.page-about {
  --about-soft-white: rgba(255, 255, 255, 0.78);
  --about-faint-line: rgba(255, 255, 255, 0.09);
  --about-faint-line-dark: rgba(255, 255, 255, 0.14);
  background: var(--c-white);
  color: var(--c-dark);
  font-family: var(--font-body);
  line-height: 1.75;
  overflow-x: hidden;
}

.page-about .about-section {
  padding: 56px 0;
}

.page-about .c-section-head {
  margin-bottom: 32px;
}

.page-about .c-section-title {
  margin-top: 10px;
  font-size: 32px;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.page-about .about-section__lead {
  margin-top: 12px;
  max-width: 640px;
  font-size: 15px;
}

.page-about .about-inline-link {
  color: var(--c-red);
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 1px;
}

.page-about .about-inline-link:hover {
  background: var(--c-red);
  color: var(--c-white);
  text-decoration: none;
}

/* ===== 首屏内容地图 ===== */
.page-about .about-hero {
  position: relative;
  padding: 40px 0 72px;
  background: var(--c-black);
  color: var(--c-white);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 46%;
  height: 100%;
  background: linear-gradient(135deg, transparent 0%, transparent 57%, rgba(212, 0, 0, 0.18) 60%, transparent 63%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--about-faint-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-faint-line) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

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

.page-about .about-hero .c-breadcrumb__link {
  color: var(--c-silver);
  text-decoration: none;
}

.page-about .about-hero .c-breadcrumb__link:hover {
  color: var(--c-red);
}

.page-about .about-hero .c-breadcrumb__current {
  color: var(--c-white);
}

.page-about .about-hero .c-kicker,
.page-about .about-data .c-kicker,
.page-about .about-cred .c-kicker {
  display: inline-block;
  background: var(--c-red);
  color: var(--c-white);
  padding: 4px 10px;
  font-size: 12px;
  letter-spacing: 0.14em;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 32px;
  margin-top: 40px;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-size: 40px;
  line-height: 1.18;
  letter-spacing: -0.03em;
  font-family: var(--font-title);
}

.page-about .about-hero__subtitle {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.14em;
  color: var(--c-red);
  text-transform: uppercase;
}

.page-about .about-hero__lead {
  margin: 20px 0 0;
  max-width: 560px;
  color: var(--about-soft-white);
  font-size: 16px;
}

.page-about .about-hero__map {
  border-top: 1px solid var(--about-faint-line-dark);
  padding-top: 24px;
}

.page-about .about-hero__map-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--c-silver);
}

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

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

.page-about .about-hero__list a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 4px;
  color: var(--c-white);
  text-decoration: none;
  transition: padding-left var(--speed), color var(--speed);
}

.page-about .about-hero__list a:hover {
  padding-left: 10px;
  color: var(--c-red);
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-red);
}

.page-about .about-hero__side {
  display: none;
}

/* ===== 品牌档案 ===== */
.page-about .about-brand {
  background: var(--c-white);
}

.page-about .about-brand__media {
  aspect-ratio: 3 / 1;
  overflow: hidden;
  background: var(--c-light);
  margin-bottom: 36px;
}

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

.page-about .about-brand__grid {
  display: grid;
  gap: 32px;
}

.page-about .about-brand__intro p {
  margin: 0;
  max-width: 640px;
}

.page-about .about-brand__intro p + p {
  margin-top: 16px;
}

.page-about .about-brand__facts {
  background: var(--c-light);
  padding: 24px;
}

.page-about .about-brand__facts ul {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
}

.page-about .about-brand__facts li {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: baseline;
  padding: 11px 0;
  border-bottom: 1px solid var(--c-silver);
  font-size: 15px;
}

.page-about .about-brand__facts li span {
  color: var(--c-dark);
}

.page-about .about-brand__facts li strong {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-black);
}

.page-about .about-brand__facts .c-btn {
  width: 100%;
  text-align: center;
  box-sizing: border-box;
}

/* ===== 发展历程 ===== */
.page-about .about-history {
  background: var(--c-light);
}

.page-about .about-history__layout {
  display: grid;
  gap: 40px;
}

.page-about .about-timeline {
  border-left: 2px solid var(--c-black);
  padding-left: 24px;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 4px;
}

.page-about .about-timeline__summary {
  position: relative;
  list-style: none;
  display: grid;
  grid-template-columns: 64px 1fr auto;
  gap: 10px;
  align-items: baseline;
  cursor: pointer;
  padding: 14px 0;
  margin: 0;
}

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

.page-about .about-timeline__point {
  position: absolute;
  top: 18px;
  left: -32px;
  width: 12px;
  height: 12px;
  background: var(--c-red);
  transform: rotate(45deg);
  transition: transform var(--speed);
}

.page-about .about-timeline__item[open] .about-timeline__point {
  transform: rotate(45deg) scale(1.25);
}

.page-about .about-timeline__year {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--c-black);
}

.page-about .about-timeline__title {
  font-size: 17px;
  font-weight: 700;
  color: var(--c-black);
  line-height: 1.4;
}

.page-about .about-timeline__toggle {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-red);
  white-space: nowrap;
}

.page-about .about-timeline__toggle::after {
  content: "展开";
}

.page-about .about-timeline__item[open] .about-timeline__toggle::after {
  content: "收起";
}

.page-about .about-timeline__body {
  margin: 0 0 14px 20px;
  padding-right: 12px;
  color: var(--c-dark);
  font-size: 15px;
}

.page-about .about-timeline__body p {
  margin: 0;
  max-width: 560px;
}

.page-about .about-history__media {
  max-width: 420px;
}

.page-about .about-history__media img,
.page-about .about-data__visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .about-history__media {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  background: var(--c-black);
}

.page-about .about-history__caption {
  margin: 12px 0 0;
  font-size: 14px;
  color: var(--c-dark);
}

/* ===== 数据能力 ===== */
.page-about .about-data {
  background: var(--c-night);
  color: var(--c-white);
}

.page-about .about-data .c-section-title {
  color: var(--c-white);
}

.page-about .about-data .about-section__lead {
  color: var(--about-soft-white);
}

.page-about .about-data__grid {
  display: grid;
  gap: 40px;
  margin-bottom: 48px;
}

.page-about .about-data__features {
  display: grid;
  gap: 24px;
}

.page-about .about-data__feature {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 14px;
  border-top: 1px solid var(--about-faint-line-dark);
  padding-top: 20px;
}

.page-about .about-data__feature h3 {
  margin: 0 0 6px;
  font-size: 19px;
  line-height: 1.3;
}

.page-about .about-data__feature p {
  margin: 0;
  color: var(--about-soft-white);
  font-size: 15px;
}

.page-about .about-data__icon {
  width: 12px;
  height: 12px;
  background: var(--c-red);
  transform: rotate(45deg);
  margin-top: 6px;
}

.page-about .about-data__visual {
  aspect-ratio: 8 / 5;
  overflow: hidden;
  background: var(--c-black);
}

.page-about .about-path {
  display: grid;
  gap: 12px;
  margin-top: 8px;
}

.page-about .about-path__step {
  position: relative;
  border: 1px solid var(--about-faint-line-dark);
  padding: 20px;
  background: transparent;
  transition: background var(--speed), border-color var(--speed), transform var(--speed);
}

.page-about .about-path__step:hover {
  background: var(--c-red);
  border-color: var(--c-red);
  transform: translateY(-2px);
}

.page-about .about-path__num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-red);
}

.page-about .about-path__step h3 {
  margin: 8px 0 0;
  font-size: 18px;
  line-height: 1.3;
}

.page-about .about-path__step p {
  margin: 8px 0 0;
  font-size: 14px;
  color: var(--about-soft-white);
}

.page-about .about-path__step:hover h3,
.page-about .about-path__step:hover p,
.page-about .about-path__step:hover .about-path__num {
  color: var(--c-white);
}

.page-about .about-data__cta {
  margin-top: 36px;
}

.page-about .about-data__cta .c-btn {
  display: inline-flex;
}

/* ===== 组织与服务 ===== */
.page-about .about-team {
  background: var(--c-white);
  padding: 56px 0;
}

.page-about .about-team__intro p {
  margin: 0;
  max-width: 760px;
  font-size: 16px;
}

.page-about .about-team__groups {
  display: grid;
  gap: 24px;
  margin-top: 36px;
}

.page-about .about-team__group {
  border-left: 3px solid var(--c-black);
  padding: 4px 0 4px 20px;
  transition: border-color var(--speed);
}

.page-about .about-team__group:hover {
  border-color: var(--c-red);
}

.page-about .about-team__code {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-red);
}

.page-about .about-team__group h3 {
  margin: 6px 0 8px;
  font-size: 20px;
}

.page-about .about-team__group p {
  margin: 0;
  color: var(--c-dark);
  font-size: 15px;
}

.page-about .about-team__promise {
  margin-top: 40px;
  background: var(--c-light);
  padding: 24px;
}

.page-about .about-team__promise-list {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
}

.page-about .about-team__promise-list li {
  display: flex;
  gap: 12px;
  align-items: baseline;
  padding: 11px 0;
  border-bottom: 1px solid var(--c-silver);
  font-size: 15px;
}

.page-about .about-team__promise-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-red);
  min-width: 24px;
}

.page-about .about-team__promise .c-btn {
  display: inline-flex;
}

/* ===== 资质与合作 ===== */
.page-about .about-cred {
  background: var(--c-black);
  color: var(--c-white);
  padding: 56px 0 64px;
}

.page-about .about-cred .c-section-title {
  color: var(--c-white);
}

.page-about .about-cred__grid {
  display: grid;
  gap: 32px;
  margin-top: 32px;
}

.page-about .about-cred__block {
  border-top: 1px solid var(--about-faint-line-dark);
  padding-top: 20px;
}

.page-about .about-cred__block h3 {
  margin: 0 0 12px;
  font-size: 18px;
}

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

.page-about .about-cred__list li {
  position: relative;
  padding: 8px 0 8px 18px;
  border-bottom: 1px solid var(--about-faint-line);
  color: var(--c-silver);
  font-size: 15px;
}

.page-about .about-cred__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 8px;
  height: 8px;
  background: var(--c-red);
  transform: rotate(45deg);
}

.page-about .about-cred__block a.about-inline-link {
  margin-top: 16px;
  display: inline-block;
}

.page-about .about-cred__note {
  margin-top: 40px;
  border-left: 3px solid var(--c-red);
  padding-left: 16px;
  font-size: 15px;
}

.page-about .about-cred__note p {
  margin: 0;
}

.page-about .about-cred__note a.about-inline-link {
  color: var(--c-red);
}

/* ===== 响应式增强 ===== */
@media (min-width: 768px) {
  .page-about .about-hero__grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }

  .page-about .about-brand__grid {
    grid-template-columns: 1fr 0.85fr;
    gap: 40px;
    align-items: start;
  }

  .page-about .about-history__layout {
    grid-template-columns: 1fr 0.55fr;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-data__grid {
    grid-template-columns: 1fr 0.9fr;
    gap: 48px;
    align-items: center;
  }

  .page-about .about-data__features {
    gap: 20px;
  }

  .page-about .about-team__groups {
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }

  .page-about .about-team__promise-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0 24px;
  }

  .page-about .about-cred__grid {
    grid-template-columns: 1fr 1fr;
    gap: 48px;
  }

  .page-about .about-cred__note {
    max-width: 640px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero {
    padding: 56px 0 88px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: 3fr 2fr;
    gap: 64px;
    margin-top: 56px;
  }

  .page-about .about-hero__title {
    font-size: 56px;
  }

  .page-about .about-hero__side {
    display: block;
    position: absolute;
    top: 32px;
    right: 0;
    writing-mode: vertical-rl;
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.3em;
    color: var(--c-silver);
    pointer-events: none;
  }

  .page-about .about-history__layout {
    grid-template-columns: 1fr 0.42fr;
    gap: 64px;
  }

  .page-about .about-history__media {
    margin-top: 24px;
  }

  .page-about .about-path {
    grid-template-columns: repeat(5, 1fr);
    gap: 16px;
  }

  .page-about .about-path__step {
    padding: 24px 20px;
  }

  .page-about .about-brand__grid {
    grid-template-columns: 1fr 0.75fr;
  }

  .page-about .about-team__groups {
    gap: 28px;
  }

  .page-about .about-team__promise {
    padding: 32px;
  }
}