/* ==========================================================================
   BIM 净高专题页
   --------------------------------------------------------------------------
   三个模块：滑块对比 / 净高计算器 / 施工节点时间轴
   沿用主站设计变量，不引入新色板。
   ========================================================================== */

/* ---------- 一、首屏 ---------- */
.bim-hero {
  padding: 152px 0 96px;
  background: linear-gradient(180deg, #FFFFFF 0%, #F5F5F7 100%);
  border-bottom: 1px solid var(--line);
}
.bim-hero__eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 12px; letter-spacing: .18em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 24px;
}
.bim-hero__eyebrow::before {
  content: ""; width: 32px; height: 1px; background: var(--accent);
}
.bim-hero__title {
  font-size: clamp(44px, 7vw, 88px);
  line-height: 1.15; letter-spacing: -.045em;
  font-weight: 650; color: var(--ink); margin: 0 0 28px;
}
.bim-hero__title em {
  font-style: normal; color: var(--accent);
  position: relative;
}
.bim-hero__title em::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: .06em;
  height: .09em; background: var(--accent); opacity: .18; border-radius: 2px;
}
.bim-hero__sub {
  font-size: clamp(15px, 1.6vw, 18px); line-height: 1.85;
  color: var(--ink-2); max-width: 34em; margin: 0 0 44px;
}
.bim-hero__scroll {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 13px; color: var(--muted); letter-spacing: .04em;
}
.bim-hero__scroll svg { animation: bimBob 2.2s ease-in-out infinite; }
@keyframes bimBob {
  0%, 100% { transform: translateY(0); opacity: .55; }
  50%      { transform: translateY(5px); opacity: 1; }
}

/* ---------- 通用区块 ---------- */
.bim-sec { padding: 96px 0; }
.bim-sec--soft { background: var(--surface); }
.bim-head { margin-bottom: 48px; }
.bim-head__no {
  display: inline-block; font-size: 12px; letter-spacing: .2em;
  color: var(--accent); font-weight: 600; margin-bottom: 14px;
}
.bim-head__t {
  font-size: clamp(28px, 3.4vw, 42px); line-height: 1.25;
  letter-spacing: -.035em; color: var(--ink); margin: 0 0 16px;
}
.bim-head__d {
  font-size: 16px; line-height: 1.8; color: var(--muted);
  max-width: 40em; margin: 0;
}

/* ---------- 二、滑块对比 ---------- */
.cmp { max-width: 1000px; }
.cmp__stage {
  position: relative; width: 100%; aspect-ratio: 800 / 340;
  border-radius: var(--radius-lg); overflow: hidden;
  border: 1px solid var(--line); background: #fff;
  box-shadow: 0 12px 40px rgba(29,29,31,.06);
  --split: 50%;
  cursor: ew-resize;
  user-select: none;
}
.cmp__layer {
  position: absolute; inset: 0; width: 100%; height: 100%; display: block;
}
/* 上层（做了管线综合）从左往右揭示 */
.cmp__layer--good { clip-path: inset(0 0 0 var(--split)); }
.cmp__divider {
  position: absolute; top: 0; bottom: 0; left: var(--split);
  width: 2px; background: #fff; box-shadow: 0 0 0 1px rgba(0,0,0,.12);
  transform: translateX(-1px); pointer-events: none;
}
.cmp__knob {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  width: 44px; height: 44px; border-radius: 50%;
  background: #fff; color: var(--ink-2);
  display: grid; place-items: center;
  box-shadow: 0 3px 14px rgba(0,0,0,.18);
}
.cmp__range {
  width: 100%; margin: 26px 0 0; appearance: none;
  height: 4px; border-radius: 999px; background: var(--line);
  outline: none;
}
.cmp__range::-webkit-slider-thumb {
  appearance: none; width: 26px; height: 26px; border-radius: 50%;
  background: var(--accent); border: 3px solid #fff;
  box-shadow: 0 2px 10px rgba(0,113,227,.35); cursor: grab;
}
.cmp__range::-moz-range-thumb {
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--accent); border: 3px solid #fff; cursor: grab;
}
.cmp__hint {
  margin: 14px 0 0; font-size: 13px; color: var(--muted); text-align: center;
}

.bim-note {
  max-width: 1000px; margin-top: 40px; padding: 26px 30px;
  background: #fff; border: 1px solid var(--line);
  border-left: 3px solid var(--accent); border-radius: 12px;
}
.bim-note strong {
  display: block; font-size: 14px; color: var(--ink); margin-bottom: 10px;
}
.bim-note p {
  margin: 0; font-size: 15px; line-height: 1.85; color: var(--ink-2);
}

/* ---------- 三、净高计算器 ---------- */
.calc {
  display: grid; grid-template-columns: 1fr 1fr; gap: 28px;
  max-width: 1000px;
}
.calc__panel {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 32px; display: grid; gap: 28px; align-content: start;
}
.calc__field { display: grid; gap: 12px; }
.calc__field > span {
  font-size: 14px; color: var(--ink-2); font-weight: 500;
}
.calc__field b {
  color: var(--accent); font-weight: 650; font-variant-numeric: tabular-nums;
}
.calc__field input[type="range"] {
  width: 100%; appearance: none; height: 4px; border-radius: 999px;
  background: var(--line); outline: none;
}
.calc__field input[type="range"]::-webkit-slider-thumb {
  appearance: none; width: 22px; height: 22px; border-radius: 50%;
  background: var(--accent); border: 3px solid #fff;
  box-shadow: 0 2px 8px rgba(0,113,227,.3); cursor: grab;
}
.calc__field input[type="range"]::-moz-range-thumb {
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--accent); border: 3px solid #fff; cursor: grab;
}
.calc__seg {
  display: inline-flex; gap: 8px;
}
.calc__seg button {
  padding: 9px 22px; border-radius: 980px; font-size: 13px;
  border: 1px solid var(--line); background: #fff; color: var(--ink-2);
  cursor: pointer; transition: all .18s var(--ease);
}
.calc__seg button:hover { border-color: var(--accent); color: var(--accent); }
.calc__seg button.is-on {
  background: var(--accent); border-color: var(--accent); color: #fff;
}

.calc__result {
  background: var(--dark, #1D1D1F); color: #F5F5F7;
  border-radius: var(--radius-lg); padding: 32px;
  display: grid; gap: 24px; align-content: start;
}
.calc__rows { display: grid; gap: 12px; }
.calc__row {
  display: flex; justify-content: space-between; align-items: baseline;
  font-size: 14px; color: #A1A1A6;
  padding-bottom: 10px; border-bottom: 1px solid rgba(255,255,255,.08);
}
.calc__row b { font-size: 19px; color: #F5F5F7; font-variant-numeric: tabular-nums; }
.calc__row--hl b { color: #4B9BE8; }
.calc__gap { display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap; }
.calc__gap-num {
  font-size: 64px; font-weight: 650; line-height: 1;
  color: #4B9BE8; letter-spacing: -.04em; font-variant-numeric: tabular-nums;
}
.calc__gap-unit { font-size: 18px; color: #A1A1A6; }
.calc__gap p {
  flex-basis: 100%; margin: 6px 0 0; font-size: 13px; color: #86868B;
}
.calc__vol {
  font-size: 14px; line-height: 1.8; color: #A1A1A6;
  padding-top: 20px; border-top: 1px solid rgba(255,255,255,.08);
}
.calc__vol b { color: #F5F5F7; font-size: 19px; font-variant-numeric: tabular-nums; }
.calc__vol small { display: block; margin-top: 6px; font-size: 12px; color: #6E6E73; }

.bim-disclaimer {
  max-width: 1000px; margin: 32px 0 0; font-size: 12.5px; line-height: 1.9;
  color: var(--muted);
}

/* ---------- 四、施工时间轴 ---------- */
.tl { max-width: 1000px; }
.tl__rail {
  position: relative; height: 2px; background: var(--line);
  margin: 0 0 28px; border-radius: 2px; overflow: hidden;
}
.tl__progress {
  position: absolute; left: 0; top: 0; height: 100%; width: 8%;
  background: var(--accent); border-radius: 2px;
  transition: width .3s var(--ease);
}
.tl__list {
  list-style: none; margin: 0 0 32px; padding: 0 0 6px;
  display: flex; gap: 4px; overflow-x: auto;
  scrollbar-width: thin;
}
.tl__item { flex: 0 0 auto; }
.tl__item button {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  width: 78px; padding: 10px 2px; border: 0; background: transparent;
  cursor: pointer; color: var(--muted);
  transition: color .18s var(--ease);
}
.tl__dot {
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--line); border: 2px solid #fff;
  box-shadow: 0 0 0 1px var(--line);
  transition: all .18s var(--ease);
}
.tl__no { font-size: 11px; letter-spacing: .1em; opacity: .7; }
.tl__name { font-size: 12.5px; white-space: nowrap; }
.tl__item:hover button { color: var(--ink-2); }
.tl__item.is-on button { color: var(--accent); }
.tl__item.is-on .tl__dot {
  background: var(--accent); box-shadow: 0 0 0 1px var(--accent), 0 0 0 5px rgba(0,113,227,.12);
}

.tl__detail {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius-lg); padding: 36px;
}
.tl__detail-head {
  display: flex; align-items: baseline; gap: 14px; margin-bottom: 26px;
  padding-bottom: 20px; border-bottom: 1px solid var(--line);
}
.tl__detail-no {
  font-size: 13px; letter-spacing: .12em; color: var(--accent); font-weight: 600;
}
.tl__detail-title {
  font-size: 24px; letter-spacing: -.02em; color: var(--ink); margin: 0;
}
.tl__detail-body {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px;
}
.tl__col h4 {
  font-size: 12px; letter-spacing: .12em; text-transform: uppercase;
  color: var(--muted); margin: 0 0 12px; font-weight: 600;
}
.tl__col p { margin: 0; font-size: 14.5px; line-height: 1.85; color: var(--ink-2); }
.tl__col--warn h4 { color: #B4541F; }
.tl__col--warn p { color: #8A4A22; }

/* ---------- 五、收尾 ---------- */
.bim-end {
  max-width: 720px; margin: 0 auto; text-align: center;
}
.bim-end h2 {
  font-size: clamp(26px, 3.2vw, 40px); line-height: 1.3;
  letter-spacing: -.035em; color: var(--ink); margin: 0 0 20px;
}
.bim-end p {
  font-size: 16px; line-height: 1.85; color: var(--muted);
  margin: 0 0 36px;
}
.bim-end .btn-row { justify-content: center; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .calc { grid-template-columns: 1fr; }
  .tl__detail-body { grid-template-columns: 1fr; gap: 22px; }
  .tl__detail { padding: 26px; }
}
@media (max-width: 640px) {
  .bim-hero { padding: 112px 0 64px; }
  .bim-sec { padding: 64px 0; }
  .bim-head { margin-bottom: 32px; }
  .calc__panel, .calc__result { padding: 24px; }
  .calc__gap-num { font-size: 52px; }
  .cmp__knob { width: 38px; height: 38px; }
  .tl__item button { width: 66px; }
  .tl__name { font-size: 11.5px; }
  .bim-note { padding: 22px; }
}