/* ===== RESET & BASE ===== */
*{margin:0;padding:0;box-sizing:border-box;-webkit-tap-highlight-color:transparent}
:root{
  --primary:#6C63FF;--primary-dark:#5A52E0;--primary-light:#8B85FF;
  --accent:#FF6B9D;--accent2:#FFD93D;--accent3:#6BCB77;--accent4:#4D96FF;
  --bg:#F0F0FF;--card:#FFFFFF;--text:#2D2D3F;--text-light:#8888AA;
  --success:#4CAF50;--danger:#FF6B6B;
  --shadow:0 8px 32px rgba(108,99,255,0.15);
  --shadow-sm:0 4px 12px rgba(108,99,255,0.1);
  --radius:24px;--radius-sm:16px;--radius-xs:12px;
}
html,body{
  height:100%;width:100%;
  font-family:'Nunito',system-ui,-apple-system,sans-serif;
  background:var(--bg);color:var(--text);
  overflow:hidden;touch-action:manipulation;
  user-select:none;-webkit-user-select:none;
}
#app{display:flex;flex-direction:column;height:100dvh;width:100%;position:relative}

/* ===== HEADER ===== */
#app-header{
  display:flex;align-items:center;gap:12px;
  padding:14px 20px;
  background:linear-gradient(135deg,var(--primary),var(--accent4));
  color:white;min-height:64px;z-index:10;
  box-shadow:0 4px 20px rgba(108,99,255,0.3);
}
#header-title{font-size:22px;font-weight:900;flex:1;text-shadow:0 2px 4px rgba(0,0,0,0.15)}
.icon-btn{
  background:rgba(255,255,255,0.2);border:none;color:white;
  width:48px;height:48px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;cursor:pointer;
  transition:background 0.15s,transform 0.15s;
}
.icon-btn:active{background:rgba(255,255,255,0.4);transform:scale(0.9)}
.star-counter{
  display:flex;align-items:center;gap:6px;
  background:rgba(255,255,255,0.2);
  padding:8px 16px;border-radius:30px;
  font-size:20px;font-weight:800;
  animation:bounceIn 0.5s ease;
}
.star-icon{font-size:22px}
.hidden{display:none!important}

/* ===== SCREENS ===== */
.screen{flex:1;overflow-y:auto;overflow-x:hidden;padding:20px;display:none}
.screen.active{display:block;animation:fadeIn 0.3s ease}

/* ===== HOME ===== */
.hero{text-align:center;padding:28px 0 20px}
.hero-emoji{font-size:72px;margin-bottom:12px;animation:float 3s ease-in-out infinite}
.hero h2{font-size:32px;color:var(--primary);font-weight:900}
.hero p{font-size:17px;color:var(--text-light);margin-top:4px;font-weight:600}

.categories-grid{
  display:grid;grid-template-columns:repeat(2,1fr);gap:18px;
  padding-bottom:32px;max-width:600px;margin:0 auto;
}

/* ===== CATEGORY CARDS ===== */
.cat-card{
  background:var(--card);border-radius:var(--radius);
  padding:20px 16px;text-align:center;
  box-shadow:var(--shadow);cursor:pointer;
  transition:transform 0.2s,box-shadow 0.2s;
  border:3px solid transparent;position:relative;overflow:hidden;
}
.cat-card::before{
  content:'';position:absolute;top:0;left:0;right:0;height:6px;
  border-radius:var(--radius) var(--radius) 0 0;
}
.cat-card:nth-child(1)::before{background:linear-gradient(90deg,#FF6B9D,#FF8E53)}
.cat-card:nth-child(2)::before{background:linear-gradient(90deg,#6BCB77,#4D96FF)}
.cat-card:nth-child(3)::before{background:linear-gradient(90deg,#FFD93D,#FF8E53)}
.cat-card:nth-child(4)::before{background:linear-gradient(90deg,#FF6B9D,#6C63FF)}
.cat-card:nth-child(5)::before{background:linear-gradient(90deg,#4D96FF,#6BCB77)}
.cat-card:nth-child(6)::before{background:linear-gradient(90deg,#6C63FF,#FF6B9D)}
.cat-card:active{transform:scale(0.95);border-color:var(--primary-light)}
.cat-card img{width:80px;height:80px;border-radius:16px;margin-bottom:10px;object-fit:contain}
.cat-name{font-size:16px;font-weight:800;color:var(--text)}
.cat-count{font-size:13px;color:var(--text-light);margin-top:2px;font-weight:600}
.cat-progress{
  margin-top:8px;display:flex;gap:4px;justify-content:center;
}
.cat-dot{width:10px;height:10px;border-radius:50%;background:#E0E0F0}
.cat-dot.done{background:var(--accent3)}

/* ===== WORKSHEET LIST ===== */
.worksheet-list{display:flex;flex-direction:column;gap:14px;padding-bottom:32px;max-width:600px;margin:0 auto}
.ws-card{
  background:var(--card);border-radius:var(--radius-sm);
  padding:18px;display:flex;align-items:center;gap:16px;
  box-shadow:var(--shadow-sm);cursor:pointer;
  transition:transform 0.2s;position:relative;
}
.ws-card:active{transform:scale(0.97)}
.ws-card.completed{border-left:5px solid var(--accent3)}
.ws-card.completed .ws-check{display:flex}
.ws-check{
  display:none;position:absolute;top:12px;right:12px;
  width:28px;height:28px;border-radius:50%;
  background:var(--accent3);color:white;
  font-size:16px;align-items:center;justify-content:center;
  font-weight:700;
}
.ws-preview{
  width:72px;height:72px;border-radius:var(--radius-xs);
  display:flex;align-items:center;justify-content:center;
  font-size:40px;flex-shrink:0;
}
.ws-info{flex:1}
.ws-name{font-size:16px;font-weight:800}
.ws-desc{font-size:13px;color:var(--text-light);margin-top:2px;font-weight:600}
.ws-diff{display:flex;gap:4px;margin-top:4px}
.ws-diff-dot{width:8px;height:8px;border-radius:50%;background:#E0E0F0}
.ws-diff-dot.filled{background:var(--accent)}
.ws-arrow{
  width:40px;height:40px;border-radius:50%;
  background:#F0F0FF;display:flex;align-items:center;justify-content:center;
  font-size:20px;color:var(--primary);flex-shrink:0;
}

/* ===== WORKSHEET SCREEN ===== */
#screen-worksheet{
  display:none;flex-direction:column;padding:0;overflow:hidden;
}
#screen-worksheet.active{display:flex}

/* Instruction Banner */
.instruction-banner{
  padding:14px 20px;
  background:linear-gradient(135deg,var(--accent2),#FFB347);
  color:#5D4037;text-align:center;
  font-size:17px;font-weight:800;
  min-height:50px;display:flex;align-items:center;justify-content:center;
  flex-shrink:0;
}

/* Canvas */
#canvas-container{flex:1;position:relative;overflow:hidden;background:white}
#worksheet-canvas{display:block;width:100%;height:100%;touch-action:none}

/* Toolbar */
.canvas-toolbar{
  display:flex;align-items:center;padding:10px 16px;
  background:white;border-top:1px solid #F0F0F0;
  flex-shrink:0;gap:12px;
}
.color-palette{
  display:flex;gap:8px;flex:1;overflow-x:auto;
  padding:4px 0;-webkit-overflow-scrolling:touch;
  scrollbar-width:none;
}
.color-palette::-webkit-scrollbar{display:none}
.color-dot{
  width:40px;height:40px;border-radius:50%;
  border:4px solid transparent;cursor:pointer;
  flex-shrink:0;transition:transform 0.15s,border-color 0.15s;
  box-shadow:0 2px 8px rgba(0,0,0,0.15);
}
.color-dot:active{transform:scale(0.85)}
.color-dot.active{border-color:var(--text);transform:scale(1.15);box-shadow:0 2px 12px rgba(0,0,0,0.25)}

.toolbar-actions{display:flex;gap:8px;align-items:center}
.tool-btn{
  width:48px;height:48px;border:none;border-radius:var(--radius-xs);
  background:#F0F0FF;display:flex;align-items:center;justify-content:center;
  cursor:pointer;color:var(--primary);transition:background 0.15s,transform 0.15s;
}
.tool-btn:active{background:#DDD;transform:scale(0.9)}
.tool-btn.active{background:var(--primary);color:white}

.brush-size-group{display:flex;gap:6px;align-items:center;background:#F0F0FF;padding:4px 8px;border-radius:12px}
.brush-btn{
  width:40px;height:40px;border:none;border-radius:10px;
  background:transparent;display:flex;align-items:center;justify-content:center;
  cursor:pointer;transition:background 0.15s;
}
.brush-btn.active{background:var(--primary)}
.brush-btn.active span{background:white}
.dot-sm,.dot-md,.dot-lg{border-radius:50%;background:var(--text)}
.dot-sm{width:8px;height:8px}
.dot-md{width:14px;height:14px}
.dot-lg{width:20px;height:20px}

/* Done Button */
.done-btn{
  margin:12px 16px 20px;padding:18px 32px;
  background:linear-gradient(135deg,var(--accent3),#4CAF50);
  color:white;border:none;border-radius:var(--radius);
  font-size:20px;font-weight:900;font-family:'Nunito',sans-serif;
  cursor:pointer;
  box-shadow:0 6px 20px rgba(76,175,80,0.4);
  transition:transform 0.15s;
  flex-shrink:0;
}
.done-btn:active{transform:scale(0.95)}

/* ===== CELEBRATION OVERLAY ===== */
.celebration-overlay{
  position:fixed;top:0;left:0;width:100%;height:100%;
  background:rgba(255,255,255,0.95);z-index:100;
  display:flex;align-items:center;justify-content:center;
  flex-direction:column;
}
.confetti-container{position:absolute;top:0;left:0;width:100%;height:100%;pointer-events:none;overflow:hidden}
.confetti{
  position:absolute;width:12px;height:12px;border-radius:2px;
  animation:confettiFall linear forwards;
}
.celebration-content{
  text-align:center;z-index:2;
  animation:bounceIn 0.6s cubic-bezier(0.68,-0.55,0.27,1.55);
}
.celebration-emoji{font-size:100px;animation:spin 1s ease}
.celebration-text{font-size:42px;font-weight:900;color:var(--primary);margin-top:8px}
.celebration-sub{font-size:20px;color:var(--text-light);font-weight:600;margin-top:4px}
.next-btn{
  margin-top:24px;padding:18px 48px;
  background:linear-gradient(135deg,var(--primary),var(--accent4));
  color:white;border:none;border-radius:50px;
  font-size:22px;font-weight:900;font-family:'Nunito',sans-serif;
  cursor:pointer;
  box-shadow:0 8px 30px rgba(108,99,255,0.4);
  animation:pulse 1.5s infinite;
}
.next-btn:active{transform:scale(0.95);animation:none}

/* ===== ANIMATIONS ===== */
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
@keyframes bounceIn{0%{transform:scale(0);opacity:0}50%{transform:scale(1.15)}100%{transform:scale(1);opacity:1}}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-10px)}}
@keyframes pulse{0%,100%{box-shadow:0 8px 30px rgba(108,99,255,0.4)}50%{box-shadow:0 8px 40px rgba(108,99,255,0.7),0 0 0 10px rgba(108,99,255,0.1)}}
@keyframes spin{0%{transform:rotate(-30deg) scale(0)}50%{transform:rotate(10deg) scale(1.2)}100%{transform:rotate(0deg) scale(1)}}
@keyframes confettiFall{
  0%{transform:translateY(-20px) rotate(0deg);opacity:1}
  100%{transform:translateY(110vh) rotate(720deg);opacity:0}
}
@keyframes pop{0%{transform:scale(0.8);opacity:0}100%{transform:scale(1);opacity:1}}
.cat-card,.ws-card{animation:pop 0.4s cubic-bezier(0.68,-0.55,0.27,1.55)}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar{width:4px}
::-webkit-scrollbar-thumb{background:#CCC;border-radius:4px}

/* ===== RESPONSIVE ===== */
@media(min-width:768px){
  .categories-grid{grid-template-columns:repeat(3,1fr);gap:24px}
  .color-dot{width:44px;height:44px}
}