.page-about {
  --about-gap: clamp(2.75rem, 6vw, 5rem);
  --about-cut: 18px;
  background: var(--abyss-950);
  color: var(--steel-100);
  overflow-x: clip;
  font-family: var(--font-body);
}

.page-about .breadcrumb {
  margin: 1.1rem 0 0;
  font-size: 0.82rem;
}

.page-about .eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.6rem, 4vw, 3rem) 0 clamp(2rem, 5vw, 3.4rem);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(41, 199, 201, 0.13), transparent 62%),
    radial-gradient(90% 80% at 0% 100%, rgba(214, 168, 75, 0.11), transparent 64%);
}

.page-about .about-hero__ghost {
  position: absolute;
  top: -0.14em;
  right: -0.05em;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(7rem, 30vw, 21rem);
  line-height: 0.8;
  letter-spacing: -0.05em;
  color: rgba(214, 168, 75, 0.07);
  transform: rotate(-6deg);
  pointer-events: none;
  user-select: none;
}

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

.page-about .about-hero__title {
  margin: 0.75rem 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.4rem, 8.5vw, 5.2rem);
  line-height: 0.96;
  letter-spacing: -0.015em;
}

.page-about .about-hero__title-accent {
  color: var(--gold-500);
  display: inline-block;
  border-bottom: 3px solid var(--cyan-400);
  padding-bottom: 0.06em;
}

.page-about .about-hero__lead {
  max-width: 60ch;
  margin: 1.2rem 0 0;
  color: var(--steel-400);
  font-size: 1rem;
  line-height: 1.78;
}

.page-about .about-stats {
  list-style: none;
  margin: clamp(1.8rem, 4vw, 2.6rem) 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  background: var(--abyss-900);
  padding: 1rem 1.05rem;
}

.page-about .about-stat:last-child {
  grid-column: span 2;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.45rem, 5vw, 2.2rem);
  line-height: 1.05;
  color: var(--gold-300);
}

.page-about .about-stat--cyan .about-stat__num {
  color: var(--cyan-400);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 0.38rem;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--steel-400);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding-block: var(--about-gap);
  border-top: 1px solid var(--line);
}

.page-about .about-section__head {
  max-width: 64ch;
}

.page-about .about-section__head h2 {
  margin: 0.55rem 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.55rem, 4.6vw, 2.7rem);
  line-height: 1.12;
  letter-spacing: -0.01em;
}

.page-about .about-section__lead {
  margin: 0.95rem 0 0;
  color: var(--steel-400);
  font-size: 1rem;
  line-height: 1.8;
}

/* ---------- 历程时间线 ---------- */
.page-about .about-history {
  margin-top: clamp(1.8rem, 4vw, 2.6rem);
  display: grid;
  gap: clamp(1.6rem, 4vw, 2.4rem);
}

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

.page-about .about-timeline__item {
  position: relative;
  padding: 0.2rem 0 1.6rem 1.55rem;
  border-left: 1px solid var(--line);
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 0.85rem;
  width: 9px;
  height: 9px;
  background: var(--gold-500);
  transform: rotate(45deg);
}

.page-about .about-timeline__item--now::before {
  background: var(--cyan-400);
}

.page-about .about-timeline__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.6rem, 6vw, 2.5rem);
  line-height: 1;
  color: var(--gold-500);
  transform: skewX(-8deg);
  transform-origin: left bottom;
}

.page-about .about-timeline__year--word {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 4.6vw, 1.9rem);
  color: var(--cyan-400);
  letter-spacing: 0.08em;
}

.page-about .about-timeline__body {
  margin-top: 0.6rem;
}

.page-about .about-timeline__body h3 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .about-timeline__body p {
  margin: 0.45rem 0 0;
  color: var(--steel-400);
  font-size: 0.94rem;
  line-height: 1.75;
}

/* ---------- 通用媒体框 ---------- */
.page-about .media {
  display: block;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--abyss-800);
  overflow: hidden;
}

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

.page-about .media__caption {
  padding: 0.7rem 0.9rem;
  border-top: 1px solid var(--line);
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--steel-400);
}

/* ---------- 四条主线 ---------- */
.page-about .about-lines {
  margin-top: clamp(1.6rem, 4vw, 2.4rem);
  border-top: 1px solid var(--line);
}

.page-about .about-line {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.35rem 1rem;
  padding: 1.4rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-line__idx {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.35rem;
  line-height: 1.2;
  color: var(--gold-500);
}

.page-about .about-line__body h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: 0.01em;
}

.page-about .about-line__body p {
  margin: 0.45rem 0 0;
  color: var(--steel-400);
  font-size: 0.94rem;
  line-height: 1.78;
}

.page-about .about-line__link {
  grid-column: 2;
  justify-self: start;
  margin-top: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  color: var(--gold-300);
  text-decoration: none;
  border-bottom: 1px solid var(--line-gold);
  padding-bottom: 2px;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-line__link:hover,
.page-about .about-line__link:focus-visible {
  color: var(--gold-500);
  border-color: var(--gold-500);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  margin-top: clamp(1.8rem, 4vw, 2.6rem);
  display: grid;
  gap: clamp(1.4rem, 4vw, 2rem);
}

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

.page-about .about-team__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.15rem 0.85rem;
  align-items: baseline;
  background: var(--abyss-900);
  padding: 1rem 1.1rem;
}

.page-about .about-team__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.35rem;
  color: var(--cyan-400);
}

.page-about .about-team__name {
  font-weight: 700;
  font-size: 1rem;
}

.page-about .about-team__desc {
  grid-column: 2;
  margin: 0.2rem 0 0;
  color: var(--steel-400);
  font-size: 0.9rem;
  line-height: 1.7;
}

.page-about .about-tags {
  list-style: none;
  margin: 1.1rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-about .about-tags li {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  color: var(--gold-300);
  border: 1px solid var(--line-gold);
  padding: 0.36rem 0.72rem;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}

/* ---------- 版本对比 ---------- */
.page-about .about-version {
  margin-top: clamp(1.6rem, 4vw, 2.4rem);
  display: grid;
  gap: 1px;
  padding: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-version__col {
  background: var(--abyss-900);
  padding: clamp(1rem, 3vw, 1.6rem);
}

.page-about .about-version__col--new {
  background: linear-gradient(160deg, var(--abyss-800), var(--abyss-900));
  box-shadow: inset 3px 0 0 var(--gold-500);
}

.page-about .about-version__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--steel-400);
}

.page-about .about-version__col--new .about-version__label {
  color: var(--gold-300);
}

.page-about .about-version__title {
  margin: 0.5rem 0 0.85rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: 0.01em;
}

.page-about .about-version__list {
  margin: 0;
  padding-left: 1.15rem;
  color: var(--steel-400);
  font-size: 0.92rem;
  line-height: 1.72;
}

.page-about .about-version__list li + li {
  margin-top: 0.45rem;
}

.page-about .about-steps {
  margin-top: clamp(1.4rem, 3.5vw, 2rem);
  border-top: 1px solid var(--line);
}

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

.page-about .about-step summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.95rem 0;
  cursor: pointer;
  font-weight: 700;
  font-size: 0.98rem;
  list-style: none;
}

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

.page-about .about-step summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--gold-500);
}

.page-about .about-step[open] summary::after {
  content: "–";
  color: var(--cyan-400);
}

.page-about .about-step p {
  margin: 0 0 1rem;
  max-width: 68ch;
  color: var(--steel-400);
  font-size: 0.92rem;
  line-height: 1.78;
}

/* ---------- 认证与荣誉 ---------- */
.page-about .about-honors {
  margin-top: clamp(1.6rem, 4vw, 2.4rem);
  display: grid;
  gap: 1rem;
}

.page-about .about-honor {
  position: relative;
  padding: clamp(1.1rem, 3vw, 1.6rem);
  background: linear-gradient(160deg, var(--abyss-800), var(--abyss-900));
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, var(--about-cut) 100%, 0 calc(100% - var(--about-cut)));
}

.page-about .about-honor__badge {
  position: absolute;
  top: 1.1rem;
  right: 1.1rem;
  width: 26px;
  height: 26px;
  border: 1px solid var(--line-gold);
  transform: rotate(45deg);
}

.page-about .about-honor__badge::after {
  content: "";
  position: absolute;
  inset: 6px;
  background: var(--gold-500);
}

.page-about .about-honor__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.2em;
  color: var(--cyan-400);
}

.page-about .about-honor h3 {
  margin: 0.6rem 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.25rem;
  line-height: 1.2;
  max-width: 16ch;
}

.page-about .about-honor p {
  margin: 0.6rem 0 0;
  color: var(--steel-400);
  font-size: 0.92rem;
  line-height: 1.75;
}

.page-about .about-cert {
  margin-top: 1rem;
  padding: 1rem 1.1rem;
  border: 1px solid var(--line-gold);
  background: rgba(214, 168, 75, 0.06);
  display: grid;
  gap: 0.55rem;
}

.page-about .about-cert p {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.86rem;
  color: var(--steel-100);
  word-break: break-word;
}

.page-about .about-cert__key {
  display: inline-block;
  min-width: 5.6rem;
  margin-right: 0.5rem;
  font-family: var(--font-body);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--gold-300);
}

.page-about .about-skyline {
  margin-top: clamp(1.6rem, 4vw, 2.4rem);
}

.page-about .about-skyline .media__img {
  opacity: 0.55;
  filter: saturate(0.7);
}

/* ---------- 联系方式 ---------- */
.page-about .about-contact {
  margin-top: clamp(1.6rem, 4vw, 2.4rem);
  display: grid;
  gap: 1px;
  padding: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-contact__item {
  background: var(--abyss-900);
  padding: 1.1rem 1.15rem;
}

.page-about .about-contact__label {
  margin: 0 0 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--steel-400);
}

.page-about .about-contact__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 1.02rem;
  color: var(--steel-100);
  word-break: break-word;
}

.page-about .about-contact__value--text {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.72;
  color: var(--steel-400);
}

.page-about .about-contact__hint {
  margin: 0.5rem 0 0;
  font-size: 0.8rem;
  color: var(--graphite-600);
}

.page-about .about-copy-btn {
  display: inline-block;
  margin-top: 0.75rem;
  padding: 0.42rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--gold-300);
  background: transparent;
  border: 1px solid var(--line-gold);
  cursor: pointer;
  text-decoration: none;
  transition: color 0.2s var(--ease), background 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .about-copy-btn:hover,
.page-about .about-copy-btn:focus-visible {
  color: var(--abyss-950);
  background: var(--gold-500);
  transform: translateY(-2px);
}

.page-about .about-cta {
  margin-top: clamp(1.8rem, 4vw, 2.6rem);
  padding-top: clamp(1.4rem, 3.5vw, 2rem);
  border-top: 1px solid var(--line);
  display: grid;
  gap: 1rem;
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 48ch;
  font-size: 0.98rem;
  line-height: 1.75;
  color: var(--steel-100);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-stat:last-child {
    grid-column: auto;
  }

  .page-about .about-line {
    grid-template-columns: 4.5rem minmax(0, 1fr) 11rem;
    align-items: start;
    gap: 0 1.4rem;
    padding: 1.6rem 0;
  }

  .page-about .about-line__link {
    grid-column: 3;
    grid-row: 1;
    justify-self: end;
    margin-top: 0.4rem;
  }

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

@media (min-width: 900px) {
  .page-about .about-history {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 7.5rem minmax(0, 1fr);
    gap: 0 1.4rem;
    padding: 0.2rem 0 2rem 1.9rem;
  }

  .page-about .about-timeline__body {
    margin-top: 0;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    align-items: start;
  }

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

  .page-about .about-honors {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.2rem;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 1.5rem;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero__lead {
    font-size: 1.06rem;
  }

  .page-about .about-section__lead {
    font-size: 1.06rem;
  }

  .page-about .about-line__body p,
  .page-about .about-team__desc,
  .page-about .about-version__list {
    font-size: 0.97rem;
  }
}