:root {
    --blue--50: #E6F1FB;
    --blue--100: #B5D4F4;
    --blue--200: #85B7EB;
    --blue--400: #378ADD;
    --blue--600: #185FA5;
    --blue--800: #0C447C;
    --blue--900: #042C53;
    --gray--50: #F7F8FA;
    --gray--100: #EAECF0;
    --gray--200: #D1D5DB;
    --gray--400: #9CA3AF;
    --gray--600: #4B5563;
    --gray--800: #1F2937;
    --red--50: #FCEBEB;
    --red--400: #E24B4A;
    --red--600: #A32D2D;
    --green--50: #EAF3DE;
    --green--400: #639922;
    --green--600: #3B6D11;
    --amber-50: #FAEEDA;
    --amber-400: #BA7517;
  }
 
  .main {
    max-width: 1280px;
    margin: 0 auto;
  }
 
  .main .panel {
    background: #fff;
    border: 1px solid var(--gray--100);
    border-radius: 14px;
    padding: 1.5rem;
    margin-bottom: 1.25rem;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
  }
 
  .main .panel-label {
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--blue--600);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 6px;
  }
 
  .main .panel-label svg {
    width: 14px;
    height: 14px;
    stroke: var(--blue--400);
    fill: none;
    stroke-width: 2;
    stroke-linecap: round;
  }
 
  .main textarea {
    width: 100%;
    min-height: 180px;
    border: 1.5px solid var(--gray--200);
    border-radius: 8px;
    padding: 0.85rem 1rem;
    font-family: 'DM Mono', monospace;
    font-size: 0.85rem;
    color: var(--gray--800);
    background: var(--gray--50);
    resize: vertical;
    outline: none;
    transition: border-color 0.15s, background 0.15s;
    line-height: 1.65;
  }
 
  .main textarea:focus {
    border-color: var(--blue--400);
    background: #fff;
    box-shadow: 0 0 0 3px rgba(55,138,221,0.1);
  }
 
  .main textarea::placeholder {
    color: var(--gray--400);
    font-style: italic;
  }
 
  .main textarea:read-only {
    cursor: default;
    background: var(--gray--50);
  }
 
  .main .options-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 1rem 0;
    padding: 0.85rem 1rem;
    background: var(--blue--50);
    border-radius: 8px;
    border: 1px solid var(--blue--100);
  }
 
  .main .options-row label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.88rem;
    color: var(--blue--800);
    font-weight: 500;
    cursor: pointer;
    user-select: none;
  }
 
  .main .options-row input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--blue--600);
    cursor: pointer;
  }
 
  .main .options-hint {
    margin-left: auto;
    font-size: 0.76rem;
    color: var(--blue--600);
    font-weight: 400;
    font-family: 'DM Mono', monospace;
  }
 
  .main .buttons {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 0.65rem;
    margin-bottom: 1.25rem;
  }
 
  .main button {
    font-family: 'Syne', sans-serif;
    font-weight: 600;
    font-size: 0.82rem;
    letter-spacing: 0.03em;
    border: none;
    border-radius: 8px;
    padding: 0.7rem 1rem;
    cursor: pointer;
    transition: transform 0.1s, filter 0.15s, box-shadow 0.15s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
  }
 
  .main button svg {
    width: 15px;
    height: 15px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2.2;
    stroke-linecap: round;
    stroke-linejoin: round;
    flex-shrink: 0;
  }
 
  .main button:active { transform: scale(0.97); }
 
  .btn-remove {
    background: var(--blue--600);
    color: #fff;
    box-shadow: 0 2px 8px rgba(24,95,165,0.3);
  }
  .btn-remove:hover { filter: brightness(1.1); box-shadow: 0 3px 12px rgba(24,95,165,0.4); }
 
  .btn-find {
    background: var(--blue--50);
    color: var(--blue--800);
    border: 1.5px solid var(--blue--200);
  }
  .btn-find:hover { background: var(--blue--100); border-color: var(--blue--400); }
 
  .btn-clear {
    background: var(--gray--100);
    color: var(--gray--600);
    border: 1.5px solid var(--gray--200);
  }
  .btn-clear:hover { background: var(--gray--200); color: var(--gray--800); }
 
  .results-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.75rem;
  }
 
  .stats-row {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 0.85rem;
  }
 
  .stat-badge {
    font-family: 'DM Mono', monospace;
    font-size: 0.75rem;
    font-weight: 500;
    padding: 3px 10px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    gap: 5px;
  }
 
  .stat-badge.total { background: var(--gray--100); color: var(--gray--600); }
  .stat-badge.unique { background: var(--green--50); color: var(--green--600); }
  .stat-badge.dupes  { background: var(--red--50);   color: var(--red--600);   }
  .stat-badge.removed { background: var(--amber-50); color: var(--amber-400); }
 
  .stat-badge .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: currentColor;
    opacity: 0.7;
  }
 
  .copy-btn {
    font-family: 'Syne', sans-serif;
    font-size: 0.78rem;
    font-weight: 600;
    padding: 0.45rem 0.85rem;
    background: transparent;
    color: var(--blue--600);
    border: 1.5px solid var(--blue--200);
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: all 0.15s;
    letter-spacing: 0.02em;
  }
 
  .copy-btn svg {
    width: 13px;
    height: 13px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2.2;
    stroke-linecap: round;
    stroke-linejoin: round;
  }
 
  .copy-btn:hover { background: var(--blue--50); border-color: var(--blue--400); }
  .copy-btn.copied { background: var(--green--50); color: var(--green--600); border-color: #a3c96a; }
 
  .empty-state {
    min-height: 120px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
    color: var(--gray--400);
    font-size: 0.82rem;
    font-style: italic;
    border: 1.5px dashed var(--gray--200);
    border-radius: 8px;
    background: var(--gray--50);
  }
 
  .empty-state svg {
    width: 24px;
    height: 24px;
    stroke: var(--gray--300);
    fill: none;
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
  }
 
  .mode-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-family: 'DM Mono', monospace;
    font-size: 0.7rem;
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--blue--50);
    color: var(--blue--600);
    border: 1px solid var(--blue--100);
    font-weight: 500;
  }
 
  #result-area {
    display: none;
  }
  
  .about-section {
    margin-top: 2rem;
    padding-top: 2rem;
	margin-bottom: 1rem;
  }
 
  .about-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--blue--600);
    margin-bottom: 1.25rem;
  }
 
  .about-header svg {
    width: 16px;
    height: 16px;
    stroke: var(--blue--400);
  }
 
  .about-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
  }
 
  .about-card-title {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--blue--800);
    letter-spacing: 0.01em;
    margin-bottom: 0.65rem;
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.08em;
  }
 
  .about-card p {
    font-size: 0.875rem;
    line-height: 1.75;
    margin-bottom: 0.65rem;
  }
 
  .about-card p:last-child { margin-bottom: 0; }
 
  .about-card strong {
    color: var(--blue--800);
    font-weight: 600;
  }
 
  .about-card code {
    font-family: 'DM Mono', monospace;
    font-size: 0.8rem;
    background: var(--gray--100);
    color: var(--blue--800);
    padding: 1px 5px;
    border-radius: 4px;
  }
 
  .about-card ul {
    padding-left: 1.1rem;
    margin: 0;
  }
 
  .about-card ul li {
    font-size: 0.875rem;
    line-height: 1.75;
    color: var(--gray--600);
    margin-bottom: 0.3rem;
  }
 
  .about-card ul li:last-child { margin-bottom: 0; }