/* ─── Reset & Base ──────────────────────────────── */
*, *::before, *::after {
  margin: 0; padding: 0; box-sizing: border-box;
}

html {
  height: 100%; font-size: 17px;
  -webkit-text-size-adjust: 100%;
}

body {
  height: 100%; overflow: hidden;
  font-family: -apple-system, 'Apple SD Gothic Neo', 'Malgun Gothic',
               'Noto Sans KR', 'Noto Sans', system-ui, sans-serif;
  background: #0F172A;
  color: var(--c-dark);
  -webkit-font-smoothing: antialiased;
  line-height: 1.5;
}

/* ─── Slide Deck ────────────────────────────────── */
#deck {
  position: relative;
  width: 100vw;
  height: calc(100vh - var(--slide-nav-h));
  overflow: hidden;
}

/* ─── Individual Slide ───────────────────────────── */
.slide {
  position: absolute; inset: 0;
  display: none; flex-direction: column;
  background: var(--c-bg);
  overflow: hidden;
}

.slide.active {
  display: flex;
  animation: slide-in var(--t-slow) ease;
}

@keyframes slide-in {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: none; }
}

@media (prefers-reduced-motion: reduce) {
  .slide.active { animation: none; }
}

/* ─── Slide: Cover (section/title) ───────────────── */
.slide-cover {
  justify-content: center;
  align-items: center;
  text-align: center;
  color: var(--c-white);
  padding: 0;
}

/* nav bar 여백: 각 커버 슬라이드 내부 div의 인라인 스타일에서 padding-bottom으로 직접 처리 */

/* ─── Slide: Cover — dot grid overlay (all section covers) ── */
.slide-cover > div {
  position: relative;
  isolation: isolate;
}
.slide-cover > div::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='30'%3E%3Ccircle cx='2.5' cy='2.5' r='1.5' fill='white' fill-opacity='0.15'/%3E%3C/svg%3E");
  background-size: 30px 30px;
  pointer-events: none;
  z-index: -1;
}

/* ─── Slide: Content ────────────────────────────── */
.slide-content {
  flex-direction: column;
}

.slide-header {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-5) var(--slide-pad-x) var(--sp-4);
  border-bottom: 2px solid var(--c-border);
  height: var(--slide-header-h);
}

.slide-section-tag {
  flex-shrink: 0;
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--r-full);
  white-space: nowrap;
}

.slide-title {
  font-size: var(--fs-2xl);
  font-weight: 800;
  line-height: 1.25;
  color: var(--c-dark);
  word-break: keep-all;
}

.slide-body {
  flex: 1;
  padding: var(--sp-7) var(--slide-pad-x);
  padding-bottom: calc(var(--slide-nav-h) + var(--sp-6));
  overflow-y: auto;
  overflow-x: hidden;
}

/* Scrollbar styling */
.slide-body::-webkit-scrollbar { width: 4px; }
.slide-body::-webkit-scrollbar-track { background: transparent; }
.slide-body::-webkit-scrollbar-thumb { background: var(--c-muted); border-radius: var(--r-full); }

/* ─── Typography ────────────────────────────────── */
.text-xs   { font-size: var(--fs-xs); }
.text-sm   { font-size: var(--fs-sm); }
.text-base { font-size: var(--fs-base); }
.text-lg   { font-size: var(--fs-lg); }
.text-xl   { font-size: var(--fs-xl); }
.text-2xl  { font-size: var(--fs-2xl); }
.text-3xl  { font-size: var(--fs-3xl); }
.text-4xl  { font-size: var(--fs-4xl); }
.text-5xl  { font-size: var(--fs-5xl); }

.font-medium { font-weight: 500; }
.font-bold   { font-weight: 700; }
.font-black  { font-weight: 900; }

.text-dark  { color: var(--c-dark); }
.text-mid   { color: var(--c-mid); }
.text-pale  { color: var(--c-pale); }
.text-white { color: var(--c-white); }

.leading-tight  { line-height: 1.25; }
.leading-normal { line-height: 1.5; }
.leading-loose  { line-height: 1.75; }

.word-break { word-break: keep-all; }

/* ─── Utility ───────────────────────────────────── */
.flex        { display: flex; }
.flex-col    { flex-direction: column; }
.items-start { align-items: flex-start; }
.items-center{ align-items: center; }
.items-end   { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between{ justify-content: space-between; }
.flex-1      { flex: 1; }
.flex-shrink-0{ flex-shrink: 0; }
.gap-2  { gap: var(--sp-2); }
.gap-3  { gap: var(--sp-3); }
.gap-4  { gap: var(--sp-4); }
.gap-5  { gap: var(--sp-5); }
.gap-6  { gap: var(--sp-6); }
.gap-8  { gap: var(--sp-8); }

.mt-2 { margin-top: var(--sp-2); }
.mt-3 { margin-top: var(--sp-3); }
.mt-4 { margin-top: var(--sp-4); }
.mt-5 { margin-top: var(--sp-5); }
.mt-6 { margin-top: var(--sp-6); }
.mt-8 { margin-top: var(--sp-8); }
.mb-2 { margin-bottom: var(--sp-2); }
.mb-3 { margin-bottom: var(--sp-3); }
.mb-4 { margin-bottom: var(--sp-4); }
.mb-6 { margin-bottom: var(--sp-6); }

.opacity-75 { opacity: .75; }
.opacity-60 { opacity: .60; }
.sr-only { position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; }