:root{
  --bg:#0b0c10; --panel:#111317; --text:#e8eaed; --muted:#9aa0a6; --line:#1f2229;
  --brand:#64ffda; --brand-ink:#0f3d38; --shadow: 0 8px 24px rgba(0,0,0,.24);
}
@media (prefers-color-scheme: light){
  :root{ --bg:#f8fafc; --panel:#ffffff; --text:#0f172a; --muted:#475569; --line:#e2e8f0; --brand:#0ea5e9; --brand-ink:#0b3a55; --shadow: 0 8px 24px rgba(2,6,23,.12); }
}

*{box-sizing:border-box}
html,body{margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:Inter,system-ui,Segoe UI,Apple SD Gothic Neo,sans-serif;background:var(--bg);color:var(--text)}
a{color:inherit}

.container{max-width:1060px;margin:0 auto;padding:24px}

/* Header / Hero */
.site-header{display:flex;align-items:center;justify-content:space-between}
.brand{font-weight:700;letter-spacing:.2px;text-decoration:none;color:var(--text)}
.nav a{color:var(--text);text-decoration:none;margin-left:18px;opacity:.85}
.nav a.active{opacity:1}
.nav .cta{background:var(--brand);color:#0b1020;padding:8px 12px;border-radius:12px;font-weight:700}
.hero{padding:40px 0}
.hero h1{font-size:clamp(28px,5vw,44px);line-height:1.15;margin:0 0 8px}
.subtitle{color:var(--muted);max-width:760px;margin:0 0 16px}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap}

/* Buttons */
.btn{display:inline-block;padding:12px 16px;border-radius:14px;background:var(--brand);color:#0b1020;text-decoration:none;font-weight:700;box-shadow:var(--shadow)}
.btn.ghost{background:transparent;color:var(--brand);border:1px solid var(--brand)}
.btn.sm{padding:8px 12px;border-radius:10px;font-weight:600}

/* Sections / Cards */
.section-title{margin:28px 0 12px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:16px}
.card-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}
.tags{display:flex;gap:6px;flex-wrap:wrap}
.tag{border:1px solid var(--line);padding:4px 8px;border-radius:999px;color:var(--muted);font-size:12px}
.card-actions{display:flex;gap:8px;margin-top:12px}
.quick-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:12px}
.quick{display:flex;flex-direction:column;gap:4px;padding:14px;border:1px solid var(--line);border-radius:14px;background:var(--panel);text-decoration:none;color:var(--text)}
.quick .meta, .quick span{color:var(--muted)}

/* Tables */
.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:12px}
.table{width:100%;border-collapse:collapse}
.table th,.table td{padding:12px 14px;border-bottom:1px solid var(--line);text-align:left}
.table th{background:var(--panel);font-weight:700}

/* Footer */
.site-footer{display:flex;align-items:center;justify-content:space-between;border-top:1px solid var(--line);margin-top:40px;padding-top:20px;color:var(--muted)}

/* Prose */
.prose h1,.prose h2,.prose h3{margin-top:20px}
.prose pre{background:var(--panel);border:1px solid var(--line);padding:12px;border-radius:12px;overflow:auto}
.prose a{color:var(--brand);text-decoration:underline}
.muted{color:var(--muted)}
.card-inline{display:flex;gap:10px;margin:16px 0}

/* ===== Notes list ===== */
.list{display:flex;flex-direction:column;gap:12px;margin-top:12px}
.list-item{
  position:relative; display:flex; align-items:baseline; justify-content:space-between;
  gap:14px; padding:14px 16px 14px 40px; border:1px solid var(--line);
  border-radius:14px; background:var(--panel); text-decoration:none; color:var(--text);
  transition:border-color .15s ease, transform .06s ease;
}
.list-item:hover{border-color:var(--brand);transform:translateY(-1px)}
.list-item::before{
  content:""; position:absolute; left:14px; top:50%; transform:translateY(-50%);
  width:10px; height:10px; border-radius:50%; background:var(--brand);
  box-shadow:0 0 0 3px rgba(100,255,218,.12);
}
.list-item .title{font-weight:700;letter-spacing:.1px}
.list-item .meta{color:var(--muted);font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
@media (max-width:560px){
  .list-item{flex-direction:column;align-items:flex-start;padding-right:16px}
  .list-item .meta{white-space:normal}
}

/* (옵션) Filters */
.filters{display:flex;flex-direction:column;gap:10px;margin:10px 0 18px}
.input{width:100%;padding:10px 12px;border:1px solid var(--line);background:var(--panel);color:var(--text);border-radius:12px}
.input::placeholder{color:var(--muted)}

/* ===== Article + TOC (COMPACT) ===== */
.article{display:grid;grid-template-columns:220px 1fr;gap:20px}
@media (max-width:980px){.article{grid-template-columns:1fr}}

.toc{
  position:sticky; top:20px; align-self:start;
  background:var(--panel); border:1px solid var(--line);
  border-radius:12px; padding:10px; font-size:.95em; line-height:1.3;
  max-height:70vh; overflow:auto;
}
.toc-title{font-weight:700;margin:0 0 6px 2px}
.toc ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:4px}
.toc a{display:block;padding:6px 8px;border-radius:8px;color:var(--text);text-decoration:none;opacity:.86}
.toc a:hover{opacity:1}
.toc a.active{
  color:var(--brand); opacity:1;
  background:color-mix(in oklab, var(--brand) 12%, transparent);
  border:1px solid var(--brand);
}
.toc li.level-3{padding-left:12px;opacity:.95}

/* 앵커 점프 보정(헤더 높이) */
.section{scroll-margin-top:90px}

/* Figures / Callouts */
.figure{border:1px solid var(--line);border-radius:12px;overflow:hidden;margin:12px 0;background:var(--panel)}
.figure img{
  display:block;
  max-width:100%;
  height:auto;
  margin: 0 auto;}
.figure figcaption{padding:8px 12px;color:var(--muted);font-size:14px;border-top:1px solid var(--line)}
.callout{border:1px solid var(--line);background:var(--panel);border-radius:12px;padding:12px;margin:12px 0; text-align:center;}
.callout.info{border-color:var(--brand)}

.prose h2.section{
  position:relative;
  padding-top:18px;      /* 바와 제목 사이 여백 */
  margin-top:42px;       /* 이전 섹션과 거리 */
}
.prose h2.section::before{
  content:"";
  position:absolute;
  left:0; right:0; top:0;
  height:1px;
  background:var(--line);        /* 얇은 구분 바 */
}
.prose h3.section{
  position:relative;
  padding-top:14px;
  margin-top:28px;
}
.prose h3.section::before{
  content:"";
  position:absolute;
  left:0; right:0; top:0;
  height:1px;
  background:rgba(255,255,255,.06); /* 더 은은한 바 (라이트 모드에서도 보임) */
}
.prose p{ margin:10px 0 12px; }       /* 문단 간격 안정화 */
.figure img{ display:block; max-width:80%; height:auto; margin:0 auto; }
.figure figcaption{ text-align:center; }