.page-about {
  --about-grid: rgba(58, 107, 138, 0.22);
  --about-surface: rgba(16, 47, 74, 0.62);
  background: var(--navy-900);
  color: var(--paper);
  overflow-x: clip;
}

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

.page-about .about-hero {
  position: relative;
  padding: calc(var(--header-h) + 32px) 0 44px;
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(45, 226, 230, 0.16), transparent 62%),
    radial-gradient(90% 70% at 4% 100%, rgba(255, 122, 26, 0.14), transparent 66%),
    linear-gradient(180deg, #071a2f 0%, #0b2742 100%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--about-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-grid) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 78%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 78%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: clamp(28px, 5vw, 56px);
  align-items: end;
}

.page-about .breadcrumb {
  margin-bottom: 18px;
}

.page-about .about-hero__title {
  margin: 10px 0 18px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(34px, 8vw, 68px);
  line-height: 1.02;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  max-width: 58ch;
  color: var(--mist);
  font-family: var(--font-editorial);
  font-size: clamp(15px, 2.6vw, 18px);
  line-height: 1.85;
  margin: 0;
}

.page-about .about-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

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

.page-about .about-hero__figure .figure__media {
  border: 1px solid var(--line-soft);
  box-shadow: 0 0 0 1px rgba(45, 226, 230, 0.12), 0 24px 60px rgba(0, 0, 0, 0.36);
}

.page-about .about-stats {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 40px 0 0;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-stat {
  padding: 16px 14px;
  background: rgba(7, 26, 47, 0.86);
}

.page-about .about-stat__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
  margin: 0 0 8px;
}

.page-about .about-stat__value {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 5.6vw, 34px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-stat__value span {
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--mist);
  margin-left: 4px;
}

.page-about .about-filter {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 22px 0 6px;
}

.page-about .about-filter__label {
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mist);
  margin-right: 4px;
}

.page-about .filter-btn {
  appearance: none;
  cursor: pointer;
  padding: 8px 16px;
  border: 1px solid var(--line-soft);
  background: var(--about-surface);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.04em;
  border-radius: 0;
  transition: border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .filter-btn:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .filter-btn[aria-pressed="true"] {
  border-color: var(--orange);
  color: var(--orange);
  box-shadow: inset 0 -2px 0 var(--orange);
}

.page-about .about-flow {
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .about-chapter {
  display: grid;
  gap: clamp(18px, 3vw, 28px);
  padding: clamp(40px, 6vw, 64px) 0;
  border-top: 1px solid var(--line-soft);
  opacity: 1;
  transform: none;
}

.page-about .about-chapter[hidden],
.page-about .filter-item[hidden] {
  display: none;
}

.page-about .about-chapter[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.page-about .about-chapter[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

.page-about .about-chapter__side {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .chapter-no {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(48px, 12vw, 88px);
  line-height: 0.8;
  color: transparent;
  -webkit-text-stroke: 1px var(--line);
  letter-spacing: 0.02em;
}

.page-about .about-chapter__kicker {
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--orange);
}

.page-about .about-chapter__main h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 4.6vw, 40px);
  line-height: 1.12;
  color: var(--paper);
}

.page-about .lede {
  font-family: var(--font-editorial);
  font-size: clamp(15px, 2.4vw, 17px);
  line-height: 1.9;
  color: var(--mist);
  margin: 0 0 22px;
  max-width: 66ch;
}

.page-about .prose p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(244, 248, 255, 0.86);
  max-width: 72ch;
}

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

.page-about .about-note {
  margin-top: 24px;
  padding: 18px 20px;
  border-left: 3px solid var(--orange);
  background: var(--about-surface);
}

.page-about .about-note__label {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .about-note p {
  margin: 0;
  font-family: var(--font-editorial);
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper);
}

/* 时间线 */
.page-about .timeline {
  list-style: none;
  margin: 8px 0 28px;
  padding: 0;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 14px;
  bottom: 14px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--orange));
  opacity: 0.45;
}

.page-about .timeline__item {
  position: relative;
  padding-left: 30px;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 20px;
  width: 12px;
  height: 12px;
  background: var(--navy-900);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 10px rgba(45, 226, 230, 0.4);
}

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

.page-about .tl__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl__year {
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--orange);
  padding: 2px 8px;
  border: 1px solid rgba(255, 122, 26, 0.45);
}

.page-about .tl__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(17px, 2.6vw, 21px);
  color: var(--paper);
}

.page-about .tl__body {
  padding: 0 0 18px;
}

.page-about .tl__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 248, 255, 0.8);
  max-width: 66ch;
}

.page-about .about-timeline-figure {
  margin: 8px 0 0;
}

.page-about .about-timeline-figure .figure__media {
  border: 1px solid var(--line-soft);
}

/* 人群 */
.page-about .about-audience {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr;
}

.page-about .about-card {
  padding: 20px;
  background: linear-gradient(160deg, rgba(16, 47, 74, 0.92), rgba(11, 39, 66, 0.55));
  border: 1px solid var(--line-soft);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.page-about .about-card:hover {
  border-color: var(--cyan);
  box-shadow: 0 0 24px rgba(45, 226, 230, 0.14);
}

.page-about .about-card h3 {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(18px, 3vw, 22px);
  color: var(--paper);
}

.page-about .about-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(244, 248, 255, 0.82);
}

.page-about .about-inline-link {
  margin: 22px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-inline-link a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(45, 226, 230, 0.5);
}

.page-about .about-inline-link a:hover {
  color: var(--cyan-soft);
}

/* 维护 */
.page-about .about-team {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-roles {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-roles > li {
  display: grid;
  gap: 6px;
  padding-left: 16px;
  border-left: 2px solid var(--line);
}

.page-about .about-roles__no {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .about-roles p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(244, 248, 255, 0.82);
}

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

.page-about .about-team__figure .figure__media {
  border: 1px solid var(--line-soft);
}

/* 视觉色卡 */
.page-about .swatches {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  display: grid;
  gap: 12px;
  grid-template-columns: 1fr;
}

.page-about .swatch {
  padding: 14px;
  border: 1px solid var(--line-soft);
  background: rgba(16, 47, 74, 0.45);
}

.page-about .swatch__chip {
  display: block;
  height: 34px;
  margin-bottom: 10px;
}

.page-about .swatch__chip--navy {
  background: linear-gradient(90deg, #071a2f, #0b2742);
  border: 1px solid var(--line-soft);
}

.page-about .swatch__chip--orange {
  background: linear-gradient(90deg, #ff7a1a, #ffb070);
}

.page-about .swatch__chip--cyan {
  background: linear-gradient(90deg, #2de2e6, #7cf0f2);
}

.page-about .swatch__chip--green {
  background: linear-gradient(90deg, #38e8a0, rgba(56, 232, 160, 0.35));
}

.page-about .swatch__chip--yellow {
  background: linear-gradient(90deg, #ffc857, rgba(255, 200, 87, 0.35));
}

.page-about .swatch__name {
  display: block;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 17px;
  color: var(--paper);
  margin-bottom: 6px;
}

.page-about .swatch p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(244, 248, 255, 0.78);
}

.page-about .about-visual-note {
  margin: 0;
  font-family: var(--font-editorial);
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  max-width: 64ch;
}

/* 承诺 */
.page-about .about-commit {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-commit__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.page-about .about-commit__panel {
  padding: 20px;
  background: var(--about-surface);
  border: 1px solid var(--line-soft);
}

.page-about .about-contact {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-contact > li {
  display: grid;
  gap: 4px;
}

.page-about .about-contact .footer-contact__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mist);
}

.page-about .about-contact .footer-contact__value {
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper);
  word-break: break-word;
}

.page-about .about-commit__tip {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-commit__tip a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(45, 226, 230, 0.5);
}

/* 平板及以上 */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-stat {
    padding: 20px 18px;
  }

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

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

/* 桌面 */
@media (min-width: 960px) {
  .page-about .about-hero {
    padding: calc(var(--header-h) + 56px) 0 56px;
  }

  .page-about .about-hero__inner {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 56px;
  }

  .page-about .about-chapter {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .about-chapter__side {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

  .page-about .about-team {
    grid-template-columns: 1.5fr 1fr;
    align-items: start;
  }

  .page-about .about-commit {
    grid-template-columns: 1.6fr 1fr;
    align-items: start;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-chapter[data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}