/* ==========================================================================
   p-history.css — 发展历程页专属（几何数值取自 03_发展历程.psd，1rem=100px）
   内容区 702-1577（高 8.75rem），雪山底图 407-1577
   ========================================================================== */

/* --------------------------------------------------------------------------
   0. 外壳校正（与 download / join 一致的「关于我们」系列标准）
      banner：PSD 已把压暗层合进图里，去掉 CSS 叠加遮罩；标题 80px，红块压在字后
   -------------------------------------------------------------------------- */
/* banner 压暗交给 sub.css 的统一遮罩（30.2% 纯黑），素材本身不含压暗与文字 *//* banner 标题块（80px + 红斜块压在字后）统一由 sub.css 定义，本页不再覆写 */

/* banner 与二级导航之间 40px 留白（PSD 二级 641-702） */

.hist {
  position: relative;
  height: 8.77rem;
  background: #fff;
  overflow: hidden;
}
.hist__bg {
  position: absolute;
  left: 0;
  top: -2.95rem;
  width: 100%;
  height: auto;
  pointer-events: none;
}
.hist .container {
  position: relative;
  height: 100%;
}

/* 区块标题：居中（y821-866） */
.hist__title {
  position: absolute;
  left: 0;
  right: 0;
  top: 1.2rem;
  text-align: center;
  font-size: 0.48rem;
  letter-spacing: 0.01rem;
  line-height: 1;
  font-weight: 400;
  color: var(--c-ink);
}

/* 轮播舞台：4 屏叠放，靠 is-on / is-done 控制进出方向 */
.hist__stage {
  position: absolute;
  inset: 0;
}
.hist__item {
  position: absolute;
  inset: 0;
  opacity: 0;
  visibility: hidden;
  transform: translateX(0.5rem);
  transition: opacity 0.45s ease, transform 0.45s ease, visibility 0.45s;
}
.hist__item.is-done { transform: translateX(-0.5rem); }
.hist__item.is-on {
  opacity: 1;
  visibility: visible;
  transform: none;
}

/* 左图：被矩形644 裁切，可见区 x283-955 y946-1325（672x379，与素材 1:1） */
.hist__fig {
  position: absolute;
  left: 1.25rem;
  top: 2.45rem;
  width: 6.72rem;
  height: 3.79rem;
  overflow: hidden;
}
.hist__fig img {
  display: block;
  width: 6.72rem;
  max-width: none;
  height: 3.79rem;
  object-fit: cover;
}

/* 右侧文字组：竖线 x1042 y1011-1262 */
.hist__line {
  position: absolute;
  left: 8.84rem;
  top: 3.09rem;
  width: 0.04rem;
  height: 2.51rem;
  background: #d7e1ec;
}
.hist__year {
  position: absolute;
  left: 9.56rem;
  top: 3.04rem;
  font-family: var(--ff-en);
  font-size: 0.32rem;
  line-height: 1;
  font-weight: 700;
  color: var(--c-primary);
}
.hist__big {
  position: absolute;
  left: 9.56rem;
  top: 3.72rem;
  font-size: 0.36rem;
  line-height: 1;
  font-weight: 500;
  white-space: nowrap;
  color: #000;
}
.hist__small {
  position: absolute;
  left: 9.55rem;
  top: 4.29rem;
  font-size: 0.18rem;
  line-height: 1;
  white-space: nowrap;
  color: #666;
}
.hist__quote {
  position: absolute;
  left: 15.37rem;
  top: 3.07rem;
  width: 0.29rem;
  height: auto;
}

/* 时间轴：轨道 x239-1770 y1413（虚线），年份刻度 x575/858/1140/1423
   条目多到放不下时整条左右滚动（滚轮 / 拖拽 / 触摸），年份不再叠字、不再隐藏。
   · 虚线画在容器自身的背景上 —— 它是静止的轨道，滚动时只有刻度与年份在动；
   · 右端 0.96rem 用 mask 硬遮住：这段正好是「下一屏」圆钮压着的位置，
     padding 挡不住滚动中的内容（padding 本身是可以被滚过去的），只有 mask 能裁；
   · overflow-x:auto 会连带把 overflow-y 变成 auto，所以容器必须有足够高度
     容纳下方那排年份，否则会被裁掉。 */
.timeline {
  position: absolute;
  left: 0.81rem;
  top: 7.13rem;
  width: 15.31rem;
  height: 0.62rem;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;            /* Firefox */
  -ms-overflow-style: none;         /* 老 Edge */
  overscroll-behavior-x: contain;   /* 滚到头别把整页带走 */
  background: repeating-linear-gradient(
    90deg,
    #bbbbbb 0,
    #bbbbbb 0.01rem,
    transparent 0.01rem,
    transparent 0.08rem
  );
  background-position: 0.01rem 0;
  background-size: auto 0.06rem;
  background-repeat: repeat-x;
  -webkit-mask-image: linear-gradient(
    90deg, #000 calc(100% - var(--tl-mask, 0px)), transparent calc(100% - var(--tl-mask, 0px) + 1px));
  mask-image: linear-gradient(
    90deg, #000 calc(100% - var(--tl-mask, 0px)), transparent calc(100% - var(--tl-mask, 0px) + 1px));
}
.timeline::-webkit-scrollbar { display: none; }
.timeline.is-scrollable { cursor: grab; }
.timeline.is-dragging { cursor: grabbing; }
.timeline.is-dragging .timeline__year { cursor: grabbing; }
.timeline__track {
  position: relative;
  width: 100%;                      /* 实际宽度由脚本按条目数改成 px */
  height: 100%;
}
.timeline__tick {
  position: absolute;
  top: 0;
  width: 0.11rem;
  height: 0.06rem;
  background: #a9aaaa;
  transform: translateX(-50%);
}
.timeline__tick.is-on { background: var(--c-primary); }
/* 刻度/年份的 left 由 p-history.js 按条目数与可视宽算出，写在行内 style 上 */
.timeline__year {
  position: absolute;
  top: 0.24rem;
  transform: translateX(-50%);
  padding: 0;
  border: 0;
  background: none;
  appearance: none;
  cursor: pointer;
  font-family: var(--ff-en);
  font-size: 0.24rem;
  line-height: 1;
  font-weight: 700;
  color: #a9aaaa;
  transition: color 0.2s ease;
}
/* 年份上下扩大点击热区，不改变文字位置 */
.timeline__year::after {
  content: "";
  position: absolute;
  left: -0.3rem;
  right: -0.3rem;
  top: -0.3rem;
  bottom: -0.1rem;
}
.timeline__year:hover { color: var(--c-primary); }
.timeline__year:focus-visible {
  outline: 0.02rem solid var(--c-primary);
  outline-offset: 0.06rem;
}
.timeline__year.is-on { color: var(--c-primary); }
/* 条目太多时只显示每第 k 个年份，当前项始终可见 */
.timeline__year.is-minor { visibility: hidden; }
.timeline__year.is-minor.is-on { visibility: visible; }

/* 左右切换圆钮 */
.hist__btn {
  position: absolute;
  top: 6.87rem;
  display: grid;
  place-items: center;
  width: 0.58rem;
  height: 0.58rem;
  border: 0;
  border-radius: 50%;
  background: var(--c-accent);
  cursor: pointer;
}
.hist__btn--prev { left: .34rem; }
.hist__btn--next {
  right: -0.34rem;
  width: 0.6rem;
  height: 0.6rem;
  background: #fff;
  border: 0.02rem solid var(--c-accent);
}
.hist__btn::before {
  content: "";
  width: 0.13rem;
  height: 0.13rem;
  border-left: 0.02rem solid #fff;
  border-bottom: 0.02rem solid #fff;
}
.hist__btn--prev::before { transform: rotate(45deg) translate(0.02rem, -0.02rem); }
.hist__btn--next::before {
  border-color: var(--c-accent);
  transform: rotate(-135deg) translate(0.02rem, -0.02rem);
}
.hist__btn { transition: background 0.2s ease; }
.hist__btn--prev:hover { background: #b8080e; }
.hist__btn--next:hover { background: var(--c-accent); }
.hist__btn--next:hover::before { border-color: #fff; }
.hist__btn:focus-visible {
  outline: 0.02rem solid var(--c-primary);
  outline-offset: 0.06rem;
}
/* 只有一屏时没有「上一/下一」，按钮由脚本给 .hist 加 is-single 隐藏 */
.hist.is-single .hist__btn { display: none; }

@media (prefers-reduced-motion: reduce) {
  .hist__item,
  .hist__btn,
  .timeline__year { transition: none; }
}

/* 响应式：窄屏退化为纵向流式（只显示当前屏） */
@media (max-width: 1024px) {
  .hist { height: auto; padding-block: 0.6rem 0.8rem; }
  .hist__bg { top: 0; height: 100%; object-fit: cover; }
  .hist .container { height: auto; }
  .hist__stage { position: static; inset: auto; }
  .hist__item {
    position: static;
    inset: auto;
    display: none;
    opacity: 1;
    visibility: visible;
    transform: none;
   /* padding-inline: 0.4rem; */
  }
  .hist__item.is-on { display: block; }
  .hist__title,
  .hist__fig,
  .hist__line,
  .hist__year,
  .hist__big,
  .hist__small,
  .hist__quote,
  .timeline,
  .hist__btn { position: static; }
  .hist__fig { width: min(6.72rem, 86%); height: auto; margin: 0.5rem auto 0; }
  .hist__fig img { width: 100%; max-width: 100%; height: auto; margin: 0; }
  .hist__quote { display: none; }
  .hist__line { display: none; }
  .hist__year { margin-top: 0.4rem; font-size: 0.32rem; }
  .hist__big { margin-top: 0.14rem; font-size: 0.3rem; white-space: normal; }
  .hist__small { margin-top: 0.12rem; font-size: 0.2rem; white-space: normal; }
  .timeline { position: relative; top: auto; left: 0; margin: 0.7rem auto 0; width: 86%; }
  .hist__btn { position: absolute; top: auto; bottom: 0.75rem; }
  .hist__btn--prev { left: 0.3rem; }
  .hist__btn--next { right: 0.3rem; left: auto; }
}

@media (max-width: 768px) {
  .hist { padding-block: 0.5rem 0.9rem; }
  .hist .container { text-align: center; }
  .hist__title { font-size: 0.42rem; }
  .hist__big { font-size: 0.28rem; }
  .timeline__year { font-size: 0.18rem; }
  .hist__btn,
  .hist__btn--next { position: static; display: inline-grid; vertical-align: middle; margin: 0.5rem 0.25rem 0; }
}