/* ===== 品牌总览 / about ===== */
.page-about {
  --ab-sec-pad: clamp(2.25rem, 5vw, 3.5rem);
  --ab-gap: clamp(1.25rem, 3vw, 2rem);
  background: var(--ky-night);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 84% 14%, rgba(22, 147, 126, 0.34), transparent 58%),
    linear-gradient(166deg, var(--ky-sand) 0%, var(--ky-night) 76%);
  color: var(--ky-paper);
  padding-top: clamp(6.5rem, 13vw, 9.5rem);
  padding-bottom: clamp(5rem, 11vw, 8rem);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: min(46%, 420px);
  height: 100%;
  background-image: repeating-linear-gradient(
    90deg,
    rgba(243, 234, 223, 0.16) 0 1px,
    transparent 1px 24px
  );
  opacity: 0.55;
  pointer-events: none;
}

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

.page-about .ab-crumb {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: rgba(243, 234, 223, 0.62);
}

.page-about .ab-crumb a {
  color: rgba(243, 234, 223, 0.78);
  text-decoration: none;
}

.page-about .ab-crumb a:hover,
.page-about .ab-crumb a:focus-visible {
  color: var(--ky-orange-mist);
}

.page-about .ab-hero__kicker {
  margin: 1.6rem 0 0;
  color: var(--ky-green-mist);
}

.page-about .ab-hero__title {
  margin: 0.9rem 0 0;
  max-width: 22ch;
  font-weight: 200;
  letter-spacing: -0.02em;
  color: var(--ky-paper);
}

.page-about .ab-hero__lede {
  margin: 1.5rem 0 0;
  max-width: 64ch;
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(243, 234, 223, 0.82);
}

.page-about .ab-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 3rem;
  margin: 2.25rem 0 0;
  padding: 1.5rem 0 0;
  list-style: none;
  border-top: 1px solid var(--ky-line);
}

.page-about .ab-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.page-about .ab-hero__facts .ky-mono {
  font-size: clamp(1.6rem, 3vw, 2.15rem);
  font-weight: 300;
  line-height: 1;
  color: var(--ky-signal);
}

.page-about .ab-hero__facts li > span:last-child {
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: rgba(243, 234, 223, 0.58);
}

/* ---------- 纸面主体 ---------- */
.page-about .ab-sheet {
  position: relative;
  background: var(--ky-paper);
  color: var(--ky-night);
  padding-bottom: clamp(2rem, 6vw, 4rem);
}

.page-about .ab-sheet::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: -2.5rem;
  height: 2.5rem;
  background: var(--ky-paper);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  pointer-events: none;
}

.page-about .ab-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  padding-block: clamp(2rem, 5vw, 3.5rem);
}

/* ---------- 章节索引 ---------- */
.page-about .ab-index__title {
  margin: 0 0 0.85rem;
  color: var(--ky-mud);
}

.page-about .ab-index__list {
  display: flex;
  gap: 0.4rem;
  margin: 0;
  padding: 0 0 0.5rem;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-index__list > li {
  flex: 0 0 auto;
}

.page-about .ab-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  white-space: nowrap;
  padding: 0.4rem 0.7rem;
  border: 1px solid var(--ky-line-dark);
  color: var(--ky-mud);
  font-size: 0.8125rem;
  text-decoration: none;
  transition: color 0.2s var(--ky-ease), background-color 0.2s var(--ky-ease),
    border-color 0.2s var(--ky-ease);
}

.page-about .ab-index__link .ky-mono {
  font-size: 0.7rem;
  color: var(--ky-orange);
}

.page-about .ab-index__link:hover,
.page-about .ab-index__link:focus-visible {
  color: var(--ky-night);
  border-color: var(--ky-green);
  background: rgba(15, 107, 92, 0.08);
}

/* ---------- 章节 ---------- */
.page-about .ab-sec {
  padding-block: var(--ab-sec-pad);
  border-top: 1px solid var(--ky-line-dark);
}

.page-about .ab-sec:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.page-about .ab-sec__kicker {
  margin: 0 0 0.7rem;
  color: var(--ky-green);
}

.page-about .ab-sec__title {
  margin: 0 0 1rem;
}

.page-about .ab-sec__lead {
  margin: 0 0 1.5rem;
  max-width: 66ch;
  line-height: 1.8;
  color: var(--ky-mud);
}

.page-about .ab-p {
  margin: 0 0 1rem;
  max-width: 68ch;
  line-height: 1.82;
}

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

.page-about .ab-tagrow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.5rem;
}

/* ---------- 历程时间轴 ---------- */
.page-about .ab-tl__figure {
  margin: 0 0 2rem;
}

.page-about .ab-tl__list {
  display: grid;
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-tl__node {
  position: relative;
  padding: 1rem 1rem 1rem 1.15rem;
  background: linear-gradient(180deg, rgba(15, 107, 92, 0.1), rgba(15, 107, 92, 0.03));
  border-left: 2px solid var(--ky-green);
}

.page-about .ab-tl__node::after {
  content: "";
  position: absolute;
  left: -5px;
  top: 1.05rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ky-orange);
}

.page-about .ab-tl__season {
  display: block;
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  color: var(--ky-green);
}

.page-about .ab-tl__name {
  margin: 0.4rem 0 0.4rem;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
}

.page-about .ab-tl__text {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--ky-mud);
}

/* ---------- 团队 ---------- */
.page-about .ab-teamfig {
  margin: 0 0 1.75rem;
  border: 2px solid var(--ky-sand);
}

.page-about .ab-team {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--ky-line-dark);
  border: 1px solid var(--ky-line-dark);
}

.page-about .ab-team__cell {
  position: relative;
  background: var(--ky-paper);
  padding: 1.15rem 1rem 1.25rem;
}

.page-about .ab-team__num {
  display: block;
  font-size: 1.9rem;
  font-weight: 300;
  line-height: 1;
  color: var(--ky-green);
}

.page-about .ab-team__name {
  margin: 0.55rem 0 0.45rem;
  font-size: 1rem;
  font-weight: 600;
}

.page-about .ab-team__text {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.72;
  color: var(--ky-mud);
}

/* ---------- 四步流程 ---------- */
.page-about .ab-flow {
  display: grid;
  gap: 1.25rem;
  margin: 1.75rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-flow__step {
  position: relative;
  padding: 1.15rem 1rem 1.25rem;
  background: rgba(255, 255, 255, 0.62);
  border: 2px solid var(--ky-sand);
  box-shadow: var(--ky-shadow-paper-sm);
}

.page-about .ab-flow__no {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--ky-orange);
}

.page-about .ab-flow__name {
  margin: 0.45rem 0 0.5rem;
  font-size: 1.0625rem;
  font-weight: 600;
}

.page-about .ab-flow__text {
  margin: 0 0 0.8rem;
  font-size: 0.875rem;
  line-height: 1.72;
  color: var(--ky-mud);
}

.page-about .ab-flow__more > summary {
  cursor: pointer;
  list-style: none;
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--ky-green);
}

.page-about .ab-flow__more > summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-flow__more > summary::before {
  content: "+ ";
  font-family: var(--ky-font-mono);
  color: var(--ky-orange);
}

.page-about .ab-flow__more[open] > summary::before {
  content: "– ";
}

.page-about .ab-flow__more ul {
  margin: 0.7rem 0 0;
  padding-left: 1.1rem;
  font-size: 0.8125rem;
  line-height: 1.72;
  color: var(--ky-mud);
}

.page-about .ab-flowfig {
  max-width: 380px;
  margin: 2rem auto 1.75rem;
  border: 2px solid var(--ky-sand);
}

/* ---------- 覆盖规模 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 1.5rem 0 1.75rem;
  background: var(--ky-line-dark);
  border: 1px solid var(--ky-line-dark);
}

.page-about .ab-stat {
  background: var(--ky-paper);
  padding: 1.25rem 1.05rem;
}

.page-about .ab-stat__num {
  display: block;
  font-size: clamp(1.7rem, 4vw, 2.3rem);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ky-night);
}

.page-about .ab-stat__suffix {
  font-size: 0.5em;
  color: var(--ky-orange);
  margin-left: 0.08em;
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 0.65rem;
  font-size: 0.9rem;
  font-weight: 600;
}

.page-about .ab-stat__note {
  margin: 0.35rem 0 0;
  font-size: 0.79rem;
  line-height: 1.6;
  color: var(--ky-mud);
}

/* ---------- 协作与认可 ---------- */
.page-about .ab-tags {
  display: grid;
  gap: 0.85rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-tags > li {
  padding: 0.95rem 1rem;
  background: rgba(255, 255, 255, 0.55);
  border: 2px solid var(--ky-sand);
  box-shadow: var(--ky-shadow-paper-sm);
}

.page-about .ab-tags .ky-index {
  color: var(--ky-green);
}

.page-about .ab-tags p {
  margin: 0.45rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
}

/* ---------- 承诺清单 ---------- */
.page-about .ab-promise {
  display: grid;
  gap: 0.75rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-promise > li {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 0.85rem;
  align-items: baseline;
  padding-bottom: 0.8rem;
  border-bottom: 1px dashed var(--ky-sand-gray);
}

.page-about .ab-promise > li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .ab-promise__no {
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--ky-orange);
}

.page-about .ab-promise p {
  margin: 0;
  line-height: 1.78;
}

/* ---------- 下一步 ---------- */
.page-about .ab-cta {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
  padding: clamp(1.5rem, 4vw, 2.25rem);
  background: linear-gradient(140deg, var(--ky-sand) 0%, var(--ky-night) 78%);
  color: var(--ky-paper);
}

.page-about .ab-cta__kicker {
  margin: 0;
  color: var(--ky-green-mist);
}

.page-about .ab-cta__text {
  margin: 0;
  max-width: 54ch;
  line-height: 1.8;
  color: rgba(243, 234, 223, 0.85);
}

.page-about .ab-cta__btns {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about .ab-cta__note {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.75;
  color: rgba(243, 234, 223, 0.66);
}

.page-about .ab-cta__note a {
  color: var(--ky-green-mist);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .ab-cta__note a:hover,
.page-about .ab-cta__note a:focus-visible {
  color: var(--ky-orange-mist);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .ab-tags {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 780px) {
  .page-about .ab-tl__list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 1.1rem;
    align-items: start;
  }

  .page-about .ab-tl__node:nth-child(2) { margin-top: 1.4rem; }
  .page-about .ab-tl__node:nth-child(3) { margin-top: 2.8rem; }
  .page-about .ab-tl__node:nth-child(4) { margin-top: 4.2rem; }
  .page-about .ab-tl__node:nth-child(5) { margin-top: 5.6rem; }

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

  .page-about .ab-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    column-gap: 2rem;
  }

  .page-about .ab-cta__kicker { grid-column: 1 / -1; }
  .page-about .ab-cta__text { grid-column: 1; }
  .page-about .ab-cta__btns { grid-column: 2; grid-row: 2; }
  .page-about .ab-cta__note { grid-column: 1 / -1; }
}

@media (min-width: 860px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.5rem;
  }

  .page-about .ab-flow__step + .ab-flow__step::before {
    content: "";
    position: absolute;
    left: -1.5rem;
    top: 2.15rem;
    width: 1.5rem;
    border-top: 2px dashed var(--ky-sand-gray);
  }

  .page-about .ab-flow__step + .ab-flow__step::after {
    content: "";
    position: absolute;
    left: -0.62rem;
    top: calc(2.15rem - 6px);
    border-left: 7px solid var(--ky-orange);
    border-top: 6px solid transparent;
    border-bottom: 6px solid transparent;
  }
}

@media (min-width: 900px) {
  .page-about .ab-layout {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.25rem);
  }

  .page-about .ab-index {
    position: sticky;
    top: 7rem;
    align-self: start;
  }

  .page-about .ab-index__list {
    flex-direction: column;
    gap: 0.1rem;
    padding-bottom: 0;
    overflow: visible;
  }

  .page-about .ab-index__link {
    display: flex;
    width: 100%;
    padding: 0.5rem 0.6rem;
    border: 0;
    border-left: 2px solid transparent;
  }

  .page-about .ab-index__link:hover,
  .page-about .ab-index__link:focus-visible {
    border-color: transparent;
    border-left-color: var(--ky-orange);
    background: rgba(15, 107, 92, 0.07);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-index__link,
  .page-about .ab-flow__more > summary {
    transition: none;
  }
}