.page-about {
  --about-line: rgba(38, 68, 95, 0.72);
  --about-step: 14px;
  background: var(--ink-900);
  color: var(--text);
}

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(24px, 5vw, 52px) 0 clamp(40px, 7vw, 84px);
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -12% -12% 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.72;
  background:
    repeating-linear-gradient(118deg, rgba(38, 68, 95, 0.5) 0 1px, transparent 1px 54px),
    radial-gradient(120% 90% at 90% 6%, rgba(240, 90, 40, 0.18), transparent 62%),
    linear-gradient(118deg, transparent 68%, rgba(232, 178, 58, 0.1) 68%, rgba(232, 178, 58, 0.1) 69%, transparent 69%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(28px, 5vw, 52px);
  margin-top: clamp(20px, 4vw, 36px);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.24em;
  color: var(--flag-yellow);
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6.6vw, 68px);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.page-about .about-hero__intro {
  margin: clamp(18px, 3vw, 26px) 0 0;
  max-width: 48ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 4vw, 32px);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--about-line);
  border: 1px solid var(--about-line);
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 0 100%);
}

.page-about .about-facts__item {
  background: var(--ink-800);
  padding: 18px 16px;
}

.page-about .about-facts__label {
  margin: 0;
  font-family: var(--font-body);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--text-3);
}

.page-about .about-facts__value {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 30px);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
  color: var(--accent);
}

.page-about .about-facts__unit {
  margin-left: 2px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
}

.page-about .about-section {
  padding: clamp(38px, 6.5vw, 78px) 0;
}

.page-about .about-section + .about-section {
  border-top: 1px solid var(--about-line);
}

.page-about .about-section__grid {
  display: grid;
  gap: clamp(14px, 3vw, 24px);
}

.page-about .about-section__rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-left: 14px;
  border-left: 2px solid var(--accent);
}

.page-about .about-section__num {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--accent);
}

.page-about .about-section__label {
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--text-3);
  white-space: nowrap;
}

.page-about .about-h2 {
  margin: 0 0 clamp(16px, 3vw, 26px);
  max-width: 18em;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.8vw, 40px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  text-wrap: balance;
  scroll-margin-top: calc(var(--nav-h) + 24px);
}

.page-about .about-text {
  margin: 0 0 1.05em;
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 16.5px);
  line-height: 1.9;
  color: var(--text-2);
}

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

.page-about .about-text--lead {
  max-width: 58ch;
  padding-left: 14px;
  border-left: 2px solid var(--about-line);
  color: var(--text);
}

.page-about .about-split {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

.page-about .about-figure {
  position: relative;
  margin: 0;
}

.page-about .about-figure--wide {
  margin-top: clamp(26px, 4vw, 40px);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--about-line);
  background: var(--ink-800);
  object-fit: cover;
}

.page-about .about-figure::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 48px;
  height: 3px;
  background: var(--accent);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--text-3);
}

.page-about .principles {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
}

.page-about .principle {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 4px 16px;
  padding: clamp(16px, 2.4vw, 24px) 0;
  border-top: 1px solid var(--about-line);
}

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

.page-about .principle__key {
  grid-row: span 2;
  padding-top: 6px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent);
}

.page-about .principle__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

.page-about .principle__text {
  margin: 6px 0 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(18px, 3vw, 26px) 0 clamp(22px, 3vw, 30px);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(12px, 2vw, 18px);
}

.page-about .mile {
  position: relative;
  padding: clamp(14px, 2.2vw, 20px) clamp(16px, 2.4vw, 24px);
  background: linear-gradient(155deg, rgba(23, 59, 92, 0.55), rgba(14, 36, 57, 0.95));
  border: 1px solid var(--about-line);
  border-left: 3px solid var(--flag-blue);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.page-about .mile[data-tags~="内容"] {
  border-left-color: var(--flag-green);
}

.page-about .mile[data-tags~="合作"] {
  border-left-color: var(--flag-yellow);
}

.page-about .mile__stage {
  margin: 0 0 8px;
  font-family: var(--font-body);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--accent-soft);
}

.page-about .mile__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

.page-about .mile__text {
  margin: 8px 0 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .team-list {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .team {
  background: var(--ink-800);
  border: 1px solid var(--about-line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .team summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px clamp(16px, 2.4vw, 22px);
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  color: var(--text);
  transition: color var(--dur) var(--ease);
}

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

.page-about .team summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--accent);
}

.page-about .team[open] summary {
  color: var(--accent-soft);
}

.page-about .team[open] summary::after {
  content: "−";
}

.page-about .team summary:hover {
  color: var(--accent-soft);
}

.page-about .team__count {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
}

.page-about .team__body {
  padding: 14px clamp(16px, 2.4vw, 22px) clamp(16px, 2.4vw, 22px);
  border-top: 1px solid var(--about-line);
}

.page-about .team__body p {
  margin: 0 0 10px;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .team__body ul {
  margin: 0;
  padding-left: 1.15em;
  display: grid;
  gap: 6px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-2);
}

.page-about .eco-grid {
  display: grid;
  gap: 1px;
  margin-top: clamp(20px, 3vw, 30px);
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .eco {
  background: var(--ink-900);
  padding: clamp(18px, 2.4vw, 24px);
  border-top: 2px solid var(--flag-blue);
}

.page-about .eco:nth-child(2) {
  border-top-color: var(--flag-green);
}

.page-about .eco:nth-child(3) {
  border-top-color: var(--flag-yellow);
}

.page-about .eco:nth-child(4) {
  border-top-color: var(--accent);
}

.page-about .eco__value {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .eco__label {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(17px, 2vw, 19px);
  font-weight: 700;
  color: var(--text);
}

.page-about .eco__text {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .reasons {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(12px, 2.2vw, 18px);
}

.page-about .reason {
  position: relative;
  padding: clamp(16px, 2.2vw, 22px) clamp(16px, 2.2vw, 22px) clamp(16px, 2.2vw, 22px) clamp(20px, 2.6vw, 26px);
  background: var(--ink-800);
  border: 1px solid var(--about-line);
}

.page-about .reason::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--accent);
}

.page-about .reason__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  color: var(--text);
}

.page-about .reason__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .about-cta {
  display: grid;
  gap: 18px;
  margin-top: clamp(28px, 4vw, 44px);
  padding: clamp(22px, 3.4vw, 34px);
  background: linear-gradient(120deg, rgba(240, 90, 40, 0.16), rgba(14, 36, 57, 0.92) 58%);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 52ch;
  font-size: clamp(15px, 1.6vw, 16.5px);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

@media (min-width: 720px) {
  .page-about .eco-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
    align-items: end;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.82fr);
    align-items: start;
  }

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

@media (min-width: 900px) {
  .page-about .about-section__grid {
    grid-template-columns: 136px minmax(0, 1fr);
    gap: clamp(26px, 4vw, 64px);
  }

  .page-about .about-section__rail {
    align-self: start;
    position: sticky;
    top: calc(var(--nav-h) + 22px);
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding: 14px 0 0;
    border-left: 0;
    border-top: 2px solid var(--accent);
  }

  .page-about .about-section__num {
    font-size: clamp(30px, 3vw, 44px);
  }

  .page-about .mile:nth-child(2) {
    margin-left: calc(var(--about-step) * 1);
  }

  .page-about .mile:nth-child(3) {
    margin-left: calc(var(--about-step) * 2);
  }

  .page-about .mile:nth-child(4) {
    margin-left: calc(var(--about-step) * 3);
  }

  .page-about .mile:nth-child(5) {
    margin-left: calc(var(--about-step) * 4);
  }

  .page-about .mile:nth-child(6) {
    margin-left: calc(var(--about-step) * 5);
  }
}

@media (min-width: 1080px) {
  .page-about .eco-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team summary {
    transition: none;
  }
}