/* ===================================================================
   AiTenderChat — Glass + iOS Spring Transitions
   View transitions, modal slides, ripple, haptic-feel
   =================================================================== */

/* === SPA view transitions === */
.at-view {
  animation: at-view-in var(--at-dur) var(--at-ease-spring);
  will-change: transform, opacity, filter;
}
@keyframes at-view-in {
  from { opacity: 0; transform: translateY(8px) scale(.985); filter: blur(6px); }
  to   { opacity: 1; transform: translateY(0)   scale(1);    filter: blur(0); }
}

/* Slide between bottom-nav tabs (left↔right) */
.at-tab-in-right { animation: at-tab-right var(--at-dur) var(--at-ease-spring); }
.at-tab-in-left  { animation: at-tab-left  var(--at-dur) var(--at-ease-spring); }
@keyframes at-tab-right {
  from { opacity: 0; transform: translateX(24px); filter: blur(4px); }
  to   { opacity: 1; transform: translateX(0);    filter: blur(0); }
}
@keyframes at-tab-left {
  from { opacity: 0; transform: translateX(-24px); filter: blur(4px); }
  to   { opacity: 1; transform: translateX(0);     filter: blur(0); }
}

/* === Glass overlay/backdrop for modals === */
.at-glass-backdrop {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(15,23,42,.32);
  backdrop-filter: var(--at-glass-blur);
  -webkit-backdrop-filter: var(--at-glass-blur);
  animation: at-backdrop-in var(--at-dur-fast) var(--at-ease-out);
  opacity: 1;
}
[data-theme="dark"] .at-glass-backdrop { background: rgba(0,0,0,.55); }
@keyframes at-backdrop-in {
  from { opacity: 0; backdrop-filter: blur(0); -webkit-backdrop-filter: blur(0); }
  to   { opacity: 1; backdrop-filter: var(--at-glass-blur); -webkit-backdrop-filter: var(--at-glass-blur); }
}
.at-glass-backdrop.closing { animation: at-backdrop-out var(--at-dur-fast) var(--at-ease-out) forwards; }
@keyframes at-backdrop-out {
  to { opacity: 0; backdrop-filter: blur(0); -webkit-backdrop-filter: blur(0); }
}

/* === iOS modal sheet === */
.at-modal {
  animation: at-modal-in var(--at-dur) var(--at-ease-spring);
  transform-origin: center 50%;
  will-change: transform, opacity;
}
@keyframes at-modal-in {
  from { opacity: 0; transform: scale(.94) translateY(12px); }
  to   { opacity: 1; transform: scale(1)   translateY(0); }
}
.at-modal.closing { animation: at-modal-out 180ms var(--at-ease-out) forwards; }
@keyframes at-modal-out {
  to { opacity: 0; transform: scale(.96) translateY(8px); }
}

/* Bottom-sheet variant (mobile) */
@media (max-width: 600px) {
  .at-modal.sheet {
    transform-origin: center bottom;
    animation: at-sheet-in var(--at-dur) var(--at-ease-spring);
  }
  @keyframes at-sheet-in {
    from { opacity: 0; transform: translateY(40px); }
    to   { opacity: 1; transform: translateY(0); }
  }
}

/* === Ripple on tap (iOS-flavour subtle) === */
.at-ripple { position: relative; overflow: hidden; }
.at-ripple::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--ripple-x, 50%) var(--ripple-y, 50%),
    rgba(99,102,241,.28) 0%, rgba(99,102,241,0) 60%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 380ms var(--at-ease-out);
}
.at-ripple.ripple-active::after { opacity: 1; }

/* Tap-down feedback (no layout shift, just brightness) */
.at-tap { transition: filter 120ms var(--at-ease-out), transform 120ms var(--at-ease-out); }
.at-tap:active { filter: brightness(.92); transform: scale(.97); }

/* === Loading bar (top of viewport — YouTube/Insta style) === */
.at-loadbar {
  position: fixed;
  top: 0; left: 0;
  height: 2.5px;
  background: var(--at-grad);
  z-index: 9999;
  border-radius: 0 2px 2px 0;
  box-shadow: 0 0 8px rgba(99,102,241,.6);
  width: 0;
  opacity: 0;
  transition: width 800ms var(--at-ease-out), opacity 200ms var(--at-ease-out);
  pointer-events: none;
}
.at-loadbar.show { opacity: 1; width: 90%; }
.at-loadbar.done { width: 100%; opacity: 0; transition: width 220ms var(--at-ease-out), opacity 300ms var(--at-ease-out) 220ms; }

/* === Skeleton shimmer === */
.at-skel {
  position: relative;
  overflow: hidden;
  background: linear-gradient(90deg,
    rgba(0,0,0,.06) 0%,
    rgba(0,0,0,.10) 40%,
    rgba(0,0,0,.06) 80%);
  background-size: 200% 100%;
  animation: at-skel 1.4s linear infinite;
  border-radius: 8px;
}
[data-theme="dark"] .at-skel {
  background: linear-gradient(90deg,
    rgba(255,255,255,.06) 0%,
    rgba(255,255,255,.12) 40%,
    rgba(255,255,255,.06) 80%);
  background-size: 200% 100%;
}
@keyframes at-skel { 0% { background-position: 100% 0; } 100% { background-position: -100% 0; } }

/* === Reduced motion === */
@media (prefers-reduced-motion: reduce) {
  .at-view, .at-tab-in-right, .at-tab-in-left, .at-modal, .at-glass-backdrop,
  .at-skel { animation: none !important; }
}