.page-about {
  --band-w: 100%;
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-body);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 24px 0 44px;
  background:
    radial-gradient(60% 55% at 82% 0%, rgba(177, 75, 255, 0.20), transparent 62%),
    radial-gradient(45% 45% at 4% 45%, rgba(34, 230, 216, 0.13), transparent 70%),
    var(--ink);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(to bottom, rgba(232, 236, 245, 0.04) 0 1px, transparent 1px 3px);
}

.page-about .breadcrumb {
  position: relative;
  z-index: 1;
  font-size: 13px;
}

.page-about .hero-frame {
  position: relative;
  z-index: 1;
  margin-top: 16px;
  padding: 24px 18px 22px;
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(27, 15, 46, 0.88), rgba(7, 6, 15, 0.6) 55%, rgba(15, 27, 46, 0.8));
  box-shadow: inset 0 0 0 1px rgba(177, 75, 255, 0.1);
}

.page-about .hero-frame::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(to bottom, var(--violet), var(--cyan));
}

.page-about .hero-frame .eyebrow {
  margin: 0;
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: 0.16em;
}

.page-about .hero-frame h1 {
  margin: 12px 0 14px;
  font-size: clamp(30px, 7.2vw, 56px);
  line-height: 1.12;
  letter-spacing: 0.01em;
  color: var(--text);
  text-shadow: 0 0 26px rgba(177, 75, 255, 0.42);
}

.page-about .hero-frame .lede {
  max-width: 62ch;
  color: var(--text);
  font-size: 16px;
  line-height: 1.85;
}

.page-about .hero-metrics {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 0;
  margin: 22px 0 0;
  padding: 16px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .hero-metrics li {
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.page-about .hero-metrics__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1.1;
  color: var(--yellow);
  font-variant-numeric: tabular-nums;
}

.page-about .hero-metrics__label {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  color: var(--muted);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

/* ---------- 章节目录 ---------- */
.page-about .chapter-nav {
  position: sticky;
  top: 0;
  z-index: 6;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(7, 6, 15, 0.94);
  backdrop-filter: blur(8px);
}

.page-about .chapter-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 2px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .chapter-nav__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 12px;
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
  text-decoration: none;
  border-bottom: 2px solid transparent;
}

.page-about .chapter-nav__list a:hover,
.page-about .chapter-nav__list a:focus-visible {
  color: var(--text);
  border-bottom-color: var(--violet);
  background: rgba(177, 75, 255, 0.1);
}

.page-about .chapter-nav__list .mono {
  font-size: 12px;
  color: var(--cyan);
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding: 38px 0 46px;
}

.page-about .chapter--ink {
  background: var(--ink);
}

.page-about .chapter--deep {
  background: var(--band-deep);
}

.page-about .chapter--indigo {
  background: var(--band-indigo);
}

.page-about .chapter__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .chapter__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.3em;
  color: var(--yellow);
}

.page-about .chapter__body .eyebrow {
  margin: 0 0 6px;
  color: var(--violet);
  font-size: 12px;
  letter-spacing: 0.18em;
}

.page-about .chapter__body h2 {
  margin: 0 0 16px;
  font-size: clamp(24px, 5.4vw, 40px);
  line-height: 1.2;
  color: var(--text);
}

.page-about .chapter__body > p {
  max-width: 62ch;
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.page-about .chapter__body h3 {
  margin: 26px 0 12px;
  font-size: 18px;
  color: var(--text);
}

.page-about .note-rail {
  border: 1px solid var(--line);
  padding: 16px;
  background: rgba(7, 6, 15, 0.5);
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .note-rail__title {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .note-rail p {
  margin: 0;
}

.page-about .note-rail__link {
  display: inline-block;
  margin-top: 12px;
  color: var(--violet);
  font-size: 13px;
  text-decoration: none;
  border-bottom: 1px solid rgba(177, 75, 255, 0.5);
}

.page-about .note-rail__link:hover {
  color: var(--yellow);
  border-bottom-color: var(--yellow);
}

/* ---------- 年份刻度 ---------- */
.page-about .yearline {
  list-style: none;
  margin: 22px 0 0;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line);
}

.page-about .yearline__item {
  position: relative;
  margin-bottom: 12px;
}

.page-about .yearline__item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 18px;
  width: 9px;
  height: 9px;
  background: var(--cyan);
  box-shadow: var(--glow-cyan);
}

.page-about .year-tick {
  border: 1px solid var(--line-soft);
  background: rgba(15, 27, 46, 0.55);
}

.page-about .year-tick summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 12px 14px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .year-tick summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--violet);
}

.page-about .year-tick[open] summary::after {
  content: "−";
  color: var(--cyan);
}

.page-about .year-tick__year {
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--yellow);
  font-variant-numeric: tabular-nums;
}

.page-about .year-tick__label {
  color: var(--text);
  font-size: 14px;
}

.page-about .year-tick[open] {
  border-color: var(--violet);
}

.page-about .year-tick p {
  margin: 0;
  padding: 0 14px 14px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

/* ---------- 配图 ---------- */
.page-about .chapter-figure {
  margin: 22px 0;
  border: 1px solid var(--line);
  background: var(--ink);
}

.page-about .chapter-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.94) contrast(1.05);
}

.page-about .chapter-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 三列梯形分工 ---------- */
.page-about .roles {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.page-about .role {
  padding: 20px 18px 22px;
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 14px, 100% 100%, 0 100%);
}

.page-about .role h3 {
  margin: 0 0 8px;
  font-size: 18px;
  color: var(--text);
}

.page-about .role p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .role--write {
  background: var(--band-deep);
  border-color: rgba(34, 230, 216, 0.55);
}

.page-about .role--test {
  background: var(--band-indigo);
  border-color: rgba(177, 75, 255, 0.6);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 calc(100% - 14px));
}

.page-about .role--proof {
  background: var(--band-wine);
  border-color: rgba(255, 122, 47, 0.55);
}

/* ---------- 工序 ---------- */
.page-about .steps {
  list-style: none;
  counter-reset: st;
  margin: 12px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .steps li {
  position: relative;
  padding: 14px 14px 14px 52px;
  border: 1px solid var(--line-soft);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .steps li strong {
  display: block;
  margin-bottom: 2px;
  color: var(--text);
  font-size: 15px;
}

.page-about .steps li::before {
  counter-increment: st;
  content: "0" counter(st);
  position: absolute;
  left: 14px;
  top: 13px;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cyan);
}

/* ---------- 表格与错位图 ---------- */
.page-about .chapter__split {
  display: grid;
  gap: 20px;
  margin: 22px 0;
}

.page-about .table-scroll {
  overflow-x: auto;
  border: 1px solid var(--line-soft);
}

.page-about .data-table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
  font-size: 14px;
}

.page-about .data-table caption {
  padding: 10px 12px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
  background: rgba(7, 6, 15, 0.5);
}

.page-about .data-table th,
.page-about .data-table td {
  padding: 12px 12px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .data-table thead th {
  font-size: 13px;
  font-weight: 600;
  color: var(--cyan);
  border-bottom: 1px solid var(--cyan);
  background: rgba(34, 230, 216, 0.06);
}

.page-about .data-table tbody th {
  color: var(--text);
  white-space: nowrap;
}

.page-about .data-table td {
  color: var(--muted);
  line-height: 1.7;
}

.page-about .data-table tbody tr:hover {
  background: rgba(177, 75, 255, 0.1);
}

/* ---------- 发布节奏 ---------- */
.page-about .rhythm {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .rhythm__item {
  display: grid;
  gap: 8px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .rhythm__text h3 {
  margin: 0 0 6px;
  font-size: 17px;
  color: var(--text);
}

.page-about .rhythm__text p {
  margin: 0;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .rhythm .tag {
  justify-self: start;
}

/* ---------- 今年方向 ---------- */
.page-about .focus {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .focus__row {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 16px;
  border: 1px solid var(--line-soft);
  background: rgba(42, 14, 30, 0.32);
}

.page-about .focus__idx {
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  color: var(--orange);
}

.page-about .focus__row h3 {
  margin: 0 0 8px;
  font-size: 17px;
  color: var(--text);
}

.page-about .focus__row p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 联系 ---------- */
.page-about .contact-list {
  margin: 22px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .contact-list__row {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .contact-list dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .contact-list dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  word-break: break-word;
}

.page-about .prep-list {
  margin: 12px 0 18px;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .prep-list li::marker {
  color: var(--yellow);
}

.page-about .about-links {
  display: grid;
  gap: 10px;
  margin-top: 26px;
}

.page-about .about-links a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: rgba(15, 27, 46, 0.6);
  color: var(--text);
  font-size: 15px;
  text-decoration: none;
}

.page-about .about-links a::after {
  content: "→";
  color: var(--violet);
  font-family: var(--font-mono);
}

.page-about .about-links a:hover,
.page-about .about-links a:focus-visible {
  border-color: var(--violet);
  background: rgba(177, 75, 255, 0.14);
}

/* ---------- 章节色带 ---------- */
.page-about .chapter-band {
  padding: 22px 0;
  background: var(--band-deep);
}

.page-about .chapter-band--indigo {
  background: var(--band-indigo);
}

.page-about .chapter-band--wine {
  background: var(--band-wine);
}

.page-about .chapter-band__inner {
  display: flex;
  align-items: baseline;
  gap: 14px;
  width: var(--band-w, 100%);
  padding-left: 14px;
  border-left: 3px solid var(--violet);
}

.page-about .chapter-band__num {
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--yellow);
}

.page-about .chapter-band__inner p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .hero-frame {
    padding: 34px 32px 30px;
  }

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

  .page-about .hero-metrics li + li {
    padding-left: 16px;
  }

  .page-about .roles {
    grid-template-columns: 1.15fr 0.85fr 1.3fr;
    align-items: stretch;
  }

  .page-about .role--test {
    margin-top: 20px;
  }

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

  .page-about .rhythm__item {
    grid-template-columns: 112px minmax(0, 1fr);
    column-gap: 20px;
    align-items: start;
  }

  .page-about .contact-list__row {
    grid-template-columns: 140px minmax(0, 1fr);
    align-items: baseline;
  }

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

  .page-about .chapter-band {
    padding: 26px 0;
  }
}

@media (min-width: 900px) {
  .page-about .chapter {
    padding: 54px 0 62px;
  }

  .page-about .chapter__inner {
    grid-template-columns: 74px minmax(0, 7fr) minmax(0, 3fr) 46px;
    column-gap: 38px;
    row-gap: 0;
    align-items: start;
  }

  .page-about .chapter__num {
    position: sticky;
    top: 118px;
    min-height: 140px;
    padding: 6px 0 6px 12px;
    border-left: 1px solid var(--line);
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-size: 16px;
    letter-spacing: 0.5em;
  }

  .page-about .note-rail {
    position: sticky;
    top: 88px;
  }

  .page-about .chapter__split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.65fr);
    align-items: start;
    gap: 26px;
  }

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

  .page-about .chapter-band--w1 .chapter-band__inner {
    --band-w: 100%;
  }

  .page-about .chapter-band--w2 .chapter-band__inner {
    --band-w: 88%;
  }

  .page-about .chapter-band--w3 .chapter-band__inner {
    --band-w: 76%;
  }

  .page-about .chapter-band--w4 .chapter-band__inner {
    --band-w: 64%;
  }

  .page-about .chapter-band--w5 .chapter-band__inner {
    --band-w: 52%;
  }
}