/* =============================================================
   Swipe Post Navigation — swipe-post-nav.css
   ============================================================= */

/* ----------------------------------------------------------
   CSS Custom Properties (overridden by JS from settings)
   ---------------------------------------------------------- */
:root {
  --spn-color:    #c9a84c;
  --spn-radius:   12px;
  --spn-shadow:   0 8px 32px rgba(0,0,0,.25);
  --spn-z:        9999;
  --spn-duration: 320ms;
  --spn-ease:     cubic-bezier(.4,0,.2,1);
}

/* ----------------------------------------------------------
   OVERLAY — hiện khi đang vuốt
   ---------------------------------------------------------- */
.spn-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--spn-z);
  pointer-events: none;
  opacity: 0;
  transition: opacity 150ms ease;
}

.spn-overlay.spn-overlay--visible {
  opacity: 1;
}

/* Nền mờ bên trái */
.spn-overlay.spn-overlay--left {
  background: linear-gradient(
    to right,
    rgba(0,0,0,.55) 0%,
    rgba(0,0,0,.0) 60%
  );
}

/* Nền mờ bên phải */
.spn-overlay.spn-overlay--right {
  background: linear-gradient(
    to left,
    rgba(0,0,0,.55) 0%,
    rgba(0,0,0,.0) 60%
  );
}

.spn-overlay-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 24px 32px;
  border-radius: var(--spn-radius);
  background: rgba(0,0,0,.65);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255,255,255,.1);
  box-shadow: var(--spn-shadow);
  max-width: 260px;
  transform: scale(.88);
  transition: transform var(--spn-duration) var(--spn-ease);
}

.spn-overlay--visible .spn-overlay-inner {
  transform: scale(1);
}

.spn-overlay-icon {
  font-size: 2rem;
  line-height: 1;
  color: #fff;
}

/* Icon mũi tên bên trong overlay */
.spn-overlay--left  .spn-overlay-icon::before { content: "←"; color: var(--spn-color); }
.spn-overlay--right .spn-overlay-icon::before { content: "→"; color: var(--spn-color); }

.spn-overlay-title {
  font-size: .875rem;
  color: rgba(255,255,255,.9);
  text-align: center;
  line-height: 1.4;
  font-family: inherit;
  max-width: 200px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ----------------------------------------------------------
   PROGRESS BAR — dải mỏng báo hiệu vuốt
   ---------------------------------------------------------- */
.spn-progress {
  position: fixed;
  top: 0;
  height: 3px;
  z-index: calc(var(--spn-z) + 1);
  background: var(--spn-color);
  width: 0%;
  transition: width 80ms linear;
  pointer-events: none;
}

.spn-progress--left  { left: 0; }
.spn-progress--right { right: 0; left: auto; }

/* ----------------------------------------------------------
   ARROW BUTTONS
   ---------------------------------------------------------- */
.spn-arrows {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  pointer-events: none;
  z-index: var(--spn-z);
  padding: 0 12px;
}

.spn-arrow {
  pointer-events: all;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: rgba(0,0,0,.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,.1);
  border-radius: var(--spn-radius);
  color: #fff;
  text-decoration: none;
  box-shadow: var(--spn-shadow);
  transition:
    transform var(--spn-duration) var(--spn-ease),
    opacity var(--spn-duration) var(--spn-ease),
    background var(--spn-duration) ease;
  max-width: 200px;

  /* Hidden by default, show on hover of document */
  opacity: 0;
  transform: translateX(0);
}

.spn-arrow--prev { transform: translateX(-12px); }
.spn-arrow--next { transform: translateX(12px); }

/* Show arrows on body hover (desktop) */
body:hover .spn-arrow,
.spn-arrows--visible .spn-arrow {
  opacity: 1;
  transform: translateX(0);
}

.spn-arrow:hover {
  background: rgba(0,0,0,.9);
  border-color: var(--spn-color);
}

.spn-arrow-icon {
  font-size: 1.25rem;
  color: var(--spn-color);
  flex-shrink: 0;
}

.spn-arrow-label {
  display: flex;
  flex-direction: column;
}

.spn-arrow-hint {
  font-size: .65rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--spn-color);
  opacity: .85;
}

.spn-arrow-title {
  font-size: .8rem;
  color: rgba(255,255,255,.9);
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 140px;
}

/* ----------------------------------------------------------
   SWIPE HINT TOAST
   ---------------------------------------------------------- */
.spn-hint {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 22px;
  background: rgba(0,0,0,.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 999px;
  color: rgba(255,255,255,.9);
  font-size: .85rem;
  z-index: var(--spn-z);
  white-space: nowrap;
  box-shadow: var(--spn-shadow);
  opacity: 0;
  pointer-events: none;
  transition:
    opacity 400ms ease,
    transform 400ms var(--spn-ease);
}

.spn-hint--visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.spn-hint-icon {
  font-size: 1.1rem;
  animation: spn-bounce 1.4s ease-in-out infinite;
}

.spn-hint-icon:first-child  { animation-direction: reverse; }

@keyframes spn-bounce {
  0%, 100% { transform: translateX(0); }
  50%       { transform: translateX(6px); }
}

/* ----------------------------------------------------------
   PAGE TRANSITION ANIMATIONS
   ---------------------------------------------------------- */

/* === SLIDE === */
@keyframes spn-slide-out-left  { to { transform: translateX(-100vw); opacity: 0; } }
@keyframes spn-slide-out-right { to { transform: translateX(100vw);  opacity: 0; } }
@keyframes spn-slide-in-left   { from { transform: translateX(-100vw); opacity: 0; } }
@keyframes spn-slide-in-right  { from { transform: translateX(100vw);  opacity: 0; } }

/* === FADE === */
@keyframes spn-fade-out { to   { opacity: 0; } }
@keyframes spn-fade-in  { from { opacity: 0; } }

/* === FLIP === */
@keyframes spn-flip-out-left  { to   { transform: perspective(600px) rotateY(90deg);  opacity: 0; } }
@keyframes spn-flip-out-right { to   { transform: perspective(600px) rotateY(-90deg); opacity: 0; } }
@keyframes spn-flip-in-left   { from { transform: perspective(600px) rotateY(-90deg); opacity: 0; } }
@keyframes spn-flip-in-right  { from { transform: perspective(600px) rotateY(90deg);  opacity: 0; } }

/* Applied to body > main wrapper during navigation */
body.spn-transitioning {
  overflow: hidden;
}

/* ----------------------------------------------------------
   DRAGGING STATE — kéo nội dung trang
   ---------------------------------------------------------- */
body.spn-dragging {
  user-select: none;
  cursor: grabbing;
}

body.spn-dragging * {
  pointer-events: none !important;
}

/* Hiệu ứng kéo thực tế trên trang */
.spn-page-drag {
  transition: none !important;
  will-change: transform;
}

/* ----------------------------------------------------------
   MOBILE RESPONSIVE
   ---------------------------------------------------------- */
@media (max-width: 768px) {
  /* Ẩn arrow buttons trên mobile (dùng swipe là chính) */
  .spn-arrows {
    display: none;
  }

  .spn-hint {
    bottom: 60px;
    font-size: .8rem;
    padding: 8px 18px;
  }
}

@media (hover: none) {
  /* Touch device: luôn ẩn arrows */
  .spn-arrows {
    display: none;
  }
}

/* ----------------------------------------------------------
   REDUCED MOTION
   ---------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  .spn-overlay,
  .spn-overlay-inner,
  .spn-arrow,
  .spn-hint,
  .spn-hint-icon {
    transition: none !important;
    animation: none !important;
  }
}