.page-about {
  --about-hero-deco: rgba(242, 92, 5, 0.9);
  overflow-x: hidden;
}

/* ========== Hero 首屏 ========== */
.page-about .about-hero {
  position: relative;
  background: var(--primary-900);
  color: var(--neutral-100);
  padding: 3.25rem 1.25rem 4rem;
  overflow: hidden;
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, rgba(242, 92, 5, 0.28) 0%, transparent 35%),
    radial-gradient(circle at 88% 8%, rgba(27, 77, 142, 0.85) 0%, transparent 55%);
  pointer-events: none;
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -6rem;
  bottom: -4rem;
  width: 17rem;
  height: 17rem;
  border: 2rem solid rgba(255, 122, 80, 0.28);
  border-radius: 1.5rem;
  transform: rotate(14deg);
  pointer-events: none;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin-inline: auto;
  display: grid;
  gap: 2rem;
  align-items: center;
}
.page-about .about-hero__content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}
.page-about .about-hero__eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin: 0 0 1rem;
}
.page-about .about-hero__brand {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--accent-300);
  border-left: 2px solid var(--accent-500);
  padding-left: 0.75rem;
}
.page-about .about-hero__title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(2.25rem, 6vw, 4rem);
  line-height: 1.15;
  letter-spacing: 0.01em;
  margin: 0 0 1.25rem;
  color: var(--neutral-100);
}
.page-about .about-hero__lead {
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.82);
  max-width: 34rem;
  margin: 0 0 1.75rem;
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.875rem;
  align-items: center;
}
.page-about .about-hero__media {
  margin: 0;
  position: relative;
}
.page-about .about-hero__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 1rem;
  box-shadow: 0 1.5rem 3rem rgba(0, 0, 0, 0.38);
  background: var(--primary-700);
}
.page-about .about-hero__caption {
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--neutral-400);
  text-align: right;
  letter-spacing: 0.08em;
}

/* ========== 我们的使命 ========== */
.page-about .about-mission {
  position: relative;
  background: var(--neutral-100);
  padding: 4.5rem 0;
}
.page-about .about-mission::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 0.5rem;
  background: var(--accent-500);
  clip-path: polygon(0 0, 100% 0, 96% 100%, 0 100%);
}
.page-about .about-mission__inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding: 0 1.25rem;
  display: grid;
  gap: 2.25rem;
}
.page-about .about-mission__label,
.page-about .about-stats__label,
.page-about .about-timeline__label,
.page-about .about-security__label,
.page-about .about-eco__label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0 0 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.page-about .about-mission__index,
.page-about .about-stats__index,
.page-about .about-timeline__index,
.page-about .about-security__index,
.page-about .about-eco__index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.25rem;
  height: 2.25rem;
  padding: 0 0.4rem;
  background: var(--accent-500);
  color: var(--neutral-100);
  border-radius: 0.25rem;
  font-weight: 700;
}
.page-about .about-mission__title,
.page-about .about-stats__title,
.page-about .about-timeline__title,
.page-about .about-security__title,
.page-about .about-eco__title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(1.75rem, 3.4vw, 2.5rem);
  line-height: 1.2;
  margin: 0;
  color: var(--primary-900);
}
.page-about .about-mission__body {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}
.page-about .about-mission__statement {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  font-weight: 600;
  line-height: 1.8;
  color: var(--neutral-800);
  margin: 0;
  border-left: 4px solid var(--accent-500);
  padding-left: 1rem;
}
.page-about .about-mission__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.875rem;
}
.page-about .about-mission__item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background: var(--neutral-200);
  border-radius: 0.75rem;
  padding: 1.1rem 1.25rem;
}
.page-about .about-mission__item-title {
  flex: none;
  min-width: 3.25rem;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 1.05rem;
  color: var(--accent-500);
}
.page-about .about-mission__item-text {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--neutral-600);
}

/* ========== 关键数据 ========== */
.page-about .about-stats {
  position: relative;
  background: var(--primary-900);
  color: var(--neutral-100);
  padding: 4.5rem 1.25rem;
  overflow: hidden;
}
.page-about .about-stats::before {
  content: "";
  position: absolute;
  top: -7rem;
  right: -7rem;
  width: 17rem;
  height: 17rem;
  background: var(--primary-700);
  border-radius: 2.5rem;
  transform: rotate(45deg);
  pointer-events: none;
}
.page-about .about-stats::after {
  content: "";
  position: absolute;
  bottom: 2rem;
  left: 8%;
  width: 6rem;
  height: 6rem;
  border: 1px solid rgba(242, 92, 5, 0.4);
  border-radius: 50%;
  pointer-events: none;
}
.page-about .about-stats__inner {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin-inline: auto;
}
.page-about .about-stats__head {
  margin-bottom: 2.25rem;
}
.page-about .about-stats__title {
  color: var(--neutral-100);
}
.page-about .about-stats__lead {
  margin: 0.75rem 0 0;
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.95rem;
}
.page-about .about-stats__grid {
  display: grid;
  gap: 1rem;
}
.page-about .about-stat-card {
  position: relative;
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 1rem;
  padding: 1.5rem;
  backdrop-filter: blur(6px);
  transition: border-color 0.25s ease, background 0.25s ease;
}
.page-about .about-stat-card:hover,
.page-about .about-stat-card:focus-within {
  border-color: rgba(242, 92, 5, 0.6);
  background: rgba(255, 255, 255, 0.1);
}
.page-about .about-stat-card__num {
  display: block;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(2.4rem, 5vw, 3.4rem);
  line-height: 1.1;
  color: var(--accent-500);
}
.page-about .about-stat-card__label {
  display: block;
  margin-top: 0.35rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.9);
}
.page-about .about-stat-card__note {
  margin: 0.75rem 0 0;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--neutral-400);
  max-height: none;
  opacity: 1;
}

/* ========== 发展历程时间轴 ========== */
.page-about .about-timeline {
  background: var(--neutral-200);
  padding: 4.5rem 1.25rem;
}
.page-about .about-timeline__inner {
  max-width: var(--container-max);
  margin-inline: auto;
}
.page-about .about-timeline__head {
  margin-bottom: 2rem;
}
.page-about .about-timeline__list {
  list-style: none;
  margin: 0 0 2.25rem;
  padding: 0;
  position: relative;
  display: grid;
  gap: 1.5rem;
}
.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  left: 0.875rem;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent-500) 0%, var(--primary-500) 100%);
}
.page-about .about-timeline__item {
  position: relative;
  padding-left: 3rem;
}
.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0.25rem;
  top: 1.5rem;
  width: 1.25rem;
  height: 1.25rem;
  border-radius: 50%;
  background: var(--accent-500);
  border: 4px solid var(--neutral-200);
  box-shadow: 0 0 0 2px var(--accent-500);
}
.page-about .about-timeline__item--media::before {
  display: none;
}
.page-about .about-timeline__year {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-700);
  margin-bottom: 0.35rem;
}
.page-about .about-timeline__card {
  background: var(--neutral-100);
  border-radius: 0.75rem;
  box-shadow: 0 0.5rem 1.5rem rgba(10, 30, 60, 0.07);
  overflow: hidden;
}
.page-about .about-timeline__card summary {
  list-style: none;
  cursor: pointer;
  padding: 1rem 2.5rem 1rem 1.25rem;
  font-family: var(--font-heading);
  font-weight: 800;
  color: var(--primary-900);
  position: relative;
  transition: background-color 0.2s ease;
}
.page-about .about-timeline__card summary::-webkit-details-marker {
  display: none;
}
.page-about .about-timeline__card summary:hover,
.page-about .about-timeline__card summary:focus-visible {
  background-color: var(--neutral-200);
}
.page-about .about-timeline__card summary:focus-visible {
  outline: 2px solid var(--primary-500);
  outline-offset: -2px;
}
.page-about .about-timeline__card summary::after {
  content: "+";
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 400;
  color: var(--accent-500);
  transition: transform 0.2s ease;
}
.page-about .about-timeline__card[open] summary::after {
  content: "–";
}
.page-about .about-timeline__card p {
  margin: 0;
  padding: 0 1.25rem 1.25rem;
  color: var(--neutral-600);
  font-size: 0.95rem;
  line-height: 1.75;
}
.page-about .about-timeline__media {
  margin: 0;
}
.page-about .about-timeline__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: 0.875rem;
  box-shadow: 0 0.75rem 1.75rem rgba(10, 30, 60, 0.16);
}
.page-about .about-timeline__media figcaption {
  margin-top: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--neutral-400);
  letter-spacing: 0.06em;
}
.page-about .about-timeline__actions {
  text-align: center;
}

/* ========== 技术安全 ========== */
.page-about .about-security {
  position: relative;
  background: linear-gradient(135deg, var(--primary-900) 0%, var(--primary-700) 100%);
  color: var(--neutral-100);
  padding: 4.5rem 1.25rem;
  overflow: hidden;
}
.page-about .about-security::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 45%;
  height: 100%;
  background: linear-gradient(150deg, rgba(242, 92, 5, 0.28) 0%, transparent 62%);
  clip-path: polygon(22% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}
.page-about .about-security__inner {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin-inline: auto;
}
.page-about .about-security__title {
  color: var(--neutral-100);
}
.page-about .about-security__lead {
  margin: 0.75rem 0 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.95rem;
}
.page-about .about-security__grid {
  display: grid;
  gap: 1rem;
  margin-top: 2.25rem;
}
.page-about .about-security__card {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-left: 4px solid var(--accent-500);
  border-radius: 0.875rem;
  padding: 1.4rem 1.5rem;
  backdrop-filter: blur(4px);
}
.page-about .about-security__card h3 {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  color: var(--accent-300);
}
.page-about .about-security__card p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.84);
}
.page-about .about-security__link {
  display: inline-block;
  margin-top: 0.5rem;
  color: var(--accent-300);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.page-about .about-security__note {
  margin: 2rem 0 0;
  text-align: center;
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.9rem;
}
.page-about .about-security__note a {
  color: var(--accent-300);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}
.page-about .about-security__note a:hover {
  border-bottom-color: var(--accent-300);
}

/* ========== 内容生态 ========== */
.page-about .about-eco {
  background: var(--neutral-100);
  padding: 4.5rem 1.25rem;
}
.page-about .about-eco__inner {
  max-width: var(--container-max);
  margin-inline: auto;
}
.page-about .about-eco__head {
  margin-bottom: 1.25rem;
}
.page-about .about-eco__lead {
  margin: 0.75rem 0 0;
  color: var(--neutral-600);
  font-size: 0.95rem;
  line-height: 1.7;
}
.page-about .about-eco__flow {
  background: var(--neutral-200);
  border-left: 4px solid var(--primary-500);
  border-radius: 0 0.75rem 0.75rem 0;
  padding: 1rem 1.25rem;
  margin: 0 0 2rem;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--neutral-800);
}
.page-about .about-eco__grid {
  display: grid;
  gap: 1.25rem;
}
.page-about .about-eco__card {
  position: relative;
  background: var(--neutral-200);
  border-radius: 1rem;
  padding: 1.75rem;
  overflow: hidden;
  border: 1px solid transparent;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}
.page-about .about-eco__card:hover,
.page-about .about-eco__card:focus-within {
  transform: translateY(-4px);
  border-color: rgba(242, 92, 5, 0.35);
  box-shadow: 0 0.75rem 2rem rgba(10, 30, 60, 0.1);
}
.page-about .about-eco__card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3.5rem;
  height: 0.4rem;
  background: var(--accent-500);
  border-radius: 0 0 0.25rem 0;
}
.page-about .about-eco__card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}
.page-about .about-eco__card h3 {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 1.15rem;
  color: var(--primary-900);
  margin: 0;
}
.page-about .about-eco__tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--accent-500);
  background: rgba(242, 92, 5, 0.1);
  border-radius: 999px;
  padding: 0.25rem 0.6rem;
}
.page-about .about-eco__card p {
  margin: 0 0 1rem;
  color: var(--neutral-600);
  font-size: 0.93rem;
  line-height: 1.75;
}
.page-about .about-eco__media {
  margin: 2.25rem 0 0;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  background: var(--primary-900);
  border-radius: 1rem;
  padding: 1.5rem;
}
.page-about .about-eco__media img {
  display: block;
  width: 9rem;
  height: 9rem;
  object-fit: cover;
  border-radius: 0.75rem;
  flex: none;
}
.page-about .about-eco__media figcaption {
  max-width: 20rem;
  color: rgba(255, 255, 255, 0.82);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.05rem;
  line-height: 1.6;
}

/* ========== 联系入口 ========== */
.page-about .about-contact {
  background: var(--primary-900);
  color: var(--neutral-100);
  padding: 4.5rem 1.25rem;
  position: relative;
  overflow: hidden;
}
.page-about .about-contact::after {
  content: "";
  position: absolute;
  left: -4rem;
  top: -4rem;
  width: 14rem;
  height: 14rem;
  background: rgba(242, 92, 5, 0.12);
  border-radius: 2rem;
  transform: rotate(30deg);
  pointer-events: none;
}
.page-about .about-contact__inner {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin-inline: auto;
}
.page-about .about-contact__title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(1.75rem, 3.4vw, 2.5rem);
  color: var(--neutral-100);
  margin: 0 0 0.75rem;
}
.page-about .about-contact__text p {
  margin: 0;
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.95rem;
  line-height: 1.75;
  max-width: 40rem;
}
.page-about .about-contact__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.875rem;
  margin: 2rem 0;
}
.page-about .about-contact__item {
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 0.875rem;
  padding: 1rem 1.25rem;
}
.page-about .about-contact__item dt {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-300);
  margin: 0 0 0.25rem;
}
.page-about .about-contact__item dd {
  margin: 0;
  font-size: 1rem;
  color: var(--neutral-100);
  word-break: break-word;
}

/* ========== 桌面增强 ========== */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 5rem 1.25rem;
  }
  .page-about .about-hero__inner {
    grid-template-columns: 7fr 5fr;
    gap: 3rem;
  }
  .page-about .about-hero__lead {
    font-size: 1.1rem;
  }
  .page-about .about-mission__inner {
    padding: 0 1.25rem;
  }
  .page-about .about-mission__list {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .about-mission__item {
    flex-direction: column;
    gap: 0.6rem;
  }
  .page-about .about-stats__grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 1.25rem;
  }
  .page-about .about-stat-card__note {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, opacity 0.4s ease;
  }
  .page-about .about-stat-card:hover .about-stat-card__note,
  .page-about .about-stat-card:focus-within .about-stat-card__note {
    max-height: 9rem;
    opacity: 1;
  }
  .page-about .about-security__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
  }
  .page-about .about-eco__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }
  .page-about .about-eco__media {
    padding: 2rem;
  }
  .page-about .about-contact__list {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero__inner {
    gap: 4rem;
  }
  .page-about .about-mission__inner {
    grid-template-columns: 5fr 7fr;
    gap: 4rem;
  }
  .page-about .about-stats,
  .page-about .about-security,
  .page-about .about-contact {
    padding-inline: 2rem;
  }
  .page-about .about-mission,
  .page-about .about-timeline,
  .page-about .about-eco {
    padding-left: 2rem;
    padding-right: 2rem;
  }
  .page-about .about-timeline__list::before {
    left: 50%;
    transform: translateX(-50%);
  }
  .page-about .about-timeline__item {
    width: 50%;
    padding-left: 0;
    padding-right: 3rem;
  }
  .page-about .about-timeline__item:nth-child(even) {
    margin-left: 50%;
    padding-left: 3rem;
    padding-right: 0;
  }
  .page-about .about-timeline__item::before {
    left: auto;
    right: -0.625rem;
    top: 1.9rem;
  }
  .page-about .about-timeline__item:nth-child(even)::before {
    left: -0.625rem;
    right: auto;
  }
  .page-about .about-timeline__item--media::before {
    display: none;
  }
  .page-about .about-timeline__item--media {
    padding-left: 0;
    padding-right: 3rem;
  }
  .page-about .about-timeline__item--media:nth-child(4) {
    margin-left: 50%;
    padding-left: 3rem;
    padding-right: 0;
  }
  .page-about .about-eco__inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: 3rem;
    align-items: start;
  }
  .page-about .about-eco__head,
  .page-about .about-eco__flow {
    grid-column: 1 / -1;
  }
  .page-about .about-eco__media {
    grid-column: 1 / -1;
  }
  .page-about .about-contact__text {
    max-width: 60%;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .page-about .about-eco__card,
  .page-about .about-stat-card,
  .page-about .about-hero__img {
    transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
  }
}