:root{
    --paper:#EEF0F2;
    --card:#FFFFFF;
    --ink:#15171B;
    --muted:#6A6F76;
    --line:#D6DADE;
    --line-soft:#E3E6E9;
    --accent:#2E9E8E;
    --accent-fg:#FFFFFF;
    --radius-card:22px;
    --shadow:0 1px 0 rgba(0,0,0,0.04);
  }
  @media (prefers-reduced-motion: reduce){
    *{ animation-duration:0.001ms !important; transition-duration:0.001ms !important; }
  }
  *{ box-sizing:border-box; }
  html,body{ margin:0; padding:0; }
  body{
    background:var(--paper);
    color:var(--ink);
    font-family:'Space Grotesk', sans-serif;
    min-height:100vh;
    padding:48px 20px 80px;
  }
  .page{ max-width:760px; margin:0 auto; }

  /* ---------- header ---------- */
  .masthead{ margin-bottom:36px; }
  .eyebrow{
    font-family:'IBM Plex Mono', monospace;
    font-size:12px;
    letter-spacing:0.14em;
    color:var(--muted);
    text-transform:uppercase;
  }
  h1{
    font-size:clamp(28px,5vw,38px);
    font-weight:700;
    margin:8px 0 10px;
    letter-spacing:-0.01em;
  }
  .tagline{
    font-size:15px;
    color:var(--muted);
    margin:0;
    max-width:46ch;
    line-height:1.55;
  }

  /* ---------- paint chip card (signature element) ---------- */
  .chip-card{
    background:var(--card);
    border:1px solid var(--line);
    border-radius:var(--radius-card);
    box-shadow:var(--shadow);
    overflow:hidden;
    margin-bottom:28px;
  }
  .chip-top{
    display:flex;
    justify-content:space-between;
    align-items:center;
    padding:16px 20px 0;
  }
  .chip-actions{ display:flex; gap:8px; }
  .ghost-btn{
    font-family:'IBM Plex Mono', monospace;
    font-size:12px;
    letter-spacing:0.03em;
    color:var(--muted);
    background:transparent;
    border:1px solid var(--line);
    border-radius:8px;
    padding:6px 12px;
    cursor:pointer;
    transition:border-color .15s ease, color .15s ease;
  }
  .ghost-btn:hover{ border-color:var(--ink); color:var(--ink); }
  .ghost-btn:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }

  .chip-swatch{
    position:relative;
    height:180px;
    margin:14px 20px 0;
    border-radius:16px 16px 0 0;
    background:var(--accent);
    transition:background .12s ease;
    display:flex;
    align-items:flex-end;
    padding:14px 18px;
  }
  .chip-hole{
    position:absolute;
    top:16px; left:50%;
    transform:translateX(-50%);
    width:22px; height:22px;
    border-radius:50%;
    background:var(--card);
    border:1px solid rgba(0,0,0,0.08);
  }
  .chip-fg-note{
    font-family:'IBM Plex Mono', monospace;
    font-size:12px;
    color:var(--accent-fg);
    letter-spacing:0.02em;
    display:flex;
    align-items:center;
    gap:6px;
    opacity:0.9;
  }
  .chip-fg-dot{ width:8px; height:8px; border-radius:50%; background:var(--accent-fg); }

  .chip-perf{
    height:0;
    margin:0 20px;
    border-top:1.5px dashed var(--line);
  }

  .chip-label{ padding:20px; }
  .field{ margin-bottom:18px; }
  .field:last-child{ margin-bottom:0; }
  .field-head{
    display:flex;
    justify-content:space-between;
    align-items:center;
    margin-bottom:8px;
  }
  .field-head label{
    font-family:'IBM Plex Mono', monospace;
    font-size:11px;
    letter-spacing:0.12em;
    color:var(--muted);
    text-transform:uppercase;
  }
  .copy-btn{
    font-family:'IBM Plex Mono', monospace;
    font-size:11px;
    color:var(--muted);
    background:transparent;
    border:none;
    cursor:pointer;
    padding:4px 6px;
    border-radius:6px;
    transition:color .15s ease, background .15s ease;
  }
  .copy-btn:hover{ color:var(--ink); background:var(--line-soft); }
  .copy-btn:focus-visible{ outline:2px solid var(--accent); outline-offset:1px; }
  .copy-btn.copied{ color:var(--accent); }

  .hex-input{
    width:100%;
    font-family:'IBM Plex Mono', monospace;
    font-size:20px;
    font-weight:500;
    letter-spacing:0.02em;
    color:var(--ink);
    background:var(--paper);
    border:1px solid var(--line);
    border-radius:10px;
    padding:10px 14px;
  }
  .hex-input:focus-visible{ outline:2px solid var(--accent); outline-offset:1px; }

  .slider-row{
    display:grid;
    grid-template-columns:16px 1fr 44px;
    align-items:center;
    gap:12px;
    margin-bottom:8px;
  }
  .slider-row:last-child{ margin-bottom:0; }
  .slider-tag{
    font-family:'IBM Plex Mono', monospace;
    font-size:12px;
    color:var(--muted);
  }
  input[type=range]{
    -webkit-appearance:none;
    appearance:none;
    width:100%;
    height:4px;
    border-radius:2px;
    background:var(--line);
    outline:none;
  }
  input[type=range]::-webkit-slider-thumb{
    -webkit-appearance:none;
    width:16px; height:16px;
    border-radius:50%;
    background:var(--card);
    border:2px solid var(--ink);
    cursor:pointer;
    margin-top:0;
  }
  input[type=range]::-moz-range-thumb{
    width:16px; height:16px;
    border-radius:50%;
    background:var(--card);
    border:2px solid var(--ink);
    cursor:pointer;
  }
  input[type=range]:focus-visible{ outline:2px solid var(--accent); outline-offset:3px; }
  .slider-val{
    font-family:'IBM Plex Mono', monospace;
    font-size:12px;
    color:var(--ink);
    text-align:right;
  }

  /* ---------- palette section ---------- */
  .palette-card{
    background:var(--card);
    border:1px solid var(--line);
    border-radius:var(--radius-card);
    box-shadow:var(--shadow);
    padding:20px;
  }
  .palette-head{
    display:flex;
    justify-content:space-between;
    align-items:baseline;
    margin-bottom:14px;
    flex-wrap:wrap;
    gap:8px;
  }
  .palette-head h2{
    font-size:15px;
    font-weight:600;
    margin:0;
  }
  .palette-hint{
    font-size:12px;
    color:var(--muted);
    margin:0;
  }
  .tabs{
    display:flex;
    gap:6px;
    flex-wrap:wrap;
    margin-bottom:16px;
    border-bottom:1px solid var(--line-soft);
    padding-bottom:14px;
  }
  .tab-btn{
    font-family:'IBM Plex Mono', monospace;
    font-size:12px;
    letter-spacing:0.02em;
    color:var(--muted);
    background:transparent;
    border:1px solid var(--line);
    border-radius:20px;
    padding:7px 14px;
    cursor:pointer;
    transition:all .15s ease;
  }
  .tab-btn:hover{ border-color:var(--ink); color:var(--ink); }
  .tab-btn.active{ background:var(--ink); border-color:var(--ink); color:var(--card); }
  .tab-btn:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }

  .swatch-grid{
    display:grid;
    grid-template-columns:repeat(auto-fit, minmax(96px, 1fr));
    gap:10px;
  }
  .pal-swatch{
    border:1px solid var(--line);
    border-radius:12px;
    overflow:hidden;
    cursor:pointer;
    background:none;
    padding:0;
    text-align:left;
    transition:transform .12s ease, box-shadow .12s ease;
    font-family:inherit;
  }
  .pal-swatch:hover{ transform:translateY(-2px); box-shadow:0 4px 10px rgba(0,0,0,0.08); }
  .pal-swatch:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }
  .pal-swatch .fill{ height:64px; }
  .pal-swatch .code{
    font-family:'IBM Plex Mono', monospace;
    font-size:11px;
    padding:8px 10px;
    color:var(--ink);
    background:var(--card);
  }

  .drop-zone{
    display:block;
    width:100%;
    border:1.5px dashed var(--line);
    border-radius:14px;
    padding:28px 16px;
    text-align:center;
    color:var(--muted);
    font-size:13px;
    line-height:1.6;
    cursor:pointer;
    transition:border-color .15s ease, background .15s ease;
  }
  .drop-zone:hover, .drop-zone.drag{ border-color:var(--accent); background:var(--paper); }
  .drop-zone strong{ color:var(--ink); font-weight:600; }
  .drop-zone input{ display:none; }

  .toast{
    position:fixed;
    left:50%;
    bottom:28px;
    transform:translate(-50%, 12px);
    background:var(--ink);
    color:var(--card);
    font-family:'IBM Plex Mono', monospace;
    font-size:12px;
    padding:10px 18px;
    border-radius:20px;
    opacity:0;
    pointer-events:none;
    transition:opacity .18s ease, transform .18s ease;
  }
  .toast.show{ opacity:1; transform:translate(-50%, 0); }

  @media (max-width:520px){
    .slider-row{ grid-template-columns:14px 1fr 40px; gap:8px; }
    .chip-swatch{ height:150px; }
  }

  .site-footer-note{
    margin-top:32px;
    padding-top:18px;
    border-top:1px solid var(--line-soft);
    font-size:11.5px;
    color:var(--muted);
    text-align:center;
    line-height:1.6;
  }
  .site-footer-note .legal-links{
    margin-top:8px;
  }
  .site-footer-note .legal-links a{
    color:var(--muted);
    text-decoration:none;
  }
  .site-footer-note .legal-links a:hover{
    color:var(--accent);
  }

/* ---- SY Project 안내/FAQ 섹션 ---- */
.sy-info{ margin-top:32px; padding-top:22px; border-top:1px solid var(--line-soft); }
.sy-info h2{ font-family:'Space Grotesk', sans-serif; font-size:16px; color:var(--ink); margin-bottom:10px; }
.sy-info > p{ font-size:13.5px; line-height:1.75; color:var(--muted); margin-bottom:16px; }
.sy-faq details{ border-top:1px solid var(--line-soft); padding:12px 0; }
.sy-faq summary{ cursor:pointer; font-weight:600; font-size:13.5px; color:var(--ink); list-style:none; }
.sy-faq summary::-webkit-details-marker{ display:none; }
.sy-faq summary::before{ content:'● '; color:var(--accent); font-size:9px; }
.sy-faq details p{ margin-top:8px; font-size:13px; color:var(--muted); line-height:1.7; }