.page-about {
  --about-line: 1px solid var(--steel);
  --about-panel: linear-gradient(180deg, rgba(11, 34, 57, 0.92) 0%, rgba(6, 20, 38, 0.72) 100%);
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 5vw, 52px) 0 clamp(34px, 6vw, 72px);
  background: linear-gradient(158deg, #0b2239 0%, #061426 58%, #04101d 100%);
  border-bottom: var(--about-line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(30, 90, 122, 0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 90, 122, 0.3) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: linear-gradient(128deg, #000 0%, rgba(0, 0, 0, 0.35) 48%, transparent 78%);
  mask-image: linear-gradient(128deg, #000 0%, rgba(0, 0, 0, 0.35) 48%, transparent 78%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -34%;
  right: -18%;
  width: 58%;
  height: 170%;
  background: linear-gradient(180deg, rgba(255, 106, 42, 0.26) 0%, rgba(255, 106, 42, 0) 72%);
  transform: rotate(16deg);
  clip-path: polygon(24% 0, 100% 0, 76% 100%, 0 100%);
  pointer-events: none;
}

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

.page-about .about-hero__kicker {
  margin: 18px 0 14px;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 7.6vw, 76px);
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: var(--paper);
}

.page-about .about-hero__title br {
  display: none;
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 60ch;
  color: var(--text-soft);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px 14px;
  border: var(--about-line);
  border-left: 2px solid var(--grid);
  background: rgba(11, 34, 57, 0.6);
}

.page-about .about-hero__num {
  font-family: var(--font-num);
  font-size: clamp(22px, 4vw, 30px);
  font-weight: 700;
  color: var(--orange);
  line-height: 1;
}

.page-about .about-hero__label {
  font-size: 13px;
  color: var(--mist);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

/* ---------- 章节索引 ---------- */
.page-about .chapter-nav {
  background: rgba(8, 24, 42, 0.94);
  border-bottom: var(--about-line);
}

.page-about .chapter-nav__inner {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-top: 10px;
  padding-bottom: 10px;
  scrollbar-width: thin;
}

.page-about .chapter-nav a {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 13px;
  font-size: 14px;
  color: var(--text-soft);
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 2px;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.page-about .chapter-nav a .mono {
  font-size: 11px;
  color: var(--cyan);
  letter-spacing: 0.08em;
}

.page-about .chapter-nav a:hover {
  color: var(--paper);
  border-color: var(--steel);
  background: rgba(30, 90, 122, 0.22);
}

/* ---------- 通用区块 ---------- */
.page-about .about-sec {
  padding: clamp(40px, 6vw, 84px) 0;
  border-bottom: var(--about-line);
}

.page-about .about-sec--alt {
  background: linear-gradient(180deg, rgba(11, 34, 57, 0.55) 0%, rgba(6, 20, 38, 0.2) 100%);
}

.page-about .about-sec__lede {
  max-width: 68ch;
  margin: 0 0 clamp(20px, 3vw, 32px);
  color: var(--text-soft);
}

.page-about .figure-cap {
  margin: 10px 0 0;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
  text-transform: uppercase;
}

.page-about .media-frame {
  border: var(--about-line);
  background:
    linear-gradient(rgba(30, 90, 122, 0.24) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 90, 122, 0.24) 1px, transparent 1px),
    linear-gradient(180deg, #0b2239 0%, #061426 100%);
  background-size: 32px 32px, 32px 32px, 100% 100%;
  overflow: hidden;
}

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

/* ---------- 01 品牌起点 ---------- */
.page-about .origin-grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

.page-about .origin-copy p {
  margin: 0;
  color: var(--text-soft);
}

.page-about .origin-copy p:first-child {
  color: var(--text);
  font-size: 1.05rem;
}

.page-about .origin-copy__link {
  padding-top: 4px;
  border-top: var(--about-line);
  font-size: 14px;
}

.page-about .origin-copy__link a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(55, 214, 232, 0.4);
}

.page-about .origin-copy__link a:hover {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

/* ---------- 02 服务原则 ---------- */
.page-about .principles {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .principle {
  position: relative;
  padding: 22px 20px 24px;
  background: var(--about-panel);
  border: var(--about-line);
  border-left: 3px solid var(--steel);
  transition: transform 0.2s ease, border-left-color 0.2s ease, background 0.2s ease;
}

.page-about .principle:hover,
.page-about .principle:focus-within {
  transform: translateY(-3px);
  border-left-color: var(--orange);
  background: linear-gradient(180deg, rgba(18, 48, 76, 0.95) 0%, rgba(6, 20, 38, 0.8) 100%);
}

.page-about .principle__idx {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .principle__title {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-size: clamp(20px, 3.4vw, 26px);
  font-weight: 800;
  color: var(--paper);
  letter-spacing: -0.01em;
}

.page-about .principle__text {
  margin: 0 0 16px;
  font-size: 15px;
  color: var(--text-soft);
}

.page-about .principle__do {
  margin: 0;
  padding: 12px 14px;
  font-size: 14px;
  color: var(--text);
  background: rgba(42, 67, 86, 0.35);
  border-left: 2px solid var(--amber);
  transition: border-left-color 0.2s ease, background 0.2s ease;
}

.page-about .principle:hover .principle__do {
  border-left-color: var(--orange);
  background: rgba(255, 177, 90, 0.12);
}

.page-about .principle__do-tag {
  display: block;
  margin-bottom: 6px;
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--amber);
  text-transform: uppercase;
}

/* ---------- 03 版本演进 ---------- */
.page-about .version-figure {
  margin: 0 0 clamp(24px, 4vw, 38px);
}

.page-about .tl {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__row {
  display: grid;
  grid-template-columns: 66px minmax(0, 1fr);
  gap: 12px;
  padding-bottom: 14px;
}

.page-about .tl__scale {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding-top: 14px;
}

.page-about .tl__scale::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: -18px;
  left: 50%;
  width: 1px;
  transform: translateX(-50%);
  background: linear-gradient(180deg, rgba(55, 214, 232, 0.5) 0%, rgba(42, 67, 86, 0.9) 100%);
}

.page-about .tl__row:last-child .tl__scale::before {
  display: none;
}

.page-about .tl__ver {
  position: relative;
  z-index: 1;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  background: var(--void);
  padding: 2px 3px;
}

.page-about .tl__dot {
  position: relative;
  z-index: 1;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--grid);
  border: 1px solid var(--cyan);
}

.page-about .tl__row--now .tl__ver {
  color: var(--orange);
}

.page-about .tl__row--now .tl__dot {
  background: var(--orange);
  border-color: var(--orange);
  box-shadow: 0 0 0 5px rgba(255, 106, 42, 0.18);
}

.page-about .tl__card {
  background: var(--about-panel);
  border: var(--about-line);
}

.page-about .tl__card[open] {
  border-color: var(--grid);
}

.page-about .tl__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
  transition: color 0.18s ease;
}

.page-about .tl__summary::-webkit-details-marker {
  display: none;
}

.page-about .tl__summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-num);
  font-size: 20px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .tl__card[open] .tl__summary {
  color: var(--amber);
}

.page-about .tl__card[open] .tl__summary::after {
  content: "–";
  color: var(--orange);
}

.page-about .tl__summary:hover {
  color: var(--cyan);
}

.page-about .tl__body {
  padding: 0 16px 18px;
  border-top: 1px solid rgba(42, 67, 86, 0.7);
  padding-top: 14px;
}

.page-about .tl__body p {
  margin: 0;
  font-size: 15px;
  color: var(--text-soft);
}

.page-about .tl__cadence {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 20px 0 0;
  padding: 14px 16px;
  font-size: 14px;
  color: var(--text-soft);
  border: var(--about-line);
  border-left: 3px solid var(--cyan);
  background: rgba(30, 90, 122, 0.16);
}

/* ---------- 04 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .team-copy p {
  margin: 0;
  color: var(--text-soft);
}

.page-about .team-copy a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(55, 214, 232, 0.4);
}

.page-about .team-copy a:hover {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

.page-about .team-bars {
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .team-bar {
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr) 32px;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: var(--text-soft);
}

.page-about .team-bar__track {
  display: block;
  height: 8px;
  background: rgba(42, 67, 86, 0.65);
  border-radius: 2px;
  overflow: hidden;
}

.page-about .team-bar__fill {
  display: block;
  height: 100%;
  border-radius: 2px;
}

.page-about .team-bar__fill--edit {
  width: 39%;
  background: linear-gradient(90deg, rgba(55, 214, 232, 0.55), var(--cyan));
}

.page-about .team-bar__fill--product {
  width: 30%;
  background: linear-gradient(90deg, rgba(255, 177, 90, 0.5), var(--amber));
}

.page-about .team-bar__fill--service {
  width: 30%;
  background: linear-gradient(90deg, rgba(89, 214, 167, 0.5), var(--mint));
}

.page-about .team-bar__num {
  text-align: right;
  font-family: var(--font-num);
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .team-chart__figure .media-frame {
  border-left: 3px solid var(--orange);
}

/* ---------- 05 认证标识 ---------- */
.page-about .cert-grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}

.page-about .cert-seal {
  max-width: 220px;
  padding: 16px;
  border: var(--about-line);
  background:
    linear-gradient(rgba(30, 90, 122, 0.2) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 90, 122, 0.2) 1px, transparent 1px),
    rgba(11, 34, 57, 0.7);
  background-size: 24px 24px, 24px 24px, 100% 100%;
}

.page-about .cert-seal svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .section-head--inline {
  margin-bottom: 8px;
}

.page-about .cert-copy p {
  margin: 0;
  color: var(--text-soft);
}

.page-about .cert-list {
  margin: 4px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .cert-list li {
  padding: 12px 14px;
  font-size: 14px;
  color: var(--text-soft);
  border-left: 2px solid var(--grid);
  background: rgba(11, 34, 57, 0.55);
}

.page-about .cert-list .tag {
  display: inline-block;
  margin-right: 8px;
  vertical-align: 1px;
}

/* ---------- 06 合作生态 ---------- */
.page-about .partner-stats {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .partner-stat {
  padding: 18px 16px;
  border: var(--about-line);
  border-top: 2px solid var(--grid);
  background: var(--about-panel);
}

.page-about .partner-stat:nth-child(4) {
  border-top-color: var(--orange);
}

.page-about .partner-stat__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(26px, 5vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
}

.page-about .partner-stat:nth-child(4) .partner-stat__num {
  color: var(--orange);
}

.page-about .partner-stat__name {
  display: block;
  margin: 8px 0 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--cyan);
}

.page-about .partner-stat__text {
  margin: 0;
  font-size: 14px;
  color: var(--text-soft);
}

.page-about .partner-note {
  margin-top: 18px;
  padding: 16px 18px;
  border: var(--about-line);
  border-left: 3px solid var(--amber);
  background: rgba(30, 90, 122, 0.14);
}

.page-about .partner-note p {
  margin: 0;
  font-size: 15px;
  color: var(--text-soft);
}

/* ---------- 下一步 ---------- */
.page-about .about-cta {
  padding: clamp(40px, 6vw, 76px) 0;
  background: linear-gradient(152deg, #0b2239 0%, #061426 70%);
}

.page-about .about-cta__title {
  margin: 0 0 clamp(20px, 3vw, 30px);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 4.6vw, 40px);
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-cta__links {
  display: grid;
  gap: 10px;
}

.page-about .about-cta__link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas:
    "idx title"
    "idx desc";
  gap: 2px 14px;
  align-items: baseline;
  padding: 16px 18px;
  text-decoration: none;
  border: var(--about-line);
  background: rgba(11, 34, 57, 0.6);
  transition: border-color 0.18s ease, background 0.18s ease, transform 0.18s ease;
}

.page-about .about-cta__link .mono {
  grid-area: idx;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--orange);
}

.page-about .about-cta__link strong {
  grid-area: title;
  font-size: 16px;
  color: var(--paper);
}

.page-about .about-cta__link span:last-child {
  grid-area: desc;
  font-size: 13px;
  color: var(--mist);
}

.page-about .about-cta__link:hover {
  transform: translateY(-2px);
  border-color: var(--orange);
  background: rgba(255, 106, 42, 0.1);
}

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

  .page-about .about-hero__title br {
    display: inline;
  }

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

  .page-about .tl__row {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 18px;
  }

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

@media (min-width: 900px) {
  .page-about .origin-grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    align-items: start;
  }

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

  .page-about .principle:nth-child(2) {
    margin-top: 22px;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .cert-grid {
    grid-template-columns: 240px minmax(0, 1fr);
  }

  .page-about .partner-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 1024px) {
  .page-about .chapter-nav {
    position: sticky;
    top: 0;
    z-index: 5;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
  }

  .page-about .chapter-nav__inner {
    justify-content: flex-start;
    gap: 10px;
  }

  .page-about .about-hero__inner {
    max-width: 74%;
  }

  .page-about .tl__row {
    grid-template-columns: 110px minmax(0, 1fr);
    gap: 26px;
    padding-bottom: 18px;
  }

  .page-about .tl__summary {
    font-size: 17px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .principle,
  .page-about .about-cta__link {
    transition: none;
  }

  .page-about .principle:hover,
  .page-about .about-cta__link:hover {
    transform: none;
  }
}