.page-about {
  --about-rule: rgba(42, 26, 15, .18);
  --about-rule-dark: rgba(169, 187, 178, .2);
  --about-soft: rgba(42, 26, 15, .78);
  background: var(--ink);
  color: var(--text);
  overflow-x: hidden;
}

.page-about .section {
  padding: clamp(48px, 8vw, 104px) 0;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(16px, 3vw, 28px);
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .12em;
  color: var(--sage);
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .breadcrumb li {
  display: inline-flex;
  align-items: center;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin: 0 .6em;
  color: var(--line);
}

.page-about .breadcrumb a {
  color: var(--sage);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

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

.page-about .breadcrumb [aria-current="page"] {
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(20px, 4vw, 48px) 0 clamp(40px, 7vw, 96px);
  background:
    radial-gradient(85% 75% at 90% -15%, rgba(200, 255, 61, .13), transparent 62%),
    radial-gradient(70% 65% at -8% 105%, rgba(13, 34, 54, .95), transparent 68%);
}

.page-about .about-hero-inner {
  display: grid;
  gap: clamp(30px, 5vw, 64px);
  align-items: end;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 7.2vw, 5rem);
  line-height: 1.02;
  letter-spacing: .04em;
  font-weight: 800;
  margin: clamp(12px, 2vw, 20px) 0 clamp(16px, 3vw, 26px);
  max-width: 11em;
  text-wrap: balance;
}

.page-about .about-hero .lede {
  max-width: 56ch;
  margin: 0;
  font-size: clamp(.98rem, 1.6vw, 1.08rem);
  line-height: 1.9;
  color: var(--sage);
}

.page-about .hero-aside {
  border-top: 1px solid var(--line);
  padding-top: clamp(16px, 2.5vw, 24px);
}

.page-about .hero-aside-label {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .18em;
  color: var(--lime);
}

.page-about .hero-aside ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .hero-aside li {
  display: grid;
  grid-template-columns: 10px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  font-size: .95rem;
  line-height: 1.72;
  color: var(--text);
}

.page-about .hero-aside li::before {
  content: "";
  height: 2px;
  margin-top: .78em;
  background: var(--lime);
}

/* ---------- 品牌起点 ---------- */
.page-about .about-origin {
  background: var(--cream);
  color: var(--brown);
}

.page-about .about-origin-grid {
  display: grid;
  gap: clamp(32px, 5vw, 64px);
}

.page-about .about-origin-figure {
  position: relative;
  margin: 0;
  max-width: 520px;
}

.page-about .about-origin-figure::before {
  content: "";
  position: absolute;
  inset: -14px;
  border: 1px dashed rgba(28, 75, 64, .28);
  pointer-events: none;
}

.page-about .about-origin .eyebrow,
.page-about .about-timeline .eyebrow,
.page-about .about-eco .eyebrow {
  color: rgba(42, 26, 15, .62);
}

.page-about .about-origin .section-title,
.page-about .about-timeline .section-title,
.page-about .about-eco .section-title {
  font-family: var(--font-serif);
  font-weight: 400;
  letter-spacing: .01em;
  line-height: 1.3;
  color: var(--brown);
  font-size: clamp(1.65rem, 3.6vw, 2.6rem);
  margin: clamp(10px, 1.6vw, 16px) 0 clamp(16px, 2.4vw, 24px);
}

.page-about .about-origin-copy p {
  margin: 0 0 1em;
  max-width: 56ch;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--about-soft);
}

.page-about .origin-notes {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .origin-notes li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--about-rule);
  font-size: .94rem;
  line-height: 1.75;
  color: rgba(42, 26, 15, .82);
}

.page-about .origin-tag {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .1em;
  padding: 3px 8px;
  border: 1px solid rgba(28, 75, 64, .4);
  color: var(--brown);
  white-space: nowrap;
}

.page-about .media-caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: .78rem;
  line-height: 1.7;
  letter-spacing: .02em;
  color: var(--sage);
}

.page-about .about-origin .media-caption,
.page-about .about-eco .media-caption {
  color: rgba(42, 26, 15, .62);
}

/* ---------- 产品哲学 ---------- */
.page-about .about-philosophy {
  background: var(--indigo);
}

.page-about .about-philosophy .section-title,
.page-about .about-team .section-title,
.page-about .about-next .section-title {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: .04em;
  line-height: 1.14;
  font-size: clamp(1.7rem, 4vw, 3rem);
  margin: clamp(10px, 1.6vw, 16px) 0 clamp(14px, 2.2vw, 22px);
}

.page-about .about-philosophy .lede,
.page-about .about-team .lede {
  max-width: 60ch;
  margin: 0;
  color: var(--sage);
  line-height: 1.85;
}

.page-about .philosophy-list {
  margin-top: clamp(26px, 4vw, 44px);
  border-top: 1px solid var(--line);
}

.page-about .philosophy-item {
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr);
  grid-template-areas:
    "num title"
    "num text";
  gap: 6px clamp(12px, 3vw, 28px);
  padding: clamp(20px, 3.4vw, 34px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .philosophy-num {
  grid-area: num;
  font-family: var(--font-mono);
  font-size: .95rem;
  letter-spacing: .06em;
  color: var(--lime);
}

.page-about .philosophy-item h3 {
  grid-area: title;
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.05rem, 2vw, 1.32rem);
  letter-spacing: .03em;
  color: var(--text);
}

.page-about .philosophy-item p {
  grid-area: text;
  margin: 0;
  max-width: 58ch;
  font-size: .96rem;
  line-height: 1.85;
  color: rgba(233, 251, 240, .76);
}

/* ---------- 版本演进 ---------- */
.page-about .about-timeline {
  background: var(--cream);
  color: var(--brown);
}

.page-about .about-timeline .lede {
  max-width: 58ch;
  margin: 0;
  color: var(--about-soft);
  line-height: 1.85;
}

.page-about .timeline {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  max-width: 80ch;
}

.page-about .timeline-item {
  position: relative;
  padding-left: clamp(22px, 4vw, 44px);
  padding-bottom: clamp(8px, 1.6vw, 14px);
}

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--about-rule);
}

.page-about .timeline-item:last-child::before {
  bottom: auto;
  height: 2.1rem;
}

.page-about .timeline-item::after {
  content: "";
  position: absolute;
  left: -4px;
  top: 1.35rem;
  width: 9px;
  height: 9px;
  background: var(--ember);
  box-shadow: 0 0 0 3px var(--cream);
}

.page-about .timeline summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 0 clamp(10px, 2vw, 18px);
  padding: clamp(10px, 1.6vw, 14px) 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .timeline summary:hover .timeline-name,
.page-about .timeline summary:focus-visible .timeline-name {
  color: var(--brown);
  text-decoration: underline;
  text-decoration-color: var(--ember);
  text-underline-offset: 5px;
  text-decoration-thickness: 2px;
}

.page-about .timeline-badge {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
}

.page-about .timeline-badge .mono {
  font-family: var(--font-mono);
  font-size: clamp(1.15rem, 3vw, 1.9rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.01em;
  color: var(--brown);
  font-variant-numeric: tabular-nums;
}

.page-about .timeline-badge .tag {
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .1em;
  padding: 1px 6px;
  border: 1px solid var(--ember);
  background: rgba(255, 107, 74, .12);
  color: var(--brown);
  white-space: nowrap;
}

.page-about .timeline-name {
  font-family: var(--font-serif);
  font-size: clamp(1.02rem, 2.2vw, 1.3rem);
  line-height: 1.45;
  color: var(--brown);
}

.page-about .timeline-plus {
  position: relative;
  width: 14px;
  height: 14px;
  flex: none;
}

.page-about .timeline-plus::before,
.page-about .timeline-plus::after {
  content: "";
  position: absolute;
  background: rgba(42, 26, 15, .55);
}

.page-about .timeline-plus::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.page-about .timeline-plus::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
  transition: transform var(--ease);
}

.page-about .timeline details[open] .timeline-plus::after {
  transform: scaleY(0);
}

.page-about .timeline-body {
  max-width: 58ch;
  padding: 0 0 clamp(14px, 2vw, 20px);
}

.page-about .timeline-body p {
  margin: 0;
  font-size: .96rem;
  line-height: 1.85;
  color: rgba(42, 26, 15, .76);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  background: var(--panel);
}

.page-about .team-head {
  max-width: 62ch;
}

.page-about .team-figure {
  margin: clamp(26px, 4vw, 40px) 0 0;
}

.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(26px, 4vw, 44px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .team-cell {
  background: var(--panel);
  padding: clamp(20px, 3vw, 30px);
}

.page-about .team-count {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 4.5vw, 2.7rem);
  line-height: 1;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .team-cell h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 1rem;
  letter-spacing: .04em;
  color: var(--text);
}

.page-about .team-cell p {
  margin: 0;
  font-size: .9rem;
  line-height: 1.78;
  color: rgba(233, 251, 240, .72);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  background: var(--cream);
  color: var(--brown);
}

.page-about .about-eco-grid {
  display: grid;
  gap: clamp(30px, 5vw, 56px);
}

.page-about .about-eco-copy p {
  margin: 0 0 1em;
  max-width: 56ch;
  line-height: 1.9;
  color: var(--about-soft);
}

.page-about .eco-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .eco-tags li {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
  padding: 5px 10px;
  border: 1px solid rgba(28, 75, 64, .35);
  background: rgba(18, 58, 49, .05);
  color: rgba(42, 26, 15, .82);
  transition: border-color var(--ease), background var(--ease);
}

.page-about .eco-tags li:hover {
  border-color: var(--amber);
  background: rgba(255, 180, 84, .2);
}

.page-about .eco-honors {
  margin-top: clamp(30px, 5vw, 56px);
  padding-top: clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--about-rule);
}

.page-about .eco-honors h3 {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(1.15rem, 2.4vw, 1.5rem);
  color: var(--brown);
}

.page-about .eco-honors ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  max-width: 70ch;
}

.page-about .eco-honors li {
  position: relative;
  padding-left: 20px;
  font-size: .94rem;
  line-height: 1.8;
  color: var(--about-soft);
}

.page-about .eco-honors li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 8px;
  height: 2px;
  background: var(--ember);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  background:
    radial-gradient(70% 90% at 100% 0%, rgba(200, 255, 61, .1), transparent 60%),
    var(--ink);
  border-top: 1px solid var(--line);
}

.page-about .about-next-inner {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: end;
}

.page-about .about-next-copy p {
  margin: 0;
  max-width: 54ch;
  line-height: 1.9;
  color: var(--sage);
}

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

.page-about .about-next-note {
  display: grid;
  gap: 10px;
  margin: clamp(18px, 3vw, 26px) 0 0;
}

.page-about .about-next-note .link-arrow {
  display: inline-block;
  width: fit-content;
  padding-bottom: 2px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: .82rem;
  letter-spacing: .04em;
  color: var(--sage);
  text-decoration: none;
  transition: color var(--ease), border-color var(--ease);
}

.page-about .about-next-note .link-arrow:hover,
.page-about .about-next-note .link-arrow:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .philosophy-item {
    grid-template-columns: 3.2rem minmax(0, 14rem) minmax(0, 1fr);
    grid-template-areas: "num title text";
    align-items: start;
  }

  .page-about .philosophy-item h3 {
    margin-bottom: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  }

  .page-about .about-origin-grid {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .about-eco-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }

  .page-about .about-next-inner {
    grid-template-columns: minmax(0, 1fr) auto;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .breadcrumb a,
  .page-about .timeline-plus::after,
  .page-about .eco-tags li,
  .page-about .about-next-note .link-arrow {
    transition: none;
  }
}