.page-about {
  --about-cut: 20px;
  --about-hair: rgba(143, 167, 158, .22);
  --about-body: rgba(243, 237, 226, .8);
  --about-dim: rgba(243, 237, 226, .62);
  background: var(--ink);
  color: var(--cream);
  overflow-x: hidden;
}

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(2rem, 5vw, 3.25rem) 0 clamp(2.5rem, 7vw, 5rem);
  background:
    linear-gradient(164deg, var(--ink-2) 0 44%, transparent 44.2%),
    linear-gradient(164deg, transparent 0 72%, rgba(255, 106, 31, .16) 72.2% 100%),
    var(--ink);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  right: -10%;
  width: 42%;
  background: repeating-linear-gradient(112deg, rgba(47, 224, 200, .07) 0 1px, transparent 1px 14px);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.75rem, 5vw, 3.5rem);
}

.page-about .about-hero__title {
  margin: .75rem 0 1.25rem;
  font-size: clamp(2.05rem, 7vw, 4.1rem);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--cream);
}

.page-about .about-hero__lead {
  max-width: 46ch;
  color: var(--about-body);
}

.page-about .hero-facts {
  list-style: none;
  margin: 0;
  padding: 0 0 0 clamp(.9rem, 2vw, 1.4rem);
  border-left: 1px solid var(--about-hair);
  display: grid;
  gap: clamp(.9rem, 2.4vw, 1.35rem);
}

.page-about .hero-facts__row {
  display: grid;
  gap: .2rem;
}

.page-about .hero-facts__num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 5vw, 2.1rem);
  line-height: 1;
  color: var(--orange);
  letter-spacing: -.01em;
}

.page-about .hero-facts__u {
  font-size: .5em;
  margin-left: .18em;
  color: var(--orange-soft);
}

.page-about .hero-facts__lbl {
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--mist);
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
  }
}

/* 章节流 */
.page-about .about-flow {
  padding-bottom: clamp(2rem, 5vw, 3.5rem);
}

.page-about .trace {
  display: block;
  width: 100%;
  height: clamp(38px, 6vw, 58px);
  color: var(--about-hair);
}

.page-about .trace line {
  stroke: currentColor;
  stroke-width: 1;
  stroke-dasharray: 4 10;
}

.page-about .trace circle {
  fill: var(--cyan);
}

.page-about .chapter {
  position: relative;
  display: grid;
  gap: clamp(1.1rem, 3vw, 1.75rem);
  padding-block: clamp(1.5rem, 4vw, 2.5rem);
  scroll-margin-top: calc(var(--band-h, 46px) + 96px);
}

.page-about .chapter__num {
  justify-self: start;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  line-height: 1;
  letter-spacing: .18em;
  color: var(--cyan);
  text-decoration: none;
  padding: 0 0 .55rem;
  border-bottom: 2px solid rgba(47, 224, 200, .38);
}

.page-about .chapter__num:hover,
.page-about .chapter__num:focus-visible {
  color: var(--orange);
  border-bottom-color: rgba(255, 106, 31, .55);
}

.page-about .chapter__title {
  margin: 0 0 1rem;
  font-size: clamp(1.55rem, 4.4vw, 2.5rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.02em;
  color: var(--cream);
}

.page-about .chapter__body p {
  max-width: 64ch;
  margin: 0 0 1.05em;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--about-body);
  overflow-wrap: break-word;
}

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

.page-about .inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 224, 200, .45);
  padding-bottom: 1px;
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  color: var(--orange);
  border-bottom-color: rgba(255, 106, 31, .6);
}

.page-about .chapter__aside {
  min-width: 0;
  border-top: 1px solid var(--about-hair);
  padding-top: 1rem;
}

@media (min-width: 960px) {
  .page-about .chapter {
    grid-template-columns: 68px minmax(0, 1fr) minmax(230px, 290px);
    column-gap: clamp(1.25rem, 3vw, 2.75rem);
    align-items: start;
  }

  .page-about .chapter__num {
    writing-mode: vertical-rl;
    padding: 0 .55rem 0 0;
    border-bottom: 0;
    border-right: 2px solid rgba(47, 224, 200, .38);
    letter-spacing: .3em;
    margin-top: .35rem;
  }

  .page-about .chapter__num:hover,
  .page-about .chapter__num:focus-visible {
    border-right-color: rgba(255, 106, 31, .55);
    border-bottom-color: transparent;
  }
}

/* 侧栏数字 */
.page-about .factlist {
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

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

.page-about .factlist dt {
  font-size: .66rem;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--mist);
  margin-bottom: .22rem;
}

.page-about .factlist__val {
  position: relative;
  margin: 0;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(1.1rem, 3vw, 1.35rem);
  line-height: 1.25;
  color: var(--cream);
  outline: none;
}

.page-about .factlist__val[data-note] {
  cursor: default;
  border-bottom: 1px dotted rgba(143, 167, 158, .45);
  padding-bottom: .1rem;
}

.page-about .factlist__val[data-note]::after {
  content: attr(data-note);
  position: absolute;
  left: 0;
  top: calc(100% + .45rem);
  width: max-content;
  max-width: min(260px, 74vw);
  padding: .42rem .62rem;
  background: var(--cyan);
  color: var(--ink);
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 500;
  letter-spacing: .02em;
  line-height: 1.55;
  border-radius: 2px;
  opacity: 0;
  transform: translateY(-5px);
  transition: opacity .22s ease, transform .22s ease;
  pointer-events: none;
  z-index: 4;
}

.page-about .factlist__val[data-note]:hover::after,
.page-about .factlist__val[data-note]:focus-visible::after {
  opacity: 1;
  transform: translateY(0);
}

/* 版本轨迹 */
.page-about .mile {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0 0 0 1.35rem;
  position: relative;
}

.page-about .mile::before {
  content: "";
  position: absolute;
  left: 0;
  top: .6rem;
  bottom: 1.4rem;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(47, 224, 200, .06));
}

.page-about .mile__item {
  position: relative;
  padding-bottom: 1.15rem;
}

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

.page-about .mile__item::before {
  content: "";
  position: absolute;
  left: -1.35rem;
  top: .5rem;
  width: 7px;
  height: 7px;
  margin-left: -3px;
  border-radius: 50%;
  background: var(--cyan);
}

.page-about .mile__ver {
  display: inline-block;
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .18em;
  color: var(--cyan);
  border: 1px solid rgba(47, 224, 200, .42);
  border-radius: 2px;
  padding: .08rem .42rem;
  margin-bottom: .35rem;
}

.page-about .mile__text {
  margin: 0;
  max-width: 62ch;
  font-size: .92rem;
  line-height: 1.72;
  color: var(--about-body);
}

/* 节奏 */
.page-about .pace {
  display: grid;
  gap: 1px;
  margin: 1.6rem 0 1.4rem;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, var(--about-cut) 100%, 0 calc(100% - var(--about-cut)));
}

.page-about .pace__item {
  background: var(--ink-2);
  padding: 1.05rem .95rem;
}

.page-about .pace__num {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(1.55rem, 5vw, 2.15rem);
  line-height: 1;
  color: var(--orange);
}

.page-about .pace__unit {
  display: block;
  margin-top: .35rem;
  font-size: .7rem;
  letter-spacing: .22em;
  color: var(--mist);
}

.page-about .pace__say {
  margin: .5rem 0 0;
  font-size: .8rem;
  line-height: 1.6;
  color: var(--about-dim);
}

@media (min-width: 700px) {
  .page-about .pace {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* 覆盖范围 */
.page-about .reach {
  list-style: none;
  margin: 1.5rem 0 1.4rem;
  padding: 0;
  display: grid;
  gap: 1.25rem;
}

.page-about .reach__item {
  border-left: 2px solid var(--orange);
  padding-left: .9rem;
}

.page-about .reach__item:nth-child(2) {
  border-left-color: var(--cyan);
}

.page-about .reach__item:nth-child(3) {
  border-left-color: var(--warn);
}

.page-about .reach__item:nth-child(4) {
  border-left-color: var(--orange-soft);
}

.page-about .reach__num {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(1.8rem, 6vw, 2.7rem);
  line-height: 1;
  color: var(--cream);
}

.page-about .reach__lbl {
  display: block;
  margin-top: .38rem;
  font-size: .78rem;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--mist);
}

@media (min-width: 700px) {
  .page-about .reach {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* 合作生态 */
.page-about .eco {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
  margin: 1.6rem 0 1.4rem;
}

.page-about .eco__visual {
  display: grid;
  gap: .9rem;
  justify-items: center;
}

.page-about .eco-ring {
  width: min(100%, 300px);
  height: auto;
}

.page-about .eco-ring__orbit {
  fill: none;
  stroke: rgba(47, 224, 200, .3);
  stroke-width: 1;
  stroke-dasharray: 3 7;
}

.page-about .eco-ring__orbit--outer {
  stroke: rgba(255, 106, 31, .38);
  stroke-dasharray: 3 10;
}

.page-about .eco-ring__core {
  fill: var(--orange);
}

.page-about .eco-ring__label {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  fill: var(--ink);
}

.page-about .eco-ring__dot--a {
  fill: var(--cyan);
}

.page-about .eco-ring__dot--b {
  fill: var(--orange-soft);
}

.page-about .eco__legend {
  margin: 0;
  font-size: .74rem;
  letter-spacing: .08em;
  line-height: 1.7;
  color: var(--mist);
  text-align: center;
}

.page-about .eco__key {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  margin-right: .3rem;
  vertical-align: middle;
}

.page-about .eco__key--a {
  background: var(--cyan);
}

.page-about .eco__key--b {
  background: var(--orange-soft);
}

.page-about .eco__side {
  min-width: 0;
  display: grid;
  gap: 1rem;
  align-content: start;
}

.page-about .eco__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .eco__item {
  background: var(--ink-2);
  padding: .9rem 1rem;
  border-left: 2px solid transparent;
}

.page-about .eco__item[data-tag="数据源"] {
  border-left-color: var(--cyan);
}

.page-about .eco__item[data-tag="社群"] {
  border-left-color: var(--orange-soft);
}

.page-about .eco__item.is-hidden {
  display: none;
}

.page-about .eco__tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: .64rem;
  letter-spacing: .22em;
  color: var(--mist);
  margin-bottom: .32rem;
}

.page-about .eco__text {
  margin: 0;
  font-size: .88rem;
  line-height: 1.7;
  color: var(--about-body);
}

@media (min-width: 880px) {
  .page-about .eco {
    grid-template-columns: minmax(0, 300px) minmax(0, 1fr);
    align-items: start;
  }
}

/* 收尾 */
.page-about .about-cta {
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
  padding: clamp(2rem, 5vw, 3.25rem) 0 clamp(2.25rem, 5vw, 3.5rem);
  background: linear-gradient(196deg, var(--ink-3) 0 58%, rgba(255, 106, 31, .14) 58.2% 100%);
  border-top: 1px solid var(--about-hair);
}

.page-about .about-cta__inner {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-cta__title {
  margin: 0 0 .7rem;
  font-size: clamp(1.4rem, 4vw, 2.1rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.02em;
  color: var(--cream);
}

.page-about .about-cta__say {
  margin: 0;
  max-width: 52ch;
  font-size: .95rem;
  line-height: 1.75;
  color: var(--about-dim);
}

.page-about .about-cta__acts {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

@media (min-width: 880px) {
  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }
}

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

@media (prefers-reduced-motion: reduce) {
  .page-about .factlist__val[data-note]::after {
    transition: none;
  }
}