/* ===== GPU·CUDA 학습 노트 — "컴퓨트 계측기 / 블루프린트" 테마 ===== */
@import url('https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/static/pretendard.min.css');
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,400;0,500;0,700;1,400&display=swap');

:root {
  --bg: #0a0e14;
  --bg-elev: #11161f;
  --bg-elev2: #19202c;
  --border: #232c3a;
  --border-soft: #1a2230;
  --text: #e7eef6;
  --text-dim: #93a1b3;
  --text-faint: #6b7889;
  --accent: #76b900;        /* NVIDIA green */
  --accent-soft: #9ee03a;
  --accent-glow: rgba(118,185,0,.45);
  --accent-2: #58a6ff;
  --accent-warn: #f0883e;
  --accent-violet: #a371f7;
  --code-bg: #0c1117;
  --radius: 14px;
  --radius-sm: 9px;
  --maxw: 880px;
  --sidebar-w: 286px;
  --font: "Pretendard", -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Noto Sans KR", sans-serif;
  --mono: "JetBrains Mono", "SF Mono", "Fira Code", Consolas, monospace;
  --shadow: 0 18px 50px -12px rgba(0,0,0,.7);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 28px; }
body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.78;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  position: relative;
}
/* 블루프린트 그리드 + 상단 그린 글로우 배경 */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(900px 480px at 78% -8%, rgba(118,185,0,.10), transparent 60%),
    radial-gradient(760px 520px at 8% 4%, rgba(88,166,255,.07), transparent 55%);
}
body::after {
  content: "";
  position: fixed; inset: 0; z-index: -2; pointer-events: none; opacity: .5;
  background-image:
    linear-gradient(var(--border-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-soft) 1px, transparent 1px);
  background-size: 44px 44px;
  -webkit-mask-image: radial-gradient(circle at 50% 0%, #000 0%, transparent 78%);
  mask-image: radial-gradient(circle at 50% 0%, #000 0%, transparent 78%);
}

/* 상단 읽기 진행률 바 */
.reading-progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 12px var(--accent-glow);
  z-index: 100; transition: width .1s linear;
}

::selection { background: rgba(118,185,0,.28); color: #fff; }

/* ===== 레이아웃 ===== */
.layout { display: flex; min-height: 100vh; }

.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: linear-gradient(180deg, rgba(17,22,31,.96), rgba(10,14,20,.96));
  backdrop-filter: blur(8px);
  border-right: 1px solid var(--border);
  padding: 28px 18px 40px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
.sidebar::-webkit-scrollbar { width: 8px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 8px; }
.sidebar::-webkit-scrollbar-thumb:hover { background: #33404f; }

.sidebar .brand {
  display: flex; align-items: center; gap: 11px;
  font-weight: 800; font-size: 1.12rem; margin-bottom: 4px;
  text-decoration: none; color: var(--text); letter-spacing: -.01em;
}
.sidebar .brand .logo {
  width: 32px; height: 32px; border-radius: 9px;
  background: linear-gradient(135deg, var(--accent-soft), #4a7c00);
  display: grid; place-items: center; font-family: var(--mono);
  font-size: 1rem; color: #0a0e14; font-weight: 800;
  box-shadow: 0 0 0 1px rgba(118,185,0,.3), 0 4px 14px -4px var(--accent-glow);
}
.sidebar .tagline {
  color: var(--text-faint); font-size: .72rem; margin: 0 0 22px 2px;
  font-family: var(--mono); letter-spacing: .02em;
}

.nav-group { margin-bottom: 20px; }
.nav-group h4 {
  text-transform: uppercase; letter-spacing: .12em;
  font-size: .66rem; color: var(--text-faint); margin: 0 0 8px 8px; font-weight: 700;
  font-family: var(--mono);
}
.nav-group a {
  position: relative; display: block; padding: 7px 12px; border-radius: var(--radius-sm);
  color: var(--text-dim); text-decoration: none; font-size: .89rem;
  transition: background .16s, color .16s, padding .16s;
}
.nav-group a:hover { background: var(--bg-elev2); color: var(--text); }
.nav-group a.active {
  background: linear-gradient(90deg, rgba(118,185,0,.16), rgba(118,185,0,.04));
  color: var(--accent-soft); font-weight: 600;
}
.nav-group a.active::before {
  content: ""; position: absolute; left: -18px; top: 50%; transform: translateY(-50%);
  width: 3px; height: 20px; border-radius: 0 3px 3px 0;
  background: var(--accent); box-shadow: 0 0 10px var(--accent-glow);
}
.nav-group a.sub { padding-left: 26px; font-size: .82rem; }
.nav-group a.sub::after {
  content: ""; position: absolute; left: 14px; top: 50%; transform: translateY(-50%);
  width: 4px; height: 4px; border-radius: 50%; background: var(--border);
  transition: background .16s;
}
.nav-group a.sub:hover::after,
.nav-group a.sub.active::after { background: var(--accent); }

/* ===== 본문 ===== */
.content { flex: 1; padding: 52px 60px 120px; max-width: calc(var(--maxw) + 120px); }
.content-inner { max-width: var(--maxw); margin: 0 auto; animation: rise .5s ease both; }
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }

h1 {
  font-size: 2.2rem; line-height: 1.22; margin: 0 0 10px; font-weight: 800;
  letter-spacing: -.025em;
}
h2 {
  font-size: 1.5rem; margin: 56px 0 16px; padding-top: 26px;
  font-weight: 700; letter-spacing: -.015em; position: relative;
}
h2::before {
  content: ""; position: absolute; top: 0; left: 0; width: 100%; height: 1px;
  background: linear-gradient(90deg, var(--border) 0%, var(--border) 70%, transparent 100%);
}
h2::after {
  content: ""; position: absolute; top: 0; left: 0; width: 38px; height: 2px;
  background: var(--accent); box-shadow: 0 0 8px var(--accent-glow);
}
h2:first-of-type { margin-top: 36px; }
h3 { font-size: 1.16rem; margin: 34px 0 12px; font-weight: 700; color: #f3f8fe; letter-spacing: -.01em; }
p { margin: 14px 0; }
a { color: var(--accent-2); text-decoration-color: rgba(88,166,255,.4); text-underline-offset: 2px; }
a:hover { text-decoration-color: currentColor; }
strong { color: #fff; font-weight: 700; }
em { color: var(--accent-soft); font-style: normal; }
ul, ol { padding-left: 24px; }
li { margin: 8px 0; }
li::marker { color: var(--accent); }
.lead { font-size: 1.12rem; color: var(--text-dim); margin-bottom: 8px; line-height: 1.7; }

.breadcrumb {
  font-size: .76rem; color: var(--text-faint); margin-bottom: 18px;
  font-family: var(--mono); letter-spacing: .02em;
}
.breadcrumb a { color: var(--text-dim); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }

/* ===== 코드 ===== */
code {
  font-family: var(--mono); font-size: .82em;
  background: var(--bg-elev2); padding: 2px 6px; border-radius: 5px; color: #ffd9a0;
  border: 1px solid var(--border-soft);
}
pre {
  position: relative;
  background: var(--code-bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 40px 20px 18px; overflow-x: auto;
  font-size: .85rem; line-height: 1.65; margin: 20px 0;
  box-shadow: var(--shadow);
}
/* 터미널 창 상단 스트립 + 신호등 + CUDA 태그 */
pre::before {
  content: ""; position: absolute; top: 14px; left: 18px;
  width: 11px; height: 11px; border-radius: 50%;
  background: #ff5f56;
  box-shadow: 18px 0 #ffbd2e, 36px 0 #27c93f;
}
pre::after {
  content: "CUDA"; position: absolute; top: 11px; right: 16px;
  font-family: var(--mono); font-size: .64rem; font-weight: 700; letter-spacing: .14em;
  color: var(--accent); opacity: .8;
}
pre code { background: none; padding: 0; border: none; color: #c9d1d9; font-size: inherit; }
.copy-btn {
  position: absolute; top: 8px; right: 62px;
  padding: 3px 10px; border-radius: 6px; cursor: pointer;
  background: var(--bg-elev2); border: 1px solid var(--border); color: var(--text-dim);
  font-family: var(--mono); font-size: .66rem; letter-spacing: .04em;
  opacity: 0; transition: opacity .15s, color .15s, border-color .15s;
}
pre:hover .copy-btn, .copy-btn:focus-visible { opacity: 1; }
.copy-btn:hover { color: var(--text); border-color: var(--accent); }
.copy-btn.done { color: var(--accent-soft); border-color: var(--accent); opacity: 1; }
.tok-key { color: #ff7b72; }
.tok-fn { color: #d2a8ff; }
.tok-type { color: #79c0ff; }
.tok-num { color: #79c0ff; }
.tok-str { color: #a5d6ff; }
.tok-com { color: #6e7681; font-style: italic; }
.tok-pp { color: #f0883e; }

/* ===== 박스 컴포넌트 ===== */
.callout {
  position: relative; overflow: hidden;
  border-left: 3px solid var(--accent-2);
  background: linear-gradient(100deg, rgba(88,166,255,.07), rgba(88,166,255,.01));
  padding: 15px 18px; border-radius: 0 var(--radius) var(--radius) 0; margin: 22px 0;
}
.callout.tip { border-color: var(--accent); background: linear-gradient(100deg, rgba(118,185,0,.08), rgba(118,185,0,.01)); }
.callout.warn { border-color: var(--accent-warn); background: linear-gradient(100deg, rgba(240,136,62,.08), rgba(240,136,62,.01)); }
.callout.cpu { border-color: var(--accent-violet); background: linear-gradient(100deg, rgba(163,113,247,.09), rgba(163,113,247,.01)); }
.callout .title { font-weight: 700; margin-bottom: 4px; font-size: .92rem; color: var(--accent-2); }
.callout.tip .title { color: var(--accent-soft); }
.callout.warn .title { color: var(--accent-warn); }
.callout.cpu .title { color: #c29bff; }
.callout p { margin: 6px 0; }

.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(232px,1fr)); gap: 16px; margin: 26px 0; }
.card {
  position: relative; overflow: hidden;
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px;
  transition: border-color .22s, transform .22s, box-shadow .22s;
  text-decoration: none; color: inherit; display: block;
}
.card::before {
  content: ""; position: absolute; inset: 0 0 auto 0; height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transform: scaleX(0); transform-origin: left; transition: transform .25s;
}
.card:hover { border-color: rgba(118,185,0,.5); transform: translateY(-4px); box-shadow: var(--shadow); }
.card:hover::before { transform: scaleX(1); }
.card .num {
  display: inline-block; font-family: var(--mono); font-size: .72rem; color: var(--accent);
  font-weight: 700; letter-spacing: .04em; padding: 3px 9px; border-radius: 999px;
  background: rgba(118,185,0,.1); border: 1px solid rgba(118,185,0,.22);
}
.card h3 { margin: 12px 0 8px; font-size: 1.08rem; }
.card p { margin: 0; font-size: .88rem; color: var(--text-dim); }

table {
  width: 100%; border-collapse: collapse; margin: 22px 0; font-size: .9rem;
  border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden;
}
th, td { text-align: left; padding: 11px 15px; border-bottom: 1px solid var(--border-soft); }
th { color: var(--accent); font-weight: 700; background: var(--bg-elev2); font-family: var(--mono); font-size: .82rem; letter-spacing: .02em; }
td { color: var(--text-dim); }
tr:last-child td { border-bottom: none; }
tr:hover td { background: rgba(118,185,0,.03); color: var(--text); }

.pill {
  display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: .72rem; font-weight: 600;
  background: rgba(118,185,0,.14); color: var(--accent-soft); margin-right: 6px;
  font-family: var(--mono); border: 1px solid rgba(118,185,0,.2);
}

.pager { display: flex; justify-content: space-between; gap: 16px; margin-top: 60px; }
.pager a {
  flex: 1; padding: 16px 20px; border: 1px solid var(--border); border-radius: var(--radius);
  text-decoration: none; color: var(--text); background: var(--bg-elev);
  transition: border-color .22s, transform .22s, background .22s;
}
.pager a:hover { border-color: rgba(118,185,0,.5); transform: translateY(-2px); background: var(--bg-elev2); }
.pager .dir { font-size: .72rem; color: var(--text-faint); font-family: var(--mono); letter-spacing: .04em; }
.pager .ttl { font-weight: 700; margin-top: 3px; }
.pager .next { text-align: right; }

/* ===== 히어로 (홈) ===== */
.hero { text-align: center; padding: 56px 0 28px; position: relative; }
.hero .badge {
  display: inline-block; padding: 6px 16px; border-radius: 999px;
  background: rgba(118,185,0,.1); color: var(--accent-soft);
  font-size: .78rem; font-weight: 600; margin-bottom: 22px;
  border: 1px solid rgba(118,185,0,.3); font-family: var(--mono); letter-spacing: .02em;
}
.hero h1 { font-size: 2.9rem; letter-spacing: -.03em; }
.hero .grad {
  background: linear-gradient(120deg, var(--accent-soft), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.hero p { font-size: 1.16rem; color: var(--text-dim); max-width: 640px; margin: 18px auto 0; }

/* 모바일 토글 */
.menu-toggle {
  display: none; position: fixed; top: 14px; left: 14px; z-index: 50;
  background: var(--bg-elev); border: 1px solid var(--border); color: var(--text);
  width: 42px; height: 42px; border-radius: 11px; font-size: 1.3rem; cursor: pointer;
  box-shadow: var(--shadow);
}

@media (max-width: 860px) {
  .menu-toggle { display: block; }
  .sidebar {
    position: fixed; left: 0; top: 0; z-index: 40;
    transform: translateX(-100%); transition: transform .25s;
    box-shadow: 0 0 50px rgba(0,0,0,.6);
  }
  .sidebar.open { transform: translateX(0); }
  .content { padding: 72px 22px 80px; }
  .hero h1 { font-size: 2.1rem; }
}

/* ===== 사이트 검색 ===== */
.search-box { position: relative; margin: 0 0 22px; }
.search-box input {
  width: 100%; padding: 10px 12px; border-radius: var(--radius-sm);
  background: var(--bg); border: 1px solid var(--border); color: var(--text);
  font-size: .85rem; font-family: var(--font); transition: border-color .16s, box-shadow .16s;
}
.search-box input::placeholder { color: var(--text-faint); }
.search-box input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(118,185,0,.12); }
.search-results {
  display: none; position: absolute; left: 0; right: 0; top: calc(100% + 6px); z-index: 60;
  background: var(--bg-elev2); border: 1px solid var(--border); border-radius: var(--radius-sm);
  max-height: 340px; overflow-y: auto; box-shadow: var(--shadow);
}
.search-results.open { display: block; }
.sr-item { display: block; padding: 10px 12px; text-decoration: none; border-bottom: 1px solid var(--border-soft); }
.sr-item:last-child { border-bottom: none; }
.sr-item:hover { background: rgba(118,185,0,.12); }
.sr-title { display: block; color: var(--text); font-size: .85rem; font-weight: 600; }
.sr-sec { display: block; color: var(--text-faint); font-size: .73rem; margin-top: 2px; font-family: var(--mono); }
.sr-empty { padding: 12px; color: var(--text-dim); font-size: .82rem; }

/* ===== 다이어그램(구조도) ===== */
.figure {
  margin: 26px 0; overflow-x: auto;
  background: linear-gradient(180deg, var(--bg-elev), var(--bg));
  border: 1px solid var(--border); border-radius: var(--radius); padding: 18px;
  box-shadow: var(--shadow);
}
.figure svg { display: block; min-width: 660px; width: 100%; height: auto; }
.figcap { color: var(--text-faint); font-size: .79rem; margin-top: 12px; text-align: center; font-family: var(--mono); }