/* ================= 平台介绍页 · page-about ================= */
.page-about {
  --about-hair: rgba(166, 188, 178, 0.22);
  --about-hair-cy: rgba(111, 242, 206, 0.38);
  --about-hair-or: rgba(255, 139, 61, 0.42);
  --about-tl-offset: 2.4rem;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  margin-bottom: clamp(1.4rem, 4.5vw, 2.6rem);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero__lead {
  align-items: end;
  row-gap: clamp(1.8rem, 5vw, 2.8rem);
}

.page-about .about-hero__head h1 {
  margin: 0.5rem 0 0;
}

.page-about .about-hero__head .lede {
  margin-top: 1.1rem;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-hero__stats > .stat {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: clamp(0.9rem, 2.6vw, 1.2rem);
  background: var(--panel);
}

.page-about .about-hero__stats .stat__num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4.2vw, 2.1rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--cream);
}

.page-about .about-hero__stats .stat__label {
  font-size: 0.76rem;
  line-height: 1.5;
  letter-spacing: 0.03em;
  color: var(--gray-green);
}

.page-about .about-hero__figure {
  margin: clamp(2rem, 6vw, 3.4rem) 0 0;
}

.page-about .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
}

.page-about .media__caption {
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--gray-green);
}

/* ---------- 使用者标签页 ---------- */
.page-about .about-audience .section__head {
  max-width: 46rem;
}

.page-about .about-tabs {
  margin: clamp(1.4rem, 4vw, 2rem) 0 clamp(1.1rem, 3vw, 1.5rem);
}

.page-about .about-tabpanel {
  max-width: 62ch;
  padding: clamp(1.1rem, 3vw, 1.7rem) clamp(1.1rem, 3vw, 1.8rem);
  border: 1px solid var(--about-hair);
  border-left: 2px solid var(--cyan);
  border-radius: var(--radius);
  background: rgba(7, 35, 29, 0.55);
  color: var(--cream);
  line-height: 1.85;
}

.page-about .about-tabpanel p {
  margin: 0;
}

/* ---------- 收录历程 ---------- */
.page-about .about-history .section__head {
  max-width: 54rem;
}

.page-about .about-history__figure {
  margin: clamp(1.6rem, 4.5vw, 2.4rem) 0 clamp(2.2rem, 6vw, 3.4rem);
}

.page-about .about-tl {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--about-tl-offset);
  display: grid;
  gap: clamp(1.4rem, 4.5vw, 2.4rem);
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 0.7rem;
  bottom: 0.7rem;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(111, 242, 206, 0.22) 42%, var(--orange) 100%);
}

.page-about .about-tl__item {
  position: relative;
  padding: 0.3rem 0.9rem 0.9rem 0;
  border-radius: var(--radius);
  transition: background-color 260ms var(--ease);
}

.page-about .about-tl__item:hover {
  background: rgba(20, 82, 67, 0.26);
}

.page-about .about-tl__dot {
  position: absolute;
  left: calc(-1 * var(--about-tl-offset));
  top: 0.55rem;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(7, 35, 29, 0.92);
}

.page-about .about-tl__dot--orange {
  border-color: var(--orange);
}

.page-about .about-tl__date {
  margin: 0;
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-tl__item:has(.about-tl__dot--orange) .about-tl__date {
  color: var(--orange-soft);
}

.page-about .about-tl__title {
  margin: 0.4rem 0 0.5rem;
  color: var(--cream);
}

.page-about .about-tl__text {
  margin: 0;
  max-width: 60ch;
  color: var(--cream);
  line-height: 1.85;
}

/* ---------- 留白呼吸段 ---------- */
.page-about .about-breath {
  height: clamp(4rem, 13vw, 10rem);
  margin: 0 auto;
  max-width: var(--shell);
  background-image:
    linear-gradient(to right, var(--about-hair) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-hair) 1px, transparent 1px);
  background-size: 88px 88px;
  -webkit-mask-image: linear-gradient(90deg, transparent 0%, #000 32%, #000 68%, transparent 100%);
  mask-image: linear-gradient(90deg, transparent 0%, #000 32%, #000 68%, transparent 100%);
}

/* ---------- 协作流程 ---------- */
.page-about .about-flow .section__head {
  max-width: 52rem;
  margin-bottom: clamp(1.6rem, 5vw, 2.6rem);
}

.page-about .about-flow__grid {
  align-items: start;
  row-gap: clamp(1.6rem, 5vw, 2.4rem);
}

.page-about .about-flow__media .media {
  margin: 0;
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-steps > li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(0.8rem, 2.4vw, 1.2rem);
  padding: clamp(1rem, 3vw, 1.5rem);
  border-top: 1px solid var(--about-hair);
  background: rgba(14, 54, 44, 0.75);
  transition: background-color 240ms var(--ease);
}

.page-about .about-steps > li:first-child {
  border-top: 0;
}

.page-about .about-steps > li:hover {
  background: var(--raise);
}

.page-about .about-steps__no {
  font-size: 1.05rem;
  line-height: 1.4;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .about-steps__title {
  margin: 0 0 0.4rem;
  font-size: 1.02rem;
  letter-spacing: 0.02em;
  color: var(--cream);
}

.page-about .about-steps p {
  margin: 0;
  max-width: 54ch;
  color: var(--gray-green);
  line-height: 1.8;
}

/* ---------- 两版并排 ---------- */
.page-about .about-versions__grid {
  align-items: start;
  row-gap: clamp(1.6rem, 5vw, 2.6rem);
}

.page-about .about-versions__head h2 {
  margin: 0.5rem 0 0;
}

.page-about .about-versions__big {
  display: block;
  margin-top: clamp(1.2rem, 4vw, 2.2rem);
  font-size: clamp(3.6rem, 12vw, 7rem);
  line-height: 0.86;
  letter-spacing: -0.04em;
  color: transparent;
  -webkit-text-stroke: 1px var(--about-hair-cy);
}

.page-about .about-versions__body p + p {
  margin-top: 1rem;
}

.page-about .about-diff {
  list-style: none;
  margin: clamp(1.4rem, 4vw, 2rem) 0 0;
  padding: 0;
  display: grid;
  gap: 0.65rem;
}

.page-about .about-diff__row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.9rem;
  align-items: start;
  padding: 0.9rem 1rem;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  background: rgba(14, 54, 44, 0.6);
}

.page-about .about-diff__row--match {
  border-color: var(--about-hair-cy);
}

.page-about .about-diff__row--note {
  border-color: var(--about-hair-or);
}

.page-about .about-diff__tag {
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  white-space: nowrap;
  color: var(--ink);
}

.page-about .about-diff__row--match .about-diff__tag {
  background: var(--cyan);
}

.page-about .about-diff__row--note .about-diff__tag {
  background: var(--orange);
}

.page-about .about-diff__text {
  color: var(--cream);
  line-height: 1.75;
}

/* ---------- 反馈闭环 ---------- */
.page-about .about-feedback .section__head {
  max-width: 50rem;
  margin-bottom: clamp(1.6rem, 5vw, 2.4rem);
}

.page-about .about-feed {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(1rem, 3vw, 1.5rem);
}

.page-about .about-feed > li {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: clamp(0.8rem, 2.4vw, 1.4rem);
  padding-bottom: clamp(0.9rem, 2.6vw, 1.3rem);
  border-bottom: 1px solid var(--about-hair);
}

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

.page-about .about-feed__no {
  font-size: 1.35rem;
  line-height: 1.3;
  color: var(--orange);
}

.page-about .about-feed__title {
  margin: 0 0 0.35rem;
  font-size: 1.02rem;
  letter-spacing: 0.02em;
  color: var(--cream);
}

.page-about .about-feed p {
  margin: 0;
  max-width: 58ch;
  color: var(--cream);
  line-height: 1.82;
}

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

.page-about .about-feedback__note {
  margin-top: clamp(1.4rem, 4vw, 2rem);
  max-width: 62ch;
}

/* ---------- 收尾指引 ---------- */
.page-about .about-next__inner {
  display: grid;
  gap: clamp(1rem, 3vw, 1.4rem);
  padding-top: clamp(0.4rem, 2vw, 1rem);
  border-top: 1px solid var(--about-hair);
}

.page-about .about-next__lead {
  margin: 0;
  color: var(--gray-green);
  font-size: 0.92rem;
  letter-spacing: 0.02em;
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 768px) {
  .page-about {
    --about-tl-offset: 3.4rem;
  }

  .page-about .about-hero__lead {
    row-gap: 0;
  }

  .page-about .about-feed > li {
    grid-template-columns: 3.4rem minmax(0, 1fr);
  }

  .page-about .about-next__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-versions__big {
    margin-top: clamp(1.6rem, 3vw, 2.6rem);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__item,
  .page-about .about-steps > li {
    transition: none;
  }
}