:root {
  --bg-primary: #0a0f1d;
  --bg-card: rgba(18, 26, 47, 0.85);
  --bg-card-hover: rgba(28, 40, 70, 0.95);
  --border-color: rgba(56, 189, 248, 0.22);
  --border-glow: rgba(56, 189, 248, 0.5);
  --accent-cyan: #38bdf8;
  --accent-blue: #3b82f6;
  --accent-indigo: #6366f1;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --diff-highlight: #ff0055;
  --diff-highlight-bg: rgba(255, 0, 85, 0.15);
  --diff-highlight-border: #ff0055;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Pretendard", "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  overflow: hidden;
  height: 100vh;
  width: 100vw;
  user-select: none;
  background-image: 
    radial-gradient(circle at 15% 20%, rgba(56, 189, 248, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 85% 80%, rgba(99, 102, 241, 0.08) 0%, transparent 40%),
    linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 40px 40px, 40px 40px;
}

/* Presentation Container */
.presentation-container {
  position: relative;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
}

/* Top Floating Bar */
.top-bar {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  padding: 1.2rem 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(10, 15, 29, 0.6);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.brand-badge {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  color: #fff;
}

.brand-badge .logo-icon {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-ctrl {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.45rem 0.9rem;
  border-radius: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  text-decoration: none;
}

.btn-ctrl:hover {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

/* Slides Wrapper */
.slides-wrapper {
  position: relative;
  width: 100%;
  height: 100%;
}

.slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  padding: 6.5rem 4rem 5rem 4rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  opacity: 0;
  visibility: hidden;
  transform: scale(0.96) translateY(20px);
  transition: opacity 0.4s cubic-bezier(0.16, 1, 0.3, 1), transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.4s;
}

.slide.active {
  opacity: 1;
  visibility: visible;
  transform: scale(1) translateY(0);
  z-index: 10;
}

.slide-content {
  width: 100%;
  max-width: 1180px;
  max-height: calc(100vh - 12rem);
  overflow-y: auto;
  padding-right: 0.5rem;
}

/* Slide Typography */
.slide-category {
  display: inline-block;
  text-transform: uppercase;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.3);
  padding: 0.3rem 0.8rem;
  border-radius: 9999px;
  margin-bottom: 0.75rem;
}

.slide-title {
  font-size: 2.3rem;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin-bottom: 0.6rem;
  background: linear-gradient(135deg, #ffffff 40%, var(--accent-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.slide-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 2rem;
  max-width: 820px;
}

/* Layout Grids */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.2rem;
}

/* Glass Cards */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 1.5rem;
  backdrop-filter: blur(12px);
  transition: all 0.25s ease;
  position: relative;
  overflow: hidden;
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 0.8rem;
  display: inline-block;
}

.card-title {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Cover Slide Special */
.slide-cover {
  text-align: center;
}

.slide-cover .slide-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.cover-badge {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.15), rgba(99, 102, 241, 0.2));
  border: 1px solid var(--accent-cyan);
  padding: 0.4rem 1.2rem;
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 800;
  color: var(--accent-cyan);
  margin-bottom: 1.5rem;
  box-shadow: 0 0 20px rgba(56, 189, 248, 0.2);
}

.cover-title {
  font-size: 3.4rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  background: linear-gradient(135deg, #ffffff 30%, var(--accent-cyan) 80%, #a855f7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.cover-subtitle {
  font-size: 1.35rem;
  color: var(--text-muted);
  max-width: 800px;
  line-height: 1.6;
  margin-bottom: 2.5rem;
}

.cover-meta {
  display: flex;
  gap: 2rem;
  margin-top: 1rem;
}

.cover-meta-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
}

.cover-meta-val {
  font-size: 1.4rem;
  font-weight: 900;
  color: #fff;
}

.cover-meta-label {
  font-size: 0.78rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Interactive Timeline Simulation */
.timeline-track {
  display: flex;
  position: relative;
  margin: 1.5rem 0;
  padding: 1rem 0;
}

.timeline-track::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 5%;
  right: 5%;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-emerald), var(--accent-cyan), var(--accent-indigo), var(--accent-amber));
  transform: translateY(-50%);
  z-index: 1;
}

.timeline-node {
  flex: 1;
  position: relative;
  z-index: 2;
  text-align: center;
}

.node-dot {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: #0f172a;
  border: 3px solid var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 0.75rem auto;
  font-size: 0.85rem;
  font-weight: 800;
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.4);
}

.timeline-node.pol .node-dot { border-color: var(--accent-emerald); color: var(--accent-emerald); }
.timeline-node.ts1 .node-dot { border-color: var(--accent-cyan); color: var(--accent-cyan); }
.timeline-node.ts2 .node-dot { border-color: var(--accent-indigo); color: var(--accent-indigo); }
.timeline-node.pod .node-dot { border-color: var(--accent-amber); color: var(--accent-amber); }

.node-label {
  font-size: 0.95rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.2rem;
}

.node-port {
  font-size: 0.82rem;
  color: var(--accent-cyan);
  font-weight: 700;
}

.node-date {
  font-size: 0.74rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.node-vessel {
  display: inline-block;
  margin-top: 0.3rem;
  padding: 0.15rem 0.5rem;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 4px;
  font-size: 0.72rem;
  color: var(--text-dim);
}

/* Diff Highlighting Component */
.diff-box {
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.25rem;
  font-family: monospace;
  font-size: 0.88rem;
}

.diff-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.6rem 0.8rem;
  border-radius: 6px;
  margin-bottom: 0.35rem;
}

.diff-row.changed {
  background: var(--diff-highlight-bg);
  border: 1px solid var(--diff-highlight-border);
  box-shadow: 0 0 15px rgba(255, 0, 85, 0.25);
}

.diff-tag {
  background: var(--diff-highlight);
  color: #fff;
  font-weight: 800;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  font-size: 0.72rem;
  margin-right: 0.5rem;
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0% { opacity: 0.8; }
  50% { opacity: 1; filter: drop-shadow(0 0 8px #ff0055); }
  100% { opacity: 0.8; }
}

.old-val {
  text-decoration: line-through;
  color: var(--text-dim);
  margin-right: 0.5rem;
}

.new-val {
  color: #ff3377;
  font-weight: 800;
}

/* Bottom Nav Bar */
.bottom-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  padding: 1rem 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(10, 15, 29, 0.6);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.slide-nav-controls {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-arrow-btn {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-color);
  color: #fff;
  width: 38px;
  height: 38px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  transition: all 0.2s;
}

.nav-arrow-btn:hover:not(:disabled) {
  background: var(--accent-cyan);
  color: #000;
  transform: translateY(-2px);
}

.nav-arrow-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.slide-counter {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  margin: 0 0.5rem;
}

.progress-container {
  flex: 1;
  max-width: 320px;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 9999px;
  overflow: hidden;
  margin: 0 1.5rem;
}

.progress-bar {
  height: 100%;
  width: 10%;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-indigo));
  transition: width 0.3s ease;
}

.keyboard-hint {
  font-size: 0.75rem;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.key-badge {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-family: monospace;
}

/* Custom Scrollbar for slide content */
.slide-content::-webkit-scrollbar {
  width: 6px;
}
.slide-content::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.02);
}
.slide-content::-webkit-scrollbar-thumb {
  background: rgba(56, 189, 248, 0.2);
  border-radius: 4px;
}
.slide-content::-webkit-scrollbar-thumb:hover {
  background: var(--accent-cyan);
}

/* Responsive adjustments */
@media (max-width: 900px) {
  .slide { padding: 5rem 1.5rem 4.5rem 1.5rem; }
  .cover-title { font-size: 2.2rem; }
  .slide-title { font-size: 1.7rem; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .timeline-track { flex-direction: column; gap: 1rem; }
  .timeline-track::before { display: none; }
  .progress-container { display: none; }
}