/* ==========================================================================
   NatureFractal — Design Tokens & Base
   다크 퍼스트 엔지니어링 톤: 낮은 채도 · 1px 정밀선 · 모노스페이스 메타 ·
   절제된 단일 액센트 · 짧고 정확한 모션
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Fonts — Pretendard(본문) / JetBrains Mono 대체는 시스템 모노
   @font-face 선언은 /static/fonts/pretendard-variable.css 에 있습니다.
   -------------------------------------------------------------------------- */

/* --------------------------------------------------------------------------
   2. Tokens — 기본값은 다크
   -------------------------------------------------------------------------- */
:root {
  color-scheme: dark;

  /* --- Surface --- */
  --nf-bg:            #08080b;   /* 페이지 바닥 */
  --nf-bg-subtle:     #0b0b0f;   /* 교차 섹션 */
  --nf-bg-elevated:   #101014;   /* 카드 */
  --nf-bg-raised:     #16161c;   /* 카드 위 요소 */
  --nf-bg-inset:      #050507;   /* 코드/콘솔 */
  --nf-bg-inverse:    #ffffff;

  /* --- Ink --- */
  --nf-ink:           #e8e8ec;
  --nf-ink-strong:    #ffffff;
  --nf-ink-muted:     #a5a5b0;
  --nf-ink-subtle:    #7e7e8a;
  --nf-ink-faint:     #63636e;
  --nf-ink-inverse:   #08080b;

  /* --- Line (1px 정밀선) --- */
  --nf-line:          rgba(255, 255, 255, .07);
  --nf-line-strong:   rgba(255, 255, 255, .13);
  --nf-line-bright:   rgba(255, 255, 255, .22);

  /* --- Accent (단 하나. 남용 금지) --- */
  --nf-accent:        #6e79f0;
  --nf-accent-hi:     #8b93ff;
  --nf-accent-dim:    #4d56c4;
  --nf-accent-soft:   rgba(110, 121, 240, .13);
  --nf-accent-line:   rgba(110, 121, 240, .32);

  /* --- Signal (데이터 표현 전용) --- */
  --nf-sig-good:      #3ecf8e;
  --nf-sig-warn:      #e0a944;
  --nf-sig-bad:       #f16a70;
  --nf-sig-info:      #4cc4e0;
  --nf-sig-alt:       #b18cf0;

  /* --- Effects --- */
  --nf-glow:          radial-gradient(60% 60% at 50% 0%, rgba(110,121,240,.14), transparent 70%);
  --nf-hairline:      inset 0 1px 0 rgba(255, 255, 255, .05);
  --nf-shadow-sm:     0 1px 2px rgba(0,0,0,.6);
  --nf-shadow-md:     0 4px 16px -4px rgba(0,0,0,.7);
  --nf-shadow-lg:     0 16px 48px -12px rgba(0,0,0,.8);

  /* --- Radius (엔지니어링 톤: 작고 일관되게) --- */
  --nf-r-xs:  4px;
  --nf-r-sm:  6px;
  --nf-r-md:  10px;
  --nf-r-lg:  14px;
  --nf-r-xl:  18px;
  --nf-r-pill: 999px;

  /* --- Motion (짧고 정확하게) --- */
  --nf-ease:      cubic-bezier(.32, .72, 0, 1);
  --nf-ease-out:  cubic-bezier(.25, .46, .45, .94);
  --nf-dur-fast:  .12s;
  --nf-dur:       .22s;
  --nf-dur-slow:  .45s;

  /* --- Layout --- */
  --nf-container:        1180px;
  --nf-container-wide:   1400px;
  --nf-container-narrow: 720px;
  --nf-gutter:      clamp(20px, 4vw, 36px);
  --nf-nav-h:       56px;
  --nf-section-y:   clamp(64px, 8vw, 120px);

  /* --- Type scale --- */
  --nf-fs-display: clamp(2.4rem, 1.4rem + 3.6vw, 4.25rem);
  --nf-fs-h1:      clamp(2rem, 1.3rem + 2.9vw, 3.25rem);
  --nf-fs-h2:      clamp(1.6rem, 1.2rem + 1.9vw, 2.4rem);
  --nf-fs-h3:      clamp(1.2rem, 1.05rem + .7vw, 1.55rem);
  --nf-fs-h4:      1.0625rem;
  --nf-fs-lead:    clamp(1rem, .96rem + .3vw, 1.1875rem);
  --nf-fs-body:    .9688rem;
  --nf-fs-sm:      .875rem;
  --nf-fs-xs:      .8125rem;
  --nf-fs-mono:    .75rem;

  --nf-font: 'Pretendard Variable', Pretendard, -apple-system, BlinkMacSystemFont,
             'Apple SD Gothic Neo', 'Segoe UI', system-ui, 'Malgun Gothic', sans-serif;
  --nf-font-mono: ui-monospace, 'SF Mono', SFMono-Regular, 'JetBrains Mono',
                  'Cascadia Mono', Consolas, 'Liberation Mono', monospace;

  --nf-z-nav: 900;
  --nf-z-drawer: 950;
  --nf-z-modal: 1000;
  --nf-z-toast: 1100;
}

/* --------------------------------------------------------------------------
   3. 라이트 영역 — 관리자 화면, 인쇄, 일부 반전 섹션
   -------------------------------------------------------------------------- */
.nf-light,
[data-surface='light'] {
  color-scheme: light;
  --nf-bg:          #ffffff;
  --nf-bg-subtle:   #f7f7f8;
  --nf-bg-elevated: #ffffff;
  --nf-bg-raised:   #fafafb;
  --nf-bg-inset:    #0b0b0f;
  --nf-bg-inverse:  #08080b;
  --nf-ink:         #16161a;
  --nf-ink-strong:  #000000;
  --nf-ink-muted:   #5b5b64;
  --nf-ink-subtle:  #767680;
  --nf-ink-faint:   #91919b;
  --nf-ink-inverse: #ffffff;
  --nf-line:        rgba(0, 0, 0, .09);
  --nf-line-strong: rgba(0, 0, 0, .15);
  --nf-line-bright: rgba(0, 0, 0, .26);
  --nf-accent:      #4f57d4;
  --nf-accent-hi:   #3b43b8;
  --nf-accent-soft: rgba(79, 87, 212, .09);
  --nf-accent-line: rgba(79, 87, 212, .26);
  --nf-sig-good:    #10935f;
  --nf-sig-warn:    #a4720d;
  --nf-sig-bad:     #cc3c46;
  --nf-sig-info:    #1a7f96;
  --nf-hairline:    inset 0 1px 0 rgba(255, 255, 255, .8);
  --nf-shadow-sm:   0 1px 2px rgba(0,0,0,.05);
  --nf-shadow-md:   0 4px 16px -4px rgba(0,0,0,.10);
  --nf-shadow-lg:   0 16px 48px -12px rgba(0,0,0,.14);
  color: var(--nf-ink);
  background-color: var(--nf-bg);
}

/* --------------------------------------------------------------------------
   4. Reset
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nf-nav-h) + 24px);
  background: var(--nf-bg);
}

body {
  margin: 0;
  font-family: var(--nf-font);
  font-size: var(--nf-fs-body);
  line-height: 1.68;
  color: var(--nf-ink);
  background-color: var(--nf-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: 'ss01', 'cv01';
  overflow-x: hidden;
  word-break: keep-all;
  overflow-wrap: break-word;
}

body.nf-no-scroll { overflow: hidden; }

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -.022em;
  color: var(--nf-ink-strong);
  text-wrap: balance;
}
h1 { font-size: var(--nf-fs-h1); font-weight: 650; letter-spacing: -.03em; }
h2 { font-size: var(--nf-fs-h2); font-weight: 620; letter-spacing: -.028em; }
h3 { font-size: var(--nf-fs-h3); }
h4 { font-size: var(--nf-fs-h4); }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: inherit; text-decoration: none; transition: color var(--nf-dur-fast) var(--nf-ease-out); }

img, svg, video, canvas { max-width: 100%; height: auto; display: block; }
ul, ol { margin: 0; padding: 0; list-style: none; }

button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; padding: 0; }

hr { border: 0; border-top: 1px solid var(--nf-line); margin: 2rem 0; }

code, pre, kbd, samp { font-family: var(--nf-font-mono); font-size: .9em; }

::selection { background: rgba(110, 121, 240, .3); color: #fff; }

:focus-visible {
  outline: 1px solid var(--nf-accent);
  outline-offset: 2px;
  border-radius: 3px;
}

/* 스크롤바 */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--nf-line-strong) transparent;
}
*::-webkit-scrollbar { width: 10px; height: 10px; }
*::-webkit-scrollbar-track { background: transparent; }
*::-webkit-scrollbar-thumb {
  background: var(--nf-line-strong);
  border-radius: 999px;
  border: 3px solid transparent;
  background-clip: content-box;
}
*::-webkit-scrollbar-thumb:hover { background: var(--nf-line-bright); background-clip: content-box; }

/* --------------------------------------------------------------------------
   5. Layout primitives
   -------------------------------------------------------------------------- */
.nf-container {
  width: 100%;
  max-width: var(--nf-container);
  margin-inline: auto;
  padding-inline: var(--nf-gutter);
}
.nf-container--wide   { max-width: var(--nf-container-wide); }
.nf-container--narrow { max-width: var(--nf-container-narrow); }

.nf-section { padding-block: var(--nf-section-y); position: relative; }
.nf-section--tight { padding-block: clamp(44px, 5vw, 72px); }
.nf-section--subtle { background: var(--nf-bg-subtle); }

/* 섹션 경계 1px 선 — 엔지니어링 톤의 핵심 */
.nf-section--ruled { border-top: 1px solid var(--nf-line); }

.nf-grid { display: grid; gap: 1px; }
.nf-grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.nf-grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.nf-grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.nf-grid--gap { gap: clamp(14px, 1.6vw, 20px); }
.nf-grid--auto { grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr)); }

.nf-stack { display: flex; flex-direction: column; gap: 1rem; }
.nf-row   { display: flex; align-items: center; gap: .75rem; flex-wrap: wrap; }
.nf-row--between { justify-content: space-between; }
.nf-row--center  { justify-content: center; }

/* --------------------------------------------------------------------------
   6. Utilities
   -------------------------------------------------------------------------- */
.nf-center { text-align: center; }
.nf-measure { max-width: 64ch; }
.nf-measure--tight { max-width: 44ch; }
.nf-mx-auto { margin-inline: auto; }

.nf-muted   { color: var(--nf-ink-muted); }
.nf-subtle  { color: var(--nf-ink-subtle); }
.nf-lead    { font-size: var(--nf-fs-lead); line-height: 1.6; color: var(--nf-ink-muted); }
.nf-small   { font-size: var(--nf-fs-sm); }

/* 모노스페이스 메타 — 이 사이트의 시그니처 */
.nf-mono {
  font-family: var(--nf-font-mono);
  font-size: var(--nf-fs-mono);
  letter-spacing: .06em;
  text-transform: uppercase;
  font-variant-numeric: tabular-nums;
  color: var(--nf-ink-subtle);
}
.nf-mono--accent { color: var(--nf-accent); }
.nf-num { font-variant-numeric: tabular-nums; font-feature-settings: 'tnum'; }

.nf-sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap; border: 0;
}

.nf-skip-link {
  position: absolute; top: -100px; left: 16px; z-index: var(--nf-z-toast);
  background: var(--nf-accent); color: #fff; padding: 10px 18px;
  border-radius: var(--nf-r-sm); font-weight: 600; font-size: .875rem;
  transition: top var(--nf-dur) var(--nf-ease);
}
.nf-skip-link:focus { top: 12px; }

.nf-hide { display: none !important; }

/* --------------------------------------------------------------------------
   7. Scroll reveal — `.js` 아래에서만 숨김 (JS 없으면 그대로 보임)
   -------------------------------------------------------------------------- */
.js [data-reveal] {
  opacity: 0;
  transform: translate3d(0, 12px, 0);
  transition: opacity .5s var(--nf-ease), transform .5s var(--nf-ease);
  transition-delay: var(--reveal-delay, 0ms);
}
.js [data-reveal='fade'] { transform: none; }
.js [data-reveal].is-visible { opacity: 1; transform: none; }

/* --------------------------------------------------------------------------
   8. 배경 텍스처
   -------------------------------------------------------------------------- */
.nf-gridlines {
  position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(to right, var(--nf-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--nf-line) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, #000 10%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, #000 10%, transparent 75%);
}

.nf-glow-top {
  position: absolute; inset: 0 0 auto 0; height: 620px;
  background: var(--nf-glow);
  pointer-events: none;
}

/* 노이즈 (배너딩 방지 + 질감) */
.nf-noise::after {
  content: '';
  position: absolute; inset: 0;
  pointer-events: none;
  opacity: .028;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* --------------------------------------------------------------------------
   9. 접근성 · 인쇄
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
}

@media print {
  :root { color-scheme: light; }
  .nf-nav, .nf-footer, .nf-cta, .nf-drawer, .nf-scroll-cue { display: none !important; }
  body { color: #000; background: #fff; }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
  a[href^='http']::after { content: ' (' attr(href) ')'; font-size: .75em; }
}