/* ============================================================
   style.css  –  한국현 Personal Website
   ============================================================ */
:root {
  --bg: #0f1117;
  --surface: #1a1d27;
  --card: #222633;
  --accent: #4fc3f7;
  --accent2: #81d4fa;
  --text: #e0e0e0;
  --muted: #9e9e9e;
  --border: #333a4a;
  --radius: 8px;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: 'Pretendard','Noto Sans KR', -apple-system, sans-serif; background: var(--bg); color: var(--text); line-height: 1.7; }

/* ── NAV ── */
nav { position: sticky; top: 0; z-index: 100; background: rgba(15,17,23,.92); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
nav .inner { max-width: 1200px; margin: 0 auto; display: flex; align-items: center; gap: 1rem; padding: .6rem 1.2rem; overflow-x: auto; }
nav a { color: var(--muted); text-decoration: none; font-size: .85rem; white-space: nowrap; transition: color .2s; }
nav a:hover, nav a.active { color: var(--accent); }
nav .brand { font-weight: 700; color: var(--accent); font-size: 1rem; margin-right: auto; }

/* ── HERO ── */
.hero { text-align: center; padding: 3rem 1rem 2rem; }
.hero h1 { font-size: 2rem; color: #fff; }
.hero p { color: var(--muted); margin-top: .5rem; }

/* ── SECTION ── */
section { max-width: 1000px; margin: 0 auto 2rem; padding: 0 1.2rem; }
section h2 { font-size: 1.3rem; color: var(--accent); border-bottom: 2px solid var(--accent); padding-bottom: .4rem; margin-bottom: 1rem; }
section h3 { font-size: 1.05rem; color: var(--accent2); margin: 1.2rem 0 .5rem; }

/* ── CARDS / ITEMS ── */
.item { background: var(--card); border-radius: var(--radius); padding: .8rem 1rem; margin-bottom: .6rem; border-left: 3px solid var(--accent); }
.item .period { font-size: .8rem; color: var(--muted); }
.item .title { margin-top: .2rem; }
.item .desc { font-size: .88rem; color: var(--muted); margin-top: .2rem; }
.item a { color: var(--accent); text-decoration: none; }
.item a:hover { text-decoration: underline; }

/* ── FILE LINKS ── */
.files { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: .4rem; }
.files a { display: inline-flex; align-items: center; gap: .2rem; font-size: .78rem; background: rgba(79,195,247,.12); color: var(--accent); padding: .15rem .5rem; border-radius: 4px; text-decoration: none; transition: background .2s; }
.files a:hover { background: rgba(79,195,247,.25); }

/* ── TAGS ── */
.tags { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 1rem; }
.tag { background: var(--card); color: var(--accent2); padding: .3rem .7rem; border-radius: 20px; font-size: .82rem; border: 1px solid var(--border); }

/* ── COLLAPSIBLE ── */
.collapse-btn { background: var(--card); color: var(--accent); border: 1px solid var(--border); padding: .45rem 1rem; border-radius: var(--radius); cursor: pointer; font-size: .88rem; margin-bottom: .6rem; transition: background .2s; display: inline-flex; align-items: center; gap: .4rem; }
.collapse-btn:hover { background: var(--surface); }
.collapse-btn::after { content: '▼'; font-size: .7rem; transition: transform .3s; }
.collapse-btn.open::after { transform: rotate(180deg); }
.collapsible { display: none; }
.collapsible.show { display: block; }

/* ── PATENT BTNS ── */
.patent-btns { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: .5rem; }
.patent-btns a { display: inline-block; background: var(--accent); color: var(--bg); padding: .4rem .9rem; border-radius: var(--radius); text-decoration: none; font-size: .82rem; font-weight: 600; transition: opacity .2s; }
.patent-btns a:hover { opacity: .85; }

/* ── SIMPLE LIST ── */
.simple-list { list-style: disc; padding-left: 1.5rem; }
.simple-list li { margin-bottom: .3rem; font-size: .9rem; }
.simple-list li a { color: var(--accent); text-decoration: none; }

/* ── ADMIN PANEL ── */
.admin-panel { display: none; position: fixed; top: 0; right: 0; width: 50vw; height: 100vh; background: var(--surface); border-left: 2px solid var(--accent); z-index: 200; flex-direction: column; padding: 1rem; }
.admin-panel.open { display: flex; }
.admin-panel h3 { color: var(--accent); margin-bottom: .5rem; }
.admin-panel textarea { flex: 1; background: var(--bg); color: var(--text); border: 1px solid var(--border); border-radius: var(--radius); padding: .5rem; font-family: 'Fira Code', monospace; font-size: .8rem; resize: none; }
.admin-panel .btn-row { display: flex; gap: .5rem; margin-top: .5rem; }
.admin-panel button { padding: .4rem 1rem; border-radius: var(--radius); border: none; cursor: pointer; font-weight: 600; }
.admin-panel .btn-save { background: var(--accent); color: var(--bg); }
.admin-panel .btn-close { background: var(--border); color: var(--text); }

/* ── FOOTER ── */
footer { text-align: center; padding: 2rem 1rem; color: var(--muted); font-size: .8rem; border-top: 1px solid var(--border); }

/* ── RESPONSIVE ── */
@media (max-width: 600px) {
  .hero h1 { font-size: 1.4rem; }
  section h2 { font-size: 1.1rem; }
  .admin-panel { width: 95vw; }
}

/* ── 기존 style.css 끝에 아래만 추가 ── */

/* QEA Abstract */
.qea-abstract {
  background: var(--card);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  margin-bottom: 1rem;
  font-size: .92rem;
  line-height: 1.8;
  color: var(--text);
}