/* ============ 品牌总览 / about ============ */

.page-about {
  --about-gutter: 34px;
  --about-dot: 14px;
  --about-axis-x: 7px;
}

@media (min-width: 640px) {
  .page-about {
    --about-gutter: 46px;
  }
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: 36px 0 26px;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -180px;
  right: -150px;
  width: 470px;
  height: 470px;
  border-radius: 50%;
  background: radial-gradient(circle at 50% 50%, rgba(61, 240, 180, 0.16), rgba(61, 240, 180, 0) 68%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(31, 90, 76, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 90, 76, 0.22) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.55), transparent 72%);
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.55), transparent 72%);
  pointer-events: none;
  z-index: 0;
}

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

.page-about .about-h1 {
  margin: 16px 0 0;
  font-family: var(--font-display);
  font-size: clamp(32px, 7.4vw, 62px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.015em;
  color: var(--white);
  max-width: 24ch;
}

.page-about .about-lede {
  margin-top: 22px;
  max-width: 60ch;
  font-size: 17px;
  line-height: 1.88;
  color: var(--body-text);
}

/* 章节索引 */

.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  margin-top: 32px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .index-item {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 7px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--body-text);
  text-decoration: none;
  transition: border-color var(--t-fast) var(--ease),
              background-color var(--t-fast) var(--ease),
              color var(--t-fast) var(--ease);
}

.page-about .index-item:hover,
.page-about .index-item:focus-visible {
  border-color: var(--neon);
  background-color: rgba(61, 240, 180, 0.08);
  color: var(--white);
  outline: none;
}

.page-about .index-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--sand);
}

/* ---------- 主体骨架：纵向轴线 ---------- */

.page-about .about-body {
  padding: 18px 0 76px;
}

.page-about .yearbook-body {
  position: relative;
  padding-left: var(--about-gutter);
}

.page-about .yearbook-body::before {
  content: "";
  position: absolute;
  left: var(--about-axis-x);
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: linear-gradient(to bottom,
    rgba(61, 240, 180, 0.55),
    var(--line) 14%,
    var(--line) 84%,
    rgba(31, 90, 76, 0));
  pointer-events: none;
}

.page-about .chapter {
  position: relative;
  padding-bottom: 54px;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .chapter:last-child {
  padding-bottom: 0;
}

.page-about .chapter::before {
  content: "";
  position: absolute;
  left: calc(var(--about-gutter) * -1);
  top: 9px;
  width: var(--about-dot);
  height: var(--about-dot);
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--line);
  box-sizing: border-box;
  transition: background-color var(--t-base) var(--ease),
              border-color var(--t-base) var(--ease),
              box-shadow var(--t-base) var(--ease);
}

.page-about .chapter.is-visible::before {
  background: var(--neon);
  border-color: var(--neon);
  box-shadow: 0 0 0 5px rgba(61, 240, 180, 0.14);
}

/* 滚动进入时依次点亮 */
.page-about.reveal-ready .chapter[data-reveal],
.reveal-ready .page-about .chapter[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 420ms var(--ease), transform 420ms var(--ease);
}

.page-about.reveal-ready .chapter[data-reveal].is-visible,
.reveal-ready .page-about .chapter[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

.page-about .chapter-num {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--sand);
}

.page-about .chapter-title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(23px, 4.2vw, 34px);
  font-weight: 600;
  line-height: 1.26;
  letter-spacing: -0.01em;
  color: var(--white);
  max-width: 26ch;
}

.page-about .chapter-body > p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--body-text);
  max-width: 68ch;
}

.page-about .chapter-body > p:last-child {
  margin-bottom: 0;
}

.page-about .chapter-body a {
  color: var(--neon);
  text-decoration: none;
  background-image: linear-gradient(var(--neon), var(--neon));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1px;
  transition: background-size var(--t-base) var(--ease);
}

.page-about .chapter-body a:hover,
.page-about .chapter-body a:focus-visible {
  background-size: 100% 1px;
  outline: none;
}

/* ---------- 三条主线 ---------- */

.page-about .lane-grid {
  display: grid;
  gap: 14px;
  margin-bottom: 22px;
}

@media (min-width: 760px) {
  .page-about .lane-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .lane {
  display: block;
  padding: 20px 18px 22px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  text-decoration: none;
  transition: border-color var(--t-base) var(--ease),
              background-color var(--t-base) var(--ease),
              transform var(--t-base) var(--ease);
}

.page-about .lane:hover,
.page-about .lane:focus-visible {
  border-color: var(--neon);
  background-color: rgba(61, 240, 180, 0.06);
  transform: translateY(-2px);
  outline: none;
}

.page-about .lane-amber:hover,
.page-about .lane-amber:focus-visible {
  border-color: var(--amber);
  background-color: rgba(255, 144, 64, 0.07);
}

.page-about .lane-tag {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 10px;
  border: 1px solid rgba(61, 240, 180, 0.35);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--neon);
}

.page-about .lane-amber .lane-tag {
  color: var(--amber);
  border-color: rgba(255, 144, 64, 0.42);
}

.page-about .lane-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.35;
  color: var(--white);
}

.page-about .lane-brief {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--body-text);
}

.page-about .lane-more {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
  max-height: 14em;
  opacity: 1;
  overflow: hidden;
  transition: max-height var(--t-base) var(--ease), opacity var(--t-base) var(--ease);
}

@media (hover: hover) and (min-width: 860px) {
  .page-about .lane-more {
    max-height: 0;
    opacity: 0;
  }

  .page-about .lane:hover .lane-more,
  .page-about .lane:focus-visible .lane-more {
    max-height: 14em;
    opacity: 1;
  }
}

.page-about .lane-foot {
  margin: 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 15px;
  line-height: 1.82;
  color: var(--muted);
  max-width: 66ch;
}

/* ---------- 四支小组 ---------- */

.page-about .teams-layout {
  display: grid;
  gap: 26px;
}

@media (min-width: 960px) {
  .page-about .teams-layout {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, 1fr);
    align-items: start;
    gap: 32px;
  }
}

.page-about .team-table {
  border-top: 1px solid var(--line);
}

.page-about .team-row {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 4px 12px;
  padding: 18px 12px;
  border-bottom: 1px solid var(--line);
  border-radius: var(--r-sm);
  transition: background-color var(--t-fast) var(--ease);
}

.page-about .team-row:hover {
  background-color: rgba(61, 240, 180, 0.06);
}

.page-about .team-no {
  grid-column: 1;
  grid-row: 1;
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--sand);
}

.page-about .team-role {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.4;
  color: var(--white);
}

.page-about .team-desc {
  grid-column: 2;
  grid-row: 2;
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--body-text);
  max-width: 56ch;
}

/* ---------- 更新节奏 ---------- */

.page-about .rhythm-grid {
  display: grid;
  gap: 1px;
  margin-top: 8px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

@media (min-width: 720px) {
  .page-about .rhythm-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .rhythm-item {
  padding: 20px 18px 22px;
  background: var(--ink);
  transition: background-color var(--t-fast) var(--ease);
}

.page-about .rhythm-item:hover {
  background: var(--panel);
}

.page-about .rhythm-when {
  margin: 0 0 9px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--neon);
}

.page-about .rhythm-what {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--body-text);
  max-width: 42ch;
}

/* ---------- 版本演进 ---------- */

.page-about .iter-layout {
  display: grid;
  gap: 28px;
}

@media (min-width: 960px) {
  .page-about .iter-layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.86fr);
    align-items: start;
    gap: 34px;
  }
}

.page-about .iter-list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .iter-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(to bottom, var(--amber), var(--line));
}

.page-about .iter {
  position: relative;
  padding: 0 0 28px 30px;
}

.page-about .iter:last-child {
  padding-bottom: 0;
}

.page-about .iter::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--panel);
  border: 1px solid var(--amber);
  box-sizing: border-box;
}

.page-about .iter-stage {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.page-about .iter-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.4;
  color: var(--white);
}

.page-about .iter-desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--body-text);
  max-width: 46ch;
}

/* ---------- 赛事覆盖与合作 ---------- */

.page-about .eco-layout {
  display: grid;
  gap: 26px;
}

@media (min-width: 900px) {
  .page-about .eco-layout {
    grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
    align-items: start;
    gap: 32px;
  }
}

.page-about .eco-text > p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--body-text);
  max-width: 62ch;
}

.page-about .eco-text > p:last-child {
  margin-bottom: 0;
}

.page-about .eco-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 22px 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .eco-stats .stat {
  padding: 16px 16px 18px;
  background: var(--ink);
}

/* ---------- 媒体容器 ---------- */

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

.page-about .media-frame-img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--r-md);
}

.page-about .media-frame-tilt .media-frame-img {
  border-radius: var(--r-lg);
}

.page-about .media-frame-caption {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 窄屏收敛 ---------- */

@media (max-width: 479px) {
  .page-about .about-h1 {
    font-size: 30px;
  }

  .page-about .about-index {
    gap: 7px 8px;
  }

  .page-about .index-item {
    padding: 6px 11px;
    font-size: 13px;
  }

  .page-about .lane {
    padding: 18px 16px 20px;
  }

  .page-about .chapter {
    padding-bottom: 44px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  .page-about.reveal-ready .chapter[data-reveal],
  .reveal-ready .page-about .chapter[data-reveal] {
    opacity: 1;
    transform: none;
  }
}