:root{
    --bg: #0b1220;
    --bg2: #0e1729;
    --text: #e6edf6;
    --muted: #9fb0c3;
    --card: rgba(255,255,255,.06);
    --line: rgba(255,255,255,.08);
    --primary: #66d1ff;
    --primary2: #5aa0ff;
    --shadow: 0 10px 30px rgba(0,0,0,.35);
    --radius: 16px;
    /* auth-panel variables */
    --overlay-scrim: rgba(0,0,0,.5);
    --sp-surface: #0a0f1b;
    --sp-fg: var(--text);
    --sp-border: #1c2740;
    --sp-shadow: var(--shadow);
    --sp-muted: var(--muted);
    --sp-accent: #67e8f9;
  }
  
  *{ box-sizing: border-box }
  html,body{ margin:0; padding:0; }
  body{
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, "Noto Sans KR", Apple SD Gothic Neo, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans", "Microsoft YaHei", sans-serif;
    background: linear-gradient(180deg,var(--bg),var(--bg2));
    color: var(--text);
    line-height: 1.6;
  }
  
  /* Layout helpers */
  .container{ width:100%; max-width: 1120px; margin: 0 auto; padding: 0 20px; }
  .section{ padding: 72px 0; }
  .section-title{ font-size: 28px; font-weight: 800; margin: 0 0 20px; }
  .muted{ color: var(--muted); }
  .hint{ color: var(--muted); margin-left: 10px; font-size: 12px; }
  
  /* Header */
  .site-header{
    position: sticky; top:0; z-index: 20;
    backdrop-filter: blur(10px);
    background: rgba(12,18,32,.6);
    border-bottom: 1px solid var(--line);
  }
  .header-inner{ display:flex; align-items:center; justify-content:space-between; height:64px; }
  .brand{ display:flex; align-items:center; gap:10px; color:var(--text); text-decoration:none; }
  .brand-icon{
    width:36px; height:36px; border-radius:12px; display:grid; place-items:center;
    background: linear-gradient(135deg, rgba(255,255,255,.14), rgba(255,255,255,.06));
  }
  .brand-name{ font-weight:700; letter-spacing:.2px }
  .nav{ display:flex; gap:20px; }
  .nav a{ color:var(--muted); text-decoration:none; font-size:14px; }
  .nav a:hover{ color:var(--text); }
  .header-cta{ display:flex; gap:8px; }
  
  .nav-toggle{
    display:none; background:none; border:0; color:var(--text); cursor:pointer;
  }
  .nav-bar{ display:block; width:22px; height:2px; background:var(--text); margin:4px 0; border-radius:2px; }
  
  /* Buttons */
  .btn{
    display:inline-flex; align-items:center; gap:8px;
    padding: 12px 16px; border-radius: 14px; text-decoration:none;
    font-weight: 700; letter-spacing:.2px;
    transition: transform .1s ease, background .2s ease, color .2s ease, border-color .2s ease;
    border:1px solid transparent;
  }
  .btn .btn-ico{ margin-right:6px }
  .btn-primary{ background: linear-gradient(135deg,var(--primary),var(--primary2)); color:#021223; }
  .btn-primary:hover{ transform: translateY(-1px); }
  .btn-outline{ background: transparent; color: var(--text); border-color: var(--line); }
  .btn-outline:hover{ background: rgba(255,255,255,.05); }
  .btn-secondary{ background:#fff; color:#0b1220; }
  .btn-secondary:hover{ filter: brightness(.95); }
  .btn .avatar{ border-radius: 50%; display:inline-block; object-fit: cover; }
  .btn .name{ margin-left: 4px; }
  
  /* Hero */
  .hero{ position: relative; padding: 90px 0 60px; overflow:hidden; }
  .hero-inner{ text-align:center; }
  .hero-title{ font-size: clamp(32px, 6vw, 56px); line-height:1.15; margin:0; font-weight: 900; }
  .text-gradient{
    background: linear-gradient(90deg,#67e8f9,#60a5fa);
    -webkit-background-clip: text; background-clip:text; color: transparent;
  }
  .hero-sub{ margin:16px auto 0; color: var(--muted); max-width: 720px; }
  .hero-cta{ margin-top: 24px; display:flex; gap:12px; justify-content:center; flex-wrap: wrap; }
  .hero-note{ margin-top: 8px; font-size: 12px; color: var(--muted); }
  .bg-blob{
    position:absolute; inset:auto 0 auto 50%; top:-120px; width:900px; height:900px; transform: translateX(-50%);
    background: radial-gradient(closest-side, rgba(102,209,255,.18), transparent 60%);
    filter: blur(48px); pointer-events:none;
  }
  
  /* Cards / Grid */
  .grid{ display:grid; grid-template-columns: repeat(3,1fr); gap: 16px; }
  .card{
    background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px;
    box-shadow: var(--shadow);
  }
  .card.big{ padding: 26px; }
  .card-title{ margin:0 0 6px; font-size: 18px; font-weight: 800; }
  .card-desc{ margin:0 0 10px; color: var(--muted); }
  .card-list{ margin:0; padding:0 0 0 18px; color: var(--muted); }
  
  /* How */
  .how-grid{ display:grid; grid-template-columns: 1.1fr .9fr; gap: 22px; align-items: start; }
  .how-list{ margin:12px 0; padding-left: 18px; }
  .code{
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
    white-space: pre-wrap; color: #cfe7ff;
    background: #0a0f1b; border:1px solid #1c2740; border-radius: var(--radius); padding: 16px;
  }
  .code-title{ color:#7fb7ff; display:block; margin: 4px 0 8px; }
  
  /* Download / Newsletter */
  .dl-grid{ display:grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: center; }
  .newsletter{ display:flex; gap:10px; }
  .newsletter input{
    flex:1; background: rgba(0,0,0,.35); border:1px solid var(--line); color: var(--text);
    padding: 12px 14px; border-radius: 12px; outline: none;
  }
  .newsletter input:focus{ border-color: #6ab8ff; }
  
  /* FAQ */
  .faq{
    background: var(--card); border:1px solid var(--line); border-radius: 12px; padding: 14px 16px; margin: 10px 0;
  }
  .faq summary{ cursor:pointer; font-weight: 700; }
  .faq p{ margin: 8px 0 0; color: var(--muted); }
  
  /* Footer */
  .site-footer{ border-top: 1px solid var(--line); }
  .footer-inner{ display:flex; align-items:center; justify-content:space-between; padding: 20px 0; color: var(--muted); }
  .footer-links{ display:flex; gap: 14px; }
  .footer-links a{ color: var(--muted); text-decoration: none; }
  .footer-links a:hover{ color: var(--text); }
  
  /* Responsive */
  @media (max-width: 980px){
    .grid{ grid-template-columns: 1fr 1fr; }
    .how-grid{ grid-template-columns: 1fr; }
    .dl-grid{ grid-template-columns: 1fr; }
  }
  @media (max-width: 720px){
    .grid{ grid-template-columns: 1fr; }
    .nav{ display:none; }
    .nav-toggle{ display:block; }
    .site-header.is-open .nav{
      display:flex; position: absolute; top:64px; left:0; right:0; background: rgba(12,18,32,.96);
      border-bottom: 1px solid var(--line); padding: 12px 20px; gap: 16px; flex-direction: column;
    }
    .header-cta{ display:none; }
  }