:root{
  --bg-dark:#14171c;
  --panel-dark:#1c2128;
  --accent:#ff5a36;
  --accent-2:#3aa6ff;
  --text-light:#f2f2f2;
  --text-dim:#9aa2ab;
}

*{box-sizing:border-box;}

body{
  margin:0;
  font-family:'Noto Sans JP', 'Hiragino Sans', sans-serif;
  background:linear-gradient(180deg,#0f1115,#1a1d24 60%,#0f1115);
  color:var(--text-light);
  min-height:100vh;
}

#page-header{
  text-align:center;
  padding:28px 16px 10px;
}
#page-header h1{
  font-size:1.6rem;
  margin:0 0 6px;
  font-weight:900;
  letter-spacing:.02em;
}
#page-header h1 i{ color:var(--accent); margin-right:8px; }
#page-header p{
  margin:0;
  color:var(--text-dim);
  font-size:.92rem;
}

main{
  max-width:1000px;
  margin:0 auto;
  padding:10px 14px 40px;
}

/* ---------- Stage ---------- */
.stage{
  position:relative;
  background:#000;
  border-radius:14px;
  overflow:hidden;
  box-shadow:0 10px 40px rgba(0,0,0,.5);
  aspect-ratio:4/3;
  width:100%;
}

.tilt-wrapper{
  position:absolute;
  inset:0;
  display:flex;
  align-items:center;
  justify-content:center;
  perspective:1400px;
}

.canvas-frame{
  position:relative;
  width:100%;
  height:100%;
  background:#f5f1e6;
  transform-style:preserve-3d;
  transform:rotateX(0deg) rotateY(0deg);
  transition:transform 1.2s ease;
  box-shadow:0 0 60px rgba(0,0,0,.4) inset;
}

.canvas-frame canvas{
  position:absolute;
  top:0;left:0;
  width:100%;
  height:100%;
  display:block;
}
#guide-canvas, #sketch-canvas, #color-canvas{ pointer-events:none; }

/* fullscreen mode adjustments */
.stage:fullscreen{
  aspect-ratio:auto;
  width:100vw;
  height:100vh;
  border-radius:0;
}
.stage:fullscreen .tilt-wrapper{ inset:0; }
.stage:-webkit-full-screen{ width:100vw; height:100vh; border-radius:0; }

/* ---------- Loading ---------- */
.loading-overlay{
  position:absolute; inset:0;
  display:flex; flex-direction:column; align-items:center; justify-content:center;
  background:rgba(10,10,12,.88);
  gap:14px;
  z-index:20;
  transition:opacity .4s ease;
}
.loading-overlay.hidden{ opacity:0; pointer-events:none; }
.spinner{
  width:46px; height:46px;
  border:4px solid rgba(255,255,255,.15);
  border-top-color:var(--accent);
  border-radius:50%;
  animation:spin 1s linear infinite;
}
@keyframes spin{ to{ transform:rotate(360deg); } }
#loading-text{ color:var(--text-dim); font-size:.9rem; }

/* ---------- Big play overlay ---------- */
.big-play-overlay{
  position:absolute; inset:0;
  display:flex; align-items:center; justify-content:center;
  background:rgba(0,0,0,.25);
  z-index:15;
  transition:opacity .3s ease;
}
.big-play-overlay.hidden{ opacity:0; pointer-events:none; }
#big-play-btn{
  width:84px; height:84px;
  border-radius:50%;
  border:none;
  background:rgba(20,20,24,.75);
  color:#fff;
  font-size:1.8rem;
  display:flex; align-items:center; justify-content:center;
  cursor:pointer;
  box-shadow:0 6px 24px rgba(0,0,0,.5);
  transition:transform .15s ease, background .2s ease;
}
#big-play-btn:hover{ transform:scale(1.08); background:var(--accent); }

/* ---------- Controls bar (YouTube-like) ---------- */
.controls-bar{
  position:absolute;
  left:0; right:0; bottom:0;
  background:linear-gradient(to top, rgba(0,0,0,.85), rgba(0,0,0,0));
  padding:14px 14px 10px;
  z-index:25;
  opacity:1;
  transition:opacity .3s ease;
}

.progress-track{
  position:relative;
  width:100%;
  height:6px;
  background:rgba(255,255,255,.25);
  border-radius:4px;
  margin-bottom:10px;
  cursor:pointer;
}
.progress-fill{
  position:absolute; left:0; top:0; bottom:0;
  width:0%;
  background:var(--accent);
  border-radius:4px;
  transition:width .1s linear;
}
.progress-labels{
  position:absolute;
  top:-22px; left:0;
  font-size:.72rem;
  color:#fff;
  background:rgba(0,0,0,.5);
  padding:2px 8px;
  border-radius:10px;
}

.controls-row{
  display:flex;
  align-items:center;
  gap:10px;
  flex-wrap:wrap;
}

.ctrl-btn{
  background:transparent;
  border:none;
  color:#fff;
  font-size:1.05rem;
  width:38px; height:38px;
  border-radius:8px;
  cursor:pointer;
  display:flex; align-items:center; justify-content:center;
  transition:background .15s ease, color .15s ease;
}
.ctrl-btn:hover{ background:rgba(255,255,255,.15); color:var(--accent); }

.speed-control{
  display:flex;
  align-items:center;
  gap:8px;
  color:#fff;
  font-size:.85rem;
  background:rgba(255,255,255,.08);
  padding:6px 12px;
  border-radius:20px;
}
.speed-control i{ color:var(--accent-2); }
.speed-control input[type=range]{
  width:110px;
  accent-color:var(--accent);
}
#speed-value{ min-width:48px; text-align:right; font-variant-numeric:tabular-nums; }

.spacer{ flex:1; }

/* ---------- Info panel ---------- */
.info-panel{
  margin-top:26px;
  background:var(--panel-dark);
  border-radius:14px;
  padding:22px 24px;
  box-shadow:0 6px 24px rgba(0,0,0,.3);
}
.info-panel h2{
  margin:0 0 12px;
  font-size:1.1rem;
  color:var(--accent);
}
.info-panel ul{
  margin:0 0 14px;
  padding:0;
  list-style:none;
  display:flex;
  flex-direction:column;
  gap:10px;
}
.info-panel li{
  display:flex;
  align-items:flex-start;
  gap:10px;
  font-size:.9rem;
  color:#dcdfe3;
  line-height:1.5;
}
.info-panel li i{
  color:var(--accent-2);
  margin-top:3px;
  min-width:16px;
}
.info-panel .note{
  font-size:.78rem;
  color:var(--text-dim);
  line-height:1.6;
  border-top:1px solid rgba(255,255,255,.08);
  padding-top:12px;
  margin:0;
}

#page-footer{
  text-align:center;
  color:var(--text-dim);
  font-size:.78rem;
  padding:10px 16px 30px;
}

@media (max-width:600px){
  #page-header h1{ font-size:1.25rem; }
  .speed-control input[type=range]{ width:80px; }
  .controls-row{ gap:6px; }
}