/* ═══════════════════════════════════════════
   Artist World — Scroll-as-Cinema
   Apple Photos screensaver meets lyric journey
   ═══════════════════════════════════════════ */

/* ── Reset ── */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

/* ── Variables ── */
:root{
  /* Typography — Apple-grade system stack */
  --ff:-apple-system,BlinkMacSystemFont,'Segoe UI','Helvetica Neue',Arial,sans-serif;
  --fs-lyric:clamp(1.6rem,5.5vw,3.4rem);
  --fs-echo:clamp(0.85rem,2.2vw,1.15rem);
  --fs-caption:clamp(0.62rem,1.6vw,0.72rem);
  --fw-lyric:200;
  --fw-echo:300;
  --lh-lyric:1.15;
  --lh-echo:1.5;

  /* Colors */
  --c-black:#000;
  --c-white:#fff;
  --c-dark-bg:#000;
  --c-dark-text:#f5f5f7;
  --c-dark-dim:rgba(245,245,247,0.35);
  --c-light-bg:#fafafa;
  --c-light-text:#1d1d1f;
  --c-light-dim:rgba(29,29,31,0.35);
  --c-invert-bg:#0d1b2a;
  --c-invert-text:#e0d8cf;
  --c-invert-dim:rgba(224,216,207,0.35);
  --c-accent:#2997ff;

  /* Motion */
  --m-dist:20px;
  --m-blur:6px;
  --m-dur:0.9s;
  --m-ease:cubic-bezier(0.25,0.46,0.45,0.94);
  --m-ken:1.06;

  /* Layout */
  --safe-l:max(24px,env(safe-area-inset-left));
  --safe-r:max(24px,env(safe-area-inset-right));
  --safe-t:env(safe-area-inset-top,0px);
  --safe-b:env(safe-area-inset-bottom,0px);
  --radius:4px;
  --grain-opacity:0.035;
}

/* Motion intensity overrides */
body.motion-low{
  --m-dist:0px;--m-blur:0px;--m-dur:0.01s;--m-ken:1;
}
body.motion-high{
  --m-dist:40px;--m-blur:10px;--m-ken:1.1;
}

/* ── Skip Link ── */
.skip-link{
  position:fixed;top:-100px;left:50%;transform:translateX(-50%);
  z-index:9999;background:var(--c-accent);color:var(--c-white);
  padding:8px 20px;border-radius:0 0 8px 8px;font:500 0.78rem/1 var(--ff);
  text-decoration:none;transition:top 0.2s;
}
.skip-link:focus{top:0}

/* ── Body ── */
html{scroll-behavior:smooth}
body{
  font-family:var(--ff);
  background:var(--c-black);
  color:var(--c-dark-text);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
}

/* ── World Container ── */
.world{position:relative}
.world.snap-on{
  scroll-snap-type:y mandatory;
  overflow-y:scroll;
  height:100svh;height:100vh;/* fallback */
  height:100svh;
}

/* ── Chapter Base ── */
.chapter{
  position:relative;
  min-height:100vh;
  min-height:100svh;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  overflow:hidden;
  scroll-snap-align:start;
  scroll-snap-stop:always;
  padding:var(--safe-t) var(--safe-r) var(--safe-b) var(--safe-l);
}

/* ── Theme Variants ── */
.chapter.theme-dark{
  --bg:var(--c-dark-bg);--text:var(--c-dark-text);--dim:var(--c-dark-dim);
  background:var(--bg);color:var(--text);
}
.chapter.theme-light{
  --bg:var(--c-light-bg);--text:var(--c-light-text);--dim:var(--c-light-dim);
  background:var(--bg);color:var(--text);
}
.chapter.theme-invert{
  --bg:var(--c-invert-bg);--text:var(--c-invert-text);--dim:var(--c-invert-dim);
  background:var(--bg);color:var(--text);
}

/* ── Lyric Typography ── */
.lyric{
  font-size:var(--fs-lyric);
  font-weight:var(--fw-lyric);
  line-height:var(--lh-lyric);
  letter-spacing:0.01em;
  text-wrap:balance;
  max-width:16em;
  opacity:0;
  transform:translateY(var(--m-dist));
  transition:opacity var(--m-dur) var(--m-ease),
             transform var(--m-dur) var(--m-ease),
             letter-spacing var(--m-dur) var(--m-ease);
}
.chapter.is-active .lyric{
  opacity:1;
  transform:translateY(0);
  letter-spacing:-0.015em;
}

.echo{
  font-size:var(--fs-echo);
  font-weight:var(--fw-echo);
  line-height:var(--lh-echo);
  font-style:italic;
  color:var(--dim);
  max-width:20em;
  opacity:0;
  transform:translateY(calc(var(--m-dist) * 0.5));
  transition:opacity var(--m-dur) var(--m-ease) 0.35s,
             transform var(--m-dur) var(--m-ease) 0.35s;
}
.chapter.is-active .echo{
  opacity:1;
  transform:translateY(0);
}

.caption{
  font-size:var(--fs-caption);
  font-weight:400;
  letter-spacing:0.06em;
  text-transform:uppercase;
  color:var(--dim);
  max-width:28em;
  opacity:0;
  transition:opacity var(--m-dur) var(--m-ease) 0.55s;
}
.chapter.is-active .caption{opacity:1}
body.captions-off .caption{display:none}

/* ── Media Base ── */
.ch-media{position:relative;width:100%}

.media-frame{
  position:relative;
  overflow:hidden;
  border-radius:var(--radius);
  background:rgba(128,128,128,0.06);
}
.media-frame.full{border-radius:0}

.media-img,.media-video{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
  filter:blur(var(--m-blur));
  transform:scale(1.01);
  transition:filter var(--m-dur) var(--m-ease) 0.15s,
             transform 8s cubic-bezier(0.25,0.46,0.45,0.94);
}
/* Ken Burns — slow zoom while active */
.chapter.is-active .media-img,
.chapter.is-active .media-video{
  filter:blur(0);
  transform:scale(var(--m-ken));
}

.media-frame.media-error{background:rgba(128,128,128,0.08)}
.media-frame.media-error::after{
  content:'Image unavailable';
  position:absolute;inset:0;
  display:flex;align-items:center;justify-content:center;
  font:400 var(--fs-caption)/1 var(--ff);
  letter-spacing:0.04em;text-transform:uppercase;
  color:rgba(128,128,128,0.4);
}

/* ── Video Handling ── */
.vid-fallback{display:none}
.vid-fallback.is-shown{display:block}
.vid-fallback .media-img{filter:blur(0);transform:scale(1)}

.play-btn{
  position:absolute;inset:0;
  display:none;align-items:center;justify-content:center;
  background:rgba(0,0,0,0.2);border:none;
  color:rgba(255,255,255,0.8);cursor:pointer;
  transition:background 0.2s;
}
.play-btn:hover{background:rgba(0,0,0,0.35)}
.play-btn.is-shown{display:flex}
.play-btn svg{filter:drop-shadow(0 2px 8px rgba(0,0,0,0.3))}

/* ── Layout A: Centered ── */
.layout-a{gap:28px;text-align:center;padding-top:calc(var(--safe-t) + 48px);padding-bottom:calc(var(--safe-b) + 48px)}
.layout-a .ch-content{display:flex;flex-direction:column;align-items:center;gap:10px;z-index:2}
.layout-a .ch-media{max-width:min(70vw,420px)}
.layout-a .media-frame{aspect-ratio:4/5;border-radius:6px}
.layout-a .caption{text-align:center}

/* ── Layout B: Split ── */
.layout-b{padding-top:calc(var(--safe-t) + 32px);padding-bottom:calc(var(--safe-b) + 32px)}
.layout-b .ch-split{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:32px;
  align-items:center;
  width:100%;
  max-width:900px;
}
.layout-b .ch-content{display:flex;flex-direction:column;gap:10px;z-index:2}
.layout-b .media-frame{aspect-ratio:3/4;border-radius:6px}
.layout-b .caption{margin-top:12px}

@media(max-width:680px){
  .layout-b .ch-split{grid-template-columns:1fr;gap:24px;text-align:center}
  .layout-b .ch-split .ch-content{align-items:center}
  .layout-b .ch-media{max-width:min(80vw,360px);margin:0 auto}
}

/* ── Layout C: Full-Bleed ── */
.layout-c{padding:0;justify-content:flex-end}
.layout-c .ch-media{
  position:absolute;inset:0;z-index:0;
}
.layout-c .media-frame.full{
  width:100%;height:100%;
}
.layout-c .ch-media::after{
  content:'';position:absolute;inset:0;
  background:linear-gradient(to top,rgba(0,0,0,0.7) 0%,rgba(0,0,0,0.15) 50%,rgba(0,0,0,0.05) 100%);
  z-index:1;
}
.layout-c .ch-content{
  position:relative;z-index:2;
  display:flex;flex-direction:column;gap:10px;
  padding:0 var(--safe-l) calc(var(--safe-b) + 48px) var(--safe-l);
  width:100%;max-width:680px;
  /* Force light text over dark gradient */
  --text:var(--c-dark-text);--dim:var(--c-dark-dim);
  color:var(--text);
}

/* ── Layout D: Collage ── */
.layout-d{gap:24px;padding-top:calc(var(--safe-t) + 32px);padding-bottom:calc(var(--safe-b) + 40px)}
.layout-d .ch-media{max-width:min(85vw,560px)}
.layout-d .media-collage{
  display:grid;gap:6px;
}
.layout-d .media-collage.cols-3{
  grid-template-columns:1fr 1fr;
  grid-template-rows:1fr 1fr;
}
.layout-d .media-collage.cols-3 .media-frame:nth-child(3){
  grid-column:2;grid-row:1 / -1;
}
.layout-d .media-collage.cols-2{
  grid-template-columns:1fr 1fr;
}
.layout-d .media-frame{aspect-ratio:4/5;border-radius:4px}
.layout-d .ch-content{
  display:flex;flex-direction:column;align-items:center;gap:10px;
  text-align:center;z-index:2;
}

/* ── Prologue ── */
.prologue{
  position:absolute;inset:0;z-index:10;
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:20px;
  background:var(--c-black);
  transition:opacity 1s var(--m-ease);
  pointer-events:none;
}
.prologue.is-hidden{opacity:0;visibility:hidden}
.prologue-cta{
  font:200 clamp(0.82rem,2.5vw,1rem)/1.6 var(--ff);
  letter-spacing:0.08em;text-transform:uppercase;
  color:rgba(245,245,247,0.5);
}
.prologue-hint{
  font:300 0.68rem/1.5 var(--ff);
  letter-spacing:0.06em;
  color:rgba(245,245,247,0.25);
  margin-top:8px;
}
.prologue-arrow{
  animation:float 2.4s ease-in-out infinite;
  color:rgba(245,245,247,0.3);
}
.prologue-arrow svg{display:block}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(6px)}}

/* ── Epilogue ── */
.epilogue-actions{
  display:flex;flex-direction:column;align-items:center;gap:16px;
  margin-top:32px;
}
.replay-btn{
  font:400 0.72rem/1 var(--ff);
  letter-spacing:0.08em;text-transform:uppercase;
  color:rgba(245,245,247,0.4);
  background:none;border:1px solid rgba(245,245,247,0.12);
  padding:12px 28px;border-radius:24px;
  cursor:pointer;transition:all 0.3s;
}
.replay-btn:hover,.replay-btn:focus-visible{
  color:rgba(245,245,247,0.8);border-color:rgba(245,245,247,0.3);
}

/* ── Progress Rail ── */
.progress-rail{
  position:fixed;
  right:max(10px,env(safe-area-inset-right,10px));
  top:50%;transform:translateY(-50%);
  z-index:100;
  display:flex;flex-direction:column;gap:10px;
  transition:opacity 0.35s;
}
body.sheet-open .progress-rail{opacity:0;pointer-events:none}

.pdot{
  width:5px;height:5px;border-radius:50%;
  border:none;padding:0;
  background:rgba(150,150,150,0.25);
  cursor:pointer;transition:all 0.4s var(--m-ease);
}
.pdot:hover{background:rgba(150,150,150,0.5)}
.pdot.active{
  background:var(--c-accent);
  transform:scale(1.8);
  box-shadow:0 0 8px rgba(41,151,255,0.25);
}
.pdot:focus-visible{outline:2px solid var(--c-accent);outline-offset:3px}

/* ── Controls Button ── */
.controls-btn{
  position:fixed;
  bottom:max(16px,calc(var(--safe-b) + 8px));
  right:max(16px,env(safe-area-inset-right,16px));
  z-index:150;
  width:40px;height:40px;border-radius:50%;
  border:none;
  background:rgba(40,40,40,0.6);
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  color:rgba(245,245,247,0.6);
  cursor:pointer;
  display:flex;align-items:center;justify-content:center;
  transition:all 0.25s;
}
.controls-btn:hover{background:rgba(60,60,60,0.7);color:rgba(245,245,247,0.9)}
.controls-btn:focus-visible{outline:2px solid var(--c-accent);outline-offset:2px}
.controls-btn svg{display:block}

/* ── Bottom Sheet ── */
.sheet{
  position:fixed;inset:0;z-index:200;
  display:flex;flex-direction:column;justify-content:flex-end;
  pointer-events:none;
}
.sheet:not([hidden]){pointer-events:auto}

.sheet-bg{
  position:absolute;inset:0;
  background:rgba(0,0,0,0.5);
  opacity:0;transition:opacity 0.3s;
  cursor:pointer;
}
.sheet.is-open .sheet-bg{opacity:1}

.sheet-panel{
  position:relative;
  transform:translateY(100%);
  transition:transform 0.4s cubic-bezier(0.16,1,0.3,1);
  background:rgba(28,28,30,0.92);
  backdrop-filter:blur(40px) saturate(180%);-webkit-backdrop-filter:blur(40px) saturate(180%);
  border-top:1px solid rgba(255,255,255,0.06);
  border-radius:14px 14px 0 0;
  padding:20px max(20px,env(safe-area-inset-right)) calc(20px + var(--safe-b)) max(20px,env(safe-area-inset-left));
  max-height:70svh;overflow-y:auto;
}
.sheet.is-open .sheet-panel{transform:translateY(0)}

.sheet-head{
  display:flex;align-items:center;justify-content:space-between;
  margin-bottom:20px;
}
.sheet-title{
  font:500 0.82rem/1 var(--ff);
  letter-spacing:0.03em;color:rgba(245,245,247,0.7);
}
.sheet-x{
  font-size:1.4rem;line-height:1;
  background:none;border:none;color:rgba(245,245,247,0.4);
  cursor:pointer;padding:4px 8px;border-radius:6px;
  transition:color 0.2s;
}
.sheet-x:hover{color:rgba(245,245,247,0.8)}
.sheet-x:focus-visible{outline:2px solid var(--c-accent);outline-offset:2px}

.sheet-body{display:flex;flex-direction:column;gap:16px}

.ctrl{display:flex;align-items:center;justify-content:space-between;gap:12px}
.ctrl-label{
  font:400 0.74rem/1 var(--ff);
  letter-spacing:0.02em;color:rgba(245,245,247,0.5);
}

/* Toggle switch */
.toggle{
  position:relative;width:42px;height:24px;border-radius:12px;
  border:none;padding:0;cursor:pointer;
  background:rgba(255,255,255,0.1);
  transition:background 0.25s;
  flex-shrink:0;
}
.toggle::after{
  content:'';position:absolute;top:3px;left:3px;
  width:18px;height:18px;border-radius:50%;
  background:rgba(255,255,255,0.5);
  transition:transform 0.25s,background 0.25s;
}
.toggle[aria-checked="true"]{background:var(--c-accent)}
.toggle[aria-checked="true"]::after{transform:translateX(18px);background:var(--c-white)}
.toggle:focus-visible{outline:2px solid var(--c-accent);outline-offset:2px}

/* Segmented control */
.seg{
  display:flex;gap:2px;padding:2px;border-radius:8px;
  background:rgba(255,255,255,0.06);
}
.seg-btn{
  font:400 0.68rem/1 var(--ff);
  letter-spacing:0.02em;
  padding:5px 14px;border-radius:6px;
  border:none;background:transparent;
  color:rgba(245,245,247,0.4);
  cursor:pointer;transition:all 0.2s;
}
.seg-btn[aria-checked="true"]{
  background:var(--c-accent);color:var(--c-white);
}
.seg-btn:focus-visible{outline:2px solid var(--c-accent);outline-offset:2px}

/* ── Debug Overlay ── */
.debug{
  position:fixed;
  top:max(8px,var(--safe-t));left:max(8px,env(safe-area-inset-left,8px));
  z-index:300;
  display:flex;gap:12px;
  font:500 0.65rem/1 var(--ff);
  letter-spacing:0.05em;text-transform:uppercase;
  color:var(--c-accent);
  background:rgba(0,0,0,0.6);
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
  padding:6px 12px;border-radius:6px;
}
.debug[hidden]{display:none}

/* ── Focus Mode ── */
.chapter.is-focused .ch-media{
  transform:scale(1.03);
  transition:transform 0.5s var(--m-ease);
}
.chapter.is-focused .lyric,
.chapter.is-focused .echo,
.chapter.is-focused .caption{
  opacity:0.15 !important;
  transition:opacity 0.3s;
}

/* ── Grain Overlay ── */
.grain{
  position:fixed;inset:0;z-index:9999;
  pointer-events:none;
  opacity:var(--grain-opacity);
  background-repeat:repeat;
  mix-blend-mode:overlay;
}

/* ── Reduced Motion ── */
@media(prefers-reduced-motion:reduce){
  :root{--m-dist:0px;--m-blur:0px;--m-dur:0.01s;--m-ken:1;--grain-opacity:0}
  .prologue-arrow{animation:none}
  .media-img,.media-video{transition-duration:0.01s !important}
}

/* ── Responsive ── */
@media(min-width:1024px){
  .layout-a .ch-media{max-width:480px}
  .layout-d .ch-media{max-width:640px}
  .layout-b .ch-split{max-width:1000px;gap:48px}
  .layout-c .ch-content{max-width:720px;padding-bottom:calc(var(--safe-b) + 64px)}
}

@media(max-width:390px){
  :root{--fs-lyric:clamp(1.3rem,5vw,1.8rem)}
  .layout-a .ch-media{max-width:80vw}
}