/* ===== 品牌使命 / mission ===== */
.page-about {
  --about-rail: 96px;
  --about-fade: rgba(244, 240, 232, .84);
  background: var(--ink);
  color: var(--porcelain);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(28px, 4.5vw, 56px) clamp(40px, 6vw, 80px);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(58% 70% at 82% 12%, rgba(201, 162, 77, .16), transparent 62%),
    radial-gradient(46% 60% at 8% 90%, rgba(47, 143, 163, .12), transparent 66%),
    linear-gradient(122deg, transparent 46%, rgba(47, 143, 163, .08) 46%, rgba(47, 143, 163, .08) 56%, transparent 56%);
}

.page-about .about-hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 52px);
  align-items: center;
}

.page-about .about-hero-copy .breadcrumb { margin-bottom: 18px; }

.page-about .crumb-sep {
  margin-inline: 8px;
  color: var(--mist);
}

.page-about h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 5vw, 64px);
  line-height: 1.14;
  letter-spacing: .02em;
  color: var(--porcelain);
}

.page-about .about-hero-copy .lede {
  margin-top: 18px;
  max-width: 56ch;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.85;
  color: var(--about-fade);
}

.page-about .hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 34px;
  margin-top: clamp(24px, 3vw, 34px);
  padding-top: clamp(18px, 2.4vw, 26px);
  border-top: 1px solid var(--line-soft);
}

.page-about .hero-stat { min-width: 92px; }

.page-about .hero-stat b {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--gold-soft);
}

.page-about .hero-stat span {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--mist);
}

.page-about .about-hero-visual {
  position: relative;
  margin: 0;
  isolation: isolate;
}

.page-about .about-hero-visual::before {
  content: "";
  position: absolute;
  inset: 14px -12px -14px 12px;
  z-index: 0;
  border: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(201, 162, 77, .12), transparent 70%);
}

.page-about .about-hero-visual img {
  position: relative;
  z-index: 1;
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-soft);
  filter: saturate(.92) contrast(1.04);
}

.page-about .hero-plate {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  margin: 0;
  padding: 9px 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--gold-soft);
  background: var(--ink);
  border: 1px solid var(--line);
  border-left: 2px solid var(--gold);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  padding-block: clamp(36px, 5vw, 72px) clamp(48px, 7vw, 96px);
}

.page-about .about-rail { display: none; }

.page-about .about-flow { min-width: 0; }

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  position: relative;
  padding-block: clamp(26px, 4vw, 52px);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-flow > .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: clamp(10px, 1.6vw, 18px);
  margin-bottom: clamp(16px, 2.2vw, 28px);
}

.page-about .chapter-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: clamp(24px, 2.8vw, 36px);
  line-height: 1;
  letter-spacing: .02em;
  color: var(--gold);
}

.page-about .chapter-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 2.9vw, 36px);
  line-height: 1.25;
  letter-spacing: .01em;
  color: var(--porcelain);
}

.page-about .chapter-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 30px);
}

.page-about .chapter-main p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-fade);
}

.page-about .chapter-main p:last-child { margin-bottom: 0; }

.page-about .chapter-main h3 {
  margin: 20px 0 8px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: .01em;
  color: var(--porcelain);
}

.page-about .chapter-main h3:first-child { margin-top: 0; }

.page-about .chapter-main a,
.page-about .chapter-note a {
  color: var(--lake-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(127, 195, 207, .4);
  transition: color var(--fast) var(--ease), border-color var(--fast) var(--ease);
}

.page-about .chapter-main a:hover,
.page-about .chapter-note a:hover {
  color: var(--porcelain);
  border-bottom-color: var(--gold);
}

.page-about .chapter-note {
  padding-left: 16px;
  border-left: 1px solid var(--line);
}

.page-about .chapter-note p {
  margin: 0 0 10px;
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .chapter-note p:last-child { margin-bottom: 0; }

.page-about .note-label {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--gold);
}

/* ---------- 团队 ---------- */
.page-about .team-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 40px);
}

.page-about .team-stack {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .team-chip {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  align-items: start;
  gap: 2px 14px;
  padding: 14px 18px;
  background: var(--ink-2);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--gold);
  transition: border-color var(--base) var(--ease), transform var(--base) var(--ease);
}

.page-about .team-chip:nth-child(1) { padding-block: 16px; }
.page-about .team-chip:nth-child(2) { margin-left: 6%; padding-block: 20px; border-left-color: var(--lake); }
.page-about .team-chip:nth-child(3) { margin-left: 2%; padding-block: 14px; border-left-color: var(--lake-soft); }
.page-about .team-chip:nth-child(4) { margin-left: 10%; padding-block: 22px; border-left-color: var(--ochre); }

.page-about .team-chip:hover {
  border-color: var(--line);
  transform: translateX(3px);
}

.page-about .team-chip-num {
  grid-row: 1;
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--gold-soft);
}

.page-about .team-chip-name {
  grid-row: 1;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 15px;
  line-height: 1.3;
  color: var(--porcelain);
}

.page-about .team-chip-desc {
  grid-column: 2;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .team-visual {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line-soft);
}

.page-about .team-visual img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.9);
}

.page-about .team-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, transparent 55%, rgba(7, 9, 11, .65));
}

/* ---------- 十年路径 ---------- */
.page-about .about-chapter--path { overflow: hidden; }

.page-about .path-visual {
  position: absolute;
  inset: 0;
  z-index: 0;
  margin: 0;
  opacity: .13;
  pointer-events: none;
}

.page-about .path-visual img {
  display: block;
  width: 100%;
  max-width: none;
  height: 100%;
  object-fit: cover;
}

.page-about .about-chapter--path .chapter-head,
.page-about .about-chapter--path .path-list {
  position: relative;
  z-index: 1;
}

.page-about .path-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .path-list::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 15px;
  width: 1px;
  opacity: .55;
  background: linear-gradient(180deg, var(--gold), rgba(47, 143, 163, .55));
}

.page-about .path-item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 0 0 26px 34px;
}

.page-about .path-item::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 6px;
  width: 9px;
  height: 9px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(201, 162, 77, .12);
}

.page-about .path-year {
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1.3;
  letter-spacing: .08em;
  color: var(--gold-soft);
}

.page-about .path-content h3 {
  margin: 0 0 6px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 16px;
  color: var(--porcelain);
}

.page-about .path-content p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--about-fade);
}

/* ---------- 凭据 ---------- */
.page-about .chapter-lede {
  margin: 0 0 clamp(18px, 2.4vw, 26px);
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-fade);
}

.page-about .cert-board {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .cert-item {
  position: relative;
  padding: 16px 18px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  box-shadow: 5px 5px 0 -1px rgba(201, 162, 77, .10), 10px 10px 0 -2px rgba(47, 143, 163, .07);
  transition: border-color var(--base) var(--ease), transform var(--base) var(--ease), box-shadow var(--base) var(--ease);
}

.page-about .cert-item:hover,
.page-about .cert-item:focus-within {
  border-color: var(--gold);
  transform: translateY(-2px);
  box-shadow: 6px 6px 0 -1px rgba(201, 162, 77, .18), 12px 12px 0 -2px rgba(47, 143, 163, .10);
}

.page-about .cert-item:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

.page-about .cert-kicker {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .12em;
  color: rgba(201, 162, 77, .8);
}

.page-about .cert-name {
  display: block;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 15px;
  line-height: 1.4;
  color: var(--porcelain);
}

.page-about .cert-note {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 新人四步 ---------- */
.page-about .step-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .step-list li {
  position: relative;
  padding: 14px 16px 14px 52px;
  background: rgba(26, 34, 41, .55);
  border-left: 2px solid var(--lake);
}

.page-about .step-idx {
  position: absolute;
  left: 16px;
  top: 15px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--lake-soft);
}

.page-about .step-list strong {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 15px;
  color: var(--porcelain);
}

.page-about .step-list p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .step-list a {
  color: var(--lake-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(127, 195, 207, .35);
}

.page-about .step-list a:hover {
  color: var(--porcelain);
  border-bottom-color: var(--gold);
}

/* ---------- 收尾 ---------- */
.page-about .about-close {
  margin-top: clamp(30px, 4.5vw, 56px);
  padding: clamp(24px, 3.6vw, 44px);
  border: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(201, 162, 77, .09), rgba(47, 143, 163, .07) 60%, transparent);
}

.page-about .about-close h2 {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 2.6vw, 32px);
  line-height: 1.3;
  color: var(--porcelain);
}

.page-about .about-close p {
  margin: 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-fade);
}

.page-about .about-close .close-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .about-close .close-fine {
  margin-top: 18px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-close .close-fine a {
  color: var(--lake-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(127, 195, 207, .35);
}

.page-about .about-close .close-fine a:hover {
  color: var(--porcelain);
  border-bottom-color: var(--gold);
}

/* ---------- 响应式 ---------- */
@media (min-width: 600px) {
  .page-about .path-list::before { left: 23px; }

  .page-about .path-item {
    grid-template-columns: 110px minmax(0, 1fr);
    column-gap: clamp(16px, 2.4vw, 32px);
    padding-left: 42px;
    padding-bottom: 32px;
    gap: 0;
  }

  .page-about .path-item::before { left: 23px; top: 7px; }

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

@media (min-width: 640px) {
  .page-about .cert-board { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .cert-item { min-height: 78px; }
}

@media (hover: hover) and (min-width: 640px) {
  .page-about .cert-note {
    max-height: 0;
    margin-top: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height var(--base) var(--ease), opacity var(--base) var(--ease), margin var(--base) var(--ease);
  }

  .page-about .cert-item:hover .cert-note,
  .page-about .cert-item:focus-within .cert-note {
    max-height: 140px;
    margin-top: 8px;
    opacity: 1;
  }
}

@media (min-width: 780px) {
  .page-about .chapter-grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: clamp(24px, 4vw, 56px);
    align-items: start;
  }

  .page-about .chapter-grid > .chapter-main { grid-column: 1 / span 7; }
  .page-about .chapter-grid > .chapter-note { grid-column: 9 / span 4; }

  .page-about .chapter-grid--flip > .chapter-main {
    grid-column: 6 / span 7;
    grid-row: 1;
  }

  .page-about .chapter-grid--flip > .chapter-note {
    grid-column: 1 / span 4;
    grid-row: 1;
    margin-top: clamp(10px, 2vw, 26px);
  }
}

@media (min-width: 860px) {
  .page-about .team-layout {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    align-items: start;
  }

  .page-about .team-chip:nth-child(2) { margin-left: 8%; }
  .page-about .team-chip:nth-child(4) { margin-left: 14%; }
}

@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: clamp(24px, 3.5vw, 56px);
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .about-rail .toc-link {
    display: block;
    padding: 11px 0 11px 14px;
    border-left: 1px solid var(--line-soft);
    color: var(--mist);
    text-decoration: none;
    transition: color var(--fast) var(--ease), border-color var(--fast) var(--ease);
  }

  .page-about .about-rail .toc-link .rail-num {
    display: block;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .08em;
    color: rgba(201, 162, 77, .7);
  }

  .page-about .about-rail .toc-link .rail-text {
    display: block;
    margin-top: 2px;
    font-size: 12px;
    line-height: 1.5;
  }

  .page-about .about-rail .toc-link:hover { color: var(--porcelain); }

  .page-about .about-rail .toc-link:focus-visible {
    outline: 2px solid var(--gold);
    outline-offset: 3px;
  }

  .page-about .about-rail .toc-link.is-active {
    color: var(--gold-soft);
    border-left-color: var(--gold);
  }

  .page-about .about-rail .toc-link.is-active .rail-num { color: var(--gold); }
}

@media (min-width: 960px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, .96fr);
    gap: clamp(32px, 4vw, 64px);
  }
}

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

@media (prefers-reduced-motion: reduce) {
  .page-about .team-chip,
  .page-about .cert-item,
  .page-about .about-rail .toc-link,
  .page-about .cert-note {
    transition: none;
  }

  .page-about .team-chip:hover,
  .page-about .cert-item:hover {
    transform: none;
  }
}