top: 56px;
    padding-bottom: 88px;
  }

  .page-about .about-note-wrap {
    grid-template-columns: 7fr 4fr;
    gap: 64px;
  }

  .page-about .about-note-sticky {
    position: sticky;
    top: 96px;
  }

  .page-about .about-sec {
    padding: 104px 0;
  }

  .page-about .about-head {
    grid-template-columns: 80px 1fr 20ch;
    gap: 24px;
    align-items: start;
    margin-bottom: 56px;
  }

  .page-about .about-head__no {
    padding-top: 12px;
  }

  .page-about .about-head__title {
    max-width: 20ch;
  }

  .page-about .about-head__note {
    padding-top: 12px;
    text-align: right;
  }

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

  .page-about .about-layers__item {
    padding: 30px 22px 34px;
  }

  .page-about .about-flow {
    grid-template-columns: 5fr 7fr;
    gap: 64px;
    align-items: start;
  }

  .page-about .about-roles__row {
    grid-template-columns: 180px 1fr;
    gap: 32px;
    align-items: baseline;
    padding: 26px 12px;
  }

  .page-about .about-roles__row:hover {
    background: rgba(30, 58, 110, 0.35);
  }

  .page-about .about-reach {
    grid-template-columns: 7fr 5fr;
    gap: 56px;
    align-items: start;
  }

  .page-about .about-cta__inner {
    grid-template-columns: 1fr auto;
    gap: 48px;
    padding: 44px 40px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-line {
    padding-left: 52px;
  }

  .page-about .about-line__dot {
    left: -52px;
  }

  .page-about .about-line__item {
    display: grid;
    grid-template-columns: 96px 1fr;
    column-gap: 28px;
    align-items: start;
  }

  .page-about .about-line__year {
    grid-column: 1;
    text-align: right;
    padding-top: 6px;
  }

  .page-about .about-line__title {
    grid-column: 2;
  }

  .page-about .about-line__text {
    grid-column: 2;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-layers__item,
  .page-about .about-line__dot,
  .page-about .about-roles__row {
    transition: none;
  }
}