:root{
  --indigo:#2b3a67;
  --indigo-deep:#1b2447;
  --sakura:#ef8fa3;
  --sakura-deep:#e05575;
  --cream:#faf6ef;
  --paper:#ffffff;
  --ink:#2a2a30;
  --ink-soft:#6b6b78;
  --line:rgba(43,58,103,0.12);
  --radius:18px;
}
*{margin:0;padding:0;box-sizing:border-box}
body{
  font-family:"Noto Sans KR","Hiragino Kaku Gothic ProN",sans-serif;
  background:linear-gradient(180deg,var(--cream) 0%,#f3ede0 100%);
  color:var(--ink);
  min-height:100vh;
  padding-bottom:40px;
}

.topbar{
  background:var(--indigo);
  background-image:radial-gradient(circle at 90% -10%, rgba(239,143,163,0.35), transparent 55%);
  color:#fff;
  padding:20px 20px 0;
  border-radius:0 0 24px 24px;
  box-shadow:0 8px 24px rgba(27,36,71,0.25);
}
.brand{
  font-size:20px;
  font-weight:800;
  letter-spacing:0.3px;
  padding-bottom:16px;
  display:flex;
  align-items:center;
  gap:8px;
}
.tabs{display:flex;gap:4px}
.tab-btn{
  flex:1;
  background:transparent;
  border:none;
  color:rgba(255,255,255,0.65);
  font-size:15px;
  font-weight:700;
  padding:12px 8px;
  cursor:pointer;
  border-bottom:3px solid transparent;
  font-family:inherit;
  text-decoration:none;
  text-align:center;
}
.tab-btn.active{color:#fff;border-bottom-color:var(--sakura)}

main{max-width:520px;margin:0 auto;padding:20px 16px}

.panel{display:none}
.panel.active{display:block}
.panel-desc{color:var(--ink-soft);font-size:14px;margin-bottom:18px;line-height:1.5}

/* 번역기 */
.translate-box{
  background:var(--paper);
  border-radius:var(--radius);
  padding:16px;
  box-shadow:0 4px 16px rgba(43,58,103,0.08);
}
#ko-input{
  width:100%;
  min-height:90px;
  border:1px solid var(--line);
  border-radius:12px;
  padding:12px 14px;
  font-size:15px;
  font-family:inherit;
  resize:vertical;
  color:var(--ink);
}
#ko-input:focus{outline:none;border-color:var(--sakura)}
.btn-primary{
  width:100%;
  margin-top:12px;
  background:var(--sakura-deep);
  color:#fff;
  border:none;
  border-radius:12px;
  padding:13px;
  font-size:15px;
  font-weight:700;
  cursor:pointer;
  font-family:inherit;
  transition:opacity .15s;
}
.btn-primary:hover{opacity:0.92}
.btn-primary:disabled{opacity:0.5;cursor:not-allowed}

.result-card{
  margin-top:16px;
  background:var(--paper);
  border-radius:var(--radius);
  padding:20px;
  box-shadow:0 4px 16px rgba(43,58,103,0.08);
  border-left:4px solid var(--sakura-deep);
}
.result-row{display:flex;align-items:center;justify-content:space-between;gap:10px}
.result-jp{font-size:22px;font-weight:800;color:var(--indigo-deep);line-height:1.4}
.result-kana{margin-top:6px;font-size:15px;color:var(--ink-soft)}
.result-pron{margin-top:10px;font-size:14px;color:var(--sakura-deep);font-weight:700}
.hidden{display:none !important}
.error-msg{margin-top:14px;color:#c0392b;font-size:14px}
.loading-msg{margin-top:14px;color:var(--ink-soft);font-size:14px}

.speak-btn{
  flex-shrink:0;
  width:40px;height:40px;
  border-radius:50%;
  border:none;
  background:var(--indigo);
  color:#fff;
  font-size:17px;
  cursor:pointer;
  display:flex;align-items:center;justify-content:center;
}
.speak-btn:hover{background:var(--indigo-deep)}
.speak-btn:active{transform:scale(0.94)}

/* 문장카드 */
.room-tabs{
  display:flex;
  gap:8px;
  overflow-x:auto;
  padding-bottom:6px;
  margin-bottom:18px;
  -webkit-overflow-scrolling:touch;
}
.room-tabs::-webkit-scrollbar{display:none}
.room-btn{
  flex:0 0 auto;
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:4px;
  background:var(--paper);
  border:1px solid var(--line);
  border-radius:14px;
  padding:10px 14px;
  cursor:pointer;
  font-family:inherit;
  color:var(--ink-soft);
  font-size:12px;
  font-weight:700;
}
.room-btn .room-emoji{font-size:20px}
.room-btn.active{
  background:var(--indigo);
  border-color:var(--indigo);
  color:#fff;
}

.card-nav{
  display:flex;
  align-items:center;
  justify-content:center;
  gap:20px;
  margin-bottom:14px;
}
.nav-btn{
  width:40px;height:40px;
  border-radius:50%;
  border:1px solid var(--line);
  background:var(--paper);
  font-size:20px;
  color:var(--indigo);
  cursor:pointer;
  font-family:inherit;
}
.nav-btn:hover{background:var(--indigo);color:#fff}
.card-counter{font-size:14px;font-weight:700;color:var(--ink-soft);min-width:60px;text-align:center}

.card-stage{perspective:1400px}
.flashcard{
  width:100%;
  min-height:260px;
  cursor:pointer;
}
.flashcard-inner{
  position:relative;
  width:100%;
  height:260px;
  transition:transform .5s cubic-bezier(.2,.8,.2,1);
  transform-style:preserve-3d;
}
.flashcard.flipped .flashcard-inner{transform:rotateY(180deg)}
.flashcard-face{
  position:absolute;
  inset:0;
  border-radius:22px;
  backface-visibility:hidden;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  padding:24px;
  text-align:center;
}
.flashcard-front{
  background:linear-gradient(135deg,var(--indigo) 0%,var(--indigo-deep) 100%);
  color:#fff;
  gap:16px;
}
.flip-hint{font-size:12px;opacity:0.6;letter-spacing:0.5px}
.front-ko{font-size:21px;font-weight:800;line-height:1.5}
.flashcard-back{
  background:var(--paper);
  transform:rotateY(180deg);
  box-shadow:0 6px 20px rgba(43,58,103,0.12);
  gap:10px;
}
.back-jp{font-size:23px;font-weight:800;color:var(--indigo-deep);line-height:1.4}
.back-kana{font-size:15px;color:var(--ink-soft)}
.back-pron{font-size:14px;font-weight:700;color:var(--sakura-deep)}
.back-speak{margin-top:8px}

@media (min-width:600px){
  main{padding:28px 16px}
  .front-ko{font-size:24px}
  .back-jp{font-size:26px}
}