:root {
  --bg: #fafaf9;
  --text: #1d1d1d;
  --muted: #6b6b6b;
  --line: #e6e4e0;
  --card: #fff;
  --accent: #3d5a80;
  --accent-light: #edf1f8;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-snap-type: y mandatory;
}

body {
  margin: 0;
  background: #e8e6e3;
  color: var(--text);
  font-family: "Noto Sans KR", sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.82em;
  background: #f0efed;
  padding: 2px 6px;
  border-radius: 4px;
  color: #555;
}

/* Slide wrapper — each slide occupies 100vh for snap, centers a 16:9 card */

.slide-frame {
  scroll-snap-align: start;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.page {
  aspect-ratio: 16 / 9;
  width: min(92vw, calc(94vh * 16 / 9));
  max-width: 1440px;
  padding: 40px 56px;
  background: var(--bg);
  box-shadow: 0 0 40px rgba(0,0,0,0.06);
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  overflow: hidden;
  border-radius: 4px;
}

/* Cover slide */

.cover {
  text-align: center;
  align-items: center;
  justify-content: center;
}

.cover h1 {
  margin: 14px 0 0;
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.cover h2 {
  margin: 14px 0 0;
  font-size: 26px;
  font-weight: 700;
}

.cover-label {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.cover-sub {
  margin: 8px 0 0;
  font-size: 17px;
  color: var(--muted);
}

.cover-meta {
  margin-top: 36px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  font-size: 15px;
  color: var(--muted);
}

.cover-focus {
  margin: 36px auto 0;
  max-width: 640px;
  font-size: 14px;
  color: #555;
  line-height: 1.85;
}

/* Section headings */

.proj-label {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.proj-label-lg {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.section-label {
  margin: 0;
  font-size: 12px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.06em;
}

h2 {
  margin: 6px 0 0;
  font-size: 24px;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

h3 {
  margin: 24px 0 0;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.35;
}

h3:first-child {
  margin-top: 0;
}

.desc {
  margin: 10px 0 0;
  font-size: 14px;
  color: #555;
}

/* Info grid */

.info-grid {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.info-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 14px;
  background: var(--card);
}

.info-card h4 {
  margin: 0;
  font-size: 11px;
  font-weight: 700;
  color: var(--muted);
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.info-card p {
  margin: 4px 0 0;
  font-size: 13px;
  line-height: 1.5;
}

/* Architecture diagram */

.arch-diagram {
  margin-top: 20px;
  display: flex;
  gap: 10px;
  align-items: stretch;
  flex-wrap: wrap;
}

.arch-box {
  flex: 1;
  min-width: 180px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  background: var(--card);
}

.arch-box.highlight {
  border-color: var(--accent);
  background: var(--accent-light);
}

.arch-box h4 {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
}

.arch-items {
  margin-top: 8px;
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.arch-items span {
  font-size: 11px;
  padding: 2px 7px;
  border-radius: 4px;
  background: #f0efed;
  color: #555;
  font-weight: 500;
}

.arch-arrow {
  display: flex;
  align-items: center;
  font-size: 22px;
  color: var(--muted);
}

/* Slide image */

.slide-img {
  display: block;
  width: 100%;
  max-height: 40vh;
  object-fit: contain;
  margin-top: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
}

/* API flow */

.api-flow {
  margin-top: 12px;
  display: grid;
  gap: 6px;
}

.api-flow-step {
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: 10px;
  align-items: start;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--card);
}

.api-flow-num {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  font-size: 13px;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  border-radius: 50%;
  margin-top: 2px;
}

.api-flow-step strong {
  font-size: 13px;
}

.api-flow-step p {
  margin: 2px 0 0;
  font-size: 12px;
  color: #555;
  line-height: 1.55;
}

/* Console screenshots */

.console-screenshots {
  margin-top: 10px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.console-img {
  width: 100%;
  max-height: 45vh;
  border: none;
  border-radius: 0;
  object-fit: contain;
}

/* Console tabs */

.console-tabs {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.console-tab {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 14px;
  background: var(--card);
}

.console-tab h4 {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
  font-family: "JetBrains Mono", monospace;
  color: var(--accent);
}

.console-tab p {
  margin: 4px 0 0;
  font-size: 12px;
  color: #555;
  line-height: 1.55;
}

/* Decision block */

.decision-block {
  margin-top: 12px;
  display: grid;
  gap: 10px;
}

.decision {
  border-left: 3px solid var(--line);
  padding: 0 0 0 14px;
}

.decision h4 {
  margin: 0;
  font-size: 12px;
  font-weight: 700;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.decision p, .decision ul {
  margin: 3px 0 0;
  font-size: 13px;
  color: #444;
  line-height: 1.65;
}

.decision ul {
  padding-left: 16px;
}

.decision li {
  margin-top: 3px;
}

/* Pipeline grid */

.pipeline-grid {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.pipeline-grid.cols-2 {
  grid-template-columns: repeat(2, 1fr);
}

.pipeline-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: var(--card);
}

.pipeline-card.accent {
  border-color: var(--accent);
  background: var(--accent-light);
}

.pipeline-card h4 {
  margin: 0;
  font-size: 12px;
  font-weight: 700;
  font-family: "JetBrains Mono", monospace;
}

.pipeline-flow {
  margin: 4px 0 0;
  font-size: 12px;
  color: #555;
  line-height: 1.55;
}

/* Reason list */

.reason-list {
  margin-top: 10px;
  display: grid;
  gap: 8px;
}

.reason {
  font-size: 13px;
  color: #444;
  padding: 10px 12px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  line-height: 1.65;
}

/* Troubleshooting timeline */

.trouble-timeline {
  margin-top: 10px;
  display: grid;
  gap: 6px;
}

.trouble-step {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 10px;
  align-items: start;
}

.step-label {
  font-size: 11px;
  font-weight: 700;
  color: var(--card);
  background: var(--accent);
  padding: 3px 0;
  border-radius: 4px;
  text-align: center;
  margin-top: 1px;
}

.trouble-step p, .trouble-step ul {
  margin: 0;
  font-size: 13px;
  color: #444;
  line-height: 1.65;
}

.trouble-step ul {
  padding-left: 16px;
}

.trouble-step li {
  margin-top: 2px;
}

.trouble-step code {
  grid-column: 2;
  display: block;
  margin-top: 4px;
  font-size: 11px;
  word-break: break-all;
  overflow-wrap: anywhere;
  white-space: normal;
}

/* Takeaway */

.takeaway {
  margin-top: 20px;
  padding: 12px 14px;
  border-radius: 8px;
  background: var(--accent-light);
  border: 1px solid var(--accent);
  font-size: 13px;
  color: #333;
  line-height: 1.65;
}

/* Monitor stack */

.monitor-stack {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.monitor-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: var(--card);
}

.monitor-item h4 {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
}

.monitor-item p {
  margin: 3px 0 0;
  font-size: 12px;
  color: #555;
  line-height: 1.55;
}

.monitor-item code {
  display: block;
  margin-top: 6px;
  font-size: 10px;
}

/* Summary grid */

.summary-grid {
  margin-top: 28px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  text-align: left;
}

.summary-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  background: var(--card);
}

.summary-item h4 {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
}

.summary-item p {
  margin: 6px 0 0;
  font-size: 13px;
  color: #555;
  line-height: 1.6;
}

/* Slide navigation */

.slide-nav {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(29, 29, 29, 0.85);
  backdrop-filter: blur(8px);
  padding: 8px 16px;
  border-radius: 999px;
  z-index: 100;
}

.nav-btn {
  border: none;
  background: none;
  color: #fff;
  font-size: 18px;
  cursor: pointer;
  padding: 2px 8px;
  border-radius: 6px;
  transition: background 0.15s;
}

.nav-btn:hover {
  background: rgba(255,255,255,0.15);
}

.slide-indicator {
  font-size: 13px;
  font-weight: 600;
  color: rgba(255,255,255,0.8);
  font-family: "JetBrains Mono", monospace;
  min-width: 56px;
  text-align: center;
}

/* Responsive */

@media (max-width: 800px) {
  .slide-frame {
    height: auto;
    min-height: 100vh;
  }

  .page {
    aspect-ratio: auto;
    width: 100vw;
    max-width: none;
    padding: 36px 24px;
    box-shadow: none;
    border-radius: 0;
    overflow: visible;
  }

  body {
    background: var(--bg);
  }

  h2 {
    font-size: 20px;
  }

  .cover h1 {
    font-size: 30px;
  }

  .info-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .pipeline-grid,
  .pipeline-grid.cols-2 {
    grid-template-columns: 1fr;
  }

  .monitor-stack,
  .summary-grid {
    grid-template-columns: 1fr;
  }

  .arch-diagram {
    flex-direction: column;
  }

  .arch-arrow {
    justify-content: center;
    transform: rotate(90deg);
  }

  .trouble-step {
    grid-template-columns: 1fr;
  }

  .step-label {
    width: fit-content;
    padding: 3px 12px;
  }
}

/* Print */

@media print {
  @page { size: A4 landscape; margin: 12mm; }
  * { -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  html { scroll-snap-type: none; }
  body { background: #fff; }
  .slide-frame {
    height: auto;
    page-break-after: always;
  }
  .slide-frame:last-of-type { page-break-after: auto; }
  .page {
    aspect-ratio: auto;
    max-width: none;
    width: 100%;
    padding: 16px 0;
    box-shadow: none;
    border-radius: 0;
    overflow: visible;
    justify-content: flex-start;
  }
  .slide-nav { display: none; }
}