.page-about {
  --about-paper-line: rgba(7, 11, 9, 0.14);
  --about-paper-text: #46564C;
  --about-paper-num: #B0491F;
}

.page-about a:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 2px;
}

.page-about .about-crumb {
  padding-top: clamp(18px, 4vw, 36px);
}

.page-about .section__title {
  font-size: clamp(27px, 4.4vw, 58px);
  line-height: 1.04;
  letter-spacing: -0.03em;
  max-width: 22ch;
}

.page-about .section__lead {
  max-width: 66ch;
  color: var(--paper-300);
  font-size: clamp(15px, 1.5vw, 17.5px);
  line-height: 1.75;
}

/* ---------- 01 开场 ---------- */

.page-about .about-opener {
  padding-top: clamp(20px, 4vw, 44px);
}

.page-about .about-opener .section__title {
  font-size: clamp(38px, 8.2vw, 112px);
  line-height: 0.94;
  letter-spacing: -0.05em;
  max-width: 15ch;
}

.page-about .about-opener .section__lead {
  max-width: 62ch;
  margin-top: clamp(16px, 2.4vw, 26px);
}

.page-about .about-toc {
  list-style: none;
  margin: clamp(30px, 5vw, 60px) 0 0;
  padding: 0;
  border-top: var(--hair);
}

.page-about .about-toc__item {
  border-bottom: var(--hair);
}

.page-about .about-toc__link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(12px, 3vw, 30px);
  padding: clamp(14px, 2.3vw, 22px) 2px;
  text-decoration: none;
  color: var(--paper-100);
  transition: color 200ms ease, padding-left 200ms ease, background-color 200ms ease;
}

.page-about .about-toc__link:hover {
  color: var(--lime);
  padding-left: 12px;
}

.page-about .about-toc__num {
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--ash);
  padding-top: 4px;
}

.page-about .about-toc__link:hover .about-toc__num {
  color: var(--lime);
}

.page-about .about-toc__body {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-toc__label {
  font-size: clamp(18px, 2.4vw, 27px);
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .about-toc__hint {
  font-size: 12.5px;
  color: var(--ash);
  line-height: 1.5;
}

.page-about .about-toc__arrow {
  font-size: 18px;
  color: var(--ink-700);
  transition: color 200ms ease, transform 200ms ease;
}

.page-about .about-toc__link:hover .about-toc__arrow {
  color: var(--lime);
  transform: translateX(4px);
}

.page-about .about-intro {
  margin-top: clamp(32px, 5vw, 68px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 52px);
}

.page-about .about-intro__col p {
  max-width: 70ch;
  color: var(--paper-300);
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
}

.page-about .about-intro__col p + p {
  margin-top: 1em;
}

.page-about .about-intro__stats {
  display: grid;
  gap: 10px;
  align-content: start;
}

.page-about .stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  background: var(--ink-800);
  border: var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
}

.page-about .stat__value {
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1;
  color: var(--lime);
  letter-spacing: -0.02em;
}

.page-about .stat__label {
  font-size: 12.5px;
  color: var(--ash);
  line-height: 1.5;
}

/* ---------- 02 团队 ---------- */

.page-about .about-team__grid {
  margin-top: clamp(28px, 4vw, 52px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
}

.page-about .about-team__subtitle {
  margin: 0 0 14px;
  font-size: clamp(17px, 1.9vw, 21px);
  color: var(--paper-100);
  letter-spacing: -0.01em;
}

.page-about .about-team__copy p {
  max-width: 66ch;
  color: var(--paper-300);
  font-size: 15.5px;
  line-height: 1.8;
}

.page-about .about-team__copy p + p {
  margin-top: 0.9em;
}

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

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__figure .figure__frame {
  border: var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .figure__caption {
  font-size: 12.5px;
  color: var(--ash);
  line-height: 1.6;
  margin-top: 10px;
}

.page-about .role-list {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .role-list__item {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  font-size: 13px;
}

.page-about .role-list__name {
  color: var(--paper-100);
}

.page-about .role-list__bar {
  display: block;
  height: 6px;
  background: var(--ink-800);
  border: var(--hair);
  border-radius: 999px;
  overflow: hidden;
}

.page-about .role-list__fill {
  display: block;
  height: 100%;
  border-radius: 999px;
}

.page-about .role-list__fill--a { width: 44.4%; background: var(--lime); }
.page-about .role-list__fill--b { width: 33.3%; background: var(--amber); }
.page-about .role-list__fill--c { width: 11.1%; background: var(--orange); }
.page-about .role-list__fill--d { width: 11.1%; background: var(--ash); }

.page-about .role-list__val {
  color: var(--paper-300);
  font-size: 12.5px;
}

.page-about .donut {
  margin-top: clamp(30px, 4vw, 56px);
  padding: clamp(20px, 3vw, 32px);
  background: var(--ink-800);
  border: var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 40px);
  align-items: center;
}

.page-about .donut__svg {
  display: block;
  width: 100%;
  max-width: 210px;
  height: auto;
  margin: 0 auto;
}

.page-about .donut__ring {
  fill: none;
  stroke: var(--ink-700);
  stroke-width: 12;
}

.page-about .donut__seg {
  fill: none;
  stroke-width: 12;
  transition: stroke-width 200ms ease;
}

.page-about .donut__seg--a { stroke: var(--lime); }
.page-about .donut__seg--b { stroke: var(--amber); }
.page-about .donut__seg--c { stroke: var(--orange); }
.page-about .donut__seg--d { stroke: var(--ash); }

.page-about .donut__seg:hover {
  stroke-width: 17;
}

.page-about .donut__legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--ink-700);
  border: var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .donut__legend-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  background: var(--ink-900);
  font-size: 14px;
  transition: background-color 200ms ease;
}

.page-about .donut__legend-item:hover {
  background: var(--ink-800);
}

.page-about .donut__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: block;
}

.page-about .donut__dot--a { background: var(--lime); }
.page-about .donut__dot--b { background: var(--amber); }
.page-about .donut__dot--c { background: var(--orange); }
.page-about .donut__dot--d { background: var(--ash); }

.page-about .donut__name {
  color: var(--paper-100);
}

.page-about .donut__val {
  font-size: 12.5px;
  color: var(--ash);
}

/* ---------- 03 流程 ---------- */

.page-about .about-flow__figure {
  margin: clamp(26px, 4vw, 46px) 0 0;
}

.page-about .about-flow__figure .figure__frame {
  border: var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .flow {
  list-style: none;
  margin: clamp(26px, 4vw, 46px) 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ink-700);
  border: var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .flow__step {
  position: relative;
  background: var(--ink-900);
  padding: clamp(18px, 2.6vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 9px;
  transition: background-color 200ms ease;
}

.page-about .flow__step::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--band);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 240ms ease;
}

.page-about .flow__step:hover,
.page-about .flow__step:focus-within {
  background: var(--ink-800);
}

.page-about .flow__step:hover::before,
.page-about .flow__step:focus-within::before {
  transform: scaleX(1);
}

.page-about .flow__num {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--lime);
}

.page-about .flow__title {
  margin: 0;
  font-size: clamp(18px, 2vw, 23px);
  color: var(--paper-100);
  letter-spacing: -0.01em;
}

.page-about .flow__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--paper-300);
}

.page-about .flow__note {
  margin: 0;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ash);
  border-top: var(--hair);
  padding-top: 10px;
}

/* ---------- 04 发展阶段 ---------- */

.page-about .filter-bar {
  margin-top: clamp(22px, 3vw, 36px);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.page-about .filter-btn {
  font: inherit;
  font-size: 13.5px;
  padding: 8px 15px;
  border: var(--hair);
  border-radius: 999px;
  background: transparent;
  color: var(--paper-300);
  cursor: pointer;
  transition: background-color 180ms ease, color 180ms ease, border-color 180ms ease;
}

.page-about .filter-btn:hover {
  border-color: var(--lime);
  color: var(--lime);
}

.page-about .filter-btn[aria-pressed="true"] {
  background: var(--lime);
  border-color: var(--lime);
  color: var(--ink-950);
  font-weight: 700;
}

.page-about .filter-count {
  margin-left: auto;
  font-size: 12.5px;
  color: var(--ash);
}

.page-about .stage-list {
  list-style: none;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .stage {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  padding: clamp(18px, 2.6vw, 30px);
  background: var(--ink-900);
  border: var(--hair);
  border-left: 3px solid var(--ink-700);
  border-radius: var(--radius);
  transition: border-left-color 220ms ease, background-color 220ms ease;
}

.page-about .stage:hover {
  background: var(--ink-800);
  border-left-color: var(--lime);
}

.page-about .stage--current {
  border-left-color: var(--orange);
}

.page-about .stage[hidden] {
  display: none;
}

.page-about .stage__mark {
  position: relative;
  padding-left: 22px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .stage__mark::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--amber);
}

.page-about .stage--current .stage__mark::before {
  background: var(--orange);
}

.page-about .stage__mark::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 22px;
  bottom: -30px;
  width: 1px;
  background: var(--ink-700);
}

.page-about .stage:last-child .stage__mark::after {
  content: none;
}

.page-about .stage__phase {
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--ash);
}

.page-about .stage__year {
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.05;
  color: var(--paper-100);
  letter-spacing: -0.02em;
}

.page-about .stage__title {
  margin: 0 0 8px;
  font-size: clamp(18px, 2vw, 23px);
  color: var(--paper-100);
  letter-spacing: -0.01em;
}

.page-about .stage__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--paper-300);
  max-width: 68ch;
}

.page-about .stage__gain {
  margin: 10px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--lime);
  max-width: 68ch;
}

.page-about .stage__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-content: start;
}

.page-about .about-stages__note {
  margin: clamp(20px, 3vw, 32px) 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ash);
  max-width: 72ch;
}

.page-about .about-link {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid var(--ink-700);
  transition: border-color 180ms ease;
}

.page-about .about-link:hover {
  border-bottom-color: var(--lime);
}

/* ---------- 05 服务节点 ---------- */

.page-about .about-jilin__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 54px);
  align-items: center;
}

.page-about .about-jilin__figure {
  margin: 0;
}

.page-about .about-jilin__figure .figure__frame {
  border: var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-jilin__title {
  margin: 8px 0 14px;
  font-size: clamp(26px, 4vw, 46px);
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--paper-100);
}

.page-about .about-jilin__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--paper-300);
  max-width: 62ch;
}

.page-about .about-jilin__facts {
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--ink-700);
  border: var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-jilin__facts > div {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 12px;
  padding: 12px 14px;
  background: var(--ink-800);
}

.page-about .about-jilin__facts dt {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--ash);
}

.page-about .about-jilin__facts dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--paper-100);
}

.page-about .about-jilin__contact {
  list-style: none;
  margin: clamp(18px, 2.6vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .contact-list__row {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  font-size: 14.5px;
}

.page-about .about-jilin__label {
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--ash);
}

.page-about .about-jilin__value {
  color: var(--lime);
  word-break: break-word;
}

.page-about .about-jilin__actions {
  margin-top: clamp(20px, 3vw, 30px);
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 06 原则（暖纸反转） ---------- */

.page-about .about-principles {
  color: var(--ink-900);
}

.page-about .about-principles .section__title {
  color: var(--ink-950);
}

.page-about .about-principles .section__index {
  color: var(--about-paper-num);
}

.page-about .about-principles .section__lead {
  color: var(--about-paper-text);
}

.page-about .principles {
  list-style: none;
  margin: clamp(26px, 4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 2.8vw, 30px);
}

.page-about .principle {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 16px;
  padding-bottom: clamp(16px, 2.2vw, 22px);
  border-bottom: 1px solid var(--about-paper-line);
}

.page-about .principle__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 34px;
  height: 24px;
  padding: 0 6px;
  border-radius: var(--radius);
  background: var(--lime);
  color: var(--ink-950);
  font-size: 12px;
  letter-spacing: 0.06em;
  font-weight: 700;
}

.page-about .principle__title {
  margin: 0 0 6px;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.3;
  color: var(--ink-950);
  letter-spacing: -0.01em;
}

.page-about .principle__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--about-paper-text);
  max-width: 62ch;
}

/* ---------- 收束 ---------- */

.page-about .about-next {
  padding-block: clamp(40px, 6vw, 76px);
}

.page-about .about-next__bar {
  position: relative;
  padding-top: clamp(20px, 2.6vw, 28px);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 24px;
}

.page-about .about-next__bar::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--band);
}

.page-about .about-next__text {
  margin: 0;
  font-size: clamp(17px, 2.1vw, 24px);
  line-height: 1.4;
  color: var(--paper-100);
  max-width: 42ch;
  letter-spacing: -0.01em;
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .donut {
    grid-template-columns: 190px minmax(0, 1fr);
  }

  .page-about .about-jilin__facts > div {
    grid-template-columns: 96px minmax(0, 1fr);
    padding: 13px 18px;
  }
}

@media (min-width: 900px) {
  .page-about .about-intro {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-team__figure {
    margin-top: clamp(0px, 2vw, 34px);
  }

  .page-about .donut {
    grid-template-columns: 230px minmax(0, 1fr);
  }

  .page-about .flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .stage {
    grid-template-columns: 138px minmax(0, 1fr) auto;
    gap: 0 clamp(18px, 3vw, 38px);
    align-items: start;
  }

  .page-about .stage__tags {
    justify-content: flex-end;
  }

  .page-about .about-jilin__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  }

  .page-about .principles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(22px, 2.6vw, 34px) clamp(28px, 4vw, 56px);
  }
}

@media (min-width: 900px) and (hover: hover) {
  .page-about .flow__note {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    padding-top: 0;
    border-top-color: transparent;
    transition: max-height 240ms ease, opacity 240ms ease, padding-top 240ms ease, border-color 240ms ease;
  }

  .page-about .flow__step:hover .flow__note,
  .page-about .flow__step:focus-within .flow__note {
    max-height: 8em;
    opacity: 1;
    padding-top: 10px;
    border-top-color: var(--ink-700);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}