.page-about {
  --about-gap: clamp(20px, 4vw, 56px);
  --about-arc-h: 80px;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
}

.page-about .about-p {
  font-size: 16px;
  line-height: 1.95;
  color: var(--text);
  max-width: 60ch;
  margin: 0 0 18px;
  overflow-wrap: break-word;
}

.page-about .about-p--lead {
  color: var(--text-dim);
  font-size: 17px;
}

.page-about .about-p--note {
  margin-top: 28px;
  padding-left: 20px;
  border-left: 1px solid var(--line-strong);
  color: var(--text-dim);
  font-size: 15px;
}

.page-about .about-h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(28px, 6.4vw, 50px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  margin: 10px 0 22px;
  max-width: 18ch;
}

.page-about .about-section {
  position: relative;
  padding: clamp(44px, 8vw, 96px) 0;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: clamp(28px, 7vw, 72px) 0 clamp(36px, 6vw, 72px);
  background:
    radial-gradient(120% 90% at 88% 8%, rgba(42, 10, 18, 0.85) 0%, rgba(7, 26, 22, 0) 62%),
    linear-gradient(180deg, rgba(14, 18, 32, 0.6) 0%, rgba(7, 26, 22, 0) 78%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -30%;
  width: min(520px, 78vw);
  height: min(520px, 78vw);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(55, 225, 211, 0.12) 0%, rgba(55, 225, 211, 0) 66%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(42px, 11vw, 104px);
  line-height: 1.04;
  letter-spacing: -0.025em;
  margin: 14px 0 22px;
  overflow-wrap: break-word;
}

.page-about .about-hero__lead {
  font-size: 17px;
  line-height: 1.9;
  color: var(--text);
  max-width: 54ch;
  margin: 0;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 14px;
  margin-top: 34px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-narrow);
  font-size: clamp(30px, 8vw, 46px);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--neon-gold-400);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--text-dim);
}

/* ---------- 起源 ---------- */

.page-about .about-origin {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}

.page-about .about-quote {
  margin: 26px 0 24px;
  padding: 4px 0 4px 22px;
  border-left: 2px solid var(--neon-gold-400);
  font-family: var(--font-display);
  font-size: clamp(20px, 4.6vw, 27px);
  line-height: 1.6;
  color: var(--bone-100);
}

.page-about .media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: var(--indigo-950);
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media-frame--3x4 { aspect-ratio: 4 / 5; }
.page-about .media-frame--4x3 { aspect-ratio: 4 / 3; }
.page-about .media-frame--16x9 { aspect-ratio: 16 / 9; }

.page-about .media-frame--3x4 img,
.page-about .media-frame--4x3 img,
.page-about .media-frame--16x9 img {
  height: 100%;
}

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

.page-about .media-figure__caption {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist-400);
  letter-spacing: 0.02em;
}

/* ---------- 弧形分隔 ---------- */

.page-about .about-arc {
  display: block;
  width: 100%;
  height: 44px;
  margin: 0;
  opacity: 0.7;
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  display: grid;
  gap: var(--about-gap);
  align-items: center;
  margin-bottom: 34px;
}

.page-about .about-lines {
  display: grid;
  gap: 16px;
}

.page-about .about-line {
  position: relative;
  padding: 22px 20px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(14, 18, 32, 0.95) 0%, rgba(42, 10, 18, 0.5) 100%);
}

.page-about .about-line__num {
  font-family: var(--font-narrow);
  font-size: 32px;
  line-height: 1;
  color: var(--electric-cyan-400);
}

.page-about .about-line__name {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  margin: 8px 0 10px;
}

.page-about .about-line p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ---------- 七条主线 ---------- */

.page-about .about-cols {
  display: grid;
  gap: 14px;
  margin-top: 6px;
}

.page-about .about-col {
  position: relative;
  padding: 22px 20px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: linear-gradient(150deg, rgba(14, 18, 32, 0.92) 0%, rgba(7, 26, 22, 0.85) 100%);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease), box-shadow 200ms var(--ease);
}

.page-about .about-col:hover,
.page-about .about-col:focus-within {
  transform: translateY(-2px);
  border-color: var(--line-strong);
  box-shadow: var(--glow-gold);
}

.page-about .about-col__icon {
  display: block;
  width: 26px;
  height: 26px;
  margin-bottom: 16px;
  border: 1px solid var(--electric-cyan-400);
  border-radius: 8px;
  position: relative;
  transition: transform 280ms var(--ease);
}

.page-about .about-col__icon::after {
  content: "";
  position: absolute;
  left: 6px;
  right: 6px;
  top: 12px;
  border-top: 1px solid var(--neon-gold-400);
}

.page-about .about-col:hover .about-col__icon,
.page-about .about-col:focus-within .about-col__icon {
  transform: rotate(45deg) scale(1.06);
}

.page-about .about-col__idx {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--mist-400);
}

.page-about .about-col h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  margin: 8px 0 8px;
}

.page-about .about-col p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ---------- 版本时间线 ---------- */

.page-about .about-section--timeline {
  background: linear-gradient(180deg, rgba(42, 10, 18, 0) 0%, rgba(42, 10, 18, 0.55) 30%, rgba(42, 10, 18, 0) 100%);
}

.page-about .about-timeline {
  position: relative;
  margin-top: 26px;
  padding-left: 22px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, rgba(233, 185, 73, 0.55) 0%, rgba(55, 225, 211, 0.35) 100%);
}

.page-about .accordion__item {
  position: relative;
  border-bottom: 1px solid var(--line);
}

.page-about .accordion__item::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 34px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--neon-gold-400);
  box-shadow: var(--glow-gold);
}

.page-about .accordion__btn {
  display: grid;
  grid-template-columns: minmax(64px, auto) 1fr auto;
  align-items: center;
  gap: 14px;
  width: 100%;
  padding: 22px 0;
  background: none;
  border: 0;
  color: var(--text);
  text-align: left;
  font: inherit;
  cursor: pointer;
}

.page-about .about-ver {
  font-family: var(--font-narrow);
  font-size: clamp(30px, 7.6vw, 52px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--neon-gold-400);
}

.page-about .about-ver__label {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-dim);
}

.page-about .about-ver__mark {
  width: 10px;
  height: 10px;
  border-right: 1px solid var(--electric-cyan-400);
  border-bottom: 1px solid var(--electric-cyan-400);
  transform: rotate(45deg);
  transition: transform 240ms var(--ease);
}

.page-about .accordion__btn[aria-expanded="true"] .about-ver__mark {
  transform: rotate(-135deg);
}

.page-about .accordion__panel[data-open="false"] {
  display: none;
}

.page-about .about-ver__list {
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
}

.page-about .about-ver__list li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 12px;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-dim);
}

.page-about .about-ver__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--electric-cyan-400);
}

/* ---------- 日常维护 ---------- */

.page-about .about-upkeep {
  display: grid;
  gap: 22px;
  margin: 8px 0 0;
}

.page-about .about-upkeep__item {
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.page-about .about-upkeep dt {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--bone-100);
}

.page-about .about-upkeep dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-dim);
}

/* ---------- 收束 ---------- */

.page-about .about-section--close {
  padding-bottom: clamp(56px, 10vw, 120px);
}

.page-about .about-close__figure {
  margin-bottom: 36px;
}

.page-about .about-h2--close {
  max-width: 16ch;
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* ---------- 响应式 ---------- */

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

  .page-about .about-cols {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-upkeep {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px 32px;
  }

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

@media (min-width: 900px) {
  .page-about .about-origin {
    grid-template-columns: 1.05fr 0.82fr;
    gap: var(--about-gap);
  }

  .page-about .about-team {
    grid-template-columns: 1.05fr 0.95fr;
  }

  .page-about .about-origin__figure {
    margin-top: 26px;
  }

  .page-about .about-arc {
    height: var(--about-arc-h);
  }
}

@media (min-width: 1080px) {
  .page-about .about-cols {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-timeline {
    padding-left: 34px;
  }

  .page-about .accordion__item::before {
    left: -34px;
    top: 40px;
  }

  .page-about .accordion__btn {
    gap: 28px;
    padding: 26px 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-col,
  .page-about .about-col__icon,
  .page-about .about-ver__mark {
    transition: none;
  }

  .page-about .about-col:hover {
    transform: none;
  }
}