/* ============================================================
   品牌故事页专属样式 · 作用域 .page-about
   ============================================================ */

.page-about {
  background-color: var(--cream);
  color: var(--ink);
  position: relative;
  overflow-x: hidden;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(43, 38, 32, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(43, 38, 32, .035) 1px, transparent 1px);
  background-size: 30px 30px;
  pointer-events: none;
  z-index: 0;
}

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

.page-about .breadcrumb {
  padding-top: 1.25rem;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding-top: 1rem;
  padding-bottom: 2.5rem;
}

.page-about .about-hero__inner {
  display: grid;
  gap: 2.25rem;
}

.page-about .about-hero__title {
  margin: 0 0 1.25rem;
  font-family: var(--font-heading);
  font-size: var(--fs-h1);
  line-height: 1.12;
  letter-spacing: -.01em;
  display: flex;
  flex-direction: column;
}

.page-about .about-hero__title span {
  color: var(--red);
}

.page-about .about-hero__desc {
  margin: 0;
  max-width: 38em;
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--brown);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.5rem;
}

.page-about .about-hero__preview {
  margin-top: 2rem;
  padding: 1.25rem;
  background: var(--glass-strong);
  border: 1px solid rgba(43, 38, 32, .1);
  border-radius: var(--radius);
}

.page-about .about-hero__preview-label {
  display: block;
  margin-bottom: .6rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--mid-gray);
}

.page-about .about-hero__preview-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .25rem;
  grid-template-columns: 1fr;
}

.page-about .about-hero__preview-list a {
  color: var(--ink);
  text-decoration: none;
  display: inline-flex;
  gap: .65rem;
  align-items: baseline;
  padding: .45rem .5rem;
  border-radius: 4px;
  font-weight: 500;
  transition: background-color .25s var(--ease), color .25s var(--ease);
}

.page-about .about-hero__preview-list a:hover,
.page-about .about-hero__preview-list a:focus-visible {
  background: var(--brown);
  color: var(--cream);
}

.page-about .about-hero__preview-list a:focus-visible {
  outline: 2px solid var(--red);
  outline-offset: 2px;
}

/* 指标块 */

.page-about .about-stats {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: .75rem;
}

.page-about .about-stat {
  background: var(--brown);
  color: var(--cream);
  border-radius: var(--radius);
  padding: 1.1rem 1rem;
  border-left: 3px solid var(--amber);
  transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}

.page-about .about-stat:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.page-about .about-stat dt {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(245, 239, 230, .75);
  margin-bottom: .35rem;
}

.page-about .about-stat dd {
  margin: 0;
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 700;
  line-height: 1.1;
  color: #FFFFFF;
}

/* ---------- 章节标题通用 ---------- */

.page-about .origin-section__title,
.page-about .timeline-section__title,
.page-about .design-section__title,
.page-about .commitment-section__title {
  margin: 0 0 1rem;
  font-family: var(--font-heading);
  font-size: var(--fs-h2);
  line-height: 1.25;
}

.page-about .origin-section__lead,
.page-about .timeline-section__desc,
.page-about .design-section__lead,
.page-about .commitment-section__lead {
  font-size: 1.02rem;
  line-height: 1.75;
  margin: 0;
  max-width: 42em;
}

/* ---------- 起点与使命 ---------- */

.page-about .origin-section {
  padding-bottom: 2rem;
}

.page-about .origin-section__grid {
  display: grid;
  gap: 2rem;
  align-items: center;
}

.page-about .origin-section__content p {
  line-height: 1.75;
  color: var(--brown);
}

.page-about .origin-section__point {
  display: flex;
  gap: .85rem;
  padding: .85rem 1rem;
  background: rgba(255, 255, 255, .55);
  border-left: 3px solid var(--amber);
  border-radius: 0 var(--radius) var(--radius) 0;
  align-items: center;
  margin-top: 1.5rem;
}

.page-about .origin-section__point p {
  margin: 0;
  font-size: .95rem;
  color: var(--ink);
}

.page-about .origin-section__num {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--red);
}

.page-about .origin-section__media {
  margin: 0;
}

/* ---------- 媒体图片 ---------- */

.page-about .media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  background: var(--light-gray);
}

/* ---------- 版本演进时间线 ---------- */

.page-about .timeline-section {
  padding-bottom: 2rem;
}

.page-about .timeline-section__header {
  display: grid;
  gap: .75rem;
  margin-bottom: 2rem;
}

.page-about .version-timeline {
  position: relative;
  padding-left: 2rem;
}

.page-about .version-timeline::before {
  content: "";
  position: absolute;
  top: .5rem;
  bottom: .5rem;
  left: .75rem;
  width: 2px;
  background: repeating-linear-gradient(
    to bottom,
    var(--brown) 0px,
    var(--brown) 5px,
    transparent 5px,
    transparent 11px
  );
  opacity: .45;
}

.page-about .version-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 2.25rem 1fr;
  gap: 1.25rem;
  padding-bottom: 3rem;
}

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

.page-about .version-timeline__marker {
  display: flex;
  justify-content: flex-start;
}

.page-about .version-timeline__node {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  background: var(--cream);
  border: 2px solid var(--brown);
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 700;
  color: var(--brown);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color .25s var(--ease), border-color .25s var(--ease),
    color .25s var(--ease), transform .25s var(--ease), box-shadow .25s var(--ease);
}

.page-about .version-timeline__item:hover .version-timeline__node,
.page-about .version-timeline__item:focus-within .version-timeline__node {
  background: var(--red);
  border-color: var(--red);
  color: var(--cream);
  transform: scale(1.12);
  box-shadow: 0 0 0 6px rgba(228, 87, 46, .18);
}

.page-about .version-timeline__node--current {
  background: var(--red);
  border-color: var(--red);
  color: var(--cream);
}

.page-about .version-timeline__card {
  position: relative;
  overflow: hidden;
  padding: 1.25rem;
  margin: 0;
}

.page-about .version-timeline__card--current {
  border: 2px solid rgba(228, 87, 46, .55);
}

.page-about .version-timeline__ghost {
  position: absolute;
  right: -.1rem;
  bottom: -.85rem;
  font-family: var(--font-heading);
  font-size: clamp(3.6rem, 8vw, 6rem);
  font-weight: 700;
  line-height: 1;
  color: rgba(43, 38, 32, .05);
  pointer-events: none;
  user-select: none;
  z-index: 0;
}

.page-about .version-timeline__card--current .version-timeline__ghost {
  color: rgba(228, 87, 46, .09);
}

.page-about .version-timeline__era {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--mid-gray);
  margin-bottom: .4rem;
}

.page-about .version-timeline__name {
  margin: 0 0 .5rem;
  font-family: var(--font-heading);
  font-size: var(--fs-h3);
}

.page-about .version-timeline__desc {
  margin: 0 0 .9rem;
  font-size: .95rem;
  line-height: 1.68;
  color: var(--brown);
  position: relative;
  z-index: 1;
}

.page-about .version-timeline__features {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: .5rem;
  position: relative;
  z-index: 1;
}

.page-about .version-timeline__features li {
  position: relative;
  padding-left: 1.2rem;
  font-size: .9rem;
}

.page-about .version-timeline__features li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--red);
  font-weight: 700;
}

.page-about .version-timeline__tags {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  position: relative;
  z-index: 1;
  margin-top: 1rem;
}

/* ---------- 版本对比 ---------- */

.page-about .version-compare {
  margin-top: 3rem;
  padding: 1.5rem;
  background: var(--light-gray);
  border-radius: var(--radius);
  display: grid;
  gap: 1.25rem;
}

.page-about .version-compare__title {
  margin: 0 0 .35rem;
  font-family: var(--font-heading);
  font-size: var(--fs-h3);
}

.page-about .version-compare__intro p {
  margin: 0;
  font-size: .95rem;
  line-height: 1.65;
  color: var(--mid-gray);
}

.page-about .version-compare__media {
  margin: 0;
}

.page-about .version-compare__points {
  display: flex;
  gap: 1rem;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  margin: 0 -1rem;
  padding: 0 1rem .5rem;
}

.page-about .version-compare__col {
  flex: 0 0 85%;
  scroll-snap-align: start;
  padding: 1.15rem;
  border-radius: var(--radius);
  font-size: .9rem;
}

.page-about .version-compare__col--v3 {
  background: rgba(138, 122, 104, .18);
}

.page-about .version-compare__col--v4 {
  background: var(--deep-blue);
  color: var(--cream);
}

.page-about .version-compare__col h4 {
  margin: 0 0 .6rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.page-about .version-compare__col--v4 h4 {
  color: var(--amber);
}

.page-about .version-compare__col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .4rem;
}

.page-about .version-compare__col li {
  position: relative;
  padding-left: 1.15rem;
  line-height: 1.6;
}

.page-about .version-compare__col--v3 li::before {
  content: "−";
  position: absolute;
  left: 0;
  color: var(--mid-gray);
}

.page-about .version-compare__col--v4 li::before {
  content: "+";
  position: absolute;
  left: 0;
  color: var(--amber);
  font-weight: 700;
}

/* ---------- V4设计理念 ---------- */

.page-about .design-section {
  padding-bottom: 3rem;
  background: linear-gradient(180deg, var(--cream) 0%, var(--light-gray) 100%);
}

.page-about .design-section__header {
  display: grid;
  gap: .75rem;
}

.page-about .design-grid {
  margin-top: 2rem;
  display: grid;
  gap: 1rem;
}

.page-about .design-card {
  padding: 1.5rem;
  margin: 0;
  position: relative;
  overflow: hidden;
}

.page-about .design-card::after {
  content: "";
  position: absolute;
  width: 6rem;
  height: 6rem;
  border-radius: 50%;
  right: -2rem;
  bottom: -2rem;
  background: rgba(43, 38, 32, .04);
}

.page-about .design-card__index {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: .6rem;
}

.page-about .design-card__title {
  margin: 0 0 .6rem;
  font-family: var(--font-heading);
  font-size: var(--fs-h3);
  position: relative;
  z-index: 1;
}

.page-about .design-card__text {
  margin: 0;
  font-size: .95rem;
  line-height: 1.7;
  color: var(--brown);
  position: relative;
  z-index: 1;
}

.page-about .design-card--primary {
  background: var(--glass-strong);
}

.page-about .design-card--primary .design-card__index {
  font-size: .85rem;
}

.page-about .design-card--dark {
  background: var(--deep-blue);
}

.page-about .design-card--dark .design-card__title {
  color: #FFFFFF;
}

.page-about .design-card--dark .design-card__text {
  color: rgba(245, 239, 230, .85);
}

.page-about .design-card--dark .design-card__index {
  color: var(--amber);
}

.page-about .design-card--amber {
  background: rgba(242, 169, 0, .18);
}

.page-about .design-card--light {
  background: #FFFFFF;
}

/* ---------- 用户服务承诺 ---------- */

.page-about .commitment-section {
  margin-top: 1rem;
  background: var(--brown);
  color: var(--cream);
  padding-top: 3.5rem;
  padding-bottom: 3.5rem;
}

.page-about .commitment-section__title {
  color: #FFFFFF;
}

.page-about .commitment-section__lead {
  color: rgba(245, 239, 230, .8);
}

.page-about .commitment-section .section-label {
  color: var(--amber);
}

.page-about .commitment-section__body {
  margin-top: 2rem;
  display: grid;
  gap: 2rem;
  align-items: center;
}

.page-about .commitment-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .commitment-list__item {
  background: rgba(255, 255, 255, .07);
  border-left: 3px solid var(--red);
  border-radius: var(--radius);
  padding: 1.2rem 1.25rem;
}

.page-about .commitment-list__title {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  color: #FFFFFF;
  margin: 0 0 .4rem;
}

.page-about .commitment-list__text {
  margin: 0;
  font-size: .93rem;
  line-height: 1.7;
  color: rgba(245, 239, 230, .82);
}

.page-about .commitment-list__text a {
  color: var(--amber);
}

.page-about .commitment-section__media {
  margin: 0;
}

.page-about .commitment-section__cta {
  margin-top: 2.5rem;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1rem;
}

.page-about .commitment-section__cta p {
  margin: 0;
  color: rgba(245, 239, 230, .85);
  line-height: 1.7;
}

.page-about .commitment-section__cta p a {
  color: var(--amber);
  text-underline-offset: 3px;
}

/* ---------- 响应式：平板 ---------- */

@media (min-width: 768px) {
  .page-about .section {
    padding-top: 4.5rem;
    padding-bottom: 4.5rem;
  }

  .page-about .about-hero {
    padding-top: 1.5rem;
    padding-bottom: 3rem;
  }

  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: 3rem;
    align-items: start;
  }

  .page-about .about-hero__preview-list {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .page-about .origin-section__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 3rem;
  }

  .page-about .version-timeline__features {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .version-compare__points {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin: 0;
    padding: 0;
    overflow: visible;
  }

  .page-about .version-compare__col {
    flex: none;
  }

  .page-about .commitment-section__body {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  }

  .page-about .commitment-section__cta {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .page-about .commitment-section__cta p {
    max-width: 36em;
  }
}

/* ---------- 响应式：桌面 ---------- */

@media (min-width: 1024px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .about-stat {
    text-align: left;
  }

  .page-about .version-compare {
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
    align-items: center;
  }

  .page-about .version-compare__intro p {
    font-size: 1rem;
  }

  .page-about .design-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
  }

  .page-about .design-card--primary {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    gap: 2rem;
    align-items: center;
  }

  .page-about .design-card--primary .design-card__index {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-size: 1rem;
    letter-spacing: .3em;
    margin: 0;
    align-self: stretch;
    color: var(--red);
  }

  .page-about .commitment-section__body {
    gap: 3rem;
  }
}