/* =========================================================
   品牌概况页 · 展览画册式纵向阅读
   作用域：.page-about
   ========================================================= */

.page-about {
  --about-shell: 1240px;
  --about-pad: 18px;
  --about-frame: var(--line);
  display: block;
  position: relative;
  background: var(--ink);
  color: var(--white);
  overflow-x: clip;
}

.page-about .shell {
  width: 100%;
  max-width: var(--about-shell);
  margin-inline: auto;
  padding-inline: var(--about-pad);
}

.page-about .shell--narrow {
  max-width: 860px;
}

@media (min-width: 760px) {
  .page-about {
    --about-pad: 32px;
  }
}

/* 斜切分割线 */
.page-about .about-slash {
  height: 2px;
  background: var(--line);
  transform: skewY(-1.2deg);
  margin: 0;
}

/* ---------------------------------------------------------
   1. 首屏
   --------------------------------------------------------- */
.page-about .about-hero {
  position: relative;
  padding: 22px 0 60px;
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -160px;
  right: -180px;
  width: 480px;
  height: 480px;
  background: linear-gradient(135deg, rgba(12, 42, 34, 0.95) 0%, rgba(47, 232, 198, 0.2) 100%);
  transform: rotate(-14deg);
  pointer-events: none;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 40px;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 38px;
  align-items: end;
}

.page-about .about-hero__title {
  margin: 14px 0 22px;
  font-family: var(--font-display);
  font-size: clamp(34px, 8vw, 72px);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -0.02em;
  text-transform: none;
}

.page-about .about-hero__intro {
  max-width: 46ch;
  margin: 0 0 14px;
  font-size: var(--fs-16);
  line-height: 1.75;
  color: var(--white);
}

.page-about .about-hero__intro--sub {
  color: var(--mist);
  font-size: var(--fs-14);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--bw) solid var(--line);
  border-bottom: var(--bw) solid var(--line);
}

.page-about .about-stat {
  padding: 16px 10px 16px 0;
  border-right: 1px solid var(--line);
}

.page-about .about-stat:last-child {
  border-right: 0;
}

.page-about .about-stat__num {
  display: block;
  font-size: clamp(24px, 5vw, 34px);
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 6px;
  font-size: var(--fs-12);
  line-height: 1.5;
  color: var(--mist);
}

.page-about .about-hero__figure {
  margin: 0;
  border: var(--bw) solid var(--line);
  box-shadow: var(--shadow-slab);
  background: var(--pine);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 7 / 5;
  object-fit: cover;
}

.page-about .about-hero__caption {
  padding: 12px 14px;
  border-top: var(--bw) solid var(--line);
  font-family: var(--font-serif);
  font-size: var(--fs-14);
  color: var(--mist);
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 30px 0 84px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    gap: 64px;
    align-items: center;
  }

  .page-about .about-hero__figure {
    transform: translateY(28px) rotate(-0.6deg);
  }
}

/* ---------------------------------------------------------
   2. 纵向时间轴
   --------------------------------------------------------- */
.page-about .about-timeline {
  position: relative;
  padding: 64px 0 56px;
  background: linear-gradient(180deg, rgba(12, 42, 34, 0) 0%, rgba(12, 42, 34, 0.72) 22%, rgba(12, 42, 34, 0.72) 78%, rgba(12, 42, 34, 0) 100%);
}

.page-about .about-timeline__list {
  --tl-pad: 30px;
  position: relative;
  margin: 40px 0 0;
  padding: 0 0 0 var(--tl-pad);
  list-style: none;
  border-left: var(--bw) solid var(--line);
}

.page-about .about-node {
  position: relative;
  padding: 0 0 40px 0;
  max-width: 62ch;
}

.page-about .about-node:last-child {
  padding-bottom: 0;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  top: 10px;
  left: calc(-1 * var(--tl-pad) - 7px);
  width: 12px;
  height: 12px;
  background: var(--cyan);
  border: var(--bw) solid var(--ink);
  box-shadow: 0 0 0 var(--bw) var(--cyan);
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-node:nth-child(even)::before {
  background: var(--gold);
  box-shadow: 0 0 0 var(--bw) var(--gold);
}

.page-about .about-node__index {
  display: block;
  font-size: var(--fs-12);
  letter-spacing: 0.16em;
  color: var(--mist);
  margin-bottom: 6px;
}

.page-about .about-node__title {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.35;
  color: var(--white);
}

.page-about .about-node__text {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-node:hover::before {
  background: var(--cyan);
  box-shadow: 0 0 0 var(--bw) var(--cyan), 0 0 14px var(--cyan-edge);
}

.page-about .about-node:hover .about-node__title {
  color: var(--cyan);
}

@media (min-width: 900px) {
  .page-about .about-timeline {
    padding: 88px 0 76px;
  }

  .page-about .about-timeline__list {
    --tl-pad: 56px;
    margin-top: 56px;
  }

  .page-about .about-node {
    padding-bottom: 52px;
  }

  .page-about .about-node:nth-child(even) {
    margin-left: 52px;
  }
}

/* ---------------------------------------------------------
   3. 团队分工
   --------------------------------------------------------- */
.page-about .about-team {
  padding: 64px 0;
}

.page-about .about-team__grid {
  display: grid;
  gap: 40px;
  margin-top: 40px;
}

.page-about .about-team__bars {
  display: grid;
  gap: 26px;
}

.page-about .about-bar {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "label value"
    "track track"
    "duty  duty";
  gap: 8px 12px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-bar__label {
  grid-area: label;
  font-family: var(--font-display);
  font-size: var(--fs-16);
  font-weight: 900;
  letter-spacing: -0.01em;
  text-transform: none;
}

.page-about .about-bar__value {
  grid-area: value;
  font-size: var(--fs-20);
  color: var(--cyan);
}

.page-about .about-bar__track {
  grid-area: track;
  display: block;
  height: 8px;
  background: var(--line);
  overflow: hidden;
}

.page-about .about-bar__fill {
  display: block;
  height: 100%;
  width: var(--w, 0);
  background: var(--grad-key);
  transition: width var(--dur) var(--ease);
}

.page-about .about-bar__duty {
  grid-area: duty;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-bar:hover .about-bar__value {
  color: var(--white);
}

.page-about .about-team__figure {
  margin: 0;
  border: var(--bw) solid var(--line);
  box-shadow: var(--shadow-slab);
  background: var(--pine);
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

.page-about .about-team__caption {
  padding: 12px 16px;
  border-top: var(--bw) solid var(--line);
  font-family: var(--font-serif);
  font-size: var(--fs-14);
  color: var(--mist);
}

@media (min-width: 900px) {
  .page-about .about-team {
    padding: 88px 0;
  }

  .page-about .about-team__grid {
    grid-template-columns: 7fr 5fr;
    gap: 56px;
    align-items: start;
  }

  .page-about .about-team__figure {
    transform: translateY(46px);
  }
}

/* ---------------------------------------------------------
   4. 数据流程
   --------------------------------------------------------- */
.page-about .about-flow {
  position: relative;
  padding: 64px 0;
  background:
    repeating-linear-gradient(
      -6deg,
      rgba(20, 32, 29, 0.55) 0px,
      rgba(20, 32, 29, 0.55) 1px,
      transparent 1px,
      transparent 26px
    ),
    var(--ink);
}

.page-about .about-flow__steps {
  display: grid;
  gap: 22px;
  margin: 40px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: none;
}

.page-about .about-step {
  position: relative;
  padding: 22px 20px 24px;
  border: var(--bw) solid var(--frame);
  background: var(--ink);
  box-shadow: var(--shadow-slab);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-step::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 42%;
  height: var(--bw);
  background: var(--cyan);
}

.page-about .about-step__num {
  display: block;
  font-size: var(--fs-28);
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .about-step__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: var(--fs-20);
  font-weight: 900;
  letter-spacing: -0.01em;
  text-transform: none;
}

.page-about .about-step__text {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-step:hover {
  transform: translateY(-2px);
  border-color: var(--cyan-edge);
}

@media (min-width: 720px) {
  .page-about .about-flow__steps {
    grid-template-columns: repeat(2, 1fr);
    gap: 26px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-flow {
    padding: 96px 0 104px;
  }

  .page-about .about-flow__steps {
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-top: 56px;
  }

  .page-about .about-step:nth-child(2) {
    transform: translateY(44px);
  }

  .page-about .about-step:nth-child(4) {
    transform: translateY(44px);
  }

  .page-about .about-step:nth-child(2):hover,
  .page-about .about-step:nth-child(4):hover {
    transform: translateY(42px);
  }
}

/* ---------------------------------------------------------
   5. 版本演进
   --------------------------------------------------------- */
.page-about .about-versions {
  padding: 64px 0;
}

.page-about .about-versions__grid {
  display: grid;
  gap: 40px;
}

.page-about .about-versions__text {
  max-width: 46ch;
  margin: 18px 0 0;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-versions__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 28px 0 0;
}

.page-about .about-versions__cards {
  display: grid;
  gap: 20px;
}

.page-about .about-version {
  padding: 24px 22px 26px;
  border: var(--bw) solid var(--frame);
  background: var(--pine);
}

.page-about .about-version__name {
  margin: 16px 0 10px;
  font-family: var(--font-serif);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.35;
}

.page-about .about-version__desc {
  margin: 0 0 16px;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-version__list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .about-version__list li {
  position: relative;
  padding: 10px 0 10px 20px;
  font-size: var(--fs-14);
  line-height: 1.6;
  color: var(--white);
  border-bottom: 1px solid var(--line);
}

.page-about .about-version__list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 17px;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  transform: rotate(45deg);
}

.page-about .about-version:nth-child(2) .about-version__list li::before {
  background: var(--gold);
}

@media (min-width: 900px) {
  .page-about .about-versions {
    padding: 92px 0;
  }

  .page-about .about-versions__grid {
    grid-template-columns: 7fr 5fr;
    gap: 60px;
    align-items: start;
  }

  .page-about .about-versions__cards {
    gap: 24px;
  }

  .page-about .about-versions__cards .about-version:nth-child(2) {
    margin-left: 26px;
  }
}

/* ---------------------------------------------------------
   6. 覆盖与合作
   --------------------------------------------------------- */
.page-about .about-reach {
  padding: 64px 0;
  background: linear-gradient(180deg, rgba(6, 18, 15, 0) 0%, rgba(12, 42, 34, 0.6) 40%, rgba(6, 18, 15, 0) 100%);
}

.page-about .about-reach__grid {
  display: grid;
  gap: 40px;
  align-items: center;
}

.page-about .about-reach__text {
  max-width: 48ch;
  margin: 18px 0 0;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-reach__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2px;
  margin: 34px 0 0;
  padding: 0;
  border: var(--bw) solid var(--line);
  background: var(--line);
}

.page-about .about-reach__stat {
  padding: 18px 16px;
  background: var(--ink);
}

.page-about .about-reach__stat dt {
  font-size: var(--fs-12);
  line-height: 1.5;
  color: var(--mist);
}

.page-about .about-reach__stat dd {
  margin: 8px 0 0;
  font-size: clamp(26px, 6vw, 34px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-reach__stat dd small {
  font-size: 0.5em;
  color: var(--mist);
}

.page-about .about-reach__figure {
  margin: 0;
  border: var(--bw) solid var(--line);
  background: var(--pine);
  box-shadow: var(--shadow-slab);
}

.page-about .about-reach__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-reach__caption {
  padding: 12px 16px;
  border-top: var(--bw) solid var(--line);
  font-family: var(--font-serif);
  font-size: var(--fs-14);
  color: var(--mist);
}

@media (min-width: 900px) {
  .page-about .about-reach {
    padding: 88px 0;
  }

  .page-about .about-reach__grid {
    grid-template-columns: 8fr 4fr;
    gap: 56px;
  }

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

/* ---------------------------------------------------------
   7. 常见问题
   --------------------------------------------------------- */
.page-about .about-faq {
  padding: 64px 0 80px;
}

.page-about .about-faq__list {
  margin-top: 36px;
  display: grid;
  gap: 14px;
}

.page-about .about-faq__item {
  border: var(--bw) solid var(--frame);
  background: var(--pine);
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-faq__heading {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
}

.page-about .about-faq__trigger {
  width: 100%;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  padding: 20px 22px;
  background: none;
  border: 0;
  color: var(--white);
  font-family: var(--font-display);
  font-size: var(--fs-16);
  font-weight: 900;
  line-height: 1.5;
  letter-spacing: -0.01em;
  text-align: left;
  cursor: pointer;
}

.page-about .about-faq__trigger:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .about-faq__icon {
  position: relative;
  flex: 0 0 auto;
  width: 18px;
  height: 18px;
  margin-top: 4px;
}

.page-about .about-faq__icon::before,
.page-about .about-faq__icon::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.page-about .about-faq__icon::before {
  top: 8px;
  left: 0;
  width: 18px;
  height: 2px;
}

.page-about .about-faq__icon::after {
  top: 0;
  left: 8px;
  width: 2px;
  height: 18px;
}

.page-about .about-faq__trigger[aria-expanded="true"] .about-faq__icon::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .about-faq__panel {
  padding: 0 22px 22px;
}

.page-about .about-faq__panel[hidden] {
  display: none;
}

.page-about .about-faq__panel p {
  margin: 0;
  padding-top: 4px;
  border-top: 1px solid var(--line);
  padding-block-start: 16px;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-faq__item:hover {
  border-color: var(--cyan-edge);
}

.page-about .about-faq__more {
  margin: 32px 0 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-faq__link {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-faq__link:hover {
  color: var(--white);
}

@media (min-width: 760px) {
  .page-about .about-faq {
    padding: 88px 0 108px;
  }

  .page-about .about-faq__trigger {
    padding: 24px 28px;
    font-size: var(--fs-20);
  }

  .page-about .about-faq__panel {
    padding: 0 28px 26px;
  }

  .page-about .about-faq__panel p {
    max-width: 68ch;
  }

  .page-about .about-faq__more {
    margin-top: 40px;
  }
}

/* ---------------------------------------------------------
   8. 降级与无障碍
   --------------------------------------------------------- */
.page-about .about-slash + .about-slash {
  display: none;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-step,
  .page-about .about-node::before,
  .page-about .about-bar__fill,
  .page-about .about-faq__item,
  .page-about .about-faq__icon::before,
  .page-about .about-faq__icon::after {
    transition: none;
  }

  .page-about .about-step:hover,
  .page-about .about-step:nth-child(2),
  .page-about .about-step:nth-child(4) {
    transform: none;
  }
}

.page-about {
  --frame: currentColor;
  --w: 1rem;
}