:root {
  --bg-primary: #f2f2f2;
  --bg-secondary: #e8e8e8;
  --text-main: #333333;
  --text-muted: #666666;
  --accent: #5e6b5e;
  --border-color: #d1d1d1;
  --spacing-unit: 1rem;
  --font-serif: "Playfair Display", Georgia, serif;
  --font-sans: "Inter", system-ui, -apple-system, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  background-color: #1a1a1a;
  color: var(--text-main);
  overflow-x: hidden;
}

.presentation-container {
  display: flex;
  flex-direction: column;
  gap: 80px;
  padding: 40px 20px;
  max-width: 1200px;
  margin: 0 auto;
}

.slide-wrapper {
  background: var(--bg-primary);
  width: 100%;
  aspect-ratio: 16 / 9;
  position: relative;
  overflow: hidden;
  box-shadow: 0 30px 60px rgba(0,0,0,0.3);
  display: flex;
  flex-direction: column;
}

.slide-content {
  flex: 1;
  padding: 60px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.slide-number {
  position: absolute;
  top: 40px;
  right: 40px;
  font-family: var(--font-serif);
  font-size: 1.2rem;
  color: var(--text-muted);
  opacity: 0.5;
}

.slide-tag {
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
  font-weight: 600;
}

h1, h2 {
  font-family: var(--font-serif);
  margin: 0;
  font-weight: 400;
  line-height: 1.1;
}

h1 { font-size: 4rem; }
h2 { font-size: 2.5rem; }

p {
  font-size: 1.1rem;
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 600px;
}

.slide-instruction {
  background: #2a2a2a;
  color: #aaa;
  padding: 20px 40px;
  border-radius: 0 0 8px 8px;
  font-size: 0.9rem;
  border-top: 1px solid #333;
}

.instruction-label {
  color: #fff;
  font-weight: bold;
  margin-right: 10px;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

/* Specific Layouts */
.layout-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  height: 100%;
}

.layout-split .visual {
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.placeholder-img {
  width: 80%;
  height: 70%;
  background: #dadada;
  position: relative;
  overflow: hidden;
}

.placeholder-img::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg, transparent 45%, #cecece 45%, #cecece 55%, transparent 55%);
}

.layout-center {
  text-align: center;
  align-items: center;
}

.layout-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-top: 40px;
}

.grid-item {
  background: var(--bg-secondary);
  padding: 30px;
  border-left: 1px solid var(--accent);
}

.grid-item h3 {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  margin-top: 0;
}

/* Animations */
.fade-in {
  animation: fadeIn 1s ease forwards;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.presentation-header {
  text-align: center;
  padding: 80px 20px;
  color: #fff;
}

.presentation-header h0 {
  display: block;
  font-family: var(--font-serif);
  font-size: 3rem;
  margin-bottom: 10px;
}

.presentation-header p {
  margin: 0 auto;
  opacity: 0.7;
}

/* Mini aesthetic details */
.accent-line {
  width: 60px;
  height: 2px;
  background: var(--accent);
  margin: 30px 0;
}

.accent-line.center { margin-left: auto; margin-right: auto; }

.quote-slide blockquote {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  line-height: 1.3;
  font-style: italic;
  margin: 0;
  position: relative;
}

.quote-slide blockquote::before {
  content: "“";
  position: absolute;
  left: -40px;
  top: -20px;
  font-size: 5rem;
  color: var(--accent);
  opacity: 0.3;
}