.page-about {
  --about-rail: 200px;
  --about-text: rgba(232, 241, 236, 0.78);
  --about-soft: rgba(232, 241, 236, 0.5);
  --about-panel: rgba(244, 239, 227, 0.08);
}

.page-about .about-crumb {
  padding-top: 28px;
}

/* ---------- 编辑部分栏 ---------- */
.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--grid-gap);
}

.page-about .about-rail {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-rail__note {
  margin: 0;
  font-family: var(--font-index);
  font-size: 12px;
  letter-spacing: 0.06em;
  line-height: 1.6;
  color: var(--about-soft);
}

.page-about .about-body > p {
  max-width: 62ch;
  margin: 0 0 20px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--about-text);
}

.page-about .about-body a {
  color: var(--cream);
  text-decoration: none;
  border-bottom: 1px solid rgba(244, 239, 227, 0.35);
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .about-body a:hover,
.page-about .about-body a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 卷首 ---------- */
.page-about .about-title {
  margin: 0 0 22px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(38px, 8.4vw, 84px);
  line-height: 0.98;
  letter-spacing: -0.012em;
  text-transform: uppercase;
  color: var(--cream);
}

.page-about .about-title::after {
  content: "";
  display: block;
  width: clamp(64px, 18vw, 160px);
  height: 3px;
  margin-top: 22px;
  background: var(--accent-2);
}

.page-about .about-standfirst {
  max-width: 40ch;
  margin: 0 0 26px;
  font-size: clamp(18px, 2.4vw, 21px);
  line-height: 1.62;
  font-weight: 500;
  color: var(--data-white);
}

.page-about .about-cols {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

.page-about .about-cols p {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .about-figure {
  margin: 36px 0 0;
}

.page-about .about-figure .media {
  border: 1px solid var(--rule);
}

/* ---------- 编辑部 ---------- */
.page-about .about-h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(26px, 4.4vw, 40px);
  line-height: 1.06;
  letter-spacing: -0.006em;
  text-transform: uppercase;
  color: var(--cream);
}

.page-about .desk-list {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
}

.page-about .desk-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 22px 0;
  border-top: 1px solid var(--rule);
}

.page-about .desk-row:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .desk-num {
  font-family: var(--font-data);
  font-size: 40px;
  line-height: 1;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--accent-2);
}

.page-about .desk-name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--data-white);
}

.page-about .desk-text p {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-text);
}

.page-about .desk-path {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
}

.page-about .desk-step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  grid-template-areas:
    "idx name"
    "idx desc";
  gap: 2px 14px;
  padding: 14px 16px;
  background: var(--about-panel);
  border-left: 2px solid var(--rule);
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .desk-step:hover {
  border-left-color: var(--accent-2);
  background: rgba(244, 239, 227, 0.12);
}

.page-about .desk-step__idx {
  grid-area: idx;
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--accent-2);
}

.page-about .desk-step__name {
  grid-area: name;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--data-white);
}

.page-about .desk-step__desc {
  grid-area: desc;
  font-size: 14px;
  line-height: 1.7;
  color: var(--about-soft);
}

/* ---------- 五条主线 ---------- */
.page-about .about-threads .filter-bar {
  margin: 26px 0 4px;
  flex-wrap: wrap;
}

.page-about .about-threads .filter-chip[aria-pressed="true"] {
  border-color: var(--cream);
  color: var(--cream);
}

.page-about .thread-list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .thread {
  position: relative;
  padding: 20px 20px 62px;
  background: var(--about-panel);
  border: 1px solid var(--rule-soft);
  border-left: 3px solid var(--cyan);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), 0 100%);
  transition: background 0.26s var(--ease), border-left-color 0.26s var(--ease);
}

.page-about .thread:hover {
  background: rgba(244, 239, 227, 0.13);
  border-left-color: var(--accent-2);
}

.page-about .thread__idx {
  display: block;
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--accent-2);
  margin-bottom: 10px;
}

.page-about .thread__name {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  line-height: 1.14;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--cream);
}

.page-about .thread__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: var(--about-text);
}

.page-about .thread__sample {
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: 18px;
  display: block;
  font-family: var(--font-index);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--cyan);
  opacity: 1;
  transform: none;
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease);
}

/* ---------- 口径与节奏 ---------- */
.page-about .about-code {
  position: relative;
  isolation: isolate;
}

.page-about .about-code::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(158deg, rgba(7, 19, 16, 0.96) 0%, rgba(12, 31, 26, 0.42) 72%);
  clip-path: polygon(0 4%, 100% 0, 100% 96%, 0 100%);
}

.page-about .code-panel {
  margin-top: 26px;
  padding: 8px 20px;
  border-radius: var(--radius);
}

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

.page-about .cadence__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 15px 0;
  border-bottom: 1px solid var(--rule-soft);
}

.page-about .cadence__row:last-child {
  border-bottom: 0;
}

.page-about .cadence__row dt {
  font-family: var(--font-index);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--about-soft);
}

.page-about .cadence__row dd {
  margin: 0;
  font-family: var(--font-data);
  font-size: 16px;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  color: var(--data-white);
}

.page-about .quote-block {
  margin: 40px 0 0;
  padding: 30px 26px 34px;
  background: var(--cream);
  color: var(--ink);
  border-radius: var(--radius);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), 0 100%);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(19px, 3.1vw, 26px);
  line-height: 1.5;
  letter-spacing: 0.004em;
}

/* ---------- 阶段时间线 ---------- */
.page-about .about-grid--timeline {
  gap: calc(var(--grid-gap) + 8px);
}

.page-about .about-stage-figure {
  margin: 6px 0 0;
  border: 1px solid var(--rule);
}

.page-about .stage-list {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  position: relative;
}

.page-about .stage {
  position: relative;
  padding-left: 20px;
  border-left: 1px solid var(--rule);
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 26px;
  width: 7px;
  height: 7px;
  background: var(--pitch);
  border: 2px solid var(--mist);
  border-radius: 50%;
}

.page-about .stage:has(.stage__item[open])::before {
  border-color: var(--cream);
  background: var(--cream);
}

.page-about .stage__item {
  border-bottom: 1px solid var(--rule-soft);
}

.page-about .stage__head {
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr) 24px;
  align-items: baseline;
  gap: 12px;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .stage__year {
  font-family: var(--font-data);
  font-size: 20px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--accent-2);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.page-about .stage__name {
  font-family: var(--font-display);
  font-size: clamp(19px, 3vw, 24px);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--data-white);
  transition: color 0.2s var(--ease);
}

.page-about .stage__head:hover .stage__name {
  color: var(--cream);
}

.page-about .stage__hint {
  position: relative;
  align-self: center;
  width: 16px;
  height: 16px;
}

.page-about .stage__hint::before,
.page-about .stage__hint::after {
  content: "";
  position: absolute;
  background: var(--mist);
  transition: transform 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .stage__hint::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 1px;
}

.page-about .stage__hint::after {
  left: 7px;
  top: 0;
  width: 1px;
  height: 16px;
}

.page-about .stage__item[open] .stage__hint::after {
  transform: scaleY(0);
  background: var(--cream);
}

.page-about .stage__item[open] .stage__hint::before {
  background: var(--cream);
}

.page-about .stage__body {
  padding: 0 24px 22px 0;
}

.page-about .stage__body p {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-text);
}

/* ---------- 协作生态 ---------- */
.page-about .crowd-panels {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 28px;
}

.page-about .crowd-card {
  padding: 22px 20px;
  border-radius: var(--radius);
  border-top: 2px solid var(--cyan);
}

.page-about .crowd-card__key {
  display: block;
  font-family: var(--font-data);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--cyan);
  margin-bottom: 12px;
}

.page-about .crowd-card__name {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--cream);
}

.page-about .crowd-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: var(--about-text);
}

.page-about .crowd-note {
  margin: 26px 0 0;
  padding: 16px 18px;
  border-left: 2px solid var(--accent-2);
  background: rgba(255, 106, 43, 0.07);
  font-size: 14px;
  line-height: 1.74;
  color: var(--data-white);
}

.page-about .about-figure--crowd {
  margin-top: 34px;
}

/* ---------- 继续 ---------- */
.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-links .btn {
  white-space: nowrap;
}

/* ---------- 桌面栅格 ---------- */
@media (min-width: 768px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 44px;
  }

  .page-about .about-grid--timeline {
    grid-template-columns: 240px minmax(0, 1fr);
  }

  .page-about .about-rail {
    border-right: 1px solid var(--rule-soft);
    padding-right: 20px;
  }

  .page-about .about-cols {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }

  .page-about .desk-row {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }

  .page-about .desk-num {
    font-size: 52px;
    text-align: right;
  }

  .page-about .desk-path {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 2px;
  }

  .page-about .desk-step {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas:
      "idx"
      "name"
      "desc";
    padding: 18px 16px 20px;
  }

  .page-about .cadence__row {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: baseline;
    gap: 24px;
  }

  .page-about .cadence__row dd {
    text-align: right;
  }

  .page-about .thread-list {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .page-about .thread {
    grid-column: span 2;
  }

  .page-about .thread:nth-child(1),
  .page-about .thread:nth-child(2) {
    grid-column: span 3;
  }

  .page-about .thread__sample {
    opacity: 0;
    transform: translateY(6px);
  }

  .page-about .thread:hover .thread__sample,
  .page-about .thread:focus-within .thread__sample {
    opacity: 1;
    transform: none;
  }

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

  .page-about .stage__head {
    grid-template-columns: 96px minmax(0, 1fr) 24px;
    gap: 22px;
  }

  .page-about .stage__year {
    font-size: 30px;
  }

  .page-about .stage {
    padding-left: 28px;
  }

  .page-about .stage__body {
    padding-right: 60px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-grid {
    grid-template-columns: 232px minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-grid--timeline {
    grid-template-columns: 300px minmax(0, 1fr);
  }

  .page-about .about-standfirst {
    max-width: 34ch;
  }
}

/* 窄屏：斜切降级为水平色带 */
@media (max-width: 767px) {
  .page-about .about-code::before {
    clip-path: none;
    background: linear-gradient(180deg, rgba(7, 19, 16, 0.92) 0%, rgba(12, 31, 26, 0.35) 100%);
  }

  .page-about .quote-block {
    clip-path: none;
    padding: 24px 20px 26px;
  }

  .page-about .thread {
    clip-path: none;
  }

  .page-about .about-rail {
    flex-direction: row;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 4px 14px;
    border-bottom: 1px solid var(--rule-soft);
    padding-bottom: 12px;
  }

  .page-about .about-rail__note {
    margin-left: auto;
  }

  .page-about .about-stage-figure {
    max-width: 220px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .thread__sample,
  .page-about .desk-step,
  .page-about .stage__hint::before,
  .page-about .stage__hint::after {
    transition: none;
  }

  .page-about .thread__sample {
    transform: none;
  }
}