:root {
  color-scheme: dark;
  --ink: #f1f4f8;
  --muted: #aab3c2;
  --dim: #7f8999;
  --line: rgba(255,255,255,.13);
  --surface: #162235;
  --canvas: #0c1422;
  --deep: #08101c;
  --cyan: #75e2d3;
  --cyan-soft: rgba(117,226,211,.12);
  --amber: #ffc66d;
  --serif: Georgia, "Noto Serif KR", "Nanum Myeongjo", serif;
  --sans: Inter, Pretendard, "Noto Sans KR", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--canvas); font-family: var(--sans); line-height: 1.65; }
a { color: inherit; }
.skip-link { position: fixed; top: -60px; left: 16px; z-index: 99; padding: 10px 16px; background: white; color: #111; }
.skip-link:focus { top: 12px; }
.site-header { position: absolute; inset: 0 0 auto; z-index: 10; display: flex; align-items: center; justify-content: space-between; width: min(1240px, calc(100% - 48px)); margin: auto; padding: 24px 0; border-bottom: 1px solid var(--line); }
.brand { font-size: 1.08rem; font-weight: 850; letter-spacing: -.02em; text-decoration: none; }
.brand span { color: var(--cyan); }
.site-header nav, .site-footer nav { display: flex; flex-wrap: wrap; gap: 24px; }
.site-header nav a, .site-footer nav a { color: var(--muted); font-size: .9rem; text-decoration: none; }
.site-header nav a:hover, .site-header nav a:focus-visible, .site-footer nav a:hover, .site-footer nav a:focus-visible { color: var(--cyan); }

.hero { position: relative; display: grid; grid-template-columns: minmax(0, 1.18fr) minmax(360px, .82fr); align-items: center; gap: clamp(40px, 5vw, 72px); min-height: 720px; padding: 132px max(24px, calc((100vw - 1240px) / 2)) 78px; overflow: hidden; background: radial-gradient(circle at 78% 32%, rgba(55,123,142,.22), transparent 31%), linear-gradient(145deg, #111d30 0%, #0a1320 72%); }
.hero::before { content: ""; position: absolute; inset: 0; opacity: .35; pointer-events: none; background-image: linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px); background-size: 48px 48px; mask-image: linear-gradient(to bottom, #000, transparent 92%); }
.hero-copy, .kernel-card { position: relative; z-index: 1; }
.kicker { margin: 0 0 16px; color: var(--cyan); font-size: .77rem; font-weight: 800; letter-spacing: .16em; text-transform: uppercase; }
h1, h2, h3, p { overflow-wrap: break-word; }
h1 { max-width: 780px; margin: 0; font-family: var(--serif); font-size: clamp(2.9rem, 4.35vw, 4.35rem); font-weight: 500; line-height: 1.12; letter-spacing: -.045em; text-wrap: balance; }
h1 em { color: var(--cyan); font-style: normal; }
.hero-lead { max-width: 700px; margin: 24px 0 0; color: #c2cad5; font-size: clamp(.96rem, 1.15vw, 1.08rem); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 11px 19px; border: 1px solid var(--line); border-radius: 4px; font-size: .92rem; font-weight: 800; text-decoration: none; transition: transform .2s, border-color .2s, background .2s; }
.button:hover { transform: translateY(-2px); }
.button.primary { border-color: var(--cyan); background: var(--cyan); color: #071411; }
.button.secondary { background: rgba(255,255,255,.035); }
.button.secondary:hover { border-color: var(--cyan); }
.hero-facts { display: flex; gap: 0; margin: 52px 0 0; }
.hero-facts div { min-width: 135px; padding: 0 24px; border-left: 1px solid var(--line); }
.hero-facts div:first-child { padding-left: 0; border: 0; }
.hero-facts dt { color: var(--ink); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 1rem; font-weight: 800; }
.hero-facts dd { margin: 3px 0 0; color: var(--dim); font-size: .78rem; }

.kernel-card { border: 1px solid rgba(117,226,211,.25); border-radius: 10px; background: rgba(5,12,21,.82); box-shadow: 0 30px 80px rgba(0,0,0,.35); transform: rotate(1deg); }
.terminal-bar { display: flex; align-items: center; gap: 7px; padding: 13px 16px; border-bottom: 1px solid var(--line); }
.terminal-bar span { width: 9px; height: 9px; border-radius: 50%; background: #415066; }
.terminal-bar span:first-child { background: #e27d73; }
.terminal-bar span:nth-child(2) { background: #e8b65c; }
.terminal-bar span:nth-child(3) { background: #6fc597; }
.terminal-bar b { margin-left: auto; color: var(--dim); font: 600 .7rem ui-monospace, monospace; }
.boot-log { padding: clamp(24px, 4vw, 44px); font: 600 clamp(.8rem, 1.2vw, .98rem)/1.5 ui-monospace, SFMono-Regular, Menlo, monospace; }
.boot-log p { margin: 0 0 15px; padding: 14px 16px; border: 1px solid var(--line); color: #c2cad5; }
.boot-log p span { margin-right: 14px; color: var(--dim); }
.boot-log p.active { border-color: rgba(117,226,211,.6); background: var(--cyan-soft); color: var(--cyan); }
.branch { display: flex; justify-content: space-around; height: 46px; margin: -15px 9% 0; border-top: 1px solid #435165; }
.branch i { width: 1px; height: 46px; background: #435165; }
.profiles { display: grid; grid-template-columns: repeat(4, 1fr); gap: 7px; }
.profiles b { padding: 12px 3px; border: 1px solid var(--line); color: var(--amber); font-size: clamp(.57rem, .82vw, .73rem); text-align: center; }
.boot-log .cursor { margin: 30px 0 0; padding: 0; border: 0; color: var(--dim); font-size: .7rem; }
.cursor mark { background: none; color: var(--cyan); animation: blink 1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }

.manifesto { display: grid; grid-template-columns: .48fr 1.62fr .9fr; gap: 46px; width: min(1240px, calc(100% - 48px)); margin: 0 auto; padding: 90px 0; border-bottom: 1px solid var(--line); }
.manifesto > p:first-child { color: var(--cyan); font-weight: 750; }
.manifesto h2, .section h2, .audience h2, .closing h2 { margin: 0; font-family: var(--serif); font-size: clamp(1.9rem, 3vw, 3rem); font-weight: 500; line-height: 1.2; letter-spacing: -.035em; text-wrap: balance; }
.manifesto > p:last-child { margin: 0; color: var(--muted); }
.section { width: min(1240px, calc(100% - 48px)); margin: 0 auto; padding: 92px 0; }
.section-heading { display: grid; grid-template-columns: 1.1fr .9fr; align-items: end; gap: 60px; margin-bottom: 50px; }
.section-heading > p { max-width: 500px; margin: 0 0 6px; color: var(--muted); }

.current-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.current-book { position: relative; min-height: 570px; padding: clamp(26px, 3.2vw, 42px); border: 1px solid var(--line); overflow: hidden; background: var(--surface); }
.current-book::after { content: attr(data-volume); position: absolute; right: -8px; bottom: -70px; color: rgba(255,255,255,.025); font: 800 16rem/1 var(--sans); }
.current-book.platform { background: linear-gradient(145deg, rgba(117,226,211,.07), transparent 55%), var(--surface); }
.book-topline { display: flex; align-items: center; justify-content: space-between; gap: 12px; color: var(--dim); font: 750 .72rem ui-monospace, monospace; letter-spacing: .06em; text-transform: uppercase; }
.status { padding: 5px 9px; border: 1px solid var(--line); border-radius: 99px; letter-spacing: 0; }
.status.complete { color: var(--cyan); }
.status.progress { color: var(--amber); }
.current-book h3 { margin: 48px 0 13px; font: 500 clamp(2rem, 3vw, 3.2rem)/1.1 var(--serif); letter-spacing: -.035em; text-wrap: balance; }
.book-subtitle { color: var(--cyan); font-weight: 750; }
.current-book > p:not(.book-subtitle) { color: var(--muted); }
.current-book ul { padding-left: 20px; color: #c5ccd7; }
.current-book li { margin: 7px 0; }
.sample-strip { position: absolute; right: clamp(26px, 4vw, 48px); bottom: clamp(26px, 4vw, 48px); left: clamp(26px, 4vw, 48px); padding-top: 18px; border-top: 1px solid var(--line); }
.sample-strip span { display: block; margin-bottom: 4px; color: var(--dim); font-size: .72rem; }
.sample-strip b { color: var(--ink); font-size: .83rem; }

.excerpt { display: grid; grid-template-columns: .32fr 1.68fr; gap: 48px; padding: 92px max(24px, calc((100vw - 1240px) / 2)); background: #e9e2d4; color: #172033; }
.excerpt-number { color: rgba(23,32,51,.14); font: 500 clamp(7rem, 16vw, 14rem)/.8 var(--serif); }
.excerpt .kicker { color: #346d67; }
.excerpt h2 { max-width: 980px; margin: 0; font: 500 clamp(1.9rem, 3vw, 3rem)/1.2 var(--serif); letter-spacing: -.035em; text-wrap: balance; }
blockquote { max-width: 900px; margin: 40px 0 24px; padding-left: 26px; border-left: 3px solid #397c74; font: 500 clamp(1.15rem, 2vw, 1.55rem)/1.75 var(--serif); }
.excerpt-note { max-width: 800px; color: #596170; font-size: .86rem; }

.series-section { padding-bottom: 120px; }
.series-list { margin: 0; padding: 0; border-top: 1px solid var(--line); list-style: none; }
.series-list li { display: grid; grid-template-columns: 90px 1fr 36px; gap: 24px; align-items: start; padding: 30px 12px; border-bottom: 1px solid var(--line); transition: background .2s, padding .2s; }
.series-list li:hover { padding-right: 22px; padding-left: 22px; background: rgba(255,255,255,.025); }
.series-list .volume { color: var(--dim); font: 500 2rem var(--serif); }
.series-list h3 { margin: 3px 0; font: 500 clamp(1.25rem, 1.9vw, 1.75rem) var(--serif); }
.series-list p { margin: 5px 0 0; color: var(--muted); }
.series-list .stage { color: var(--dim); font: 750 .7rem var(--sans); letter-spacing: .08em; text-transform: uppercase; }
.series-list .is-current .stage, .series-list .is-current .volume, .series-list .arrow { color: var(--cyan); }
.arrow { align-self: center; font-size: 1.3rem; }

.principles { border-top: 1px solid var(--line); }
.principle-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); }
.principle-grid article { min-height: 270px; padding: 30px; background: var(--canvas); }
.principle-grid span { color: var(--cyan); font: 700 .75rem ui-monospace, monospace; }
.principle-grid h3 { margin: 50px 0 10px; font: 500 1.5rem var(--serif); }
.principle-grid p { margin: 0; color: var(--muted); font-size: .9rem; }

.audience { display: grid; grid-template-columns: 1.15fr .85fr; gap: 68px; padding: 92px max(24px, calc((100vw - 1240px) / 2)); background: var(--deep); }
.audience ul { margin: 0; padding: 0; list-style: none; }
.audience li { display: grid; grid-template-columns: 95px 1fr; gap: 20px; padding: 22px 0; border-bottom: 1px solid var(--line); }
.audience li:first-child { border-top: 1px solid var(--line); }
.audience li b { color: var(--cyan); }
.audience li span { color: var(--muted); }
.closing { padding: 104px 24px; text-align: center; background: linear-gradient(160deg, rgba(117,226,211,.1), transparent 45%), #152136; }
.closing h2 { max-width: 900px; margin: auto; }
.closing > p:not(.kicker) { max-width: 640px; margin: 26px auto 0; color: var(--muted); }
.closing .hero-actions { justify-content: center; }
.site-footer { display: flex; justify-content: space-between; gap: 32px; padding: 46px max(24px, calc((100vw - 1240px) / 2)); background: #070d16; }
.site-footer p { margin: 7px 0 0; color: var(--dim); font-size: .78rem; }

@media (max-width: 1040px) {
  .hero { grid-template-columns: 1fr; min-height: auto; padding-top: 135px; }
  .kernel-card { width: min(620px, 100%); transform: none; }
  .manifesto { grid-template-columns: 1fr; gap: 20px; }
  .section-heading, .audience { grid-template-columns: 1fr; gap: 30px; }
  .principle-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .site-header { width: calc(100% - 32px); padding: 17px 0; }
  .site-header nav { max-width: 72%; gap: 14px; overflow-x: auto; flex-wrap: nowrap; white-space: nowrap; }
  .site-header nav a { font-size: .77rem; }
  .hero { gap: 36px; padding: 104px 16px 58px; }
  h1 { font-size: clamp(2.15rem, 10.5vw, 3rem); line-height: 1.16; }
  .hero-lead { margin-top: 18px; font-size: .94rem; }
  .hero-actions { margin-top: 25px; }
  .hero-facts { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 0; }
  .hero-facts div { min-width: 0; padding: 0 12px; }
  .hero-facts div:nth-child(3) { grid-column: 1 / -1; padding-left: 0; border: 0; }
  .profiles { grid-template-columns: 1fr 1fr; }
  .branch { display: none; }
  .boot-log p { padding: 11px; }
  .manifesto, .section { width: calc(100% - 32px); padding: 64px 0; }
  .manifesto h2, .section h2, .audience h2, .closing h2 { font-size: clamp(1.65rem, 8vw, 2.15rem); line-height: 1.25; }
  .current-grid { grid-template-columns: 1fr; }
  .current-book { min-height: 590px; padding: 24px; }
  .book-topline { align-items: flex-start; flex-direction: column; }
  .current-book h3 { margin-top: 34px; font-size: clamp(1.8rem, 9vw, 2.35rem); }
  .excerpt { grid-template-columns: 1fr; gap: 24px; padding: 64px 16px; }
  .excerpt-number { font-size: 7rem; }
  .series-list li { grid-template-columns: 52px 1fr; gap: 10px; padding: 26px 0; }
  .series-list .arrow { display: none; }
  .principle-grid { grid-template-columns: 1fr; }
  .principle-grid article { min-height: 220px; }
  .audience { padding: 64px 16px; }
  .audience li { grid-template-columns: 1fr; gap: 5px; }
  .site-footer { flex-direction: column; }
}

@media (max-width: 380px) {
  h1 { font-size: 2rem; }
  .button { width: 100%; }
  .hero-facts { grid-template-columns: 1fr; }
  .hero-facts div, .hero-facts div:nth-child(3) { grid-column: auto; padding: 0; border: 0; }
  .current-book { min-height: 620px; }
  .sample-strip { right: 24px; bottom: 24px; left: 24px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}