.page-about {
  --about-radius: var(--r-md);
  background: var(--c-mist);
  color: var(--c-ink);
  font-family: var(--f-body);
  line-height: 1.6;
}

/* ===== 英雄区 ===== */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--c-ink);
  color: var(--c-white);
  padding: 48px 0 96px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  right: -120px;
  top: -120px;
  width: 480px;
  height: 480px;
  background: radial-gradient(circle, rgb(0 194 168 / 22%), transparent 68%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgb(255 255 255 / 4%) 1px, transparent 1px),
    linear-gradient(90deg, rgb(255 255 255 / 4%) 1px, transparent 1px);
  background-size: 42px 42px;
  -webkit-mask-image: linear-gradient(to bottom, black, transparent 72%);
  mask-image: linear-gradient(to bottom, black, transparent 72%);
  pointer-events: none;
  z-index: 0;
}

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

.page-about .about-hero h1 {
  font-family: var(--f-headline);
  font-size: clamp(42px, 7vw, 76px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  margin: 16px 0 20px;
}

.page-about .about-hero__lead {
  max-width: 620px;
  font-size: 16px;
  color: var(--c-rock);
  margin: 0 0 28px;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 36px;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 44px;
  margin-top: 32px;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.page-about .about-hero-stat {
  border-left: 2px solid rgb(255 255 255 / 20%);
  padding: 4px 0 4px 14px;
}

.page-about .about-hero-stat__num {
  display: block;
  font-family: var(--f-headline);
  font-size: clamp(22px, 3.6vw, 38px);
  line-height: 1.1;
  color: var(--c-white);
  letter-spacing: -0.01em;
}

.page-about .about-hero-stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.45;
  color: var(--c-rock);
}

.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  padding-top: 24px;
  border-top: 1px solid rgb(255 255 255 / 14%);
}

.page-about .about-index a {
  font-size: 14px;
  color: var(--c-rock);
  text-decoration: none;
  padding-bottom: 4px;
  border-bottom: 1px solid rgb(255 255 255 / 24%);
  transition: color var(--ease-fast), border-color var(--ease-fast);
}

.page-about .about-index a:hover {
  color: var(--c-orange);
  border-color: var(--c-orange);
}

/* ===== 品牌理念 ===== */
.page-about .about-philosophy {
  background: var(--c-mist);
  padding: 84px 0 72px;
}

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

.page-about .about-philosophy__lead {
  font-size: 17px;
  color: var(--c-iron);
  margin: 16px 0 32px;
}

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

.page-about .about-philosophy__principle {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 14px;
  background: var(--c-white);
  border: 1px solid rgb(180 190 203 / 45%);
  border-radius: var(--about-radius);
  padding: 20px;
  transition: transform var(--ease-fast), box-shadow var(--ease-fast);
}

.page-about .about-philosophy__principle:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgb(10 31 68 / 8%);
}

.page-about .about-philosophy__index {
  font-family: var(--f-headline);
  font-size: 20px;
  color: var(--c-orange);
  letter-spacing: -0.02em;
}

.page-about .about-philosophy__principle-title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  color: var(--c-ink);
}

.page-about .about-philosophy__principle p {
  margin: 0;
  font-size: 14px;
  color: var(--c-iron);
}

.page-about .about-philosophy__figure {
  margin: 0;
  background: var(--c-ink);
  border: 1px solid rgb(10 31 68 / 12%);
  border-radius: var(--about-radius);
  overflow: hidden;
}

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

.page-about .about-philosophy__caption {
  font-size: 13px;
  line-height: 1.5;
  color: var(--c-iron);
  background: var(--c-white);
  padding: 12px 16px;
}

.page-about .about-philosophy__note {
  margin-top: 14px;
  background: var(--c-teal-light);
  border-radius: var(--about-radius);
  padding: 16px 20px;
  font-size: 14px;
  color: var(--c-ink);
}

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

/* ===== 发展历程 ===== */
.page-about .about-timeline {
  position: relative;
  background: var(--c-ink);
  color: var(--c-white);
  padding: 92px 0 100px;
  margin-top: -1px;
}

.page-about .about-timeline__header {
  max-width: 700px;
  margin-bottom: 56px;
}

.page-about .about-timeline__header h2 {
  margin: 14px 0 12px;
}

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

.page-about .about-timeline__track {
  position: relative;
  display: grid;
  gap: 32px;
}

.page-about .about-timeline__line {
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: rgb(255 255 255 / 16%);
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 36px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--c-orange);
  border: 4px solid var(--c-ink);
  outline: 2px solid var(--c-orange);
  z-index: 1;
}

.page-about .about-timeline__card {
  background: rgb(255 255 255 / 6%);
  border: 1px solid rgb(255 255 255 / 12%);
  border-radius: var(--about-radius);
  padding: 24px;
}

.page-about .about-timeline__card--teal {
  border-top: 3px solid var(--c-teal);
}

.page-about .about-timeline__card--orange {
  border-top: 3px solid var(--c-orange);
}

.page-about .about-timeline__card--current {
  border-top: 3px solid var(--c-teal);
  background: rgb(0 194 168 / 10%);
}

.page-about .about-timeline__stage {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-teal);
  background: rgb(0 194 168 / 14%);
  border-radius: var(--r-pill);
  padding: 4px 12px;
  margin-bottom: 12px;
}

.page-about .about-timeline__item:nth-child(2) .about-timeline__stage {
  color: var(--c-teal);
  background: rgb(0 194 168 / 14%);
}

.page-about .about-timeline__item:nth-child(3) .about-timeline__stage {
  color: var(--c-orange);
  background: rgb(255 107 53 / 16%);
}

.page-about .about-timeline__item:nth-child(4) .about-timeline__stage {
  color: var(--c-white);
  background: rgb(255 255 255 / 14%);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-family: var(--f-headline);
  font-size: 24px;
  letter-spacing: -0.01em;
  color: var(--c-white);
  line-height: 1.15;
}

.page-about .about-timeline__card p {
  margin: 0;
  font-size: 14px;
  color: var(--c-rock);
}

.page-about .about-timeline__points {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 6px;
  font-size: 13px;
  color: var(--c-rock);
}

.page-about .about-timeline__points li {
  position: relative;
  padding-left: 16px;
}

.page-about .about-timeline__points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-orange);
}

/* ===== 四级质检 ===== */
.page-about .about-quality {
  background: var(--c-mist);
  padding: 88px 0;
}

.page-about .about-quality__header {
  max-width: 720px;
  margin-bottom: 48px;
}

.page-about .about-quality__header h2 {
  margin: 14px 0 12px;
}

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

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

.page-about .about-quality__steps {
  display: grid;
  gap: 12px;
}

.page-about .about-quality__step {
  background: var(--c-white);
  border: 1px solid rgb(180 190 203 / 45%);
  border-radius: var(--about-radius);
  padding: 0;
  transition: border-color var(--ease-fast), box-shadow var(--ease-fast);
}

.page-about .about-quality__step:hover {
  border-color: var(--c-teal);
  box-shadow: 0 8px 20px rgb(10 31 68 / 6%);
}

.page-about .about-quality__step summary {
  display: flex;
  align-items: center;
  gap: 12px;
  list-style: none;
  cursor: pointer;
  padding: 18px 20px;
  font-weight: 600;
  font-size: 15px;
  color: var(--c-ink);
  position: relative;
}

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

.page-about .about-quality__step summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--f-headline);
  font-size: 22px;
  line-height: 1;
  color: var(--c-teal);
  transition: transform var(--ease-fast);
}

.page-about .about-quality__step[open] summary::after {
  transform: rotate(45deg);
}

.page-about .about-quality__step[open] summary {
  border-bottom: 1px solid rgb(180 190 203 / 30%);
}

.page-about .about-quality__step-no {
  font-family: var(--f-headline);
  font-size: 18px;
  color: var(--c-orange);
  letter-spacing: -0.02em;
}

.page-about .about-quality__step .expandable__content p {
  margin: 0;
  padding-bottom: 18px;
  font-size: 14px;
  color: var(--c-iron);
}

.page-about .about-quality__figure {
  margin: 0;
  background: var(--c-ink);
  border: 1px solid rgb(10 31 68 / 12%);
  border-radius: var(--about-radius);
  overflow: hidden;
}

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

.page-about .about-quality__figure-caption {
  font-size: 13px;
  color: var(--c-iron);
  background: var(--c-white);
  padding: 12px 16px;
}

.page-about .notice-bar {
  margin-top: 32px;
}

/* ===== 技术架构与性能 ===== */
.page-about .about-tech {
  background: var(--c-ink);
  color: var(--c-white);
  padding: 92px 0;
}

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

.page-about .about-tech__copy h2 {
  margin: 14px 0 12px;
  max-width: 560px;
}

.page-about .about-tech__copy > p {
  color: var(--c-rock);
  font-size: 15px;
  margin: 0;
  max-width: 620px;
}

.page-about .about-tech__list {
  list-style: none;
  margin: 28px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid rgb(255 255 255 / 14%);
  display: grid;
  gap: 14px;
}

.page-about .about-tech__list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  color: var(--c-rock);
}

.page-about .about-tech__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 7px;
  height: 7px;
  background: var(--c-teal);
  transform: rotate(45deg);
}

.page-about .about-tech__list strong {
  color: var(--c-white);
  font-weight: 600;
}

.page-about .about-tech__link {
  color: var(--c-teal);
  text-decoration: none;
  border-bottom: 1px solid rgb(0 194 168 / 50%);
  transition: color var(--ease-fast), border-color var(--ease-fast);
}

.page-about .about-tech__link:hover {
  color: var(--c-orange);
  border-color: var(--c-orange);
}

.page-about .about-tech__stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.page-about .about-tech__stat {
  background: rgb(255 255 255 / 6%);
  border: 1px solid rgb(255 255 255 / 14%);
  border-radius: var(--about-radius);
  padding: 26px 22px;
}

.page-about .about-tech__stat--orange {
  background: var(--c-orange);
  border-color: transparent;
  color: var(--c-ink);
}

.page-about .about-tech__stat--teal {
  background: var(--c-teal);
  border-color: transparent;
  color: var(--c-ink);
}

.page-about .about-tech__stat-num {
  display: block;
  font-family: var(--f-headline);
  font-size: clamp(26px, 4vw, 42px);
  line-height: 1.1;
  letter-spacing: -0.01em;
}

.page-about .about-tech__stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  opacity: 0.85;
}

/* ===== 团队与组织 ===== */
.page-about .about-team {
  background: var(--c-mist);
  padding: 88px 0;
}

.page-about .about-team__header {
  max-width: 720px;
  margin-bottom: 48px;
}

.page-about .about-team__header h2 {
  margin: 14px 0 12px;
}

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

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .about-team__role {
  position: relative;
  background: var(--c-white);
  border: 1px solid rgb(180 190 203 / 45%);
  border-radius: var(--about-radius);
  padding: 26px 24px;
  transition: transform var(--ease-fast), box-shadow var(--ease-fast);
}

.page-about .about-team__role:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgb(10 31 68 / 8%);
}

.page-about .about-team__icon {
  width: 48px;
  height: 48px;
  border-radius: var(--about-radius);
  background: var(--c-ink);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  color: var(--c-orange);
}

.page-about .about-team__icon svg {
  width: 24px;
  height: 24px;
}

.page-about .about-team__role-title {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--c-ink);
}

.page-about .about-team__role p {
  margin: 0;
  font-size: 14px;
  color: var(--c-iron);
}

.page-about .about-team__tag {
  display: inline-block;
  margin-top: 16px;
}

.page-about .about-team__note {
  background: var(--c-ink);
  color: var(--c-white);
  border-radius: var(--about-radius);
  padding: 26px 24px;
}

.page-about .about-team__note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-rock);
}

/* ===== 信任与合规 ===== */
.page-about .about-trust {
  background: var(--c-ink);
  color: var(--c-white);
  padding: 88px 0 80px;
}

.page-about .about-trust__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: center;
}

.page-about .about-trust__content h2 {
  margin: 14px 0 12px;
  max-width: 560px;
}

.page-about .about-trust__content > p {
  margin: 0;
  color: var(--c-rock);
  font-size: 15px;
  max-width: 620px;
}

.page-about .about-trust__privacy {
  margin-top: 18px !important;
  font-size: 14px;
}

.page-about .about-trust__link {
  color: var(--c-teal);
  text-decoration: none;
  border-bottom: 1px solid rgb(0 194 168 / 50%);
  transition: color var(--ease-fast), border-color var(--ease-fast);
}

.page-about .about-trust__link:hover {
  color: var(--c-orange);
  border-color: var(--c-orange);
}

.page-about .about-trust__content .btn {
  margin-top: 26px;
}

.page-about .about-trust__figure {
  margin: 0;
  background: rgb(255 255 255 / 6%);
  border: 1px solid rgb(255 255 255 / 14%);
  border-radius: var(--about-radius);
  overflow: hidden;
}

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

/* ===== 桌面端 ===== */
@media (min-width: 720px) {
  .page-about .about-team__grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-team__note {
    grid-column: 1 / -1;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: 5fr 4fr;
    gap: 64px;
    align-items: end;
  }

  .page-about .about-philosophy__grid {
    grid-template-columns: 7fr 5fr;
    gap: 64px;
  }

  .page-about .about-philosophy__visual {
    margin-top: 32px;
  }

  .page-about .about-timeline__line {
    left: 50%;
    transform: translateX(-50%);
  }

  .page-about .about-timeline__item {
    width: 50%;
    padding-left: 0;
    padding-right: 56px;
  }

  .page-about .about-timeline__item:nth-child(even) {
    margin-left: 50%;
    padding-left: 56px;
    padding-right: 0;
  }

  .page-about .about-timeline__item::before {
    left: auto;
    right: -11px;
    top: 12px;
  }

  .page-about .about-timeline__item:nth-child(even)::before {
    left: -11px;
    right: auto;
  }

  .page-about .about-timeline__card {
    padding: 28px;
  }

  .page-about .about-quality__grid {
    grid-template-columns: 6fr 5fr;
    gap: 64px;
  }

  .page-about .about-tech__grid {
    grid-template-columns: 6fr 6fr;
    gap: 64px;
  }

  .page-about .about-trust__inner {
    grid-template-columns: 7fr 5fr;
    gap: 64px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-team__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .about-team__note {
    grid-column: 1 / -1;
  }
}