/* ================= 品牌历程 / page-about ================= */

.page-about{
  --ab-axis-w: 12rem;
  --ab-gap: clamp(20px, 3vw, 44px);
  --ab-pad: clamp(16px, 2.4vw, 26px);
  --ab-radius: 6px;
  background: var(--ink-900);
  color: var(--paper-50);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.65;
  padding-bottom: clamp(36px, 6vw, 84px);
}

@media (min-width: 768px){
  .page-about{ font-size: 16px; }
}

.page-about a{ color: inherit; }

.page-about .ab-crumbs-row{
  padding-top: clamp(84px, 12vw, 112px);
}

.page-about .ab-crumbs{
  font-size: .78rem;
  letter-spacing: .06em;
  color: var(--silver-300);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.page-about .ab-crumbs a{
  text-decoration: none;
  border-bottom: 1px solid var(--line-600);
  padding-bottom: 2px;
}

.page-about .ab-crumbs a:hover{
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

.page-about .ab-crumbs [aria-current="page"]{
  color: var(--paper-50);
}

.page-about .ab-crumb-sep{
  color: var(--line-600);
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero{
  padding-block: clamp(20px, 3vw, 40px) clamp(28px, 4vw, 56px);
  border-bottom: 1px solid var(--line-600);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(56,242,214,.10), transparent 60%),
    linear-gradient(180deg, var(--ink-900) 0%, var(--night-800) 140%);
}

.page-about .ab-hero-grid{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 42px);
  align-items: start;
}

@media (min-width: 900px){
  .page-about .ab-hero-grid{
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: stretch;
  }
}

.page-about .ab-kicker{
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
}

.page-about .ab-kicker-num{
  font-size: .8rem;
  color: var(--silver-300);
  letter-spacing: .08em;
}

.page-about .ab-hero h1{
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 5.4vw, 3.5rem);
  line-height: 1.02;
  letter-spacing: -.02em;
  text-align: left;
  max-width: 18ch;
}

.page-about .ab-lede{
  margin: 0 0 22px;
  max-width: 52ch;
  color: var(--paper-200);
  font-size: .95rem;
  line-height: 1.7;
}

.page-about .ab-hero-facts{
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-600);
  border-top: 1px solid var(--line-600);
  border-bottom: 1px solid var(--line-600);
}

.page-about .ab-hero-facts li{
  background: rgba(6,23,19,.72);
  padding: 12px 14px;
  display: grid;
  grid-template-columns: 4.2rem minmax(0, 1fr);
  grid-template-areas:
    "n k"
    "n d";
  gap: 2px 14px;
  align-items: center;
}

.page-about .ab-fact-n{
  grid-area: n;
  font-size: clamp(1.6rem, 3.6vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--silver-300);
}

.page-about .ab-hero-facts li:nth-child(1) .ab-fact-n{ color: var(--cyan-400); }
.page-about .ab-hero-facts li:nth-child(2) .ab-fact-n{ color: var(--amber-500); }

.page-about .ab-fact-k{
  grid-area: k;
  font-size: .78rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--paper-50);
}

.page-about .ab-fact-d{
  grid-area: d;
  font-size: .82rem;
  color: var(--silver-300);
  line-height: 1.5;
}

.page-about .ab-hero-cta{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .ab-hero-visual{
  margin: 0;
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--night-800);
  border: 1px solid var(--line-600);
  padding: 12px 12px 14px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .ab-hero-visual img{
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  filter: saturate(.7) contrast(1.08) brightness(.86);
}

.page-about .ab-hero-cap{
  margin: 10px 0 0;
  font-size: .78rem;
  color: var(--silver-300);
  line-height: 1.55;
}

.page-about .ab-hero-scale{
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: auto;
  padding-top: 12px;
  font-size: .72rem;
  color: var(--paper-50);
}

.page-about .ab-scale-line{
  flex: 1 1 24px;
  height: 1px;
  background: linear-gradient(90deg, var(--line-600), var(--cyan-400));
}

/* ---------- 长卷主体 ---------- */

.page-about .ab-body{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  padding-block: clamp(26px, 4.5vw, 58px);
}

@media (min-width: 1024px){
  .page-about .ab-body{
    grid-template-columns: var(--ab-axis-w) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
    align-items: start;
  }
}

/* 左侧刻度 */

.page-about .ab-axis{
  border-left: 2px solid var(--line-600);
  padding-left: 14px;
}

@media (min-width: 1024px){
  .page-about .ab-axis{
    position: sticky;
    top: 104px;
    padding-top: 4px;
  }
}

.page-about .ab-axis-label{
  margin: 0 0 10px;
  font-size: .7rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--line-600);
  color: var(--silver-300);
  opacity: .7;
}

.page-about .ab-axis-list{
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 14px;
  overflow-x: auto;
  scrollbar-width: thin;
}

@media (min-width: 1024px){
  .page-about .ab-axis-list{
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .ab-axis-list li + li{ margin-top: 12px; }
}

.page-about .ab-axis-link{
  display: flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  font-size: .8rem;
  color: var(--silver-300);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding: 4px 0;
  transition: color var(--d-1) var(--ease), border-color var(--d-1) var(--ease);
}

.page-about .ab-axis-link .num{
  font-size: .72rem;
  color: var(--line-600);
  opacity: 1;
}

.page-about .ab-axis-link:hover,
.page-about .ab-axis-link:focus-visible{
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

.page-about .ab-axis-link:hover .num{ color: var(--cyan-400); }

.page-about .ab-axis-foot{
  margin: 16px 0 0;
  font-size: .7rem;
  letter-spacing: .08em;
  color: var(--silver-300);
}

@media (max-width: 1023px){
  .page-about .ab-axis-foot{ display: none; }
}

/* 章节 */

.page-about .ab-chapters{
  min-width: 0;
  display: grid;
  gap: clamp(24px, 3.6vw, 52px);
}

.page-about .ab-chapter{
  position: relative;
  scroll-margin-top: 96px;
  border-top: 1px solid var(--line-600);
  padding-top: clamp(20px, 3vw, 34px);
}

.page-about .ab-chapter::before{
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 72px;
  height: 3px;
  background: var(--cyan-400);
  transition: width var(--d-2) var(--ease), background-color var(--d-2) var(--ease);
}

.page-about [data-chapter].is-current::before{
  width: 140px;
  background: var(--amber-500);
}

.page-about .ab-chapter-head{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  margin-bottom: clamp(16px, 2.6vw, 28px);
}

@media (min-width: 640px){
  .page-about .ab-chapter-head{
    grid-template-columns: 3.6rem minmax(0, 1fr);
    gap: 4px 16px;
    align-items: start;
  }
}

.page-about .ab-chapter-index{
  margin: 0;
  font-size: clamp(1.6rem, 3.4vw, 2.6rem);
  line-height: .9;
  font-weight: 700;
  color: var(--silver-300);
  opacity: .4;
}

.page-about .ab-chapter-head h2{
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.4rem, 2.6vw, 2.1rem);
  line-height: 1.15;
  letter-spacing: -.02em;
  text-align: left;
}

.page-about .ab-chapter-lede{
  margin: 0;
  max-width: 62ch;
  font-size: .9rem;
  color: var(--paper-200);
  line-height: 1.7;
}

.page-about .ab-tail-link{
  margin: clamp(16px, 2vw, 22px) 0 0;
  font-size: .84rem;
  color: var(--silver-300);
}

.page-about .ab-tail-link a{
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(56,242,214,.45);
}

.page-about .ab-tail-link a:hover{
  border-bottom-color: var(--cyan-400);
}

/* ---------- 01 版本演进 ---------- */

.page-about .ab-era-list{
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-era{
  display: grid;
  grid-template-columns: 3.4rem minmax(0, 1fr);
  gap: 4px 14px;
  background: var(--night-800);
  border-left: 3px solid var(--line-600);
  padding: 14px 16px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
  transition: border-color var(--d-1) var(--ease), background-color var(--d-1) var(--ease);
}

.page-about .ab-era:hover{
  border-left-color: var(--cyan-400);
  background: #10263b;
}

.page-about .ab-era-tag{
  margin: 0;
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.1;
  color: var(--cyan-400);
}

.page-about .ab-era:nth-child(4) .ab-era-tag{ color: var(--amber-500); }

.page-about .ab-era-body h3{
  margin: 0 0 6px;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -.01em;
}

.page-about .ab-era-body p{
  margin: 0 0 6px;
  font-size: .86rem;
  color: var(--paper-200);
  line-height: 1.62;
}

.page-about .ab-era-meta{
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: .8rem;
  color: var(--silver-300);
  margin: 0;
}

.page-about .ab-era-key{
  color: var(--ink-900);
  background: var(--paper-200);
  padding: 1px 7px;
  font-size: .7rem;
  letter-spacing: .08em;
  border-radius: var(--r-sm);
  white-space: nowrap;
}

/* ---------- 02 口径复核 ---------- */

.page-about .ab-method-grid{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 30px);
}

@media (min-width: 900px){
  .page-about .ab-method-grid{
    grid-template-columns: minmax(0, 1.3fr) minmax(0, .85fr);
    align-items: start;
  }
}

.page-about .ab-step-list{
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-600);
  border-bottom: 1px solid var(--line-600);
}

.page-about .ab-step{
  background: rgba(12,33,54,.62);
  padding: 14px 16px 16px;
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr);
  gap: 4px 12px;
  align-items: baseline;
}

.page-about .ab-step-no{
  grid-row: span 2;
  font-size: .95rem;
  color: var(--cyan-400);
  letter-spacing: .04em;
}

.page-about .ab-step h3{
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
}

.page-about .ab-step p{
  margin: 4px 0 0;
  font-size: .85rem;
  color: var(--paper-200);
  line-height: 1.62;
  max-width: 58ch;
}

.page-about .ab-fold{
  margin-top: 16px;
  border-top: 1px dashed var(--line-600);
  padding-top: 12px;
}

.page-about .ab-fold summary{
  cursor: pointer;
  list-style: none;
  font-size: .78rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

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

.page-about .ab-fold summary::after{
  content: " +";
  font-family: var(--font-num);
}

.page-about .ab-fold[open] summary::after{ content: " −"; }

.page-about .ab-fold p{
  margin: 10px 0 0;
  font-size: .85rem;
  color: var(--paper-200);
  line-height: 1.65;
  max-width: 62ch;
}

.page-about .ab-method-side{
  margin: 0;
  background: var(--night-800);
  border: 1px solid var(--line-600);
  padding: 10px 10px 12px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .ab-method-side img{
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(.72) contrast(1.05) brightness(.9);
}

.page-about .ab-method-side figcaption{
  margin: 10px 0 0;
  font-size: .78rem;
  color: var(--silver-300);
  line-height: 1.55;
}

/* ---------- 03 青训对照 ---------- */

.page-about .ab-chapter--youth::before{
  background: linear-gradient(90deg, var(--grass-500), var(--lemon-400));
}

.page-about .ab-youth-band{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2vw, 22px);
  margin-bottom: clamp(18px, 2.4vw, 26px);
}

@media (min-width: 860px){
  .page-about .ab-youth-band{
    grid-template-columns: minmax(0, 1.45fr) minmax(0, .85fr);
    align-items: stretch;
  }
}

.page-about .ab-youth-visual{
  margin: 0;
  border: 1px solid var(--line-600);
  background: var(--night-800);
  padding: 10px;
}

.page-about .ab-youth-visual img{
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 3;
  object-fit: cover;
  filter: saturate(.85) contrast(1.05) brightness(.9);
}

.page-about .ab-youth-visual figcaption{
  margin: 10px 0 0;
  font-size: .78rem;
  color: var(--silver-300);
  line-height: 1.55;
}

.page-about .ab-youth-note{
  border: 1px solid var(--line-600);
  border-left: 3px solid var(--grass-500);
  background: var(--night-800);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .ab-youth-k{
  margin: 0;
  font-size: .72rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--lemon-400);
}

.page-about .ab-youth-note p:last-child{
  margin: 0;
  font-size: .85rem;
  color: var(--paper-200);
  line-height: 1.65;
}

.page-about .ab-cmp{
  width: 100%;
  border-collapse: collapse;
  font-size: .84rem;
}

.page-about .ab-cmp-cap{
  caption-side: top;
  text-align: left;
  font-size: .76rem;
  color: var(--silver-300);
  padding-bottom: 10px;
  line-height: 1.5;
}

.page-about .ab-cmp th,
.page-about .ab-cmp td{
  text-align: left;
  padding: 10px 10px;
  border-bottom: 1px solid var(--line-600);
  vertical-align: baseline;
}

.page-about .ab-cmp thead th{
  font-size: .72rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--silver-300);
  border-bottom-color: var(--paper-200);
  border-bottom-color: rgba(198,205,212,.4);
}

.page-about .ab-cmp tbody th{
  font-family: var(--font-num);
  font-size: .84rem;
  color: var(--paper-50);
  font-weight: 500;
}

.page-about .ab-cmp tbody td{
  color: var(--silver-300);
}

.page-about .ab-cmp tbody tr{
  transition: box-shadow var(--d-1) var(--ease);
}

.page-about .ab-cmp tbody tr:hover th:first-child{
  box-shadow: inset 2px 0 0 var(--cyan-400);
}

.page-about .ab-cmp-diff{
  display: none;
  text-align: right;
  color: var(--lemon-400);
}

@media (min-width: 768px){
  .page-about .ab-cmp-diff{
    display: table-cell;
  }
  .page-about .ab-cmp th,
  .page-about .ab-cmp td{
    padding: 11px 14px;
  }
  .page-about .ab-cmp{ font-size: .88rem; }
}

/* ---------- 04 团队排班（反色纸面） ---------- */

.page-about .ab-chapter--paper{
  background: var(--paper-50);
  color: var(--ink-900);
  border-top: none;
  padding: clamp(20px, 3vw, 34px);
  box-shadow: 10px 10px 0 0 var(--paper-200);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .ab-chapter--paper::before{
  background: var(--ink-900);
  width: 72px;
}

.page-about .ab-chapter--paper .ab-chapter-index{
  color: var(--ink-900);
  opacity: .22;
}

.page-about .ab-chapter--paper .ab-chapter-lede{
  color: rgba(6,23,19,.72);
}

.page-about .ab-team{
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr));
  gap: 1px;
  background: rgba(6,23,19,.16);
  border-top: 1px solid rgba(6,23,19,.16);
  border-bottom: 1px solid rgba(6,23,19,.16);
}

.page-about .ab-team-item{
  background: var(--paper-50);
  padding: 16px 14px;
}

.page-about .ab-team-n{
  margin: 0 0 6px;
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--ink-900);
}

.page-about .ab-team-item:nth-child(2) .ab-team-n{ color: #1c6b45; }
.page-about .ab-team-item:nth-child(3) .ab-team-n{ color: #a34a10; }

.page-about .ab-team-k{
  margin: 0 0 8px;
  font-size: .78rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(6,23,19,.68);
}

.page-about .ab-team-d{
  margin: 0;
  font-size: .85rem;
  line-height: 1.62;
  color: rgba(6,23,19,.78);
}

.page-about .ab-team-foot{
  margin: 16px 0 0;
  font-size: .85rem;
  line-height: 1.65;
  color: rgba(6,23,19,.78);
  max-width: 70ch;
}

/* ---------- 05 纠错反馈 ---------- */

.page-about .ab-check-list{
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-600);
  border-top: 1px solid var(--line-600);
  border-bottom: 1px solid var(--line-600);
}

.page-about .ab-check-list li{
  background: rgba(12,33,54,.6);
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding: 12px 14px;
  font-size: .86rem;
  color: var(--paper-200);
  line-height: 1.6;
}

.page-about .ab-check-no{
  font-size: .82rem;
  color: var(--cyan-400);
}

.page-about .ab-feedback-cta{
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 18px;
}

.page-about .ab-feedback-note{
  margin: 0;
  font-size: .82rem;
  color: var(--silver-300);
  max-width: 46ch;
  line-height: 1.6;
}

/* ---------- 06 长期原则 ---------- */

.page-about .ab-chapter--rules::before{
  background: var(--amber-500);
}

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

@media (min-width: 760px){
  .page-about .ab-rules{
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }
  .page-about .ab-rule:nth-child(even){ margin-top: 24px; }
}

.page-about .ab-rule{
  background: var(--night-800);
  border: 1px solid var(--line-600);
  padding: 16px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color var(--d-1) var(--ease);
}

.page-about .ab-rule:hover{
  border-color: var(--cyan-400);
}

.page-about .ab-rule-no{
  margin: 0;
  font-size: .78rem;
  letter-spacing: .1em;
  color: var(--silver-300);
}

.page-about .ab-rule h3{
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -.01em;
}

.page-about .ab-rule p:last-child{
  margin: 0;
  font-size: .85rem;
  color: var(--paper-200);
  line-height: 1.62;
}

.page-about .ab-end{
  margin-top: clamp(20px, 3vw, 32px);
  padding-top: clamp(16px, 2vw, 22px);
  border-top: 1px solid var(--line-600);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 20px;
}

.page-about .ab-end-line{
  margin: 0;
  font-size: .88rem;
  color: var(--silver-300);
}

.page-about .ab-end-links{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce){
  .page-about *,
  .page-about *::before,
  .page-about *::after{
    transition: none !important;
    animation: none !important;
  }
}
</style>