/* Sticky side rails — căn theo khung nội dung thật (JS sync), không đè trang */
.ft-ad-rail {
  display: none;
  position: fixed;
  top: 72px;
  bottom: 12px;
  z-index: 20;
  pointer-events: none;
  width: var(--ft-rail-w, 160px);
  box-sizing: border-box;
}
.ft-ad-rail .ft-ad-rail-inner {
  pointer-events: auto;
  height: 100%;
  max-height: calc(100vh - 84px);
  overflow-x: hidden;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 0;
  background: transparent;
  border: 0;
  box-shadow: none;
}
.ft-ad-rail .ft-ad-rail-card {
  background: #fff;
  border: 1px solid #d7e6ec;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 22px rgba(15, 39, 68, 0.09);
}
.ft-ad-rail .ft-ad-rail-rotating {
  animation: ft-rail-fade 0.45s ease;
}
@keyframes ft-rail-fade {
  from { opacity: 0.35; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}
.ft-ad-rail .ft-ad-rail-label {
  display: block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: #94a3b8;
  padding: 8px 10px 0;
  text-transform: uppercase;
}
.ft-ad-rail a.ft-ad-rail-link {
  display: block;
  text-decoration: none;
  color: inherit;
}
.ft-ad-rail img {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 2;
  height: auto;
  max-height: none;
  min-height: 0;
  object-fit: cover;
  background: #f1f5f9;
}
.ft-ad-rail .ft-ad-rail-cap {
  display: block;
  font-size: 0.78rem;
  font-weight: 650;
  color: #0f2744;
  padding: 8px 10px 10px;
  line-height: 1.35;
}
.ft-ad-rail .ft-ad-rail-empty,
.ft-ad-rail .ft-ad-rail-gs-hint {
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1 / 2;
  min-height: 0;
  padding: 16px 12px;
  text-align: center;
  font-size: 0.78rem;
  font-weight: 650;
  color: #64748b;
  text-decoration: none;
  line-height: 1.4;
  box-sizing: border-box;
}
.ft-ad-rail .ft-ad-rail-empty { color: #0e7490; }
.ft-ad-rail .ft-ad-rail-adsense {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 2;
  min-height: 0;
  padding: 0 0 8px;
  box-sizing: border-box;
}
.ft-ad-rail .ft-ad-rail-adsense ins.adsbygoogle {
  display: block !important;
  width: 100% !important;
  height: 100% !important;
  min-height: calc(var(--ft-rail-w, 160px) * 2);
}

/* Fallback CSS (trước khi JS đo); biến đặt trên body — không gắn cứng trên .ft-ad-rail */
.ft-ad-rail-left {
  left: max(6px, calc(50% - (var(--ft-content-w, 860px) / 2) - var(--ft-rail-w, 160px) - var(--ft-rail-gap, 14px)));
  right: auto;
}
.ft-ad-rail-right {
  right: max(6px, calc(50% - (var(--ft-content-w, 860px) / 2) - var(--ft-rail-w, 160px) - var(--ft-rail-gap, 14px)));
  left: auto;
}

@media (min-width: 1100px) {
  body.ft-has-rails {
    --ft-content-w: 720px;
    --ft-rail-w: 130px;
    --ft-rail-gap: 12px;
  }
  body.ft-has-rails .ft-ad-rail { display: block; }
  body.ft-has-rails .container,
  body.ft-has-rails .art-wrap,
  body.ft-has-rails .dir-seo-wrap,
  body.ft-has-rails .ph-wrap,
  body.ft-has-rails .dir-wrap,
  body.ft-has-rails .art-top,
  body.ft-has-rails .art-foot,
  body.ft-has-rails header.site-header,
  body.ft-has-rails footer.site-footer {
    /* Chừa chỗ 2 cột + khe: không để nội dung đè rails */
    max-width: min(
      var(--ft-content-w),
      calc(100vw - 2 * var(--ft-rail-w) - 2 * var(--ft-rail-gap) - 28px)
    );
    margin-left: auto;
    margin-right: auto;
  }
}

@media (min-width: 1280px) {
  body.ft-has-rails {
    --ft-content-w: 820px;
    --ft-rail-w: 150px;
    --ft-rail-gap: 14px;
  }
}

@media (min-width: 1440px) {
  body.ft-has-rails {
    --ft-content-w: 920px;
    --ft-rail-w: 168px;
    --ft-rail-gap: 16px;
  }
}

@media (min-width: 1680px) {
  body.ft-has-rails {
    --ft-content-w: 1000px;
    --ft-rail-w: 190px;
    --ft-rail-gap: 18px;
  }
}

@media (min-width: 1920px) {
  body.ft-has-rails {
    --ft-content-w: 1080px;
    --ft-rail-w: 210px;
    --ft-rail-gap: 18px;
  }
}

@media (max-width: 1099px) {
  .ft-ad-rail { display: none !important; }
}

/* JS đã căn → ưu tiên style inline; class đánh dấu */
body.ft-rails-synced .ft-ad-rail-left,
body.ft-rails-synced .ft-ad-rail-right {
  /* left/right/width do page-ads.js ghi */
}