/* ===== 平台介绍页 · 时间线卷轴 ===== */
.page-about {
  --about-dim-paper: #5A6874;
  --about-line-paper: rgba(38, 49, 61, .16);
  --about-pad: clamp(24px, 4vw, 52px);
  --about-gap: clamp(18px, 3vw, 34px);
}

.page-about .about-crumbs {
  margin-bottom: clamp(14px, 3vw, 28px);
}

/* ---------- 开场 ---------- */
.page-about .about-open .eyebrow {
  margin: 0 0 10px;
}

.page-about .about-h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--glass);
  max-width: 22ch;
}

.page-about .about-lead {
  margin-top: 18px;
  max-width: 62ch;
  color: var(--mist);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 18px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: linear-gradient(155deg, rgba(232, 240, 247, .07), rgba(19, 43, 69, .35));
}

.page-about .about-stat .stat__num {
  font-size: clamp(26px, 4vw, 40px);
  line-height: 1;
  color: var(--barley);
  letter-spacing: -.01em;
}

.page-about .about-stat .stat__label {
  font-size: var(--fs-1);
  color: var(--mist);
}

.page-about .about-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-top: clamp(24px, 4vw, 38px);
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-jump .link-sweep {
  font-size: var(--fs-1);
  color: var(--mist);
}

/* ---------- 章节公共头 ---------- */
.page-about .about-band {
  display: block;
  height: 2px;
  width: clamp(56px, 18vw, 140px);
  background: linear-gradient(90deg, var(--saffron), var(--barley));
  margin-bottom: 18px;
}

.page-about .about-chaphead {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 18px;
  margin-bottom: clamp(22px, 3.4vw, 40px);
}

.page-about .about-chaphead .chapter__num {
  font-size: clamp(26px, 3.6vw, 40px);
  line-height: 1;
  color: var(--saffron);
  opacity: .9;
}

.page-about .about-chaphead .chapter__title {
  margin: 0;
  flex: 1 1 20ch;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.4vw, 40px);
  line-height: 1.2;
  letter-spacing: -.015em;
  color: var(--glass);
}

.page-about .about-chaphead .chapter__label {
  font-size: var(--fs-1);
  color: var(--mist);
  letter-spacing: .06em;
}

/* ---------- 01 三类服务 ---------- */
.page-about .about-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}

.page-about .about-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-card .file-card__title {
  margin: 0;
  font-size: var(--fs-4);
  line-height: 1.3;
  font-weight: 700;
  color: var(--glass);
}

.page-about .about-card .file-card__text {
  margin: 0;
  color: var(--mist);
  font-size: var(--fs-2);
  line-height: 1.75;
}

.page-about .about-card .file-card__meta {
  margin: auto 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: var(--fs-1);
  color: var(--barley);
  letter-spacing: .04em;
}

/* ---------- 02 版本演进时间线 ---------- */
.page-about .about-tl {
  position: relative;
  overflow: hidden;
  border-radius: 20px;
  border: 1px solid var(--line-soft);
  padding: clamp(22px, 4vw, 48px) clamp(20px, 4vw, 46px);
  background: linear-gradient(165deg, rgba(19, 43, 69, .92), rgba(11, 27, 43, .97));
}

.page-about .about-tl__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  opacity: .2;
  pointer-events: none;
}

.page-about .about-tl__list {
  position: relative;
  margin: 0;
  padding: 0 0 0 clamp(22px, 4vw, 34px);
  list-style: none;
  display: grid;
  gap: clamp(14px, 2.4vw, 24px);
}

.page-about .about-tl__list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 14px;
  bottom: 14px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--saffron), rgba(179, 37, 43, .22) 58%, var(--barley));
}

.page-about .about-tl__item {
  position: relative;
  padding: 18px clamp(16px, 2.6vw, 26px);
  border: 1px solid var(--line-soft);
  border-left: 2px solid transparent;
  border-radius: 14px;
  background: rgba(232, 240, 247, .055);
  transition: transform .2s ease, border-color .2s ease, background-color .2s ease;
}

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: calc(-1 * clamp(22px, 4vw, 34px) - 1px);
  top: 26px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--mist);
  box-shadow: 0 0 0 3px rgba(11, 27, 43, .95);
  transition: background-color .2s ease, box-shadow .2s ease;
}

.page-about .about-tl__item:hover,
.page-about .about-tl__item:focus-within {
  transform: translateY(-2px);
  border-left-color: var(--barley);
  background: rgba(232, 240, 247, .1);
}

.page-about .about-tl__item:hover::before,
.page-about .about-tl__item:focus-within::before {
  background: var(--barley);
  box-shadow: 0 0 0 3px rgba(11, 27, 43, .95), 0 0 0 7px rgba(224, 168, 58, .22);
}

.page-about .about-tl__year {
  margin: 0 0 6px;
  font-size: var(--fs-3);
  letter-spacing: .06em;
  color: var(--barley);
}

.page-about .about-tl__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: var(--fs-4);
  font-weight: 700;
  line-height: 1.3;
  color: var(--glass);
}

.page-about .about-tl__text {
  margin: 0;
  font-size: var(--fs-2);
  line-height: 1.75;
  color: var(--mist);
  max-width: 66ch;
}

.page-about .about-tl__outcome {
  margin: 12px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: var(--fs-1);
  line-height: 1.7;
  color: var(--mist);
  transition: color .2s ease;
}

.page-about .about-tl__item:hover .about-tl__outcome,
.page-about .about-tl__item:focus-within .about-tl__outcome {
  color: var(--barley);
}

/* ---------- 03 / 05 浅色内容层 ---------- */
.page-about .about-panel {
  background: var(--paper);
  color: var(--paper-ink);
  border-radius: 22px;
  padding: var(--about-pad);
  border: 1px solid rgba(38, 49, 61, .08);
}

.page-about .about-panel .about-chaphead .chapter__title {
  color: var(--paper-ink);
}

.page-about .about-panel .about-chaphead .chapter__label {
  color: var(--about-dim-paper);
}

.page-about .about-panel .about-chaphead .chapter__num {
  color: var(--saffron);
}

.page-about .about-panel .about-band {
  background: linear-gradient(90deg, var(--saffron), var(--barley));
}

.page-about .about-panel .lead {
  color: var(--about-dim-paper);
}

.page-about .about-team__grid,
.page-about .about-region__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3.4vw, 40px);
  align-items: start;
}

.page-about .about-team__lead {
  margin: 0 0 clamp(18px, 3vw, 28px);
  max-width: 56ch;
}

.page-about .about-roles {
  list-style: none;
  margin: 0 0 clamp(22px, 3.4vw, 34px);
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-role {
  padding: 16px 18px;
  background: rgba(255, 255, 255, .72);
  border: 1px solid var(--about-line-paper);
  border-radius: 14px;
  transition: transform .2s ease, border-color .2s ease;
}

.page-about .about-role:hover {
  transform: translateY(-2px);
  border-color: rgba(179, 37, 43, .45);
}

.page-about .about-role__key {
  display: inline-block;
  margin-bottom: 6px;
  padding: 3px 10px;
  font-size: var(--fs-1);
  letter-spacing: .05em;
  color: var(--paper);
  background: var(--saffron);
  border-radius: 999px;
}

.page-about .about-role__text {
  margin: 0;
  font-size: var(--fs-2);
  line-height: 1.75;
  color: var(--paper-ink);
}

.page-about .about-chain {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(128px, 1fr));
  gap: 10px;
}

.page-about .about-chain__step {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--about-line-paper);
  border-top: 2px solid var(--cyan);
  background: rgba(255, 255, 255, .6);
}

.page-about .about-chain__step:nth-child(4),
.page-about .about-chain__step:nth-child(5) {
  border-top-color: var(--orange);
}

.page-about .about-chain__idx {
  font-size: var(--fs-1);
  color: var(--barley);
  letter-spacing: .08em;
}

.page-about .about-chain__name {
  font-size: var(--fs-1);
  line-height: 1.5;
  color: var(--paper-ink);
}

.page-about .about-team__media {
  aspect-ratio: 4 / 3;
  margin: 0;
}

/* ---------- 04 覆盖范围 ---------- */
.page-about .about-coverage__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 44px);
  align-items: center;
}

.page-about .about-layers {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 16px;
  border: 1px solid var(--line-soft);
  background: rgba(19, 43, 69, .55);
}

.page-about .about-layers .lyr rect {
  transition: fill .2s ease;
}

.page-about .about-layers .lyr--league rect {
  fill: rgba(53, 196, 200, .62);
}

.page-about .about-layers .lyr--cup rect {
  fill: rgba(53, 196, 200, .34);
}

.page-about .about-layers .lyr--round rect {
  fill: rgba(240, 130, 56, .6);
}

.page-about .about-layers .lyr:hover rect {
  fill: var(--barley);
}

.page-about .about-coverage__lead {
  margin: 0 0 18px;
  font-size: var(--fs-3);
  line-height: 1.7;
  color: var(--glass);
}

.page-about .about-layerkeys {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-layerkey {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  background: rgba(232, 240, 247, .05);
  font-size: var(--fs-2);
  color: var(--mist);
  transition: border-color .2s ease, transform .2s ease;
}

.page-about .about-layerkey:hover {
  transform: translateY(-2px);
  border-color: rgba(224, 168, 58, .55);
}

.page-about .about-layerkey strong {
  font-size: var(--fs-3);
  color: var(--barley);
}

.page-about .about-layerkey__dot {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  flex: none;
}

.page-about .about-layerkey__dot--league { background: rgba(53, 196, 200, .85); }
.page-about .about-layerkey__dot--cup { background: rgba(53, 196, 200, .45); }
.page-about .about-layerkey__dot--round { background: rgba(240, 130, 56, .8); }

.page-about .about-coverage__note {
  margin: 0 0 14px;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
  font-size: var(--fs-1);
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 05 服务地区 ---------- */
.page-about .about-region__list {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-region__item {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 12px;
  border: 1px solid var(--about-line-paper);
  background: rgba(255, 255, 255, .66);
  font-size: var(--fs-2);
  color: var(--paper-ink);
}

.page-about .about-region__key {
  flex: none;
  min-width: 5.4em;
  font-size: var(--fs-2);
  color: var(--saffron);
  letter-spacing: .02em;
}

.page-about .about-region__tip {
  margin: 0;
  font-size: var(--fs-1);
  line-height: 1.85;
  color: var(--about-dim-paper);
}

.page-about .about-region__tip .link-sweep {
  color: var(--saffron);
}

.page-about .about-region__media {
  aspect-ratio: 3 / 2;
  margin: 0;
}

/* ---------- 06 下一步 ---------- */
.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}

.page-about .about-next__card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  border-top: 2px solid var(--barley);
}

.page-about .about-next__card .file-card__title {
  margin: 0;
  font-size: var(--fs-4);
  font-weight: 700;
  line-height: 1.3;
  color: var(--glass);
}

.page-about .about-next__card .file-card__text {
  margin: 0;
  font-size: var(--fs-2);
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-cta {
  margin-top: clamp(28px, 4.4vw, 48px);
  padding-top: clamp(20px, 3vw, 30px);
  border-top: 1px solid var(--line-soft);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.page-about .about-cta p {
  margin: 0;
  max-width: 62ch;
  font-size: var(--fs-2);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cta .link-sweep {
  color: var(--barley);
}

/* ---------- 媒体框适配 ---------- */
.page-about .media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-team__grid {
    grid-template-columns: 1.7fr 1fr;
  }

  .page-about .about-coverage__grid {
    grid-template-columns: 1.6fr 1fr;
  }

  .page-about .about-region__grid {
    grid-template-columns: 1.1fr 1fr;
  }
}

@media (max-width: 560px) {
  .page-about .about-region__item {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__item,
  .page-about .about-role,
  .page-about .about-layerkey,
  .page-about .about-tl__outcome,
  .page-about .about-layers .lyr rect {
    transition: none;
  }

  .page-about .about-tl__item:hover,
  .page-about .about-role:hover,
  .page-about .about-layerkey:hover {
    transform: none;
  }
}