.page-about {
  --about-measure: 37em;
  --about-tint: rgba(27, 42, 74, 0.045);
  background: var(--paper);
  color: var(--ink);
}

/* ---------- 扉页：窄栏自述 ---------- */

.page-about .about-mast {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(24px, 5.5vw, 56px) var(--gap) clamp(36px, 7vw, 88px);
  padding-left: clamp(20px, 6vw, 118px);
}

.page-about .breadcrumb {
  margin-bottom: clamp(30px, 6vw, 68px);
}

.page-about .about-title {
  max-width: 9.5em;
  margin: 14px 0 22px;
}

.page-about .about-lede {
  max-width: var(--about-measure);
  margin: 0;
  color: rgba(11, 18, 32, 0.76);
}

.page-about .about-stamp {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(30px, 6vw, 56px) 0 0;
  padding: 0;
  background: var(--hair-light);
  border: 1px solid var(--hair-light);
  border-radius: var(--radius-s);
  overflow: hidden;
}

.page-about .stamp {
  background: var(--paper);
  padding: 15px 16px 17px;
}

.page-about .stamp__k {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--warm-gray);
}

.page-about .stamp__v {
  margin: 7px 0 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 4vw, 26px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}

/* ---------- 通用分节 ---------- */

.page-about .section {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gap);
  padding-block: clamp(44px, 8vw, 104px);
}

.page-about .about-stages__intro,
.page-about .about-zones__intro,
.page-about .about-bounds__intro {
  max-width: var(--about-measure);
}

.page-about .about-stages__intro p,
.page-about .about-zones__intro p,
.page-about .about-bounds__intro p {
  margin: 14px 0 0;
  color: rgba(11, 18, 32, 0.72);
  line-height: 1.75;
}

/* ---------- 四个发展阶段：高度递减的色带 ---------- */

.page-about .stage-stack {
  display: grid;
  gap: 12px;
  margin-top: clamp(28px, 5vw, 52px);
}

.page-about .stage {
  border-radius: var(--radius);
  color: var(--paper);
  overflow: hidden;
}

.page-about .stage--1 {
  background: linear-gradient(112deg, #0C1730 0%, #1B2A4A 78%);
}

.page-about .stage--2 {
  background: linear-gradient(112deg, #16243F 0%, #33477A 78%);
}

.page-about .stage--3 {
  background: #33477A;
  box-shadow: inset -170px 0 140px -90px rgba(255, 107, 53, 0.92);
}

.page-about .stage--4 {
  background: linear-gradient(112deg, #FF6B35 0%, #FFC9A8 78%);
  color: var(--ink);
}

.page-about .stage__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 16px;
  cursor: pointer;
  list-style: none;
  padding-inline: clamp(18px, 3.4vw, 32px);
}

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

.page-about .stage--1 .stage__head { padding-block: clamp(22px, 4vw, 36px); }
.page-about .stage--2 .stage__head { padding-block: clamp(18px, 3.2vw, 28px); }
.page-about .stage--3 .stage__head { padding-block: clamp(15px, 2.6vw, 22px); }
.page-about .stage--4 .stage__head { padding-block: clamp(13px, 2.1vw, 17px); }

.page-about .stage__head::after {
  content: "";
  flex: 0 0 auto;
  width: 8px;
  height: 8px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg) translate(-2px, -2px);
  transition: transform 0.26s var(--ease);
}

.page-about .stage[open] .stage__head::after {
  transform: rotate(-135deg) translate(-2px, -2px);
}

.page-about .stage__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  opacity: 0.68;
}

.page-about .stage__name {
  font-size: clamp(24px, 5vw, 42px);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.15;
}

.page-about .stage__tip {
  flex: 1 1 auto;
  text-align: right;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  opacity: 0.72;
}

.page-about .stage__body {
  padding: 0 clamp(18px, 3.4vw, 32px) clamp(22px, 3.8vw, 34px);
  max-width: 44em;
}

.page-about .stage__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(244, 241, 234, 0.86);
}

.page-about .stage--4 .stage__body p {
  color: rgba(11, 18, 32, 0.78);
}

/* ---------- 谁在提供服务 ---------- */

.page-about .people-grid {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
  align-items: start;
}

.page-about .about-people__body .h-section {
  margin-top: 12px;
}

.page-about .about-people__body .prose {
  max-width: var(--about-measure);
}

.page-about .grade-list {
  list-style: none;
  margin: clamp(24px, 4.4vw, 38px) 0 0;
  padding: 0;
  border-top: 1px solid var(--hair-light);
}

.page-about .grade {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  column-gap: 12px;
  padding: 15px 0;
  border-bottom: 1px solid var(--hair-light);
}

.page-about .grade__num {
  grid-column: 1;
  grid-row: 1 / span 3;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--warm-gray);
  padding-top: 4px;
}

.page-about .grade__name {
  grid-column: 2;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.page-about .grade__track {
  grid-column: 2;
  display: block;
  height: 3px;
  margin: 9px 0 8px;
  border-radius: 2px;
  background: var(--hair-light);
  overflow: hidden;
}

.page-about .grade__bar {
  display: block;
  height: 100%;
  border-radius: 2px;
  background: var(--cyan-ink);
}

.page-about .grade--1 .grade__bar { width: 24%; }
.page-about .grade--2 .grade__bar { width: 50%; }
.page-about .grade--3 .grade__bar { width: 76%; }
.page-about .grade--4 .grade__bar { width: 100%; }

.page-about .grade__note {
  grid-column: 2;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--warm-gray);
}

.page-about .about-people__body .caption {
  margin-top: 16px;
}

/* ---------- 标准从哪来 ---------- */

.page-about .standard-grid {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
  align-items: start;
}

.page-about .about-standard__body .h-section {
  margin-top: 12px;
}

.page-about .about-standard__body .prose {
  max-width: var(--about-measure);
}

.page-about .cal-list {
  list-style: none;
  margin: clamp(24px, 4.4vw, 38px) 0 0;
  padding: 0;
}

.page-about .cal {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  column-gap: 14px;
  padding: 18px 0;
  border-top: 1px solid var(--hair-light);
}

.page-about .cal:last-child {
  border-bottom: 1px solid var(--hair-light);
}

.page-about .cal__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-ink);
  padding-top: 5px;
}

.page-about .cal .h-sub {
  grid-column: 2;
  margin: 0;
}

.page-about .cal p {
  grid-column: 2;
  margin: 7px 0 0;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(11, 18, 32, 0.72);
}

.page-about .cal-foot {
  margin: clamp(20px, 3.6vw, 30px) 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--warm-gray);
}

.page-about .cal-foot a {
  color: var(--cyan-ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 区域运营中心 ---------- */

.page-about .about-zones__fig {
  margin-top: clamp(26px, 5vw, 46px);
}

.page-about .zone-board {
  display: grid;
  gap: clamp(24px, 4.4vw, 42px);
  margin-top: clamp(26px, 5vw, 48px);
  align-items: start;
}

.page-about .zmap {
  border-radius: var(--radius);
  background: linear-gradient(148deg, #0C1730 0%, #1B2A4A 62%, #253A63 100%);
  padding: clamp(14px, 3vw, 26px);
}

.page-about .zmap svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .zmap__grid line {
  stroke: rgba(244, 241, 234, 0.1);
  stroke-width: 1;
  stroke-dasharray: 3 7;
}

.page-about .zmap__dot {
  fill: rgba(0, 229, 199, 0.6);
}

.page-about .zmap__dot--lead {
  fill: var(--orange);
}

.page-about .zmap__label {
  fill: rgba(244, 241, 234, 0.72);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
}

.page-about .zone-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .zone-item {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr);
  column-gap: 14px;
  padding: 17px 0;
  border-top: 1px solid var(--hair-light);
  transition: transform 0.32s var(--ease), border-color 0.32s var(--ease);
}

.page-about .zone-item:last-child {
  border-bottom: 1px solid var(--hair-light);
}

.page-about .zone__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--warm-gray);
  padding-top: 5px;
}

.page-about .zone__name {
  grid-column: 2;
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.page-about .zone__desc {
  grid-column: 2;
  margin: 7px 0 0;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(11, 18, 32, 0.72);
}

.page-about .zone-foot {
  max-width: var(--about-measure);
  margin: clamp(24px, 4.4vw, 40px) 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(11, 18, 32, 0.72);
  border-left: 3px solid var(--cyan-ink);
  padding-left: 16px;
}

/* ---------- 我们不接的活 ---------- */

.page-about .bound-list {
  list-style: none;
  display: grid;
  gap: clamp(12px, 2.2vw, 18px);
  margin: clamp(26px, 4.8vw, 44px) 0 0;
  padding: 0;
}

.page-about .bound {
  background: var(--about-tint);
  border: 1px solid var(--hair-light);
  border-left: 3px solid var(--orange);
  border-radius: var(--radius-s);
  padding: clamp(16px, 3vw, 24px);
}

.page-about .bound__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .bound__text {
  margin: 9px 0 0;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(11, 18, 32, 0.78);
}

/* ---------- 收尾 ---------- */

.page-about .about-close {
  padding-bottom: clamp(56px, 10vw, 128px);
}

.page-about .about-close__inner {
  max-width: var(--about-measure);
  border-top: 1px solid var(--hair-light);
  padding-top: clamp(28px, 5vw, 48px);
}

.page-about .about-close__inner .h-section {
  margin-top: 12px;
}

.page-about .about-close__inner .prose {
  margin-top: 14px;
}

.page-about .close-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  margin: clamp(22px, 4vw, 34px) 0 0;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-stamp {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .bound-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .people-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }
}

@media (min-width: 940px) {
  .page-about .standard-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .zone-board {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(28px, 4vw, 52px);
  }

  .page-about .zone-item:hover {
    transform: translateX(7px);
    border-top-color: rgba(255, 107, 53, 0.5);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .zone-item,
  .page-about .stage__head::after {
    transition: none;
  }

  .page-about .zone-item:hover {
    transform: none;
  }
}