.page-about {
  --about-gap: 24px;
  --about-text-soft: rgba(244, 248, 252, .76);
  --about-text-dim: rgba(244, 248, 252, .56);
  background: var(--ki-ink);
  color: var(--ki-paper);
  overflow-x: hidden;
}

/* 面包屑 */
.page-about .about-crumb {
  padding-top: 22px;
}

/* 首屏 */
.page-about .about-hero {
  padding: 34px 0 10px;
}

.page-about .about-hero__inner {
  display: grid;
  gap: 20px;
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--ki-sans);
  font-weight: 900;
  font-size: clamp(2rem, 8.4vw, 4.4rem);
  line-height: 1.06;
  letter-spacing: -.03em;
  max-width: 17ch;
  background: linear-gradient(100deg, var(--ki-paper) 42%, var(--ki-amber) 78%, var(--ki-orange));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(1rem, 2.5vw, 1.125rem);
  line-height: 1.85;
  color: var(--about-text-soft);
}

.page-about .about-facts {
  list-style: none;
  margin: 6px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--ki-line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
}

.page-about .about-facts li {
  display: grid;
  gap: 4px;
}

.page-about .about-facts__num {
  font-family: var(--ki-mono);
  font-size: clamp(1.75rem, 7vw, 2.5rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--ki-lime);
}

.page-about .about-facts__unit {
  font-size: .5em;
  margin-left: 2px;
  color: var(--ki-amber);
}

.page-about .about-facts__label {
  font-family: var(--ki-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--ki-steel);
}

/* 跨栏大图 */
.page-about .about-banner {
  margin-top: 30px;
}

.page-about .media-frame img,
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--ki-radius-lg);
}

/* 章节骨架 */
.page-about .about-chapter {
  padding: 52px 0;
}

.page-about .about-chapter__grid {
  display: grid;
  gap: 20px;
}

.page-about .about-chapter__index {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--ki-line);
}

.page-about .about-num {
  font-family: var(--ki-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ki-cyan);
}

.page-about .about-kicker {
  font-family: var(--ki-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ki-steel);
}

.page-about .about-chapter__body {
  display: grid;
  gap: 22px;
  min-width: 0;
}

.page-about .about-chapter__body h2 {
  margin: 0;
  font-family: var(--ki-sans);
  font-weight: 900;
  font-size: clamp(1.55rem, 5.6vw, 2.6rem);
  line-height: 1.2;
  letter-spacing: -.03em;
  max-width: 22ch;
}

.page-about .about-chapter__body .prose p {
  margin: 0;
  color: var(--about-text-soft);
  font-size: 1rem;
  line-height: 1.85;
  max-width: 66ch;
}

.page-about .about-aside {
  margin: 0;
  padding-left: 16px;
  border-left: 2px solid var(--ki-lime);
  font-size: .95rem;
  line-height: 1.8;
  color: var(--about-text-dim);
  max-width: 60ch;
}

/* 场景卡 */
.page-about .about-scenes {
  display: grid;
  gap: 14px;
}

.page-about .about-scene {
  padding: 18px 18px 20px;
  border: 1px solid var(--ki-line);
  border-left: 3px solid var(--ki-orange);
  border-radius: var(--ki-radius);
  background: var(--ki-glass);
}

.page-about .about-scene h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .about-scene p {
  margin: 0;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--about-text-soft);
}

/* 时间轴 */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  display: grid;
  gap: 14px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--ki-orange), var(--ki-violet) 55%, var(--ki-cyan));
}

.page-about .about-timeline__item {
  position: relative;
  padding: 15px 16px 17px;
  border: 1px solid var(--ki-line);
  border-radius: var(--ki-radius);
  background: rgba(16, 36, 61, .62);
  transition: transform .25s ease, border-color .25s ease;
}

.page-about .about-timeline__dot {
  position: absolute;
  left: -26px;
  top: 20px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--ki-ink);
  border: 2px solid var(--ki-orange);
  transition: background .25s ease, border-color .25s ease, box-shadow .25s ease;
}

.page-about .about-timeline__item:hover,
.page-about .about-timeline__item:focus-within {
  transform: translateY(-2px);
  border-color: var(--ki-lime);
}

.page-about .about-timeline__item:hover .about-timeline__dot,
.page-about .about-timeline__item:focus-within .about-timeline__dot {
  background: var(--ki-lime);
  border-color: var(--ki-lime);
  box-shadow: 0 0 0 6px rgba(184, 255, 61, .18);
}

.page-about .about-timeline__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 14px;
  margin-bottom: 6px;
}

.page-about .about-timeline__title {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .about-timeline__meta {
  font-family: var(--ki-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--ki-amber);
}

.page-about .about-timeline__desc {
  margin: 0;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--about-text-soft);
}

/* 方法清单 */
.page-about .about-method {
  padding: 20px 18px 8px;
  border: 1px solid var(--ki-line);
  border-radius: var(--ki-radius-lg);
  background: var(--ki-glass);
}

.page-about .about-method__title {
  margin: 0 0 16px;
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .about-method__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-method__list li {
  display: grid;
  gap: 6px;
  padding-bottom: 16px;
  border-bottom: 1px dashed var(--ki-line);
}

.page-about .about-method__list li:last-child {
  border-bottom: 0;
  padding-bottom: 8px;
}

.page-about .about-method__key {
  font-family: var(--ki-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--ki-cyan);
}

.page-about .about-method__list p {
  margin: 0;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--about-text-soft);
}

/* 图注 */
.page-about .about-figure {
  margin: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-figure figcaption {
  font-family: var(--ki-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .04em;
  color: var(--ki-steel);
}

/* 大字宣言 */
.page-about .about-quote-wrap {
  padding: 12px 0 8px;
}

.page-about .about-quote {
  margin: 0;
  padding: 26px 0 26px 20px;
  border-left: 4px solid var(--ki-orange);
  background: linear-gradient(90deg, rgba(240, 107, 43, .12), transparent 72%);
}

.page-about .about-quote p {
  margin: 0;
  font-family: var(--ki-sans);
  font-weight: 900;
  font-size: clamp(1.25rem, 5.2vw, 2.1rem);
  line-height: 1.38;
  letter-spacing: -.025em;
  max-width: 26ch;
  color: var(--ki-paper);
}

/* 社区四块 */
.page-about .about-community {
  display: grid;
  gap: 14px;
}

.page-about .about-community__item {
  padding: 16px 18px 18px;
  border: 1px solid var(--ki-line);
  border-radius: var(--ki-radius);
  background: rgba(16, 36, 61, .5);
}

.page-about .about-community__item h3 {
  margin: 0 0 8px;
  font-size: 1.02rem;
  font-weight: 800;
  color: var(--ki-amber);
}

.page-about .about-community__item p {
  margin: 0;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--about-text-soft);
}

/* 协作玻璃卡 */
.page-about .about-partners {
  display: grid;
  gap: 14px;
}

.page-about .about-partner {
  padding: 20px 18px 22px;
  border: 1px solid var(--ki-line);
  border-radius: var(--ki-radius-lg);
  background: var(--ki-glass-strong);
  backdrop-filter: blur(8px);
  transition: transform .25s ease, border-color .25s ease;
}

.page-about .about-partner:hover,
.page-about .about-partner:focus-visible,
.page-about .about-partner:focus-within {
  transform: translateY(-2px);
  border-color: var(--ki-violet);
}

.page-about .about-partner:focus-visible {
  outline: 2px solid var(--ki-cyan);
  outline-offset: 3px;
}

.page-about .about-partner__badge {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 9px;
  border-radius: 999px;
  border: 1px solid rgba(123, 97, 255, .6);
  font-family: var(--ki-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--ki-paper);
  background: rgba(123, 97, 255, .18);
}

.page-about .about-partner__name {
  margin: 0 0 8px;
  font-size: 1.08rem;
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .about-partner__desc {
  margin: 0;
  font-size: .93rem;
  line-height: 1.8;
  color: var(--about-text-soft);
}

/* 加入步骤 */
.page-about .about-steps {
  display: grid;
  gap: 10px;
}

.page-about .about-step {
  border: 1px solid var(--ki-line);
  border-radius: var(--ki-radius);
  background: rgba(16, 36, 61, .55);
  overflow: hidden;
}

.page-about .about-step summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: -.01em;
  color: var(--ki-paper);
  transition: background .2s ease;
}

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

.page-about .about-step summary::after {
  content: "";
  margin-left: auto;
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--ki-steel);
  border-bottom: 2px solid var(--ki-steel);
  transform: rotate(45deg);
  transition: transform .25s ease, border-color .25s ease;
}

.page-about .about-step[open] summary::after {
  transform: rotate(-135deg);
  border-color: var(--ki-lime);
}

.page-about .about-step summary:hover {
  background: rgba(255, 255, 255, .05);
}

.page-about .about-step[open] summary {
  border-bottom: 1px solid var(--ki-line);
}

.page-about .about-step__no {
  font-family: var(--ki-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--ki-lime);
}

.page-about .about-step__body {
  padding: 14px 16px 18px;
}

.page-about .about-step__body p {
  margin: 0;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--about-text-soft);
}

/* CTA */
.page-about .about-cta {
  padding: 22px 18px;
  border-radius: var(--ki-radius-lg);
  border: 1px solid rgba(240, 107, 43, .45);
  background: linear-gradient(135deg, rgba(240, 107, 43, .18), rgba(16, 36, 61, .7) 68%);
  display: grid;
  gap: 16px;
}

.page-about .about-cta__text {
  margin: 0;
  font-size: .98rem;
  line-height: 1.8;
  color: var(--ki-paper);
  max-width: 52ch;
}

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

/* 继续了解 */
.page-about .about-more {
  display: grid;
  gap: 10px;
  padding-top: 6px;
}

.page-about .about-more a {
  display: block;
  padding: 12px 14px;
  border: 1px dashed var(--ki-line);
  border-radius: var(--ki-radius-sm);
  font-family: var(--ki-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--ki-cyan);
  text-decoration: none;
  transition: border-color .2s ease, color .2s ease, background .2s ease;
}

.page-about .about-more a:hover,
.page-about .about-more a:focus-visible {
  border-color: var(--ki-cyan);
  background: rgba(22, 224, 208, .08);
  color: var(--ki-paper);
}

.page-about a:focus-visible {
  outline: 2px solid var(--ki-cyan);
  outline-offset: 3px;
}

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

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

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

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

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

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

/* 桌面：左侧索引，右侧宽幅叙事 */
@media (min-width: 900px) {
  .page-about .about-banner {
    margin-top: 40px;
  }

  .page-about .about-chapter {
    padding: 72px 0;
  }

  .page-about .about-chapter__grid {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-chapter__index {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: calc(var(--ki-header-h) + 24px);
    padding-bottom: 0;
    border-bottom: 0;
    border-left: 1px solid var(--ki-line);
    padding-left: 14px;
  }

  .page-about .about-chapter__body {
    gap: 28px;
  }

  .page-about .about-chapter__body .prose p {
    font-size: 1.05rem;
  }

  .page-about .about-scenes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

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

  .page-about .about-figure--narrow {
    max-width: 78%;
  }

  .page-about .about-cta {
    padding: 30px 30px;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 24px;
  }

  .page-about .about-quote-wrap {
    padding: 20px 0 12px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero {
    padding-top: 52px;
  }

  .page-about .about-chapter__grid {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 72px;
  }
}