.page-about {
  --about-gap: clamp(20px, 3vw, 44px);
  --about-sticky: 104px;
  color: var(--tb-text);
}

.page-about .about-crumb-wrap {
  padding-top: clamp(18px, 3.5vw, 34px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4.5vw, 52px) 0 clamp(40px, 6.5vw, 84px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -22%;
  right: -12%;
  width: min(640px, 78vw);
  aspect-ratio: 1 / 1;
  background: radial-gradient(circle at 58% 42%, rgba(47, 243, 208, 0.15), rgba(47, 243, 208, 0) 64%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  bottom: 6%;
  left: -18%;
  width: min(420px, 60vw);
  aspect-ratio: 1 / 1;
  background: radial-gradient(circle at 50% 50%, rgba(255, 138, 61, 0.1), rgba(255, 138, 61, 0) 68%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}

.page-about .about-hero__copy .tb-eyebrow {
  margin-bottom: 14px;
}

.page-about .about-hero__copy .tb-lede {
  margin-top: clamp(16px, 2.5vw, 22px);
  max-width: 46ch;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(26px, 3.5vw, 40px) 0 0;
  padding: clamp(18px, 2.5vw, 24px) 0 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  border-top: 1px solid var(--tb-line);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-num {
  font-family: var(--tb-mono);
  font-size: clamp(17px, 3.6vw, 25px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--tb-teal);
  line-height: 1.1;
}

.page-about .about-hero__facts li span:last-child {
  font-size: 12px;
  line-height: 1.5;
  color: var(--tb-text-2);
}

.page-about .about-hero__figure {
  margin: 0;
  border-radius: var(--tb-radius-lg);
  border: 1px solid var(--tb-line);
  background: var(--tb-ink-2);
  overflow: hidden;
  box-shadow: var(--tb-shadow);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  max-width: 100%;
}

.page-about .about-hero__cap {
  margin: 0;
  padding: 13px 18px;
  font-family: var(--tb-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--tb-text-2);
  border-top: 1px solid var(--tb-line);
  background: var(--tb-ink);
}

/* ---------- 起因 ---------- */
.page-about .about-origin {
  border-top: 1px solid var(--tb-line-soft);
}

.page-about .about-origin__grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-origin__body {
  border-left: 2px solid var(--tb-line-strong);
  padding-left: clamp(16px, 2.6vw, 28px);
}

.page-about .about-origin__body .tb-p + .tb-p {
  margin-top: 16px;
}

/* ---------- 四条主线 ---------- */
.page-about .about-field {
  border-top: 1px solid var(--tb-line-soft);
  border-bottom: 1px solid var(--tb-line-soft);
  background: linear-gradient(180deg, rgba(11, 38, 33, 0.72), rgba(3, 16, 14, 0) 88%);
}

.page-about .about-field__head {
  max-width: 62ch;
  margin-bottom: clamp(24px, 4vw, 42px);
}

.page-about .about-field__intro {
  margin-top: 14px;
}

.page-about .about-field__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-line {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 20px 24px;
  border-radius: var(--tb-radius);
  border: 1px solid var(--tb-line);
  background: linear-gradient(158deg, rgba(18, 51, 44, 0.94), rgba(7, 27, 23, 0.94));
  overflow: hidden;
}

.page-about .about-line::after {
  content: "";
  position: absolute;
  right: -34%;
  bottom: -58%;
  width: 180px;
  height: 180px;
  background: radial-gradient(circle, rgba(47, 243, 208, 0.15), rgba(47, 243, 208, 0) 70%);
  pointer-events: none;
}

.page-about .about-line__num {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: var(--tb-pill);
  background: var(--tb-teal);
  color: var(--tb-void);
  font-family: var(--tb-mono);
  font-size: 13px;
  font-weight: 700;
}

.page-about .about-line .tb-h3,
.page-about .about-line .tb-p {
  position: relative;
  z-index: 1;
}

.page-about .about-line--warm .about-line__num {
  background: var(--tb-orange);
}

.page-about .about-line--warm::after {
  background: radial-gradient(circle, rgba(255, 138, 61, 0.16), rgba(255, 138, 61, 0) 70%);
}

.page-about .about-line--alert .about-line__num {
  background: var(--tb-red);
  color: #fff;
}

.page-about .about-line--alert::after {
  background: radial-gradient(circle, rgba(255, 65, 89, 0.16), rgba(255, 65, 89, 0) 70%);
}

.page-about .about-field__media {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
}

.page-about .about-field__media img {
  width: 100%;
  height: auto;
  object-fit: cover;
  max-width: 100%;
}

/* ---------- 时间线 ---------- */
.page-about .about-track__grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-track__side .tb-p {
  margin-top: 16px;
}

.page-about .about-track__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.page-about .about-mile {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px 18px;
  padding: clamp(16px, 2.4vw, 22px) 0;
  border-top: 1px solid var(--tb-line-soft);
}

.page-about .about-mile:first-child {
  border-top-color: var(--tb-line);
}

.page-about .about-mile:last-child {
  border-bottom: 1px solid var(--tb-line);
}

.page-about .about-mile__time {
  font-family: var(--tb-mono);
  font-size: 13px;
  letter-spacing: 0.03em;
  color: var(--tb-teal);
  white-space: nowrap;
  padding-top: 3px;
}

.page-about .about-mile .tb-p {
  margin-top: 8px;
}

/* ---------- 做事方式 ---------- */
.page-about .about-craft__grid {
  display: grid;
  gap: var(--about-gap);
  align-items: center;
}

.page-about .about-craft__figure {
  margin: 0;
  border-radius: var(--tb-radius-lg);
  border: 1px solid var(--tb-line);
  background: var(--tb-ink-2);
  overflow: hidden;
}

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

.page-about .about-craft__figure .tb-media__cap {
  margin: 0;
  padding: 13px 18px;
  font-family: var(--tb-mono);
  font-size: 12px;
  color: var(--tb-text-2);
  border-top: 1px solid var(--tb-line);
  background: var(--tb-ink);
}

.page-about .about-craft__body .tb-p {
  margin-top: 16px;
}

.page-about .about-rules {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-rules li {
  padding-left: 16px;
  border-left: 2px solid var(--tb-teal-deep);
  font-size: 15px;
  line-height: 1.72;
  color: var(--tb-text-2);
}

.page-about .about-rules strong {
  display: block;
  margin-bottom: 2px;
  color: var(--tb-text);
  font-weight: 600;
}

/* ---------- 结尾 ---------- */
.page-about .about-next__inner {
  display: grid;
  gap: clamp(22px, 3vw, 30px);
  padding: clamp(26px, 4vw, 44px);
  border-radius: var(--tb-radius-lg);
  border: 1px solid var(--tb-line);
  background: linear-gradient(140deg, rgba(18, 51, 44, 0.92), rgba(7, 27, 23, 0.92));
}

.page-about .about-next__copy .tb-p {
  margin-top: 14px;
  max-width: 58ch;
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-content: flex-start;
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .about-field__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-field__head .tb-h2 {
    max-width: 22ch;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 1.15fr 0.85fr;
    gap: clamp(32px, 4.4vw, 68px);
  }

  .page-about .about-origin__grid {
    grid-template-columns: 0.88fr 1.12fr;
    gap: clamp(32px, 5vw, 76px);
  }

  .page-about .about-origin__lead,
  .page-about .about-track__side {
    position: sticky;
    top: var(--about-sticky);
    align-self: start;
  }
}

@media (min-width: 960px) {
  .page-about .about-track__grid {
    grid-template-columns: 0.78fr 1.22fr;
    gap: clamp(32px, 5vw, 70px);
  }

  .page-about .about-craft__grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: clamp(32px, 4.6vw, 64px);
  }

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

  .page-about .about-next__links {
    flex-direction: column;
    align-items: stretch;
    min-width: 220px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-field__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-hero::before,
  .page-about .about-hero::after {
    display: none;
  }
}
</main>