.page-about {
  --about-rail: 96px;
  --about-hair: rgba(31, 107, 79, 0.4);
  --about-hair-strong: rgba(31, 107, 79, 0.75);
  background: var(--c-night);
  color: var(--c-text);
  font-family: var(--f-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(3rem, 9vw, 6rem) 0 clamp(2.6rem, 7vw, 5rem);
  background: linear-gradient(163deg, var(--c-night-2) 0%, var(--c-night) 48%, var(--c-ink) 100%);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -12% -6%;
  background-image:
    linear-gradient(to right, var(--about-hair) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-hair) 1px, transparent 1px);
  background-size: 88px 88px;
  opacity: 0.4;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), rgba(0, 0, 0, 0.05));
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), rgba(0, 0, 0, 0.05));
}

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

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.8rem, 5vw, 3rem);
  margin-top: clamp(1.6rem, 4vw, 2.6rem);
  align-items: end;
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(2rem, 5vw, 4.5rem);
  }
}

.page-about .about-hero__title {
  font-family: var(--f-display);
  font-weight: 300;
  font-size: var(--step-1);
  line-height: 0.94;
  letter-spacing: -0.015em;
  margin: 0.4em 0 0;
}

.page-about .about-lede {
  max-width: 50ch;
  margin: clamp(1rem, 3vw, 1.6rem) 0 0;
  font-size: clamp(0.98rem, 1.4vw, 1.08rem);
  line-height: 1.8;
  color: var(--c-text-dim);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.6rem, 4vw, 2.6rem) 0 0;
  padding: 0;
  list-style: none;
  background: var(--about-hair);
  border-top: 1px solid var(--about-hair-strong);
  border-bottom: 1px solid var(--about-hair-strong);
}

@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-stat {
  background: var(--c-night);
  padding: 0.9rem 0.6rem 0.9rem 0;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  letter-spacing: 0.02em;
  color: var(--c-volt);
  line-height: 1;
}

.page-about .about-stat__label {
  display: block;
  margin-top: 0.45rem;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-grey);
}

.page-about .about-hero__media {
  position: relative;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--about-hair);
  background: var(--c-night-2);
}

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

/* ---------- 章节刻度 ---------- */
.page-about .about-chapters {
  padding: clamp(2rem, 5vw, 3.6rem) 0 clamp(2rem, 6vw, 5rem);
}

.page-about .about-chapters__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.4rem, 4vw, 2.4rem);
}

@media (min-width: 1000px) {
  .page-about .about-chapters__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 4.5rem);
  }
}

.page-about .about-rail__label {
  margin: 0 0 0.7rem;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--c-grey);
}

.page-about .about-rail__list {
  display: flex;
  gap: 1rem;
  margin: 0;
  padding: 0 0 0.5rem;
  list-style: none;
  overflow-x: auto;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 0.45rem;
  text-decoration: none;
  color: var(--c-text-dim);
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--c-volt);
  border-bottom-color: var(--c-volt);
}

.page-about .about-rail__idx {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--c-stop);
}

.page-about .about-rail__name {
  font-size: 0.84rem;
  white-space: nowrap;
}

@media (min-width: 1000px) {
  .page-about .about-rail {
    position: sticky;
    top: clamp(5rem, 12vw, 8rem);
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    padding: 0 0 0 1.1rem;
    border-bottom: 0;
    border-left: 1px solid var(--about-hair-strong);
    overflow: visible;
  }

  .page-about .about-rail__link {
    display: grid;
    grid-template-columns: 2rem minmax(0, 1fr);
    gap: 0.4rem;
    padding: 0.7rem 0;
  }

  .page-about .about-rail__name {
    white-space: normal;
    line-height: 1.4;
  }
}

/* ---------- 章节正文 ---------- */
.page-about .about-chapter {
  padding: clamp(1.6rem, 4vw, 2.6rem) 0;
  border-bottom: 1px solid var(--about-hair);
  scroll-margin-top: 6rem;
}

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  flex-wrap: wrap;
}

.page-about .chapter-idx {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--c-ink);
  background: var(--c-volt);
  padding: 0.28rem 0.55rem;
  border-radius: var(--radius);
}

.page-about .chapter-season {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-grey);
}

.page-about .about-chapter h2 {
  font-family: var(--f-display);
  font-weight: 400;
  font-size: var(--step-2);
  line-height: 1.12;
  margin: 0.6rem 0 0;
}

.page-about .about-chapter p {
  max-width: 56ch;
  margin: 0.9rem 0 0;
  font-size: clamp(0.95rem, 1.25vw, 1.02rem);
  line-height: 1.8;
  color: var(--c-text-dim);
}

/* ---------- 栏目时间线 ---------- */
.page-about .about-tl-wrap {
  margin-top: 1.8rem;
  overflow-x: auto;
  padding-bottom: 0.4rem;
}

.page-about .about-tl {
  display: block;
  width: 100%;
  min-width: 640px;
  height: auto;
}

.page-about .about-tl .tl-line {
  stroke: var(--c-line);
  stroke-width: 1;
}

.page-about .about-tl .tl-node circle {
  fill: var(--c-volt);
}

.page-about .about-tl .tl-idx {
  fill: var(--c-text);
  font-family: var(--f-mono);
  font-size: 16px;
  letter-spacing: 0.1em;
}

.page-about .about-tl .tl-name {
  fill: var(--c-grey);
  font-family: var(--f-body);
  font-size: 17px;
}

.page-about .tl-legend {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 1.4rem 0 0;
  padding: 0;
  list-style: none;
  background: var(--about-hair);
  border-top: 1px solid var(--about-hair);
}

@media (min-width: 700px) {
  .page-about .tl-legend {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .page-about .tl-legend {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .tl-legend li {
  background: var(--c-night);
  padding: 0.9rem 1rem 0.9rem 0;
}

.page-about .tl-legend b {
  display: block;
  font-family: var(--f-display);
  font-weight: 500;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
  color: var(--c-text);
}

.page-about .tl-legend span {
  display: block;
  margin-top: 0.3rem;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--c-text-dim);
}

/* ---------- 号码表 ---------- */
.page-about .kit-table {
  margin-top: 1.6rem;
  border-top: 1px solid var(--about-hair-strong);
}

.page-about .kit-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.4rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--about-hair);
  transition: background-color 0.2s ease;
}

.page-about .kit-row:hover,
.page-about .kit-row:focus-within {
  background: rgba(216, 255, 62, 0.04);
}

@media (min-width: 760px) {
  .page-about .kit-row {
    grid-template-columns: 8.5rem minmax(0, 1fr) auto;
    align-items: center;
    gap: 1.2rem;
    padding: 1rem 0.5rem;
  }
}

.page-about .kit-id {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-grey);
}

.page-about .kit-track {
  font-family: var(--f-mono);
  font-size: clamp(0.95rem, 1.7vw, 1.15rem);
  letter-spacing: 0.06em;
  color: var(--c-volt);
}

.page-about .kit-arrow {
  color: var(--c-stop);
  padding: 0 0.3rem;
}

.page-about .kit-count {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-grey);
}

@media (min-width: 760px) {
  .page-about .kit-count {
    text-align: right;
  }
}

.page-about .kit-note {
  grid-column: 1 / -1;
  font-size: 0.85rem;
  line-height: 1.65;
  color: var(--c-text-dim);
}

@media (hover: hover) and (min-width: 760px) {
  .page-about .kit-note {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.28s ease, opacity 0.22s ease;
  }

  .page-about .kit-row:hover .kit-note,
  .page-about .kit-row:focus-within .kit-note {
    max-height: 5rem;
    opacity: 1;
  }
}

/* ---------- 图注 ---------- */
.page-about .about-figure {
  margin: 1.8rem 0 0;
}

.page-about .about-figure .media {
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--about-hair);
  background: var(--c-night-2);
}

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

.page-about .about-figure figcaption {
  margin-top: 0.7rem;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--c-grey);
}

/* ---------- 暖纸翻面层 ---------- */
.page-about .about-paper {
  position: relative;
  margin: clamp(1.6rem, 4vw, 3rem) 0;
  padding: clamp(3rem, 8vw, 5.5rem) 0;
  background: var(--c-paper);
  color: var(--c-ink);
  clip-path: polygon(0 3vw, 100% 0, 100% 100%, 0 100%);
}

.page-about .about-paper__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.4rem;
}

@media (min-width: 900px) {
  .page-about .about-paper__grid {
    grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
    gap: clamp(2rem, 5vw, 4rem);
    align-items: start;
  }
}

.page-about .about-paper__mark {
  margin: 0;
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: clamp(3rem, 9vw, 6rem);
  line-height: 0.9;
  letter-spacing: 0.02em;
  color: rgba(11, 12, 14, 0.14);
}

.page-about .about-paper .chapter-idx {
  background: var(--c-stop);
  color: var(--c-paper);
}

.page-about .about-paper .chapter-season {
  color: rgba(11, 12, 14, 0.55);
}

.page-about .about-paper p {
  color: rgba(11, 12, 14, 0.78);
}

.page-about .about-chapter--paper {
  border-bottom: 0;
  padding-top: 0;
}

/* ---------- 规划三行 ---------- */
.page-about .about-next-list {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
}

.page-about .about-next-list li {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 1rem;
  align-items: start;
  padding: 1.1rem 0;
  border-top: 1px solid var(--about-hair-strong);
}

.page-about .about-next-list li:last-child {
  border-bottom: 1px solid var(--about-hair-strong);
}

.page-about .about-next-list .num {
  font-family: var(--f-mono);
  font-size: 1.05rem;
  letter-spacing: 0.08em;
  color: var(--c-stop);
}

.page-about .about-next-list b {
  display: block;
  font-family: var(--f-display);
  font-weight: 500;
  font-size: 1.15rem;
  letter-spacing: 0.01em;
  color: var(--c-text);
}

.page-about .about-next-list p {
  margin: 0.4rem 0 0;
  max-width: 50ch;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--c-text-dim);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  padding: clamp(2.6rem, 7vw, 5rem) 0 clamp(3rem, 8vw, 6rem);
  background: linear-gradient(180deg, var(--c-night) 0%, var(--c-ink) 100%);
}

.page-about .about-cta h2 {
  font-family: var(--f-display);
  font-weight: 400;
  font-size: var(--step-2);
  line-height: 1.15;
  margin: 0;
  max-width: 22ch;
}

.page-about .about-cta .prose {
  margin: 1rem 0 0;
  max-width: 52ch;
  line-height: 1.8;
  color: var(--c-text-dim);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.8rem;
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.6rem;
  margin-top: 1.4rem;
  font-size: 0.88rem;
}

.page-about .about-cta__links a {
  color: var(--c-volt);
  text-decoration: none;
  border-bottom: 1px solid var(--about-hair-strong);
  padding-bottom: 0.15rem;
}

.page-about .about-cta__links a:hover,
.page-about .about-cta__links a:focus-visible {
  border-bottom-color: var(--c-volt);
}