.page-about {
  --c-about-river: rgba(57, 255, 20, 0.22);
  --c-about-river-deep: rgba(79, 143, 159, 0.35);
  --c-about-sheet: rgba(242, 247, 248, 0.06);
  --c-about-sheet-strong: rgba(28, 90, 102, 0.65);
  --c-about-line: rgba(197, 214, 216, 0.26);
  --c-about-muted-line: rgba(197, 214, 216, 0.12);
  color: var(--c-white);
}

.page-about a {
  color: var(--c-blue);
}

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

.page-about .container {
  max-width: var(--container);
  margin: 0 auto;
  padding-left: clamp(16px, 4vw, 40px);
  padding-right: clamp(16px, 4vw, 40px);
}

.page-about .breadcrumbs {
  margin-bottom: clamp(24px, 4vw, 48px);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-muted);
}

.page-about .breadcrumbs__sep {
  margin: 0 8px;
  color: rgba(197, 214, 216, 0.5);
}

.page-about .breadcrumbs [aria-current="page"] {
  color: var(--c-orange);
}

.page-about .lede {
  font-size: clamp(16px, 1.3vw, 18px);
  line-height: 1.8;
  color: var(--c-muted);
}

.page-about .chapter {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: clamp(28px, 4vw, 44px);
  border-left: 4px solid var(--c-orange);
  padding-left: 18px;
}

.page-about .chapter__index {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3vw, 36px);
  color: var(--c-orange);
  line-height: 1;
}

.page-about .chapter__title {
  margin: 0;
  font-family: var(--font-editorial);
  font-size: clamp(22px, 2.8vw, 32px);
  line-height: 1.3;
  color: var(--c-white);
}

.page-about .card {
  background: linear-gradient(145deg, rgba(28, 90, 102, 0.72), rgba(13, 31, 38, 0.68));
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 2.4vw, 30px);
}

.page-about .notice {
  margin-top: 28px;
}

.page-about .tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 2px;
  background: rgba(197, 214, 216, 0.12);
}

.page-about .stat {
  font-family: var(--font-display);
  font-size: 1.5em;
  line-height: 1;
  color: var(--c-orange);
}

.page-about .btn--ghost {
  border-color: var(--c-about-line);
  color: var(--c-blue);
}

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

/* ===== hero ===== */
.p-about-hero {
  position: relative;
  padding: clamp(36px, 6vw, 80px) 0 clamp(32px, 5vw, 64px);
  background:
    linear-gradient(108deg, rgba(11, 60, 73, 0.98) 0%, rgba(13, 31, 38, 0.9) 52%, rgba(176, 58, 26, 0.4) 100%);
  overflow: hidden;
}

.p-about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -18%;
  width: 54vw;
  height: 54vw;
  min-width: 360px;
  min-height: 360px;
  background: linear-gradient(135deg, rgba(79, 143, 159, 0.22), rgba(57, 255, 20, 0.14));
  transform: rotate(18deg);
  pointer-events: none;
}

.p-about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 46px;
  background: linear-gradient(to right, transparent, rgba(255, 107, 53, 0.5), transparent);
  clip-path: polygon(0 100%, 0 62%, 12% 74%, 26% 50%, 39% 72%, 54% 36%, 68% 58%, 82% 28%, 94% 48%, 100% 34%, 100% 100%);
  pointer-events: none;
}

.p-about-hero .container {
  position: relative;
  z-index: 2;
}

.p-about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
}

.p-about-eyebrow {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--c-green);
}

.p-about-hero h1 {
  margin: 0 0 22px;
  font-family: var(--font-display);
  font-size: clamp(28px, 5vw, 56px);
  line-height: 1.1;
  color: var(--c-white);
  letter-spacing: 0.02em;
  max-width: 12em;
}

.p-about-hero__copy .lede {
  max-width: 34em;
}

.p-about-hero__panel {
  position: relative;
  background: var(--c-about-sheet-strong);
  border: 1px solid var(--c-about-line);
  border-radius: var(--radius-lg);
  padding: clamp(18px, 2.4vw, 30px);
  backdrop-filter: blur(4px);
}

.p-about-hero__panel::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 48px;
  height: 48px;
  border-top: 4px solid var(--c-orange);
  border-left: 4px solid var(--c-orange);
  border-top-left-radius: var(--radius-lg);
}

.p-about-panel__title {
  margin: 0 0 18px;
  font-family: var(--font-editorial);
  font-size: clamp(15px, 1.4vw, 18px);
  color: var(--c-white);
}

.p-about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin: 0;
}

.p-about-stat {
  background: rgba(13, 31, 38, 0.55);
  border: 1px solid var(--c-about-muted-line);
  border-radius: var(--radius);
  padding: 14px 16px;
}

.p-about-stat dt {
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--c-muted);
  margin-bottom: 8px;
}

.p-about-stat dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(26px, 3vw, 38px);
  color: var(--c-white);
  line-height: 1.1;
}

.p-about-stat dd .stat {
  color: var(--c-orange);
}

/* ===== river divider ===== */
.p-about-river {
  padding: 0;
  background: var(--c-bg);
  position: relative;
}

.p-about-river .container {
  position: relative;
  height: 54px;
}

.p-about-river__line {
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 4px;
  background: linear-gradient(to right, transparent, rgba(57, 255, 20, 0.7), rgba(79, 143, 159, 0.4), transparent);
  transform: translateY(-50%);
}

.p-about-river__dash {
  position: absolute;
  left: 10%;
  top: 50%;
  width: 26%;
  height: 1px;
  background: rgba(255, 107, 53, 0.5);
  transform: translateY(-50%) rotate(-6deg);
}

.p-about-river__dot {
  position: absolute;
  right: 12%;
  top: 50%;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--c-green);
  box-shadow: 0 0 0 6px rgba(57, 255, 20, 0.12);
  transform: translateY(-50%);
  animation: p-about-breathe 2.4s ease-in-out infinite;
}

@keyframes p-about-breathe {
  0%, 100% {
    opacity: 0.6;
  }
  50% {
    opacity: 1;
  }
}

/* ===== data source ===== */
.p-about-source-card {
  position: relative;
}

.p-about-source-card::after {
  content: "";
  position: absolute;
  right: 12px;
  top: 12px;
  width: 28px;
  height: 28px;
  border-top: 2px solid var(--c-green);
  border-right: 2px solid var(--c-green);
  border-top-right-radius: 8px;
  opacity: 0.5;
}

.p-about-card-title {
  font-family: var(--font-editorial);
  font-size: clamp(18px, 1.8vw, 22px);
  line-height: 1.4;
  color: var(--c-white);
  margin: 0 0 14px;
}

.p-about-source-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-muted);
}

/* ===== scale ===== */
.p-about-scale {
  position: relative;
  background: var(--c-bg-deep);
}

.p-about-scale::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 30%;
  background: linear-gradient(90deg, rgba(255, 107, 53, 0.06), transparent);
  pointer-events: none;
}

.p-about-scale__grid {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
  align-items: center;
}

.p-about-scale__image {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--c-border);
}

.p-about-scale__image::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 30%;
  background: linear-gradient(to top, rgba(11, 60, 73, 0.65), transparent);
}

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

.p-about-scale__content .lede {
  color: var(--c-white);
  margin-bottom: 24px;
}

.p-about-scale__list {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.p-about-scale__list li {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-muted);
  border-bottom: 1px dashed var(--c-about-muted-line);
  padding-bottom: 12px;
}

.p-about-scale__content p:last-child {
  margin-bottom: 0;
  color: var(--c-muted);
  font-size: 15px;
  line-height: 1.8;
}

/* ===== timeline ===== */
.p-about-timeline {
  position: relative;
  background: var(--c-bg);
}

.p-about-timeline__layout {
  display: grid;
  gap: clamp(24px, 5vw, 64px);
}

.p-about-timeline__main {
  position: relative;
}

.p-about-timeline__wave {
  position: absolute;
  top: 0;
  left: clamp(16px, 3vw, 32px);
  width: 4px;
  height: 100%;
  background: linear-gradient(to bottom, var(--c-orange), var(--c-green), var(--c-blue), transparent);
  opacity: 0.5;
  pointer-events: none;
}

.p-about-timeline__wave::after {
  content: "";
  position: absolute;
  top: 0;
  left: 8px;
  width: 2px;
  height: 100%;
  background: linear-gradient(to bottom, transparent, rgba(255, 107, 53, 0.5), rgba(57, 255, 20, 0.4), transparent);
  pointer-events: none;
}

.p-about-timeline__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.p-about-milestone__trigger {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  text-align: left;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius);
  padding: 12px 14px;
  color: var(--c-white);
  font-family: var(--font-body);
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s, transform 0.2s;
}

.p-about-milestone__trigger:hover {
  background: rgba(28, 90, 102, 0.4);
  border-color: var(--c-about-line);
}

.p-about-milestone__trigger[aria-expanded="true"] {
  background: rgba(255, 107, 53, 0.1);
  border-color: var(--c-orange);
}

.p-about-milestone__tag {
  flex: 0 0 auto;
  min-width: 58px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--c-orange);
  background: rgba(255, 107, 53, 0.12);
  border: 1px solid rgba(255, 107, 53, 0.35);
  border-radius: 2px;
  padding: 4px 10px;
  text-align: center;
}

.p-about-milestone__name {
  font-size: 16px;
  font-weight: 600;
}

.p-about-milestone__panel {
  display: none;
  margin-top: 16px;
  padding: 22px 24px;
  background: linear-gradient(145deg, rgba(28, 90, 102, 0.45), rgba(13, 31, 38, 0.7));
  border: 1px solid var(--c-about-line);
  border-left: 4px solid var(--c-orange);
  border-radius: var(--radius-lg);
}

.p-about-milestone__panel.is-active {
  display: block;
}

.p-about-milestone__heading {
  margin: 0 0 12px;
  font-family: var(--font-editorial);
  font-size: clamp(18px, 2vw, 24px);
  color: var(--c-white);
}

.p-about-milestone__panel p {
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--c-muted);
}

.p-about-timeline__note {
  margin: 20px 0 0;
  padding-left: clamp(16px, 3vw, 32px);
  font-size: 14px;
  color: var(--c-muted);
  font-style: italic;
}

.p-about-timeline__aside {
  position: relative;
}

.p-about-timeline__aside img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--c-border);
}

.p-about-timeline__caption {
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-muted);
  text-align: center;
}

/* ===== team ===== */
.p-about-team {
  position: relative;
  background: var(--c-bg-deep);
}

.p-about-team::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 42%;
  height: 120px;
  background: linear-gradient(to top, rgba(79, 143, 159, 0.12), transparent);
  clip-path: polygon(0 100%, 28% 0, 62% 100%, 100% 0);
  pointer-events: none;
}

.p-about-team-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-muted);
}

.p-about-team__mechanism {
  margin-top: clamp(28px, 4vw, 48px);
}

.p-about-team__mechanism .p-about-card-title {
  margin-bottom: 20px;
}

.p-about-step {
  position: relative;
  padding: 20px 20px 20px 68px;
  background: rgba(11, 60, 73, 0.35);
  border: 1px solid var(--c-about-muted-line);
  border-radius: var(--radius);
}

.p-about-step__num {
  position: absolute;
  left: 16px;
  top: 16px;
  font-family: var(--font-mono);
  font-size: 22px;
  color: var(--c-green);
  line-height: 1;
}

.p-about-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-muted);
}

/* ===== ecosystem ===== */
.p-about-ecosystem {
  position: relative;
  overflow: hidden;
}

.p-about-ecosystem::before {
  content: "";
  position: absolute;
  left: -8%;
  top: 16%;
  width: 40%;
  height: 120%;
  background: linear-gradient(115deg, rgba(79, 143, 159, 0.12), transparent);
  transform: skewX(-12deg);
  pointer-events: none;
}

.p-about-ecosystem__grid {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
  align-items: center;
}

.p-about-ecosystem__content {
  position: relative;
  z-index: 2;
}

.p-about-cert-list {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  gap: 14px;
}

.p-about-cert-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: start;
  padding: 16px;
  background: rgba(13, 31, 38, 0.45);
  border: 1px solid var(--c-about-muted-line);
  border-radius: var(--radius);
}

.p-about-cert-list li .tag {
  margin-top: 2px;
}

.p-about-cert-list li span:last-child {
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-muted);
}

.p-about-ecosystem__content > p {
  font-size: 15px;
  line-height: 1.9;
  color: var(--c-muted);
  margin: 0 0 20px;
}

.p-about-ecosystem__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.p-about-ecosystem__image img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--c-border);
}

/* ===== outro ===== */
.p-about-outro {
  position: relative;
  background: var(--c-bg-deep);
  padding: clamp(36px, 6vw, 70px) 0;
  overflow: hidden;
}

.p-about-outro::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  background: radial-gradient(ellipse at 78% 30%, rgba(57, 255, 20, 0.1), transparent 60%),
    linear-gradient(180deg, transparent, rgba(11, 60, 73, 0.8));
  pointer-events: none;
}

.p-about-outro .container {
  position: relative;
  z-index: 2;
  max-width: 36rem;
}

.p-about-outro p {
  margin: 0;
  font-family: var(--font-editorial);
  font-size: clamp(18px, 2.2vw, 24px);
  line-height: 1.8;
  color: var(--c-white);
  text-align: center;
}

/* ===== reveal 动效基础 ===== */
[data-reveal] {
  opacity: 1;
  transform: none;
  transition: none;
}

.page-about [data-reveal="true"] {
  transition: opacity 0.6s ease, transform 0.6s ease;
}

/* ===== 移动优先 ===== */
@media (max-width: 767px) {
  .page-about .chapter {
    gap: 10px;
  }

  .p-about-hero__grid {
    grid-template-columns: 1fr;
  }

  .p-about-scale__grid,
  .p-about-timeline__layout,
  .p-about-ecosystem__grid {
    grid-template-columns: 1fr;
  }

  .p-about-scale__image {
    max-height: 340px;
  }

  .p-about-timeline__aside img {
    max-height: 320px;
  }

  .p-about-ecosystem__image {
    order: -1;
  }

  .p-about-ecosystem__image img {
    max-height: 320px;
  }

  .p-about-hero__stats {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }

  .p-about-stat {
    padding: 12px;
  }
}

@media (min-width: 768px) {
  .p-about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }

  .p-about-scale__grid {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  }

  .p-about-timeline__layout {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
    align-items: start;
  }

  .p-about-timeline__aside {
    position: sticky;
    top: calc(var(--header-h) + 24px);
  }

  .p-about-ecosystem__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

  .p-about-timeline__list {
    grid-template-columns: repeat(2, 1fr);
  }

  .p-about-milestone__trigger {
    padding: 16px 18px;
  }

  .p-about-milestone__panel {
    margin-top: 24px;
    padding: 28px 34px;
  }

  .p-about-timeline__note {
    margin-top: 24px;
  }
}

@media (min-width: 1024px) {
  .p-about-hero__stats {
    gap: 18px;
  }

  .p-about-scale__list {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px 24px;
  }

  .p-about-cert-list {
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
  }

  .p-about-team__mechanism .grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 520px) {
  .page-about .container {
    padding-left: 14px;
    padding-right: 14px;
  }

  .p-about-hero h1 {
    font-size: 26px;
  }

  .p-about-hero__stats {
    grid-template-columns: 1fr;
  }

  .p-about-stat {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .p-about-stat dt {
    margin: 0;
  }

  .p-about-stat dd {
    font-size: 28px;
  }

  .p-about-cert-list li {
    grid-template-columns: 1fr;
  }

  .p-about-ecosystem__links {
    flex-direction: column;
  }

  .p-about-ecosystem__links .btn {
    display: block;
    text-align: center;
  }
}

/* ===== prefers-reduced-motion ===== */
@media (prefers-reduced-motion: reduce) {
  .page-about * {
    animation: none !important;
    transition: none !important;
  }

  .p-about-river__dot {
    animation: none;
  }
}