.page-about {
  --about-gap: clamp(22px, 3.4vw, 38px);
}

/* ---------- 页头 ---------- */
.page-about .about-head {
  position: relative;
  padding: clamp(26px, 5vw, 54px) 0 clamp(26px, 4vw, 42px);
  border-bottom: 2px solid var(--line);
}
.page-about .about-head::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: clamp(90px, 14vw, 180px);
  height: 2px;
  background: var(--cyan);
}
.page-about .about-head__title {
  margin: 14px 0 0;
  font-size: clamp(31px, 6vw, 64px);
  line-height: 1.06;
  letter-spacing: -0.01em;
  max-width: 18ch;
}
.page-about .about-head__lede {
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-stats {
  list-style: none;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
@media (min-width: 820px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}
.page-about .about-stat {
  background: var(--bg);
  padding: 16px 18px 18px;
}
.page-about .about-stat__num {
  display: block;
  font-size: clamp(22px, 2.4vw, 26px);
  letter-spacing: 0.06em;
  color: var(--cyan);
}
.page-about .about-stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--muted);
}

/* ---------- 手册骨架 ---------- */
.page-about .manual {
  padding-top: clamp(26px, 4vw, 48px);
}
@media (min-width: 1020px) {
  .page-about .manual {
    display: grid;
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: start;
  }
}

.page-about .about-rail {
  display: none;
}
@media (min-width: 1020px) {
  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 112px;
  }
}
.page-about .about-rail__head {
  margin: 0 0 12px;
  padding-bottom: 10px;
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--muted);
  border-bottom: 2px solid var(--line);
}
.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-rail__link {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 10px 8px 10px 4px;
  border-left: 2px solid transparent;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.4;
  text-decoration: none;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), padding-left 0.18s var(--ease);
}
.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--cyan);
  border-left-color: var(--cyan);
  padding-left: 12px;
}
.page-about .about-rail__link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}
.page-about .about-rail__num {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
  transition: color 0.18s var(--ease);
}
.page-about .about-rail__link:hover .about-rail__num,
.page-about .about-rail__link:focus-visible .about-rail__num {
  color: var(--cyan);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding: clamp(32px, 4.6vw, 56px) 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 118px;
}
.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}
.page-about .about-sec__num {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--muted);
}
.page-about #start .about-sec__num { color: var(--cyan); }
.page-about #rooms .about-sec__num { color: var(--cyan); }
.page-about #tiers .about-sec__num { color: var(--amber); }
.page-about #team .about-sec__num { color: var(--magenta); }
.page-about #rhythm .about-sec__num { color: var(--info); }
.page-about #service .about-sec__num { color: var(--cyan); }

.page-about .about-sec__title {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  font-size: clamp(23px, 3.7vw, 40px);
  font-weight: 900;
  line-height: 1.1;
}
.page-about .about-sec__title > span {
  display: inline-block;
  padding: 8px 18px 12px;
  background: var(--mid);
  border-left: 6px solid var(--cyan);
  box-shadow: 8px 8px 0 rgba(5, 7, 15, 0.9);
}
.page-about #tiers .about-sec__title > span { border-left-color: var(--amber); }
.page-about #team .about-sec__title > span { border-left-color: var(--magenta); }
.page-about #rhythm .about-sec__title > span { border-left-color: var(--info); }

.page-about .about-text {
  max-width: 62ch;
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
}
.page-about .about-text:last-child {
  margin-bottom: 0;
}
.page-about .about-inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 2px solid var(--line);
  transition: border-color 0.18s var(--ease);
}
.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  border-bottom-color: var(--cyan);
}
.page-about .about-inline-link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  position: relative;
}
.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 26px;
  width: 2px;
  background: linear-gradient(var(--cyan), var(--line));
}
.page-about .timeline__item {
  position: relative;
  padding: 0 0 clamp(24px, 3vw, 34px) 34px;
}
.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  background: var(--bg);
  border: 2px solid var(--line);
}
.page-about .timeline__item:last-child {
  padding-bottom: 0;
}
.page-about .timeline__item:last-child::before {
  background: var(--cyan);
  border-color: var(--cyan);
}
.page-about .timeline__year {
  margin: 0 0 6px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}
.page-about .timeline__title {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 700;
  line-height: 1.35;
}
.page-about .timeline__text {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.82;
  color: var(--muted);
}
.page-about .about-badge {
  margin: 18px 0 0;
  width: min(260px, 72%);
}
.page-about .about-badge img {
  display: block;
  width: 100%;
  height: auto;
  border: 2px solid var(--line);
  box-shadow: var(--shadow-card);
  background: var(--bg-deep);
}

/* ---------- 房间准则 ---------- */
.page-about .about-banner {
  margin: 0 0 clamp(20px, 3vw, 30px);
}
.page-about .about-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border: 2px solid var(--line);
  box-shadow: var(--shadow-card);
  background: var(--bg-deep);
}

.page-about .room-rules {
  list-style: none;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  border-top: 2px solid var(--line);
}
.page-about .room-rules__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 14px 12px 14px 8px;
  border-bottom: 1px solid var(--line);
  border-left: 4px solid transparent;
  transition: border-color 0.18s var(--ease), background-color 0.18s var(--ease), padding-left 0.18s var(--ease);
}
.page-about .room-rules__row:hover,
.page-about .room-rules__row:focus-within {
  border-left-color: var(--cyan);
  background-color: rgba(53, 230, 210, 0.06);
  padding-left: 14px;
}
@media (min-width: 700px) {
  .page-about .room-rules__row {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 22px;
    align-items: baseline;
  }
}
.page-about .room-rules__name {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}
.page-about .room-rules__desc {
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .principles {
  list-style: none;
  margin: clamp(24px, 3.2vw, 36px) 0 0;
  padding: 0 0 18px;
  display: grid;
  gap: 16px;
}
@media (min-width: 760px) {
  .page-about .principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }
  .page-about .principles > li:nth-child(2) {
    transform: translateY(16px);
  }
}
.page-about .principle {
  background: var(--mid);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-card);
  padding: 18px 18px 20px;
  transition: border-color 0.18s var(--ease), transform 0.18s var(--ease);
}
.page-about .principle:hover {
  border-color: var(--cyan);
  transform: translateY(-4px);
}
.page-about .principle__num {
  display: block;
  margin-bottom: 10px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}
.page-about .principle__title {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
}
.page-about .principle__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 段位 ---------- */
.page-about .tier-track {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(20px, 2.8vw, 28px) 0 clamp(18px, 2.4vw, 24px);
}
.page-about .tier {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  padding: 9px 14px;
  border: 2px solid var(--line);
  background: var(--bg-deep);
  color: var(--ink);
}
.page-about .tier--mark {
  border-color: var(--amber);
  border-style: dashed;
  background: rgba(255, 194, 75, 0.08);
  color: var(--amber);
}

/* ---------- 团队 ---------- */
.page-about .team-block {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  align-items: start;
}
@media (min-width: 820px) {
  .page-about .team-block {
    grid-template-columns: 250px minmax(0, 1fr);
  }
}
.page-about .team-ring-wrap {
  position: relative;
  width: min(250px, 66vw);
  margin: 0 auto;
}
@media (min-width: 820px) {
  .page-about .team-ring-wrap {
    margin: 0;
  }
}
.page-about .team-ring {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .team-ring__center {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.page-about .team-ring__num {
  font-size: 34px;
  line-height: 1;
  color: var(--cyan);
}
.page-about .team-ring__label {
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--muted);
}

.page-about .team-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .team-list__item {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  transition: background-color 0.18s var(--ease);
}
.page-about .team-list__item:first-child {
  border-top: 1px solid var(--line);
}
.page-about .team-list__item:hover {
  background-color: rgba(53, 230, 210, 0.04);
}
.page-about .team-list__num {
  padding-top: 3px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}
.page-about .team-list__item:nth-child(2) .team-list__num { color: var(--magenta); }
.page-about .team-list__item:nth-child(3) .team-list__num { color: var(--amber); }
.page-about .team-list__item:nth-child(4) .team-list__num { color: var(--info); }
.page-about .team-list__title {
  margin: 0 0 5px;
  font-size: 17px;
  font-weight: 700;
}
.page-about .team-list__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 内容节奏 ---------- */
.page-about .rhythm {
  display: grid;
  gap: clamp(22px, 3.4vw, 36px);
}
@media (min-width: 900px) {
  .page-about .rhythm {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }
}
.page-about .rhythm__media {
  margin: 0;
}
.page-about .rhythm__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 2px solid var(--line);
  box-shadow: var(--shadow-card);
  background: var(--bg-deep);
}
.page-about .rhythm-stats {
  list-style: none;
  margin: 0 0 clamp(20px, 2.6vw, 26px);
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .rhythm-stat {
  background: var(--bg);
  padding: 14px 16px 16px;
}
.page-about .rhythm-stat__num {
  display: block;
  font-size: 19px;
  letter-spacing: 0.05em;
  color: var(--amber);
}
.page-about .rhythm-stat__label {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-fold {
  margin-top: 18px;
  border: 2px solid var(--line);
  background: var(--bg-deep);
  box-shadow: var(--shadow-card);
}
.page-about .about-fold > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink);
}
.page-about .about-fold > summary::-webkit-details-marker {
  display: none;
}
.page-about .about-fold > summary::after {
  content: "＋";
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cyan);
}
.page-about .about-fold[open] > summary::after {
  content: "－";
}
.page-about .about-fold > summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}
.page-about .about-fold__body {
  padding: 16px 18px 18px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 服务与联络 ---------- */
.page-about .service-panel {
  border: 2px solid var(--line);
  background: var(--mid);
  box-shadow: var(--shadow-card);
  padding: clamp(20px, 3vw, 30px);
}
.page-about .service-list {
  list-style: none;
  margin: 0 0 clamp(20px, 2.6vw, 26px);
  padding: 0;
}
.page-about .service-list li {
  display: grid;
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .service-list li:first-child {
  border-top: 1px solid var(--line);
}
.page-about .service-list__k {
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--muted);
}
.page-about .service-list__v {
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
  word-break: break-word;
}
.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(18px, 2.4vw, 24px);
}

/* ---------- 回到顶部 ---------- */
.page-about .about-totop {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 50;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 54px;
  height: 54px;
  background: var(--bg-deep);
  border: 2px solid var(--cyan);
  box-shadow: var(--shadow-card);
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-decoration: none;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease);
}
.page-about .about-totop:hover,
.page-about .about-totop:focus-visible {
  background: var(--cyan);
  color: var(--bg-deep);
}
.page-about .about-totop:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}
.page-about .about-totop[hidden] {
  display: none;
}
@media (min-width: 900px) {
  .page-about .about-totop {
    right: 28px;
    bottom: 28px;
  }
}

/* ---------- 进入时归位 ---------- */
.js .page-about [data-reveal] {
  opacity: 0;
  transform: translateX(-12px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
.js .page-about [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  .js .page-about [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}