/* ND yoga, one page magazine reader
   palette taken from the issue: cream paper, lilac, dusty pink */

:root{
  --cream:#f7f1e3;
  --lilac:#a8afdc;
  --pink:#c47ab0;
  --ink:#2b2430;

  --bg-1:#3b3038;
  --bg-2:#1e1820;

  --ui:#f2e9dd;
  --ui-dim:rgba(242,233,221,.55);
  --ui-line:rgba(242,233,221,.16);

  --pw:300px;            /* page width, set by JS */
  --ph:424px;            /* page height, set by JS */
  --dur:760ms;
  --ease:cubic-bezier(.32,.05,.22,1);

  --pad-top:calc(env(safe-area-inset-top) + 0px);
}

*{box-sizing:border-box}
html,body{height:100%}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body{
  margin:0;
  overflow:hidden;
  background:
    radial-gradient(120% 90% at 50% 8%, var(--bg-1) 0%, var(--bg-2) 68%, #150f16 100%);
  color:var(--ui);
  font:400 16px/1.45 "Avenir Next","Segoe UI",system-ui,-apple-system,sans-serif;
  -webkit-font-smoothing:antialiased;
  -webkit-tap-highlight-color:transparent;
  overscroll-behavior:none;
}
body::after{ /* vignette */
  content:"";position:fixed;inset:0;pointer-events:none;z-index:5;
  background:radial-gradient(120% 80% at 50% 45%, transparent 45%, rgba(0,0,0,.45) 100%);
}

#app{
  position:fixed;inset:0;
  display:grid;
  grid-template-rows:auto 1fr auto;
  padding:env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- top bar ---------- */
.topbar{
  position:relative;z-index:6;
  display:flex;align-items:center;gap:16px;
  padding:14px 18px 10px;
}
.brand{display:flex;align-items:baseline;gap:.32em;line-height:1;white-space:nowrap}
.brand-mark{
  font-size:22px;font-weight:600;letter-spacing:.06em;color:var(--lilac);
}
.brand-name{
  font-size:22px;font-weight:300;letter-spacing:.02em;color:var(--lilac);opacity:.92;
}
.issue{
  flex:1;margin:0;
  font-size:11.5px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--ui-dim);
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
}
.tools{display:flex;gap:6px;margin-left:auto}

.tool{
  -webkit-appearance:none;appearance:none;
  width:38px;height:38px;padding:0;
  display:grid;place-items:center;
  border:1px solid var(--ui-line);border-radius:11px;
  background:rgba(255,255,255,.04);
  color:var(--ui);cursor:pointer;
  transition:background .2s,border-color .2s,transform .12s;
}
.tool:hover{background:rgba(255,255,255,.1)}
.tool:active{transform:scale(.94)}
.tool svg{width:18px;height:18px;fill:currentColor}
.tool[aria-expanded="true"]{background:var(--lilac);border-color:var(--lilac);color:#241d24}
#btnSound .ico-off{display:none}
#btnSound:not(.is-on){color:var(--ui-dim)}
#btnSound:not(.is-on) .ico-on{display:none}
#btnSound:not(.is-on) .ico-off{display:block}

/* ---------- stage + book ---------- */
.stage{
  position:relative;
  overflow:hidden;
  display:grid;place-items:center;
  perspective:2400px;
  perspective-origin:50% 46%;
  touch-action:pan-y;
}
.book{
  position:relative;touch-action:none;
  width:var(--pw);height:var(--ph);
  transform-style:preserve-3d;
  transition:width .35s var(--ease), height .35s var(--ease), transform var(--dur) var(--ease);
  will-change:width,height;
}
.mode-spread .book.solo-right{transform:translateX(calc(var(--pw) * -0.5))}
.mode-spread .book.solo-left{transform:translateX(calc(var(--pw) * 0.5))}
/* paper drop shadow under the whole book */
.book::before{
  content:"";position:absolute;left:2%;right:2%;bottom:-2.2%;height:8%;
  background:radial-gradient(50% 50% at 50% 50%, rgba(0,0,0,.55), transparent 72%);
  filter:blur(6px);
  transform:translateZ(-2px);
}
/* the spine shadow, only in spread mode */
.gutter{
  position:absolute;top:0;bottom:0;left:50%;width:8%;
  transform:translateX(-50%) translateZ(1px);
  background:linear-gradient(90deg,transparent,rgba(40,26,34,.28) 42%,rgba(40,26,34,.42) 50%,rgba(40,26,34,.28) 58%,transparent);
  pointer-events:none;z-index:1000;opacity:0;
  transition:opacity .3s;
}
.mode-spread .gutter{opacity:1}

.leaf{
  position:absolute;top:0;left:0;
  width:var(--pw);height:var(--ph);
  transform-origin:left center;
  transform-style:preserve-3d;
  transition:transform var(--dur) var(--ease);
  will-change:transform;
}
.mode-spread .leaf{left:var(--pw)}
.leaf.flipped{transform:rotateY(-180deg)}
.leaf.dragging{transition:none !important}
.leaf.gone{visibility:hidden}

/* the sheet lifts off the stack while it swings, so the turn has some body */
.sheet{
  position:absolute;inset:0;
  transform-style:preserve-3d;
  transition:transform .25s var(--ease);
}
.leaf.dragging .sheet{transition:none}
.leaf.turning .sheet{animation:sheetLift var(--dur) var(--ease)}
@keyframes sheetLift{
  0%{transform:none}
  45%{transform:translateZ(30px) rotateX(1.4deg)}
  100%{transform:none}
}

.face{
  position:absolute;inset:0;
  backface-visibility:hidden;
  -webkit-backface-visibility:hidden;
  overflow:hidden;
  background:var(--cream);
  box-shadow:0 1px 10px rgba(0,0,0,.32);
}
.face.back{transform:rotateY(180deg)}
.face img{
  position:absolute;inset:0;
  width:100%;height:100%;
  object-fit:cover;display:block;
  opacity:0;transition:opacity .35s ease;
}
.face img.ready{opacity:1}
/* blank reverse of a sheet in single page mode */
.face.blank{
  background:
    linear-gradient(115deg, rgba(0,0,0,.05), transparent 40%),
    repeating-linear-gradient(92deg, rgba(43,36,48,.028) 0 2px, transparent 2px 5px),
    var(--cream);
}
.face.blank::after{
  content:"";position:absolute;inset:0;
  background:linear-gradient(90deg, rgba(43,36,48,.16), transparent 14%);
}

/* moving highlight/shadow while a sheet turns */
.gloss{
  position:absolute;inset:0;pointer-events:none;opacity:0;
  transition:opacity .3s linear;
}
.front .gloss{background:linear-gradient(90deg, rgba(24,16,22,.55), rgba(24,16,22,.16) 30%, transparent 62%)}
.back  .gloss{background:linear-gradient(270deg, rgba(24,16,22,.5), rgba(24,16,22,.12) 34%, transparent 66%)}
.leaf.dragging .gloss{transition:none}
.leaf.turning,.leaf.dragging{z-index:999 !important}
.book.nofx .leaf{transition:none !important}

/* corner peel affordance on the top sheet */
.leaf.peelable .front::after{
  content:"";position:absolute;right:0;bottom:0;width:64px;height:64px;
  background:linear-gradient(315deg, rgba(43,36,48,.22), transparent 58%);
  opacity:0;transition:opacity .3s;
}
.book:hover .leaf.peelable .front::after{opacity:1}

/* ---------- nav arrows ---------- */
.nav{
  position:absolute;top:50%;transform:translateY(-50%);
  width:46px;height:46px;padding:0;
  display:grid;place-items:center;
  border:1px solid var(--ui-line);border-radius:50%;
  background:rgba(20,14,20,.42);
  backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);
  color:var(--ui);cursor:pointer;z-index:950;
  transition:opacity .25s,background .2s,transform .12s;
}
.nav svg{width:22px;height:22px}
.nav-prev{left:12px}
.nav-next{right:12px}
.nav:hover{background:rgba(20,14,20,.72)}
.nav:active{transform:translateY(-50%) scale(.92)}
.nav[disabled]{opacity:0;pointer-events:none}

/* ---------- bottom controls ---------- */
.controls{
  position:relative;z-index:6;
  display:flex;align-items:center;gap:16px;
  padding:10px 20px calc(14px + env(safe-area-inset-bottom));
}
#scrub{
  -webkit-appearance:none;appearance:none;
  flex:1;height:26px;background:transparent;cursor:pointer;margin:0;
}
#scrub::-webkit-slider-runnable-track{height:3px;border-radius:3px;background:var(--ui-line)}
#scrub::-moz-range-track{height:3px;border-radius:3px;background:var(--ui-line)}
#scrub::-webkit-slider-thumb{
  -webkit-appearance:none;width:14px;height:14px;border-radius:50%;
  background:var(--lilac);border:0;margin-top:-5.5px;
  box-shadow:0 0 0 0 rgba(168,175,220,.35);transition:box-shadow .2s;
}
#scrub:hover::-webkit-slider-thumb{box-shadow:0 0 0 6px rgba(168,175,220,.2)}
#scrub::-moz-range-thumb{width:14px;height:14px;border-radius:50%;background:var(--lilac);border:0}
.counter{
  margin:0;display:flex;gap:.4em;align-items:baseline;
  font-variant-numeric:tabular-nums;
  font-size:13px;letter-spacing:.06em;white-space:nowrap;
}
.counter .of{color:var(--ui-dim);font-size:11.5px}

/* ---------- hint ---------- */
.hint{
  position:absolute;left:50%;bottom:14px;transform:translateX(-50%);
  margin:0;z-index:940;
  font-size:11.5px;letter-spacing:.14em;text-transform:uppercase;
  color:var(--ui-dim);
  background:rgba(20,14,20,.5);
  border:1px solid var(--ui-line);border-radius:999px;
  padding:7px 15px;
  backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);
  animation:hintIn .6s .9s both;
  pointer-events:none;
  white-space:nowrap;
}
.hint.hide{opacity:0;transition:opacity .4s}
@keyframes hintIn{from{opacity:0;transform:translate(-50%,10px)}to{opacity:1;transform:translate(-50%,0)}}

/* ---------- thumbnails ---------- */
.thumbs{
  position:absolute;inset:auto 0 0 0;z-index:1000;
  max-height:min(72vh,620px);
  display:flex;flex-direction:column;
  background:rgba(22,16,22,.9);
  backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);
  border-top:1px solid var(--ui-line);
  border-radius:20px 20px 0 0;
  transform:translateY(101%);
  transition:transform .42s var(--ease);
  padding-bottom:env(safe-area-inset-bottom);
}
.thumbs.open{transform:none}
.thumbs-head{
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 18px 8px;flex:none;
}
.thumbs-head h2{
  margin:0;font-size:11.5px;font-weight:500;
  letter-spacing:.18em;text-transform:uppercase;color:var(--ui-dim);
}
.thumbs-grid{
  overflow:auto;-webkit-overflow-scrolling:touch;
  display:grid;gap:12px;
  grid-template-columns:repeat(auto-fill,minmax(84px,1fr));
  padding:6px 18px 20px;
}
.thumb{
  position:relative;padding:0;border:0;background:none;cursor:pointer;
  display:block;
}
.thumb img{
  width:100%;aspect-ratio:595/842;object-fit:cover;display:block;
  border-radius:4px;background:var(--cream);
  outline:1px solid rgba(255,255,255,.1);outline-offset:-1px;
  transition:transform .18s,outline-color .18s;
}
.thumb:hover img{transform:translateY(-3px)}
.thumb.current img{outline:2px solid var(--lilac);outline-offset:1px}
.thumb span{
  display:block;margin-top:5px;text-align:center;
  font-size:10.5px;color:var(--ui-dim);font-variant-numeric:tabular-nums;
}

/* ---------- splash ---------- */
.splash{
  position:fixed;inset:0;z-index:2000;
  display:grid;place-items:center;
  background:var(--bg-2);
  transition:opacity .5s ease,visibility .5s;
}
body:not(.loading) .splash{opacity:0;visibility:hidden}
.splash-inner{display:flex;align-items:baseline;gap:.32em;position:relative}
.splash .bar{
  position:absolute;left:0;right:0;bottom:-16px;height:2px;
  background:var(--ui-line);border-radius:2px;overflow:hidden;
}
.splash .bar i{
  display:block;height:100%;width:35%;background:var(--lilac);border-radius:2px;
  animation:load 1.1s infinite var(--ease);
}
@keyframes load{0%{transform:translateX(-100%)}100%{transform:translateX(330%)}}

.noscript{position:fixed;inset:0;overflow:auto;padding:32px 16px;text-align:center;background:var(--bg-2);z-index:3000}
.noscript-pages{display:grid;gap:20px;max-width:720px;margin:24px auto 0}
.noscript-pages img{width:100%;height:auto;display:block;border-radius:3px}

/* ---------- small screens ---------- */
@media (max-width:640px){
  .topbar{padding:10px 12px 6px;gap:10px}
  .brand-mark,.brand-name{font-size:18px}
  .issue{display:none}
  .tool{width:34px;height:34px;border-radius:10px}
  .tool svg{width:16px;height:16px}
  .nav{width:38px;height:38px;background:rgba(20,14,20,.3)}
  .nav-prev{left:4px}.nav-next{right:4px}
  .controls{padding:6px 14px calc(10px + env(safe-area-inset-bottom));gap:12px}
  .hint{font-size:10.5px;letter-spacing:.1em;padding:6px 13px}
}
@media (hover:none){
  .nav{opacity:.55}
  .book:hover .leaf.peelable .front::after{opacity:0}
}

@media (prefers-reduced-motion:reduce){
  :root{--dur:1ms}
  .leaf,.book,.sheet{transition:none}
  .leaf.turning .sheet{animation:none}
  .leaf.turning .gloss{animation:none}
  .hint{animation:none}
}