.page-about {
  --about-year-col: 168px;
}

/* ---------- 首屏封面 ---------- */
.page-about .about-hero {
  position: relative;
  margin-top: calc(-1 * var(--header-h));
  padding-top: calc(var(--header-h) + clamp(48px, 8vw, 112px));
  padding-bottom: clamp(40px, 6vw, 88px);
  overflow: hidden;
  background:
    radial-gradient(120% 90% at 12% 8%, rgba(20, 64, 95, .55) 0%, rgba(5, 24, 42, 0) 62%),
    radial-gradient(80% 70% at 92% 88%, rgba(217, 166, 74, .10) 0%, rgba(5, 24, 42, 0) 70%),
    var(--ink-900);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(155, 176, 194, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(155, 176, 194, .07) 1px, transparent 1px);
  background-size: 68px 68px;
  -webkit-mask-image: radial-gradient(110% 85% at 18% 26%, #000 0%, transparent 72%);
  mask-image: radial-gradient(110% 85% at 18% 26%, #000 0%, transparent 72%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong) 22%, var(--line-strong) 78%, transparent);
  pointer-events: none;
}

.page-about .about-hero .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-hero__coord {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--jade-2024);
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  max-width: 20ch;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.18;
  letter-spacing: .06em;
  color: var(--white);
}

.page-about .about-hero__lede {
  margin: 0 0 clamp(28px, 4vw, 46px);
  max-width: 62ch;
  font-size: clamp(16px, 1.7vw, 18px);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__index {
  flex-wrap: wrap;
  gap: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__index .index-item {
  flex: 1 1 150px;
  padding: 14px 18px 14px 0;
}

.page-about .about-hero__index .index-value {
  color: var(--gold);
}

/* ---------- 品牌自述 ---------- */
.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 5vw, 64px);
  align-items: start;
}

.page-about .about-intro__text .lede {
  margin-top: 0;
}

.page-about .about-intro__text p {
  margin: 0 0 1.1em;
  max-width: 64ch;
  color: var(--mist);
  line-height: 1.85;
}

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

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

/* ---------- 沿革时间轴 ---------- */
.page-about .about-timeline {
  background:
    linear-gradient(180deg, rgba(12, 42, 66, .55) 0%, rgba(5, 24, 42, 0) 46%);
}

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

.page-about .about-years {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 8px;
  scrollbar-width: thin;
}

.page-about .about-years__link {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 108px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  background: rgba(12, 42, 66, .6);
  color: var(--mist);
  text-decoration: none;
  transition: border-color .22s ease, color .22s ease, background-color .22s ease;
}

.page-about .about-years__link:hover,
.page-about .about-years__link:focus-visible {
  border-color: var(--line-strong);
  background: var(--ink-700);
  color: var(--white);
  outline: none;
}

.page-about .about-years__num {
  font-size: 15px;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .about-years__label {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
}

.page-about .about-timeline__cards {
  counter-reset: aboutcard;
  display: grid;
  gap: clamp(18px, 3vw, 30px);
}

.page-about .about-card {
  position: relative;
  padding: clamp(22px, 3.2vw, 36px);
  padding-left: clamp(22px, 3.2vw, 36px);
  border: 1px solid var(--line);
  background: linear-gradient(150deg, var(--ink-800) 0%, rgba(12, 42, 66, .72) 100%);
  box-shadow: var(--shadow);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-card::before {
  counter-increment: aboutcard;
  content: counter(aboutcard, decimal-leading-zero);
  position: absolute;
  top: clamp(22px, 3.2vw, 36px);
  right: clamp(22px, 3.2vw, 36px);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: rgba(155, 176, 194, .5);
}

.page-about .about-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 54px;
  height: 2px;
  background: var(--gold);
}

.page-about .about-card__head {
  margin-bottom: 16px;
  padding-right: 48px;
}

.page-about .about-card__year {
  display: block;
  margin-bottom: 8px;
  font-size: 30px;
  line-height: 1;
  letter-spacing: .06em;
  color: var(--gold-soft);
}

.page-about .about-card__title {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(19px, 2.2vw, 24px);
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: .04em;
  color: var(--white);
}

.page-about .about-card p {
  margin: 0 0 12px;
  color: var(--mist);
  line-height: 1.85;
}

.page-about .about-card__note {
  margin: 0;
  padding-top: 12px;
  border-top: 1px solid var(--line-cool);
  font-size: 14px;
  color: var(--gold-soft);
}

.page-about .about-timeline__banner {
  margin: clamp(34px, 5vw, 64px) 0 0;
}

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

/* ---------- 团队 ---------- */
.page-about .about-team__bar {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 0;
}

.page-about .about-team__seg {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  border: 1px solid var(--line);
  background: var(--ink-800);
  transition: background-color .22s ease, border-color .22s ease;
  outline: none;
}

.page-about .about-team__seg--edit { border-top: 2px solid var(--gold); }
.page-about .about-team__seg--tech { border-top: 2px solid var(--jade-2023); }
.page-about .about-team__seg--support { border-top: 2px solid var(--jade-2021); }
.page-about .about-team__seg--design { border-top: 2px solid var(--cinnabar); }

.page-about .about-team__seg:hover,
.page-about .about-team__seg:focus-visible {
  background: var(--ink-700);
  border-color: var(--line-strong);
  border-top-color: var(--gold);
}

.page-about .about-team__seg-num {
  font-size: 26px;
  line-height: 1;
  letter-spacing: .04em;
  color: var(--white);
}

.page-about .about-team__seg-name {
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--gold-soft);
}

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

.page-about .about-team__meta {
  margin-top: clamp(24px, 3.4vw, 40px);
  padding-top: clamp(20px, 3vw, 32px);
  border-top: 1px solid var(--line);
}

.page-about .about-team__meta p {
  margin: 0 0 14px;
  max-width: 66ch;
  color: var(--mist);
  line-height: 1.85;
}

.page-about .about-team__meta-figure {
  margin: 0;
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--gold);
}

/* ---------- 内容产出 ---------- */
.page-about .about-process {
  background: linear-gradient(180deg, rgba(10, 14, 18, .7) 0%, rgba(5, 24, 42, 0) 60%);
}

.page-about .about-process__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(30px, 5vw, 64px);
  align-items: start;
}

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

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

.page-about .about-process__text .lede {
  margin-top: 0;
  color: var(--mist);
}

.page-about .about-steps {
  list-style: none;
  margin: clamp(24px, 3.4vw, 38px) 0 clamp(28px, 4vw, 42px);
  padding: 0;
}

.page-about .about-step {
  position: relative;
  padding: 0 0 22px 56px;
  border-left: 1px solid var(--line-cool);
  margin-left: 12px;
}

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

.page-about .about-step__idx {
  position: absolute;
  left: -13px;
  top: 0;
  display: block;
  width: 26px;
  text-align: center;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--ink-900);
  background: var(--gold);
  padding: 2px 0;
}

.page-about .about-step__name {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--white);
}

.page-about .about-step p {
  margin: 0;
  color: var(--mist);
  line-height: 1.85;
}

.page-about .about-process__figures {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding-top: clamp(20px, 3vw, 30px);
  border-top: 1px solid var(--line);
}

.page-about .about-figure {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-figure__num {
  font-size: 28px;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--gold);
  min-width: 3.2em;
}

.page-about .about-figure__label {
  font-size: 14px;
  color: var(--mist);
}

/* ---------- 服务范围 ---------- */
.page-about .about-reach__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4.5vw, 56px);
  align-items: start;
}

.page-about .about-reach__text p {
  margin: 0 0 1.1em;
  max-width: 64ch;
  color: var(--mist);
  line-height: 1.85;
}

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

.page-about .about-reach__stat {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-reach__stat-num {
  font-size: 34px;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--gold-soft);
  min-width: 2.4em;
}

.page-about .about-reach__stat-label {
  font-size: 14px;
  color: var(--mist);
}

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

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

.page-about .about-cred details {
  padding: 0;
}

.page-about .about-cred__summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 16px;
  padding: clamp(18px, 2.6vw, 26px) 0;
  cursor: pointer;
  list-style: none;
  transition: color .2s ease;
}

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

.page-about .about-cred__summary:hover,
.page-about .about-cred__summary:focus-visible {
  color: var(--gold);
  outline: none;
}

.page-about .about-cred__year {
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--jade-2024);
}

.page-about .about-cred__title {
  font-family: var(--font-head);
  font-size: clamp(16px, 1.9vw, 20px);
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--white);
}

.page-about .about-cred__toggle {
  position: relative;
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
}

.page-about .about-cred__toggle::before,
.page-about .about-cred__toggle::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  width: 16px;
  height: 1px;
  background: var(--gold);
  transition: transform .22s ease, opacity .22s ease;
}

.page-about .about-cred__toggle::after {
  transform: rotate(90deg);
}

.page-about .about-cred details[open] .about-cred__toggle::after {
  transform: rotate(0deg);
  opacity: 0;
}

.page-about .about-cred__body {
  padding: 0 0 clamp(20px, 2.8vw, 28px);
}

.page-about .about-cred__body p {
  margin: 0;
  max-width: 66ch;
  color: var(--mist);
  line-height: 1.85;
}

/* ---------- 行动区 ---------- */
.page-about .about-cta__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 40px);
  align-items: center;
  padding: clamp(28px, 4vw, 44px);
  border: 1px solid var(--line);
  background:
    radial-gradient(120% 140% at 88% 12%, rgba(217, 166, 74, .12) 0%, rgba(5, 24, 42, 0) 62%),
    var(--ink-800);
  box-shadow: var(--shadow);
}

.page-about .about-cta__text .section-title {
  margin-bottom: 12px;
}

.page-about .about-cta__text p {
  margin: 0;
  max-width: 60ch;
  color: var(--mist);
  line-height: 1.85;
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-process__figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .about-figure {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .page-about .about-figure__num {
    min-width: 0;
    font-size: 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: clamp(40px, 5vw, 76px);
  }

  .page-about .about-intro__media {
    margin-top: 12px;
  }

  .page-about .about-timeline__layout {
    grid-template-columns: var(--about-year-col) minmax(0, 1fr);
    gap: clamp(36px, 4vw, 64px);
  }

  .page-about .about-years {
    flex-direction: column;
    overflow: visible;
    padding-bottom: 0;
    gap: 6px;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

  .page-about .about-years__link {
    min-width: 0;
    width: 100%;
    border-color: transparent;
    border-left: 1px solid var(--line-cool);
    background: transparent;
    padding: 10px 12px 10px 16px;
  }

  .page-about .about-years__link:hover,
  .page-about .about-years__link:focus-visible {
    border-left-color: var(--gold);
    background: rgba(12, 42, 66, .55);
  }

  .page-about .about-team__bar {
    flex-direction: row;
    align-items: stretch;
    gap: 6px;
    min-height: 168px;
  }

  .page-about .about-team__seg {
    flex: 1 1 0;
    justify-content: flex-end;
    padding: 22px 18px;
  }

  .page-about .about-team__seg--edit { flex-grow: 15; }
  .page-about .about-team__seg--tech { flex-grow: 12; }
  .page-about .about-team__seg--support { flex-grow: 9; }
  .page-about .about-team__seg--design { flex-grow: 6; }

  .page-about .about-team__seg-detail {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height .3s ease, opacity .3s ease;
  }

  .page-about .about-team__seg:hover .about-team__seg-detail,
  .page-about .about-team__seg:focus-visible .about-team__seg-detail,
  .page-about .about-team__seg:focus-within .about-team__seg-detail {
    max-height: 160px;
    opacity: 1;
  }

  .page-about .about-process__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    gap: clamp(40px, 5vw, 72px);
  }

  .page-about .about-reach__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(40px, 5vw, 72px);
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 7fr) auto;
    gap: clamp(32px, 4vw, 56px);
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 1100px) {
  .page-about .about-timeline__cards {
    gap: clamp(24px, 2.6vw, 36px);
  }

  .page-about .about-card {
    margin-left: 0;
  }

  .page-about .about-card:nth-child(even) {
    margin-left: clamp(24px, 3vw, 48px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-years__link,
  .page-about .about-team__seg,
  .page-about .about-team__seg-detail,
  .page-about .about-cred__toggle::before,
  .page-about .about-cred__toggle::after {
    transition: none;
  }
}