.page-about {
  --about-measure: 720px;
  --about-rail-w: 236px;
  --about-ink-soft: #3B444D;
  padding-bottom: clamp(40px, 7vw, 88px);
  overflow-x: clip;
}

.page-about .about-top {
  padding-top: clamp(14px, 3vw, 24px);
}

/* ---------- 首屏声明区 ---------- */

.page-about .about-lede {
  position: relative;
  margin-top: 14px;
  background:
    radial-gradient(120% 92% at 86% 2%, rgba(47, 158, 94, .22), transparent 58%),
    linear-gradient(158deg, var(--deep) 0%, var(--night) 72%);
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 44px), 0 100%);
  padding: clamp(32px, 5.6vw, 68px) 0 clamp(66px, 8vw, 104px);
  overflow: hidden;
}

.page-about .about-lede::after {
  content: "";
  position: absolute;
  right: -10%;
  top: -34%;
  width: 48%;
  height: 168%;
  background: repeating-linear-gradient(115deg, rgba(47, 158, 94, .11) 0 2px, transparent 2px 15px);
  transform: rotate(4deg);
  pointer-events: none;
}

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

.page-about .about-lede__tag {
  margin: 0;
  color: var(--cyan);
  letter-spacing: .2em;
  font-size: 12.5px;
}

.page-about .about-lede__title {
  margin: 18px 0 0;
  max-width: 21ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.08;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-lede__lead {
  max-width: 62ch;
  margin: 20px 0 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-lede__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 20px;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-lede__facts li {
  border-left: 2px solid var(--turf-deep);
  padding-left: 12px;
}

.page-about .about-fact__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 2.6vw, 27px);
  line-height: 1.2;
  color: var(--cyan);
}

.page-about .about-fact__label {
  display: block;
  margin-top: 5px;
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--mist);
}

/* ---------- 折页式排版骨架 ---------- */

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 40px);
  margin-top: clamp(26px, 4.6vw, 54px);
}

.page-about .about-rail__kicker {
  margin: 0;
  color: var(--mist);
  letter-spacing: .22em;
  font-size: 12px;
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__list a {
  display: block;
  padding: 8px 12px;
  border-bottom: 2px solid transparent;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.4;
  white-space: nowrap;
  color: var(--mist);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out),
              background-color var(--dur-fast) var(--ease-out);
}

.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--paper);
  border-color: var(--turf);
  background: var(--turf-glow);
}

/* ---------- 章节面板 ---------- */

.page-about .about-section {
  position: relative;
  padding: clamp(26px, 3.6vw, 44px) clamp(20px, 3.2vw, 40px) clamp(30px, 4vw, 48px);
  margin-bottom: clamp(18px, 2.6vw, 28px);
  border: 1px solid var(--hairline);
  background: var(--deep);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), 0 100%);
  scroll-margin-top: 132px;
}

.page-about .about-section::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 96px;
  height: 3px;
  background: var(--turf);
}

.page-about .about-section--light {
  background: var(--paper);
  border-color: var(--paper-line);
  color: var(--ink-text);
}

.page-about .about-section__no {
  margin: 0 0 12px;
  color: var(--cyan);
  letter-spacing: .24em;
  font-size: 12px;
}

.page-about .about-section--light .about-section__no {
  color: var(--turf-deep);
}

.page-about .about-section h2 {
  margin: 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1.14;
  letter-spacing: -.005em;
  color: var(--paper);
}

.page-about .about-section--light h2 {
  color: var(--ink-text);
}

.page-about .about-text {
  max-width: var(--about-measure);
  margin: 16px 0 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-section--light .about-text {
  color: var(--about-ink-soft);
}

.page-about .about-text--tight {
  margin-top: clamp(20px, 3vw, 28px);
  padding-top: clamp(16px, 2.4vw, 22px);
  border-top: 1px solid var(--hairline);
}

.page-about .about-section--light .about-text--tight {
  border-top-color: var(--paper-line);
}

/* ---------- 通用配图 ---------- */

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--night);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), 0 100%);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .about-section--light .about-figure figcaption {
  color: #6A7480;
}

/* ---------- 01 读者画像 ---------- */

.page-about .reader-grid {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .reader-item {
  padding: 14px 0 14px 18px;
  border-left: 2px solid var(--paper-line);
}

.page-about .reader-item + .reader-item {
  margin-top: 6px;
}

.page-about .reader-item__no {
  color: var(--turf-deep);
  letter-spacing: .18em;
  font-size: 12px;
}

.page-about .reader-item h3 {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  line-height: 1.25;
  color: var(--ink-text);
}

.page-about .reader-item p {
  margin: 8px 0 0;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--about-ink-soft);
}

/* ---------- 02 生产流程 ---------- */

.page-about .workflow-banner {
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .flow {
  margin: clamp(24px, 3.4vw, 34px) 0 0;
}

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

.page-about .flow-node__box {
  fill: rgba(11, 27, 43, .78);
  stroke: var(--turf-deep);
  stroke-width: 2;
}

.page-about .flow-node__label {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 700;
  fill: var(--paper);
}

.page-about .flow-link {
  stroke: var(--turf);
  stroke-width: 2;
  stroke-dasharray: 7 6;
}

.page-about .flow__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .flow-grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .flow-card {
  padding: 16px 16px 18px;
  border: 1px solid var(--hairline);
  border-top: 2px solid var(--turf);
  background: rgba(11, 27, 43, .62);
}

.page-about .flow-card h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .flow-card p {
  margin: 9px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .flow-card__out {
  display: block;
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--cyan);
}

/* ---------- 03 发展阶段 ---------- */

.page-about .phases {
  display: grid;
  gap: 24px;
  margin-top: clamp(24px, 3.4vw, 36px);
}

.page-about .phase {
  position: relative;
  padding-top: 32px;
}

.page-about .phase::before {
  content: "";
  position: absolute;
  top: 9px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--turf-deep) 0%, rgba(47, 158, 94, .14) 100%);
}

.page-about .phase::after {
  content: "";
  position: absolute;
  top: 4px;
  left: 0;
  width: 12px;
  height: 12px;
  background: var(--turf);
  transform: rotate(45deg);
}

.page-about .phase__tag {
  color: var(--cyan);
  letter-spacing: .18em;
  font-size: 11.5px;
}

.page-about .phase__name {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .phase__desc {
  margin: 9px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 04 指标取舍 ---------- */

.page-about .metric-layout {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .metric {
  border: 1px solid var(--paper-line);
  border-left: 3px solid var(--turf);
  background: rgba(255, 255, 255, .58);
  padding: 14px 16px;
}

.page-about .metric + .metric {
  margin-top: 12px;
}

.page-about .metric summary {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--ink-text);
}

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

.page-about .metric summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--turf-deep);
}

.page-about .metric[open] summary::after {
  content: "–";
}

.page-about .metric__bar {
  width: 10px;
  height: 10px;
  flex: none;
  background: var(--turf);
  transform: rotate(45deg);
}

.page-about .metric p {
  margin: 11px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-ink-soft);
}

/* ---------- 05 协作生态 ---------- */

.page-about .partner-list {
  display: grid;
  gap: 14px;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .partner-list li {
  padding: 18px 18px 20px;
  border: 1px solid var(--hairline);
  background: rgba(11, 27, 43, .58);
}

.page-about .partner-list h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .partner-list p {
  margin: 9px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 06 更新节奏 ---------- */

.page-about .cadence-grid {
  display: grid;
  gap: 18px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .cadence-card {
  padding: 18px 18px 20px;
  border: 1px solid var(--paper-line);
  background: rgba(255, 255, 255, .58);
}

.page-about .cadence-card h3 {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  color: var(--ink-text);
}

.page-about .cadence-dot {
  width: 10px;
  height: 10px;
  flex: none;
  background: var(--turf);
  transform: rotate(45deg);
}

.page-about .cadence-dot--alt {
  background: var(--card-yellow);
}

.page-about .cadence-rows {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .cadence-rows li {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 10px;
  padding: 10px 8px;
  border-top: 1px solid var(--paper-line);
  font-size: 14.5px;
  line-height: 1.68;
  color: var(--about-ink-soft);
}

.page-about .cadence-rows li:nth-child(odd) {
  background: rgba(226, 220, 204, .38);
}

.page-about .cadence-rows__k {
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--turf-deep);
}

/* ---------- 收尾入口 ---------- */

.page-about .about-next {
  margin-top: clamp(30px, 4.6vw, 56px);
  padding-top: clamp(24px, 3.4vw, 36px);
  border-top: 1px solid var(--hairline);
}

.page-about .about-next__kicker {
  margin: 0;
  color: var(--cyan);
  letter-spacing: .22em;
  font-size: 12px;
}

.page-about .about-next h2 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.2vw, 34px);
  line-height: 1.16;
  color: var(--paper);
}

.page-about .next-grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(18px, 2.6vw, 26px);
}

.page-about .next-card {
  display: block;
  padding: 18px 18px 20px;
  border: 1px solid var(--hairline);
  border-left: 3px solid var(--turf);
  background: rgba(11, 27, 43, .7);
  text-decoration: none;
  transition: transform var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out),
              background-color var(--dur-fast) var(--ease-out);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  transform: translateY(-2px);
  border-color: var(--turf);
  background: rgba(18, 41, 58, .92);
}

.page-about .next-card h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .next-card p {
  margin: 9px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 断点 ---------- */

@media (min-width: 700px) {
  .page-about .about-lede__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 820px) {
  .page-about .phases {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .partner-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .reader-grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    align-items: start;
  }

  .page-about .metric-layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: start;
  }
}

@media (min-width: 1020px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(36px, 4vw, 64px);
    align-items: start;
  }

  .page-about .about-rail__inner {
    position: sticky;
    top: 118px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__list a {
    border-bottom: 0;
    border-left: 2px solid transparent;
    white-space: normal;
  }

  .page-about .about-rail__list a:hover,
  .page-about .about-rail__list a:focus-visible {
    border-color: var(--turf);
  }

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

  .page-about .next-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-lede__title {
    max-width: 18ch;
  }
}

@media (min-width: 1160px) {
  .page-about .about-lede {
    clip-path: polygon(0 0, 100% 0, 100% calc(100% - 60px), 0 100%);
  }

  .page-about .about-section {
    clip-path: polygon(0 0, 100% 0, 100% calc(100% - 34px), 0 100%);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
  }
}