:root {
  --ink: #f5f1e8;
  --muted: #aaa9b5;
  --dim: #747485;
  --void: #09090e;
  --panel: #111119;
  --panel-2: #171721;
  --line: rgba(255, 255, 255, 0.12);
  --line-strong: rgba(255, 255, 255, 0.22);
  --electric: #9fa9ff;
  --cyan: #79d9df;
  --acid: #c8ef83;
  --gold: #f0c674;
  --rose: #f29aa4;
  --serif: Georgia, "Times New Roman", "Noto Serif KR", "Noto Serif KR", "Nanum Myeongjo", AppleMyungjo, Batang, serif;
  --sans: Inter, "Pretendard Variable", Pretendard, "Noto Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --shell: min(1220px, calc(100vw - 64px));
  --radius: 22px;
}

/* 버튼·입력창은 body 글꼴을 물려받지 않는다(브라우저 기본 글꼴을 쓴다).
   이것 때문에 목차·설정 버튼만 시스템 글꼴로 그려지고 있었다 — 실측으로 잡았다. */
button, input, select, textarea { font-family: inherit; }
* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--void); }
body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 84% 6%, rgba(92, 104, 220, 0.16), transparent 25rem),
    radial-gradient(circle at 12% 36%, rgba(73, 151, 157, 0.08), transparent 25rem),
    var(--void);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.65;
  word-break: keep-all;
  overflow-x: hidden;
}

body.dialog-open { overflow: hidden; }
button, input, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; text-decoration-color: rgba(159, 169, 255, 0.55); text-underline-offset: 4px; }
button { color: inherit; }
img, svg { display: block; max-width: 100%; }
::selection { background: var(--electric); color: #09090e; }

:focus-visible {
  outline: 3px solid var(--acid);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 10px;
  left: 10px;
  padding: 10px 14px;
  background: var(--acid);
  color: #09090e;
  transform: translateY(-160%);
}
.skip-link:focus { transform: none; }

.reading-progress {
  position: fixed;
  z-index: 120;
  inset: 0 0 auto;
  height: 3px;
  background: transparent;
}
.reading-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--electric), var(--cyan), var(--acid));
}

.site-header {
  position: fixed;
  z-index: 100;
  inset: 3px 0 auto;
  height: 68px;
  border-bottom: 1px solid transparent;
  transition: background 180ms ease, border-color 180ms ease, backdrop-filter 180ms ease;
}
.site-header.scrolled {
  background: rgba(9, 9, 14, 0.82);
  border-color: var(--line);
  backdrop-filter: blur(18px);
}
.header-inner {
  width: var(--shell);
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}
.brand-mark {
  position: relative;
  width: 28px;
  height: 28px;
  border: 1px solid var(--electric);
  border-radius: 50%;
}
.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 6px -5px;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  transform: rotate(55deg);
}
.brand-mark::after { transform: rotate(-55deg); }
.brand strong { font: 700 14px/1 var(--mono); letter-spacing: 0.18em; }
.brand small { display: block; margin-top: 5px; color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .12em; }
.primary-nav { display: flex; align-items: center; gap: 26px; }
.primary-nav a {
  position: relative;
  color: var(--muted);
  font-size: 14.5px;
  text-decoration: none;
}
.primary-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: -8px;
  height: 1px;
  background: var(--acid);
  transition: right 160ms ease;
}
.primary-nav a:hover, .primary-nav a.active { color: var(--ink); }
.primary-nav a.active::after { right: 0; }
.home-link { color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .08em; text-decoration: none; }
.mobile-menu { display: none; width: 42px; height: 42px; border: 1px solid var(--line); border-radius: 50%; background: transparent; }
.mobile-menu span { display: block; width: 16px; height: 1px; margin: 5px auto; background: var(--ink); }
.mobile-nav {
  position: fixed;
  z-index: 95;
  inset: 71px 16px auto;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(17, 17, 25, .98);
}
.mobile-nav a { display: block; padding: 12px; text-decoration: none; border-bottom: 1px solid var(--line); }
.mobile-nav a:last-child { border: 0; }

.section-shell { width: var(--shell); margin-inline: auto; }
.section-anchor { scroll-margin-top: 92px; }
.section { padding: 118px 0; }
.section + .section { border-top: 1px solid var(--line); }
.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(240px, .55fr);
  gap: 80px;
  align-items: end;
  margin-bottom: 48px;
}
.section-heading h2 {
  margin: 12px 0 0;
  font: 400 clamp(36px, 5vw, 70px)/1.04 var(--serif);
  letter-spacing: -.045em;
}
.section-heading h2 em { color: var(--electric); font-weight: 400; }
.section-heading > p { margin: 0; color: var(--muted); font-size: 15px; }
.kicker, .section-number {
  margin: 0;
  color: var(--acid);
  font: 700 14px/1.2 var(--mono);
  letter-spacing: .17em;
  text-transform: uppercase;
}
.section-number { color: var(--dim); margin-bottom: 18px; }

.hero {
  min-height: 100svh;
  padding: 126px 0 72px;
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--line);
}
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(380px, .95fr);
  gap: clamp(46px, 8vw, 120px);
  align-items: center;
}
.hero-copy .kicker { color: var(--cyan); }
.hero-copy h1 {
  margin: 22px 0 24px;
  max-width: 760px;
  font: 400 clamp(62px, 9vw, 130px)/.82 var(--serif);
  letter-spacing: -.075em;
}
.hero-copy h1 span { display: block; }
.hero-copy h1 em {
  display: block;
  color: var(--electric);
  font-size: .42em;
  line-height: 1.25;
  letter-spacing: -.04em;
  font-weight: 400;
  margin: 18px 0 0 7px;
}
.hero-lead { max-width: 680px; margin: 0; color: #d2d0d4; font-size: clamp(17px, 2vw, 21px); line-height: 1.75; }
.hero-lead strong { color: var(--acid); font-weight: 600; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.button-primary, .button-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 19px;
  border: 1px solid var(--electric);
  border-radius: 999px;
  background: var(--electric);
  color: #09090e;
  font-size: 14.5px;
  font-weight: 700;
  text-decoration: none;
}
.button-ghost { background: transparent; border-color: var(--line-strong); color: var(--ink); }
.hero-meta { display: flex; flex-wrap: wrap; gap: 22px; margin-top: 40px; }
.hero-meta div { padding-left: 14px; border-left: 1px solid var(--line-strong); }
.hero-meta strong { display: block; font: 500 25px/1 var(--serif); }
.hero-meta span { color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .09em; }

.dirac-visual {
  position: relative;
  aspect-ratio: .82;
  max-height: 680px;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  border-radius: 50% 50% 22px 22px;
  background:
    linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px),
    radial-gradient(circle at 50% 35%, rgba(159,169,255,.22), transparent 32%),
    #0e0e16;
  background-size: 32px 32px, 32px 32px, auto, auto;
  isolation: isolate;
}
.dirac-visual::before {
  content: "";
  position: absolute;
  inset: 9%;
  border: 1px solid rgba(121,217,223,.32);
  border-radius: 50%;
  transform: rotate(-14deg);
}
.dirac-visual::after {
  content: "";
  position: absolute;
  inset: 20% 6%;
  border: 1px solid rgba(200,239,131,.22);
  border-radius: 50%;
  transform: rotate(52deg);
}
.visual-year { position: absolute; top: 10%; left: 10%; color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .15em; }
.visual-monogram {
  position: absolute;
  z-index: 2;
  inset: 20% 0 auto;
  text-align: center;
  font: 400 clamp(150px, 22vw, 330px)/1 var(--serif);
  color: rgba(245, 241, 232, .92);
  text-shadow: 0 0 80px rgba(159,169,255,.25);
}
.visual-equation {
  position: absolute;
  z-index: 3;
  left: 7%;
  right: 7%;
  bottom: 9%;
  padding: 18px 18px 16px;
  border: 1px solid var(--line-strong);
  background: rgba(9,9,14,.76);
  backdrop-filter: blur(10px);
  font: 14px/1.4 var(--mono);
  text-align: center;
}
.visual-equation small { display: block; margin-top: 8px; color: var(--dim); font-size: 14px; letter-spacing: .16em; }
.particle { position: absolute; z-index: 4; width: 9px; height: 9px; border-radius: 50%; background: var(--acid); box-shadow: 0 0 18px var(--acid); animation: orbit 9s linear infinite; }
.particle-a { top: 30%; left: 10%; }
.particle-b { top: 11%; right: 23%; background: var(--cyan); box-shadow: 0 0 18px var(--cyan); animation-duration: 13s; animation-direction: reverse; }
@keyframes orbit { to { transform: rotate(360deg) translateX(16px) rotate(-360deg); } }

.premise { padding: 74px 0; border-bottom: 1px solid var(--line); }
.premise-grid { display: grid; grid-template-columns: .45fr 1.55fr; gap: 80px; align-items: start; }
.premise h2 { margin: 0; font: 400 clamp(30px, 4vw, 52px)/1.1 var(--serif); letter-spacing: -.035em; }
.premise-copy { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.premise-copy p { margin: 0; color: var(--muted); }
.premise-copy strong { color: var(--ink); }

.ledger { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.ledger-item { min-height: 190px; padding: 24px; border-right: 1px solid var(--line); }
.ledger-item:last-child { border: 0; }
.ledger-top { display: flex; align-items: center; justify-content: space-between; }
.ledger-dot { width: 8px; height: 8px; border-radius: 50%; background: currentColor; box-shadow: 0 0 15px currentColor; }
.ledger-count { font: 400 42px/1 var(--serif); }
.ledger-item h3 { margin: 34px 0 8px; font-size: 15px; }
.ledger-item p { margin: 0; color: var(--muted); font-size: 14px; }
.status-core { --status: var(--cyan); color: var(--cyan); }
.status-confirmed { --status: var(--acid); color: var(--acid); }
.status-completed { --status: var(--gold); color: var(--gold); }
.status-open { --status: var(--rose); color: var(--rose); }

.explorer-controls { display: flex; flex-wrap: wrap; gap: 10px; margin: 26px 0 30px; }
.filter-chip {
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font-size: 14px;
  cursor: pointer;
}
.filter-chip:hover { border-color: var(--line-strong); color: var(--ink); }
.filter-chip[aria-pressed="true"] { border-color: currentColor; background: rgba(255,255,255,.06); color: var(--ink); }
.filter-chip i { display: inline-block; width: 7px; height: 7px; margin-right: 8px; border-radius: 50%; background: var(--status, var(--electric)); }

.achievement-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.achievement-card {
  position: relative;
  min-height: 356px;
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(145deg, rgba(255,255,255,.035), transparent 55%), var(--panel);
  color: var(--ink);
  text-align: left;
  cursor: pointer;
  /* 판정 색은 좌측 막대가 아니라 우하단 두께로 드러낸다. blur 0 의 단단한 면을
     두 겹 쌓아 카드가 실제로 두꺼워 보이게 하고, 올리면 두께가 깊어진다. */
  box-shadow: 5px 5px 0 color-mix(in srgb, var(--status), transparent 82%),
              10px 10px 0 color-mix(in srgb, var(--status), transparent 92%);
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease, box-shadow 180ms ease;
}
.achievement-card:hover {
  transform: translateY(-5px);
  border-color: color-mix(in srgb, var(--status), transparent 48%);
  background-color: #15151f;
  box-shadow: 7px 7px 0 color-mix(in srgb, var(--status), transparent 72%),
              14px 14px 0 color-mix(in srgb, var(--status), transparent 88%);
}
.card-top { display: flex; justify-content: space-between; gap: 18px; align-items: flex-start; }
.card-index { color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .14em; }
.status-pill { color: var(--status); font: 700 14px/1 var(--mono); letter-spacing: .1em; text-transform: uppercase; }
.card-equation { display: block; min-height: 48px; margin: 42px 0 28px; color: var(--status); font: 400 clamp(23px, 3vw, 38px)/1.2 var(--serif); letter-spacing: -.025em; }
.achievement-card h3 { margin: 0; max-width: 520px; font: 400 clamp(24px, 3vw, 36px)/1.12 var(--serif); letter-spacing: -.03em; }
.achievement-card p { margin: 15px 0 0; max-width: 570px; color: var(--muted); font-size: 14px; }
.card-bottom { position: absolute; left: 30px; right: 30px; bottom: 25px; display: flex; justify-content: space-between; color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .09em; }
.achievement-card[hidden] { display: none; }

.equation-lab { display: grid; grid-template-columns: 310px minmax(0, 1fr); min-height: 510px; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--panel); }
.equation-tabs { padding: 22px; border-right: 1px solid var(--line); background: #0d0d14; }
.equation-tab { display: block; width: 100%; padding: 19px 16px; border: 0; border-bottom: 1px solid var(--line); background: transparent; color: var(--muted); text-align: left; cursor: pointer; }
.equation-tab span { display: block; color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .12em; margin-bottom: 7px; }
.equation-tab strong { font-size: 14px; }
.equation-tab[aria-selected="true"] { color: var(--ink); background: linear-gradient(90deg, rgba(159,169,255,.12), transparent); }
.equation-stage { position: relative; padding: clamp(34px, 6vw, 80px); display: flex; flex-direction: column; justify-content: center; overflow: hidden; }
.equation-stage::after { content: "ψ"; position: absolute; right: -2%; bottom: -24%; color: rgba(255,255,255,.025); font: 400 400px/1 var(--serif); pointer-events: none; }
.equation-eyebrow { color: var(--acid); font: 700 14px/1 var(--mono); letter-spacing: .16em; }
.equation-formula { position: relative; z-index: 1; margin: 30px 0; color: var(--electric); font: 400 clamp(30px, 5vw, 64px)/1.18 var(--serif); letter-spacing: -.04em; overflow-wrap: anywhere; }
.equation-stage h3 { position: relative; z-index: 1; max-width: 700px; margin: 0; font: 400 clamp(27px, 4vw, 46px)/1.12 var(--serif); letter-spacing: -.035em; }
.equation-stage p { position: relative; z-index: 1; max-width: 700px; margin: 18px 0 24px; color: var(--muted); }
.equation-adds { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 8px; }
.equation-adds span { padding: 7px 10px; border: 1px solid var(--line); border-radius: 999px; color: #c6c5cb; font-size: 14px; }

.correction-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.correction-card { padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); }
.correction-card span { color: var(--rose); font: 700 14px/1 var(--mono); letter-spacing: .12em; }
.correction-card h3 { margin: 24px 0 12px; font: 400 28px/1.2 var(--serif); }
.correction-card p { margin: 0; color: var(--muted); font-size: 14px; }
.correction-card strong { color: var(--acid); font-weight: 600; }

.timeline-console { display: grid; grid-template-columns: 190px minmax(0, 1fr); gap: 45px; padding: 34px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); }
.timeline-readout strong { display: block; color: var(--electric); font: 400 70px/1 var(--serif); }
.timeline-readout span { color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .12em; }
.timeline-main input[type="range"] { width: 100%; accent-color: var(--electric); }
.timeline-scale { display: flex; justify-content: space-between; margin-top: 5px; color: var(--dim); font: 14px/1 var(--mono); }
.timeline-detail { min-height: 185px; margin-top: 28px; padding-top: 26px; border-top: 1px solid var(--line); }
.timeline-detail h3 { margin: 0 0 11px; font: 400 clamp(25px, 3.5vw, 40px)/1.15 var(--serif); }
.timeline-detail p { margin: 0; max-width: 740px; color: var(--muted); }
.ref-chips { display: flex; gap: 7px; margin-top: 20px; }
.ref-chip { padding: 5px 8px; border: 1px solid var(--line); border-radius: 999px; color: var(--acid); font: 14px/1 var(--mono); text-decoration: none; }
.timeline-events { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px; border-top: 1px solid var(--line); padding-top: 25px; }
.timeline-event { min-height: 74px; padding: 10px; border: 1px solid transparent; background: transparent; color: var(--dim); text-align: left; font-size: 14px; cursor: pointer; }
.timeline-event strong { display: block; margin-bottom: 5px; color: inherit; font: 600 14.5px/1 var(--mono); }
.timeline-event.active { color: var(--ink); border-color: var(--electric); background: rgba(159,169,255,.08); }

.quiz-shell { display: grid; grid-template-columns: .8fr 1.2fr; gap: 70px; align-items: start; }
.quiz-intro { position: sticky; top: 110px; }
.quiz-intro h2 { margin: 12px 0 20px; font: 400 clamp(38px, 5vw, 66px)/1.04 var(--serif); letter-spacing: -.045em; }
.quiz-intro p { color: var(--muted); }
.quiz-score { display: inline-flex; gap: 10px; align-items: baseline; margin-top: 22px; color: var(--dim); font: 14px/1 var(--mono); letter-spacing: .12em; }
.quiz-score strong { color: var(--acid); font: 400 34px/1 var(--serif); }
.quiz-list { display: grid; gap: 12px; }
.quiz-card { padding: 25px; border: 1px solid var(--line); border-radius: 18px; background: var(--panel); }
.quiz-card h3 { margin: 0 0 20px; font: 500 17px/1.55 var(--sans); }
.quiz-actions { display: flex; gap: 8px; }
.quiz-actions button { min-width: 92px; min-height: 38px; border: 1px solid var(--line-strong); border-radius: 999px; background: transparent; color: var(--muted); cursor: pointer; }
.quiz-actions button:hover { color: var(--ink); }
.quiz-card.answered .quiz-actions button { opacity: .45; }
.quiz-card.answered .quiz-actions button.correct-choice { opacity: 1; border-color: var(--acid); color: var(--acid); }
.quiz-feedback { margin: 17px 0 0; padding-top: 16px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14.5px; }
.quiz-feedback strong { color: var(--acid); }

.reference-controls { display: flex; justify-content: space-between; gap: 20px; margin-bottom: 26px; }
.reference-tabs { display: flex; flex-wrap: wrap; gap: 8px; }
.reference-tab { min-height: 39px; padding: 0 13px; border: 1px solid var(--line); border-radius: 999px; background: transparent; color: var(--muted); font-size: 14px; cursor: pointer; }
.reference-tab[aria-selected="true"] { color: var(--ink); border-color: var(--electric); }
.search-box { display: flex; align-items: center; min-width: 280px; border-bottom: 1px solid var(--line-strong); }
.search-box span { color: var(--dim); }
.search-box input { width: 100%; padding: 10px; border: 0; outline: 0; background: transparent; color: var(--ink); }
.search-box input::placeholder { color: var(--dim); }
.reference-list { border-top: 1px solid var(--line); }
.reference-item { display: grid; grid-template-columns: 55px 60px minmax(0, 1fr) 110px; gap: 18px; padding: 25px 0; border-bottom: 1px solid var(--line); align-items: start; }
.reference-id { color: var(--acid); font: 700 14px/1.4 var(--mono); }
.reference-year { color: var(--dim); font: 14px/1.4 var(--mono); }
/* 서지는 읽는 폭을 제한한다 — 1fr 로 두면 긴 제목이 900px 넘게 늘어나 눈이 줄을 놓친다 */
.reference-main { max-width: 68ch; }
.reference-main h3 { margin: 0 0 4px; font: 500 16.5px/1.4 var(--sans); }
.reference-main p { margin: 3px 0; color: var(--muted); font-size: 14px; }
.reference-main .detail { margin-top: 9px; color: var(--dim); }
.reference-meta { text-align: right; }
.reference-meta span { display: block; color: var(--dim); font: 14px/1.3 var(--mono); letter-spacing: .08em; }
/* DOI 는 밑줄 대신 테두리 알약으로 — 서지 줄이 밑줄로 지저분해지지 않는다 */
.reference-meta a {
  display: inline-flex; align-items: center; gap: 5px; margin-top: 12px; padding: 5px 11px;
  border: 1px solid var(--line-strong); border-radius: 999px;
  color: var(--electric); font: 700 14px/1 var(--mono); text-decoration: none;
  transition: border-color .15s, color .15s, background-color .15s;
}
.reference-meta a:hover, .reference-meta a:focus-visible {
  border-color: var(--electric); background: rgba(159,169,255,.10); outline: none;
}
/* 강조는 좌측 컬러 보더 대신 우하단 두께로. 흐린 그림자가 아니라 blur 0 의
   단단한 면을 두 겹 쌓아, 종이가 아래로 겹쳐 있는 듯한 입체감을 만든다. */
.source-policy {
  margin-top: 34px; padding: 24px 26px;
  border: 1px solid rgba(240,198,116,.30); border-radius: var(--radius);
  background: rgba(240,198,116,.05);
  box-shadow: 5px 5px 0 rgba(240,198,116,.16), 10px 10px 0 rgba(240,198,116,.07);
}
.source-policy h3 { margin: 0 0 10px; color: var(--gold); font: 400 24px/1.2 var(--serif); }
.source-policy p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* 스크롤바 — 기본 회색 막대가 어두운 화면에 그대로 얹히면 페이지가 싸구려로 보인다.
   폭은 항상 확보(scrollbar-gutter)해 스크롤 유무로 레이아웃이 흔들리지 않게 한다. */
html { scrollbar-gutter: stable; scrollbar-width: thin; scrollbar-color: var(--line-strong) transparent; }
::-webkit-scrollbar { width: 12px; height: 12px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  border: 3px solid transparent; border-radius: 999px;
  background: var(--line-strong); background-clip: padding-box;
}
::-webkit-scrollbar-thumb:hover { background: var(--electric); background-clip: padding-box; }
::-webkit-scrollbar-corner { background: transparent; }
.dialog-frame { scrollbar-width: thin; scrollbar-color: var(--line-strong) transparent; }

.primary-nav a.nav-book { display: inline-flex; align-items: center; gap: 6px; color: var(--gold); }
.primary-nav a.nav-book svg, .button-ghost svg { width: 16px; height: 16px; flex: 0 0 auto; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.button-ghost { display: inline-flex; align-items: center; gap: 8px; }

.site-footer { padding: 50px 0; border-top: 1px solid var(--line); }
.footer-inner { width: var(--shell); margin: auto; display: flex; justify-content: space-between; gap: 30px; align-items: flex-end; }
.footer-inner strong { display: block; font: 400 25px/1.2 var(--serif); }
.footer-inner p { margin: 10px 0 0; color: var(--dim); font-size: 14px; }
.footer-inner > a { color: var(--muted); font: 14px/1 var(--mono); letter-spacing: .12em; }

.achievement-dialog { width: min(980px, calc(100vw - 36px)); max-height: calc(100svh - 30px); padding: 0; border: 1px solid var(--line-strong); border-radius: 24px; background: var(--panel); color: var(--ink); overflow: hidden; }
.achievement-dialog::backdrop { background: rgba(0,0,0,.78); backdrop-filter: blur(8px); }
.dialog-frame { position: relative; max-height: calc(100svh - 30px); overflow-y: auto; }
.dialog-close { position: sticky; z-index: 4; float: right; top: 18px; right: 18px; display: inline-flex; align-items: center; justify-content: center; width: 44px; height: 44px; margin: 18px 18px -62px 0; border: 1px solid var(--line-strong); border-radius: 50%; background: rgba(9,9,14,.78); color: var(--ink); cursor: pointer; }
/* 아이콘은 인라인 SVG 만 — 이모지·기호 글자는 OS 마다 모양·기준선이 달라 정렬이 깨진다 */
.dialog-close svg, .dialog-source a svg { width: 18px; height: 18px; display: block; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.dialog-source a { display: inline-flex; align-items: center; justify-content: center; }
.dialog-hero { position: relative; min-height: 330px; padding: clamp(38px, 7vw, 72px); overflow: hidden; border-bottom: 1px solid var(--line); background: radial-gradient(circle at 80% 20%, color-mix(in srgb, var(--status), transparent 78%), transparent 34%), #0d0d14; }
.dialog-hero::after { content: attr(data-number); position: absolute; right: 5%; bottom: -20%; color: rgba(255,255,255,.035); font: 400 250px/1 var(--serif); }
.dialog-meta { position: relative; z-index: 1; color: var(--status); font: 700 14px/1 var(--mono); letter-spacing: .12em; }
.dialog-equation { position: relative; z-index: 1; margin: 36px 0 18px; color: var(--status); font: 400 clamp(32px, 6vw, 66px)/1.1 var(--serif); letter-spacing: -.045em; }
.dialog-hero h2 { position: relative; z-index: 1; max-width: 700px; margin: 0; font: 400 clamp(34px, 5vw, 58px)/1.06 var(--serif); letter-spacing: -.045em; }
.dialog-thesis { position: relative; z-index: 1; max-width: 740px; margin: 20px 0 0; color: var(--muted); }
.dialog-body { padding: clamp(28px, 6vw, 64px); }
.analysis-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.analysis-block { min-height: 230px; padding: 25px; border: 1px solid var(--line); border-radius: 16px; background: #0f0f17; }
.analysis-block span { color: var(--dim); font: 700 14px/1 var(--mono); letter-spacing: .12em; }
.analysis-block h3 { margin: 18px 0 10px; font: 400 24px/1.2 var(--serif); }
.analysis-block p { margin: 0; color: var(--muted); font-size: 14.5px; }
.analysis-block:last-child { grid-column: 1 / -1; min-height: 190px; }
.dialog-verdict { margin-top: 15px; padding: 26px; border: 1px solid color-mix(in srgb, var(--status), transparent 55%); border-radius: 16px; background: color-mix(in srgb, var(--status), transparent 94%); }
.dialog-verdict span { color: var(--status); font: 700 14px/1 var(--mono); letter-spacing: .12em; }
.dialog-verdict p { margin: 10px 0 0; font: 400 22px/1.4 var(--serif); }
.dialog-sources { margin-top: 30px; }
.dialog-sources h3 { font: 400 25px/1.2 var(--serif); }
.dialog-source { display: grid; grid-template-columns: 44px minmax(0,1fr) 28px; gap: 15px; padding: 15px 0; border-top: 1px solid var(--line); align-items: start; }
.dialog-source strong { color: var(--acid); font: 700 14px/1.3 var(--mono); }
.dialog-source h4 { margin: 0; font-size: 14.5px; }
.dialog-source p { margin: 4px 0 0; color: var(--dim); font-size: 14px; }
.dialog-source a { color: var(--electric); text-decoration: none; }
.dialog-nav { display: grid; grid-template-columns: 1fr 1fr; margin-top: 28px; border-top: 1px solid var(--line); }
.dialog-nav button { min-height: 80px; padding: 16px; border: 0; border-right: 1px solid var(--line); background: transparent; color: var(--muted); cursor: pointer; }
.dialog-nav button:last-child { border: 0; text-align: right; }
.dialog-nav button:hover { color: var(--ink); background: rgba(255,255,255,.025); }

.reveal { opacity: 0; transform: translateY(22px); transition: opacity 600ms ease, transform 600ms ease; }
.reveal.visible { opacity: 1; transform: none; }
.noscript { margin: 90px auto 20px; width: var(--shell); padding: 18px; border: 1px solid var(--rose); color: var(--ink); }
.empty-state { padding: 36px; color: var(--dim); text-align: center; }

@media (max-width: 980px) {
  :root { --shell: min(100% - 36px, 780px); }
  .primary-nav, .home-link { display: none; }
  .mobile-menu { display: block; }
  .hero { min-height: auto; padding-top: 130px; }
  .hero-grid { grid-template-columns: 1fr; }
  .hero-copy h1 { font-size: clamp(72px, 18vw, 120px); }
  .dirac-visual { width: min(540px, 100%); justify-self: center; }
  .premise-grid, .section-heading { grid-template-columns: 1fr; gap: 30px; }
  .ledger { grid-template-columns: repeat(2, 1fr); }
  .ledger-item:nth-child(2) { border-right: 0; }
  .ledger-item:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .equation-lab { grid-template-columns: 1fr; }
  .equation-tabs { display: grid; grid-template-columns: repeat(3, 1fr); padding: 10px; border: 0; border-bottom: 1px solid var(--line); }
  .equation-tab { border: 0; border-right: 1px solid var(--line); }
  .equation-tab:last-child { border: 0; }
  .timeline-events { grid-template-columns: repeat(4, 1fr); }
  .quiz-shell { grid-template-columns: 1fr; gap: 36px; }
  .quiz-intro { position: static; }
}

@media (max-width: 700px) {
  :root { --shell: calc(100% - 28px); }
  .section { padding: 82px 0; }
  .header-inner { gap: 10px; }
  .brand small { display: none; }
  .hero { padding-bottom: 54px; }
  .hero-copy h1 { font-size: clamp(62px, 21vw, 90px); }
  .hero-lead { font-size: 16px; }
  .hero-meta { gap: 14px; }
  .hero-meta strong { font-size: 21px; }
  .dirac-visual { aspect-ratio: .9; }
  .premise { padding: 58px 0; }
  .premise-copy { grid-template-columns: 1fr; }
  .section-heading h2 { font-size: 42px; }
  .ledger { grid-template-columns: 1fr; }
  .ledger-item, .ledger-item:nth-child(2) { min-height: 150px; border: 0; border-bottom: 1px solid var(--line); }
  .ledger-item:last-child { border-bottom: 0; }
  .ledger-item h3 { margin-top: 22px; }
  .achievement-grid { grid-template-columns: 1fr; }
  .achievement-card { min-height: 338px; padding: 24px; }
  .card-bottom { left: 24px; right: 24px; }
  .equation-tabs { grid-template-columns: 1fr; }
  .equation-tab { border: 0; border-bottom: 1px solid var(--line); padding: 14px; }
  .equation-stage { min-height: 430px; padding: 28px 22px; }
  .correction-grid { grid-template-columns: 1fr; }
  .timeline-console { grid-template-columns: 1fr; gap: 24px; padding: 22px; }
  .timeline-readout strong { font-size: 54px; }
  .timeline-events { grid-template-columns: repeat(2, 1fr); }
  .reference-controls { flex-direction: column; }
  .search-box { min-width: 0; width: 100%; }
  .reference-item { grid-template-columns: 42px 1fr; gap: 10px; }
  .reference-year { text-align: right; }
  .reference-main, .reference-meta { grid-column: 1 / -1; text-align: left; padding-left: 52px; }
  .analysis-grid { grid-template-columns: 1fr; }
  .dialog-hero { min-height: 360px; }
  .dialog-body { padding: 24px 18px; }
  .dialog-nav button { font-size: 14px; }
  .footer-inner { display: block; }
  .footer-inner > a { display: inline-block; margin-top: 24px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  .reveal { opacity: 1; transform: none; }
}

@media print {
  body { background: white; color: #111; }
  .site-header, .reading-progress, .hero-actions, .explorer-controls, .quiz, .dialog-close { display: none !important; }
  .hero { min-height: 0; padding-top: 30px; }
  .dirac-visual { max-height: 400px; border-color: #999; }
  .section { padding: 45px 0; }
  .achievement-grid { grid-template-columns: 1fr; }
  .achievement-card, .correction-card, .equation-lab, .timeline-console { break-inside: avoid; border-color: #bbb; background: white; color: #111; }
  .achievement-card p, .section-heading > p, .premise-copy p { color: #444; }
}