.result-box { margin-top: 1.25rem; padding: 16px 20px; border-radius: var(--border-radius-lg); font-size: 15px; line-height: 1.6; animation: slideDown 0.3s ease; }
  .result-box.correct { background: var(--color-background-success); color: var(--color-text-success); border: 1px solid var(--color-border-success); box-shadow: 0 4px 12px rgba(52, 211, 153, 0.1); }
  .result-box.wrong { background: var(--color-background-danger); color: var(--color-text-danger); border: 1px solid var(--color-border-danger); box-shadow: 0 4px 12px rgba(248, 113, 113, 0.1); }
  
  .diff-line { margin-top: 6px; font-size: 15px; line-height: 1.8; color: var(--color-text-primary); font-weight: 500; }
  .diff-label { font-size: 12px; color: var(--color-text-secondary); margin-top: 12px; margin-bottom: 2px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; }
  .w-ok { color: var(--color-text-success); font-weight: 700; }
  .w-wrong { color: var(--color-text-danger); text-decoration: underline wavy var(--color-border-danger); font-weight: 700; }
  .w-miss { color: var(--color-text-danger); text-decoration: underline var(--color-border-danger); font-style: italic; font-weight: 700; }
  
  .stat-row { display: flex; gap: 12px; margin-bottom: 2rem; }
  .stat { flex: 1; background: var(--color-background-primary); border-radius: var(--border-radius-lg); padding: 16px; text-align: center; border: 1px solid var(--color-border-secondary); box-shadow: 0 2px 4px rgba(0,0,0,0.02); transition: transform 0.2s; }
  .stat:hover { transform: translateY(-2px); box-shadow: 0 6px 12px rgba(0,0,0,0.05); }
  .stat-num { font-size: 28px; font-weight: 800; color: var(--color-text-primary); }
  .stat-label { font-size: 13px; color: var(--color-text-secondary); margin-top: 4px; font-weight: 600; }
  
  .mode-btns { display: flex; gap: 8px; margin-bottom: 1.5rem; flex-wrap: wrap; }
  .mode-btn { font-size: 14px; padding: 8px 16px; border-radius: 99px; background: transparent; border: 1px solid var(--color-border-primary); color: var(--color-text-secondary); cursor: pointer; transition: all 0.2s; font-weight: 500; box-shadow: none; }
  .mode-btn:hover { background: var(--color-background-secondary); color: var(--color-text-primary); transform: translateY(-1px); }
  .mode-btn.active { background: var(--primary-color); border-color: var(--primary-color); color: #fff; font-weight: 600; box-shadow: 0 4px 10px rgba(29, 158, 117, 0.3); transform: translateY(-1px); }
  
  .finish-card { text-align: center; padding: 3rem 2rem; background: var(--color-background-primary); border: 1px solid var(--color-border-tertiary); border-radius: var(--border-radius-xl); box-shadow: 0 10px 25px -5px rgba(0,0,0,0.1); animation: slideDown 0.4s cubic-bezier(0.4, 0, 0.2, 1); }
  .finish-card h2 { font-size: 24px; font-weight: 800; margin: 0 0 1rem; color: var(--color-text-primary); }
  .finish-card p { color: var(--color-text-secondary); font-size: 16px; margin: 0 0 2rem; }
  
  .korean-hint { font-size: 16px; font-weight: 600; color: var(--color-text-primary); margin-bottom: 0.75rem; line-height: 1.5; }
  .sentence-num { font-size: 13px; font-weight: 600; color: var(--color-text-tertiary); margin-bottom: 0.5rem; text-transform: uppercase; letter-spacing: 0.5px; }
  .legend { display: flex; gap: 16px; font-size: 13px; margin-top: 12px; flex-wrap: wrap; font-weight: 500; }
  .legend span { display: flex; align-items: center; gap: 6px; color: var(--color-text-secondary); }
  

  .example-item { border: 1px solid var(--color-border-secondary); border-radius: var(--border-radius-md); padding: 12px; background: var(--color-background-secondary); }
  .example-en { font-size: 15px; font-weight: 700; color: var(--color-text-primary); line-height: 1.45; word-break: break-word; }
  .example-ko { font-size: 13px; color: var(--color-text-secondary); line-height: 1.45; margin-bottom: 4px; }
  .memory-sentence { font-size: 28px; font-weight: 800; line-height: 1.35; color: var(--color-text-primary); margin: 1.25rem 0; word-break: keep-all; }
  .meaning-reveal { position: relative; min-height: 120px; overflow: hidden; border: 1px solid var(--color-border-secondary); border-radius: var(--border-radius-lg); background: var(--color-background-primary); cursor: pointer; margin-bottom: 1rem; }
  .meaning-text { padding: 24px; font-size: 18px; line-height: 1.6; color: var(--color-text-primary); opacity: 0; transition: opacity 0.25s ease 0.2s; }
  .meaning-cover { position: absolute; inset: 0; z-index: 1; display: flex; align-items: center; justify-content: center; background: var(--primary-color); color: #fff; font-weight: 800; transition: transform 0.55s cubic-bezier(0.22, 1, 0.36, 1); }
  .meaning-reveal.revealed { cursor: default; }
  .meaning-reveal.revealed .meaning-cover { transform: translateY(100%); }
  .meaning-reveal.revealed .meaning-text { opacity: 1; }
  .add-collapsed-toggle { display: inline-flex; align-items: center; gap: 6px; margin-bottom: 1rem; padding: 8px 12px; font-size: 13px; border-radius: 99px; }

  .sentence-item { display:flex; align-items:flex-start; gap:12px; padding:16px; border-radius:var(--border-radius-md); border:1px solid transparent; border-bottom:1px solid var(--color-border-tertiary); transition:all .2s ease; margin-bottom:4px; background:var(--color-background-primary); }
  .sentence-item:last-child { border-bottom-color: transparent; }
  .sentence-item:hover { background: var(--color-background-secondary); border-color: var(--color-border-secondary); transform: translateX(2px); box-shadow: 0 2px 8px rgba(0,0,0,0.02); }
  .sentence-item.dragging { opacity: 0.4; box-shadow: 0 10px 15px rgba(0,0,0,0.1); transform: scale(1.02); }
  .sentence-item.drag-over { background: var(--color-background-info); border-color: var(--color-border-primary); }
  .sentence-item.drop-before, .sentence-item.drop-after { position: relative; }
  .sentence-item.drop-before::before, .sentence-item.drop-after::after { content: ""; position: absolute; left: 12px; right: 12px; height: 3px; border-radius: 99px; background: var(--primary-color); box-shadow: 0 0 0 3px rgba(29,158,117,0.18); pointer-events: none; }
  .sentence-item.drop-before::before { top: -4px; }
  .sentence-item.drop-after::after { bottom: -6px; }
  
  .drag-handle { cursor: grab; color: var(--color-text-tertiary); font-size: 18px; padding-top: 2px; flex-shrink: 0; user-select: none; opacity: 0.4; transition: opacity 0.2s; }
  .drag-handle:active { cursor: grabbing; }
  .sentence-item:hover .drag-handle { opacity: 1; color: var(--color-text-secondary); }
  
  .sentence-idx { font-size: 13px; font-weight: 600; color: var(--color-text-tertiary); min-width: 20px; padding-top: 4px; flex-shrink: 0; }
  .sentence-texts { flex: 1; display: flex; flex-direction: column; gap: 4px; min-width: 0; }
  .sentence-en { font-size: 16px; font-weight: 500; color: var(--color-text-primary); word-break: break-word; line-height: 1.4; }
  .sentence-ko { font-size: 14px; color: var(--color-text-secondary); word-break: break-word; line-height: 1.4; }
  .item-actions { display: flex; gap: 6px; flex-shrink: 0; }
  
  .edit-block { display: flex; flex-direction: column; gap: 10px; flex: 1; min-width: 0; background: var(--color-background-secondary); padding: 12px; border-radius: var(--border-radius-md); border: 1px solid var(--color-border-primary); }
  .edit-block input { font-size: 14px; padding: 8px 12px; }
  .edit-actions { display: flex; gap: 8px; margin-top: 4px; }
  .edit-actions button { font-size: 13px; padding: 6px 14px; }
  
  .undo-bar { display: flex; align-items: center; gap: 12px; margin-bottom: 1.5rem; padding: 10px 16px; background: var(--color-text-primary); color: var(--color-background-primary); border-radius: var(--border-radius-md); box-shadow: 0 4px 6px rgba(0,0,0,0.1); animation: slideDown 0.3s ease; }
  .undo-label { font-size: 14px; font-weight: 500; color: var(--color-background-primary); flex: 1; }
  .undo-btn { font-size: 13px; padding: 6px 14px; background: rgba(255,255,255,0.2); border: none; color: #fff; border-radius: 99px; }
  .undo-btn:hover { background: rgba(255,255,255,0.3); color: #fff; transform: translateY(0); box-shadow: none; }

  /* Main & Flashcard */
  .main-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 2rem; }
  .main-card-btn { background: var(--color-background-primary); border: 2px solid var(--color-border-secondary); border-radius: var(--border-radius-xl); padding: 3rem 2rem; text-align: center; cursor: pointer; transition: all 0.3s ease; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 16px; box-shadow: 0 4px 6px rgba(0,0,0,0.05); }
  .main-card-btn:hover { border-color: var(--primary-color); transform: translateY(-5px); box-shadow: 0 12px 20px rgba(29, 158, 117, 0.15); }
  .main-card-icon { font-size: 48px; }
  .main-card-title { font-size: 24px; font-weight: 800; color: var(--color-text-primary); margin: 0; }
  .main-card-desc { font-size: 14px; color: var(--color-text-secondary); line-height: 1.5; margin: 0; }
  
  .flashcard-scene { perspective: 1000px; width: 100%; height: 300px; margin: 2rem 0; cursor: pointer; }
  .flashcard { width: 100%; height: 100%; transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1); transform-style: preserve-3d; position: relative; }
  .flashcard.flipped { transform: rotateY(180deg); }
  .flashcard-face { position: absolute; width: 100%; height: 100%; backface-visibility: hidden; display: flex; flex-direction: column; align-items: center; justify-content: center; background: var(--color-background-primary); border: 2px solid var(--color-border-secondary); border-radius: var(--border-radius-xl); box-shadow: 0 10px 25px rgba(0,0,0,0.08); padding: 2rem; box-sizing: border-box; text-align: center; }
  .flashcard-back { transform: rotateY(180deg); background: var(--color-background-secondary); border-color: var(--primary-color); }
  .fc-word { font-size: 32px; font-weight: 800; color: var(--color-text-primary); margin-bottom: 8px; word-break: break-word; }
  .fc-hint { font-size: 14px; color: var(--color-text-tertiary); font-weight: 600; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 16px; }

  /* Mobile Responsive */
  @media (max-width: 600px) {
    .main-grid { grid-template-columns: 1fr; gap: 16px; }
    .main-card-btn { padding: 2rem 1.5rem; }
    .flashcard-scene { height: 250px; }
    .fc-word { font-size: 26px; }

    .container { padding: 1.5rem 1rem; }
    .main-title { font-size: 22px; margin-bottom: 1.5rem; }
    .tab-row { flex-wrap: wrap; }
    .tab { flex: 1 1 40%; font-size: 14px; padding: 10px 4px; }
    .card { padding: 1.25rem; }
    
    .sentence-item { flex-wrap: wrap; }
    .sentence-texts { flex: 1 1 100%; order: 1; margin-top: 4px; padding-left: 28px; }
    .item-actions { flex: 1 1 100%; order: 2; justify-content: flex-end; margin-top: 12px; border-top: 1px solid var(--color-border-tertiary); padding-top: 12px; }
    
    .stat-row { flex-direction: column; gap: 8px; margin-bottom: 1.5rem; }
    .btn-row { flex-direction: column; }
    .btn-row > button { width: 100%; margin-left: 0 !important; }
    
    .finish-card > div > div { flex-direction: column !important; }
    .finish-card > div > div > button { width: 100%; margin-left: 0 !important; }
    
    .mode-btns { flex-direction: column; }
    .mode-btn { width: 100%; }
    
    .select-bar { flex-direction: column; align-items: stretch; }
    .select-count { text-align: right; margin-top: 8px; }
    .study-actions { width: 100%; }
    .study-actions button { flex: 1; }
    .modal-actions { grid-template-columns: 1fr; }
    .memory-sentence { font-size: 22px; }
    .login-shell { grid-template-columns: 1fr; }
    .login-visual { display: none; }
    .login-box { width: min(360px, 100%); }
  }