/* ========== 页面作用域：page-about ========== */
.page-about {
  --about-accent: var(--c-green);
  --about-panel: var(--c-indigo);
  --about-deep: var(--c-slate);
  --about-text: var(--c-gray);
  background: var(--c-navy);
  color: var(--c-white);
  position: relative;
  overflow-x: hidden;
}

/* 面包屑 */
.page-about .breadcrumb {
  padding: 24px 0 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  margin-bottom: 8px;
}

/* ========== 首屏 ========== */
.page-about .about-hero {
  position: relative;
  padding: 8px 0 8px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 42%;
  height: 430px;
  background: linear-gradient(135deg, rgba(0, 229, 255, 0.14), rgba(0, 229, 255, 0) 68%);
  clip-path: polygon(24% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 28px;
  padding: 20px 0 56px;
}

.page-about .about-hero__eyebrow {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.page-about .about-hero__eyebrow-dash {
  width: 28px;
  height: 2px;
  background: var(--c-orange);
  display: inline-block;
}

.page-about .about-hero__eyebrow-text {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--c-gray);
}

.page-about .about-hero__title {
  font-family: var(--font-headline);
  font-size: clamp(26px, 5.6vw, 44px);
  line-height: 1.16;
  letter-spacing: -0.015em;
  margin: 0 0 16px;
}

.page-about .about-hero__title::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 0.82em;
  margin-right: 10px;
  background: var(--c-green);
  transform: skewX(-15deg);
  vertical-align: -0.08em;
}

.page-about .about-hero__title span {
  display: block;
}

.page-about .about-hero__lead {
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-gray);
  margin: 0;
  max-width: 680px;
}

.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 32px;
  margin-top: 26px;
  padding-top: 22px;
  border-top: 1px solid rgba(176, 183, 195, 0.22);
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
}

.page-about .about-hero__stat-num {
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  font-weight: 700;
  color: var(--c-green);
}

.page-about .about-hero__stat-label {
  font-size: 12px;
  color: var(--c-gray);
  margin-top: 8px;
}

.page-about .about-hero__media {
  position: relative;
  overflow: hidden;
  background: var(--c-slate);
  clip-path: polygon(6% 0, 100% 0, 100% 86%, 94% 100%, 0 100%, 0 14%);
}

.page-about .about-hero__img {
  display: block;
  width: 100%;
  height: auto;
}

/* ========== 手册式布局 ========== */
.page-about .about-manual {
  display: grid;
  gap: 36px;
  padding-bottom: 88px;
}

/* ========== 章节索引 Rail ========== */
.page-about .about-rail__inner {
  background: var(--c-slate);
  border-left: 2px solid var(--c-green);
  padding: 18px 16px;
  position: relative;
}

.page-about .about-rail__cap {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}

.page-about .about-rail__cap-code {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--c-green);
}

.page-about .about-rail__cap-title {
  font-size: 13px;
  color: var(--c-gray);
}

.page-about .about-rail__cap .rail-pulse {
  margin-left: auto;
}

.page-about .about-rail__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  color: var(--c-white);
  text-decoration: none;
  font-size: 14px;
  padding: 8px 10px;
  border-bottom: 1px solid rgba(176, 183, 195, 0.18);
  transition: background 0.2s, color 0.2s;
}

.page-about .about-rail__link:hover {
  background: rgba(168, 255, 96, 0.08);
  color: var(--c-green);
}

.page-about .about-rail__no {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-orange);
}

.page-about .about-rail__to-top {
  display: inline-flex;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-gray);
  text-decoration: none;
  letter-spacing: 0.06em;
}

.page-about .about-rail__to-top:hover {
  color: var(--c-cyan);
}

/* ========== 章节通用 ========== */
.page-about .about-chapters {
  display: grid;
  gap: 52px;
  min-width: 0;
}

.page-about .about-chapter {
  position: relative;
  padding: 28px 0 4px;
  border-top: 1px solid rgba(168, 255, 96, 0.2);
}

.page-about .about-chapter__top {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 18px;
}

.page-about .about-chapter__no {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--c-orange);
  background: rgba(255, 107, 53, 0.12);
  border: 1px solid var(--c-orange);
  padding: 3px 10px 3px 14px;
  clip-path: polygon(8px 0, 100% 0, calc(100% - 8px) 100%, 0 100%);
}

.page-about .section-title {
  font-size: 24px;
  margin: 0;
  line-height: 1.2;
}

.page-about .about-chapter__intro p {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-gray);
  max-width: 720px;
}

/* ========== 01 我们是谁 ========== */
.page-about .about-who-cards {
  display: grid;
  gap: 16px;
  margin-top: 20px;
}

.page-about .about-who-card {
  position: relative;
  background: var(--c-indigo);
  padding: 22px 20px 20px;
}

.page-about .about-who-card__bar {
  position: absolute;
  top: 0;
  left: 18px;
  right: 18px;
  height: 3px;
}

.page-about .about-who-card--green .about-who-card__bar { background: var(--c-green); }
.page-about .about-who-card--orange .about-who-card__bar { background: var(--c-orange); }
.page-about .about-who-card--cyan .about-who-card__bar { background: var(--c-cyan); }

.page-about .about-who-card__code {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-orange);
  display: block;
  margin-bottom: 12px;
}

.page-about .about-who-card h3 {
  font-size: 18px;
  margin: 0 0 8px;
  line-height: 1.35;
}

.page-about .about-who-card p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-gray);
  margin: 0;
}

/* ========== 02 内容目录如何运作 ========== */
.page-about .about-operate__layout {
  display: grid;
  gap: 24px;
}

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

.page-about .about-operate__copy > p:first-child {
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-gray);
  margin: 0;
}

.page-about .about-operate__detail {
  margin-top: 20px;
  border: 1px solid rgba(176, 183, 195, 0.22);
  background: rgba(27, 42, 74, 0.5);
}

.page-about .about-operate__detail summary {
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-green);
  padding: 14px 16px;
  user-select: none;
  list-style: none;
}

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

.page-about .about-operate__detail summary::before {
  content: "＋ ";
  color: var(--c-orange);
}

.page-about .about-operate__detail[open] summary::before {
  content: "－ ";
}

.page-about .about-operate__detail-body {
  padding: 0 16px 16px;
}

.page-about .about-operate__detail-body ul {
  margin: 0;
  padding-left: 18px;
  color: var(--c-gray);
  font-size: 14px;
  line-height: 1.9;
}

.page-about .about-operate__tip {
  margin: 14px 0 0;
  font-size: 14px;
  color: var(--c-gray);
}

.page-about .about-operate__tip a {
  color: var(--c-green);
  text-decoration: none;
  border-bottom: 1px solid rgba(168, 255, 96, 0.4);
}

.page-about .about-operate__note-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.page-about .about-operate__visual img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-operate__caption {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-gray);
  text-align: center;
  margin-top: 8px;
}

/* ========== 03 更新频率提升 ========== */
.page-about .about-frequency__panel {
  background: var(--c-slate);
  padding: 28px 22px;
  display: grid;
  gap: 24px;
  position: relative;
}

.page-about .about-frequency__block {
  border-left: 3px solid var(--c-green);
  padding-left: 16px;
}

.page-about .about-frequency__big {
  display: block;
  font-family: var(--font-mono);
  font-size: 64px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-green);
}

.page-about .about-frequency__unit {
  display: block;
  font-size: 14px;
  color: var(--c-white);
  margin-top: 8px;
  font-weight: 600;
}

.page-about .about-frequency__sub {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-orange);
  display: block;
  margin-top: 4px;
}

.page-about .about-frequency__content p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-gray);
  margin: 0 0 12px;
}

.page-about .about-frequency__list {
  margin: 0 0 20px;
  padding-left: 18px;
  color: var(--c-gray);
  font-size: 14px;
  line-height: 1.9;
}

/* ========== 04 发展里程碑 ========== */
.page-about .about-milestones__layout {
  display: grid;
  gap: 28px;
  margin-top: 12px;
}

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

.page-about .about-milestones__line {
  display: none;
  width: 100%;
  height: auto;
  margin-bottom: 8px;
}

.page-about .about-milestones__steps {
  display: grid;
  gap: 20px;
}

.page-about .about-milestones__step {
  border-left: 2px solid rgba(168, 255, 96, 0.32);
  padding: 0 0 4px 16px;
  position: relative;
}

.page-about .about-milestones__step::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-green);
}

.page-about .about-milestones__ver {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-cyan);
}

.page-about .about-milestones__step h3 {
  font-size: 17px;
  margin: 6px 0 4px;
}

.page-about .about-milestones__step p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-gray);
  margin: 0;
}

.page-about .about-milestones__visual img {
  display: block;
  width: 100%;
  height: auto;
}

/* ========== 05 内容边界 ========== */
.page-about .about-boundary__grid {
  display: grid;
  gap: 14px;
  margin: 8px 0 24px;
}

.page-about .about-boundary__item {
  background: var(--c-indigo);
  padding: 18px 20px;
  border-left: 2px solid var(--c-cyan);
}

.page-about .about-boundary__item p {
  margin: 12px 0 0;
  color: var(--c-gray);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-boundary__contact {
  background: var(--c-slate);
  padding: 26px 22px;
  display: grid;
  gap: 22px;
}

.page-about .about-boundary__contact h3 {
  font-size: 20px;
  margin: 0 0 8px;
}

.page-about .about-boundary__contact-copy p {
  color: var(--c-gray);
  font-size: 14px;
  line-height: 1.75;
  margin: 0;
}

.page-about .about-boundary__contact-meta {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.9;
  color: var(--c-gray);
  margin-top: 14px !important;
}

.page-about .about-boundary__contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.page-about .about-boundary__contact-actions .btn {
  margin: 0;
}

/* ========== 中等屏 / 平板 ========== */
@media (min-width: 768px) {

  .page-about .about-who-cards {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }

  .page-about .about-operate__layout {
    grid-template-columns: minmax(0, 1fr) 240px;
    gap: 28px;
    align-items: start;
  }

  .page-about .about-frequency__panel {
    grid-template-columns: 190px 1fr;
    gap: 32px;
  }

  .page-about .about-milestones__line {
    display: block;
  }

  .page-about .about-milestones__steps {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

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

  .page-about .about-boundary__contact {
    grid-template-columns: 1fr auto;
    align-items: center;
  }
}

/* ========== 大屏 / 桌面 ========== */
@media (min-width: 992px) {

  .page-about .about-manual {
    grid-template-columns: var(--rail) minmax(0, 1fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-rail__inner {
    position: sticky;
    top: 24px;
    padding: 22px 18px;
  }

  .page-about .about-rail__nav {
    flex-direction: column;
    gap: 2px;
  }

  .page-about .about-rail__link {
    border-bottom: none;
    border-left: 2px solid transparent;
    padding: 10px 12px;
  }

  .page-about .about-rail__link:hover {
    border-left-color: var(--c-orange);
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) minmax(360px, 520px);
    gap: 56px;
    align-items: center;
    padding: 40px 0 72px;
  }

  .page-about .about-hero__lead {
    font-size: 16px;
  }

  .page-about .about-chapter {
    padding: 32px 4px 8px;
  }

  .page-about .section-title {
    font-size: 30px;
  }

  .page-about .about-milestones__layout {
    grid-template-columns: minmax(0, 1fr) 240px;
    gap: 36px;
    align-items: start;
  }
}