/* ============================================================
   neuroviz — 정적 스크롤리텔링 사이트
   톤: 차분하고 정직한 과학 잡지 (Quanta / Nat Geo 풍)
   무의존: 시스템 폰트만, 외부 링크 없음
   ============================================================ */

:root{
  --bg:#0f1115;
  --bg-soft:#171a21;
  --surface:#1d212b;
  --surface-2:#222734;
  --text:#e8eaed;
  --text-dim:#9aa0aa;
  --line:#2a2f3a;
  --accent:#6ea8fe;
  --stat:#ffd166;

  /* 배지 */
  --badge-new:#3ddc97;     /* 🟢 새로움 */
  --badge-refine:#f2a65a;  /* 🟡 정제/방법 */
  --badge-repro:#7d8590;   /* 🔵 재현(중립) */
  --badge-self:#b8c0cc;    /* ⚪ 자기수정(중립톤) */

  /* 개념색(그림 범례와 일치) */
  --c-fear:#e4572e; --c-num:#4a78d6; --c-space:#8a8d2f; --c-social:#d96cc0; --c-code:#e0b341;

  --maxw:1080px;
  --reading:68ch;
  --radius:12px;
  --shadow:0 8px 30px rgba(0,0,0,.35);
}

@media (prefers-color-scheme: light){
  :root{
    --bg:#f7f8fa; --bg-soft:#eef0f4; --surface:#fff; --surface-2:#f1f3f7;
    --text:#1a1d24; --text-dim:#566; --line:#dde1e8;
    --accent:#2f6fe0; --stat:#9a6b00;
    --badge-self:#566;
    --shadow:0 8px 30px rgba(20,30,50,.10);
  }
}

*{ box-sizing:border-box; }

html{ scroll-behavior:smooth; }

body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:-apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Pretendard", "Noto Sans KR", Roboto, "Segoe UI", sans-serif;
  font-size:1.0625rem;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

/* ---------- 언어 토글 (display 전환) ---------- */
.lang-ko .en{ display:none; }
.lang-en .ko{ display:none; }

.lang-toggle{
  position:fixed; top:0.75rem; right:0.75rem; z-index:50;
  display:flex; gap:2px; padding:3px;
  background:var(--surface); border:1px solid var(--line);
  border-radius:999px; box-shadow:var(--shadow);
}
.lang-btn{
  appearance:none; border:0; cursor:pointer;
  background:transparent; color:var(--text-dim);
  font:inherit; font-size:0.85rem; font-weight:600;
  padding:0.35rem 0.8rem; border-radius:999px;
  transition:background .2s, color .2s;
}
.lang-btn:hover{ color:var(--text); }
.lang-btn.is-active{ background:var(--accent); color:#0b0d12; }
.lang-btn:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }
@media (prefers-color-scheme: light){ .lang-btn.is-active{ color:#fff; } }

/* ---------- 레이아웃 공통 ---------- */
.wrap{
  width:min(100% - 2rem, var(--maxw));
  margin-inline:auto;
}

.section{
  padding-block:clamp(3rem, 8vw, 6rem);
  border-top:1px solid var(--line);
}
.section:first-of-type{ border-top:0; }

h1,h2,h3{ line-height:1.2; letter-spacing:-0.01em; font-weight:700; }
h1{ font-size:clamp(2rem, 5vw, 3.5rem); margin:0.2em 0 0.3em; }
h2{ font-size:clamp(1.5rem, 3vw, 2.25rem); margin:0 0 0.6em; }
h3{ font-size:1.25rem; margin:0 0 0.5em; }

p{ margin:0 0 1.1em; }
.prose p:last-child, .prose ul:last-child{ margin-bottom:0; }

a{ color:var(--accent); }

em{ font-style:italic; color:var(--text); }
code{
  font-family:ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size:0.85em; background:var(--surface-2);
  padding:0.1em 0.4em; border-radius:5px; word-break:break-all;
}

.stat{ color:var(--stat); font-weight:700; }

.lede{
  max-width:var(--reading); color:var(--text-dim);
  font-size:1.1rem;
}

/* ---------- 히어로 ---------- */
.hero{
  padding-block:clamp(3.5rem, 9vw, 7rem) clamp(2.5rem,7vw,5rem);
  background:
    radial-gradient(1100px 480px at 70% -10%, rgba(110,168,254,.14), transparent 60%),
    var(--bg);
  text-align:center;
}
.hero .wrap{ display:flex; flex-direction:column; align-items:center; }
.eyebrow{
  text-transform:uppercase; letter-spacing:0.12em; font-size:0.8rem;
  color:var(--accent); font-weight:700; margin:0 0 0.4em;
}
.hero h1{ max-width:18ch; }
.hero-headline{
  font-size:clamp(1.15rem, 2.6vw, 1.6rem);
  color:var(--text); max-width:34ch; font-weight:500;
  margin:0.2em 0 2rem;
}
.hero-figure{ max-width:100%; width:min(100%, 960px); text-align:left; }
.scroll-hint{
  margin-top:2rem; color:var(--text-dim); font-size:0.85rem;
  text-transform:uppercase; letter-spacing:0.1em;
}
.scroll-hint::after{ content:" ↓"; }

/* ---------- 방법 / 출처 카드 그리드 ---------- */
.method-grid, .sources-grid{
  display:grid; gap:1rem; margin-top:2rem;
  grid-template-columns:repeat(auto-fit, minmax(280px, 1fr));
}
.card{
  background:var(--surface); border:1px solid var(--line);
  border-radius:var(--radius); padding:1.4rem 1.5rem;
}
.card h3{ color:var(--text); }
.card p{ margin-bottom:0; }
.card ul{ margin:0; padding-left:1.1rem; }
.card li{ margin-bottom:0.4rem; }
.card li:last-child{ margin-bottom:0; }

.metric-list{ margin:0; padding-left:1.1rem; }
.metric-list li{ margin-bottom:0.6rem; }
.metric-list li:last-child{ margin-bottom:0; }

.mono-list code{ display:inline-block; margin:0.1rem 0.15rem 0.1rem 0; }
.path-note{ color:var(--text-dim); font-size:0.85rem; margin-bottom:0.6rem; }

/* ---------- keynote 박스 ---------- */
.keynote{
  margin-top:2rem; padding:1.4rem 1.6rem;
  background:var(--surface); border:1px solid var(--line);
  border-left:3px solid var(--accent); border-radius:var(--radius);
  max-width:var(--reading);
}
.keynote p{ margin:0; }

/* ---------- 섹션 헤더 + 배지 ---------- */
.section-head{ margin-bottom:1.4rem; }
.section-head h2{ margin:0.5rem 0 0; }

.badge{
  display:inline-flex; align-items:center; gap:0.4em;
  font-size:0.72rem; font-weight:700; text-transform:uppercase;
  letter-spacing:0.06em;
  padding:0.3em 0.7em; border-radius:999px;
  border:1px solid var(--line); margin-right:0.4rem;
  vertical-align:middle;
}
.badge .dot{
  width:0.6em; height:0.6em; border-radius:50%;
  display:inline-block; flex:0 0 auto;
}
.badge-new{ color:var(--badge-new); border-color:color-mix(in srgb, var(--badge-new) 45%, var(--line)); background:color-mix(in srgb, var(--badge-new) 12%, transparent); }
.badge-new .dot{ background:var(--badge-new); }
.badge-refine{ color:var(--badge-refine); border-color:color-mix(in srgb, var(--badge-refine) 45%, var(--line)); background:color-mix(in srgb, var(--badge-refine) 12%, transparent); }
.badge-refine .dot{ background:var(--badge-refine); }
.badge-repro{ color:var(--badge-repro); }
.badge-repro .dot{ background:var(--badge-repro); }
.badge-self{ color:var(--badge-self); }
.badge-self .dot{ background:var(--badge-self); border:1px solid var(--text-dim); }

/* 핵심 새로움 섹션 강조 */
.section-feature .section-head h2{ color:var(--text); }
.section-feature{
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--badge-new) 5%, transparent), transparent 30%),
    var(--bg);
}
.section-correction{
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--surface) 80%, transparent), transparent 30%),
    var(--bg-soft);
}

/* ---------- prose / 본문 컬럼 ---------- */
.prose{ max-width:var(--reading); }
.prose-wide{ max-width:min(100%, 78ch); }
.prose ul{ padding-left:1.2rem; }
.prose li{ margin-bottom:0.6rem; }

.rank{
  margin:1.2rem 0; padding:1rem 1.3rem;
  background:var(--surface); border:1px solid var(--line);
  border-radius:var(--radius); text-align:center;
  font-size:1.1rem;
}

/* ---------- split (그림+텍스트 2열) ---------- */
.split{
  display:grid; gap:2rem; align-items:start;
  grid-template-columns:minmax(0, 1.05fr) minmax(0, 0.95fr);
}
.split-rev .prose{ order:2; }
.split-rev figure{ order:1; }
@media (max-width: 820px){
  .split{ grid-template-columns:1fr; }
  .split-rev .prose{ order:1; }
  .split-rev figure{ order:2; }
}

/* split 안의 figure는 sticky 살짝 */
.split figure{ position:sticky; top:1.5rem; }
@media (max-width: 820px){ .split figure{ position:static; } }

/* ---------- figure ---------- */
figure{
  margin:0; background:var(--surface);
  border:1px solid var(--line); border-radius:var(--radius);
  padding:1rem; box-shadow:var(--shadow);
}
.hero-figure{ margin-top:1rem; }
figure img{
  display:block; width:100%; height:auto; max-width:100%;
  border-radius:8px; cursor:zoom-in;
  background:#000;
}
figcaption{ margin-top:0.85rem; font-size:0.875rem; }
figcaption .cap{ display:block; color:var(--text); line-height:1.6; }
figcaption .axis-note{
  display:block; margin-top:0.6rem; padding-top:0.6rem;
  border-top:1px dashed var(--line);
  color:var(--text-dim); font-size:0.8rem; line-height:1.55;
}

/* 그림 두 장 나란히 (F3, F4) */
.figure-row{
  display:grid; gap:1.2rem; margin-top:2rem;
  grid-template-columns:repeat(auto-fit, minmax(320px, 1fr));
}
.figure-row figure{ position:static; }

/* ---------- limits list ---------- */
.limits-list{
  margin-top:2rem; padding:0; list-style:none;
  display:grid; gap:0.9rem;
}
.limits-list li{
  background:var(--surface); border:1px solid var(--line);
  border-radius:var(--radius); padding:1rem 1.3rem;
}

/* ---------- footer ---------- */
.site-footer{
  border-top:1px solid var(--line);
  padding-block:2.5rem; color:var(--text-dim);
  font-size:0.9rem; text-align:center;
}

/* ---------- 스크롤 등장 ---------- */
.reveal{
  opacity:0; transform:translateY(16px);
  transition:opacity .6s ease, transform .6s ease;
  will-change:opacity, transform;
}
.reveal.in-view{ opacity:1; transform:none; }

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  .reveal{ opacity:1; transform:none; transition:none; }
  *{ transition:none !important; }
}

/* ---------- 라이트박스 ---------- */
.lightbox{
  position:fixed; inset:0; z-index:100;
  display:flex; align-items:center; justify-content:center;
  background:rgba(0,0,0,.92); padding:2rem;
}
.lightbox[hidden]{ display:none; }
.lightbox-img{
  max-width:96vw; max-height:90vh; width:auto; height:auto;
  object-fit:contain; border-radius:8px;
  box-shadow:0 20px 60px rgba(0,0,0,.6);
}
.lightbox-close{
  position:fixed; top:1rem; right:1.2rem;
  width:2.6rem; height:2.6rem; border-radius:50%;
  border:1px solid rgba(255,255,255,.3);
  background:rgba(0,0,0,.5); color:#fff;
  font-size:1.6rem; line-height:1; cursor:pointer;
}
.lightbox-close:hover{ background:rgba(0,0,0,.8); }
.lightbox-close:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }

/* 일반 포커스 가시성 */
:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }