:root {
  --color-coral: #f43f5e;
  --color-teal: #06b6d4;
  --color-amber: #f59e0b;
  --color-emerald: #10b981;
  --color-violet: #8b5cf6;
  --color-violet-light: #ede9fe;
  --color-bg: #fff8f0;
  --color-text: #1f2937;
  --color-card: #ffffff;
  --color-border: #e2e8f0;
  
  --gradient-header: linear-gradient(135deg, var(--color-teal) 0%, var(--color-violet) 100%);
  --font-main: 'Inter', system-ui, -apple-system, sans-serif;
  --spacing-base: 1rem;
  --border-radius: 12px;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-main);
  line-height: 1.6;
  margin: 0;
  padding: 0;
}

/* Premium Layout Classes */
.header-premium {
  background: var(--gradient-header);
  color: white;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  box-shadow: 0 4px 12px rgba(6,182,212,0.25);
}

.app-layout {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

.sidebar-toc {
  width: 280px;
  background: var(--color-card);
  border-right: 1px solid var(--color-border);
  padding: 1rem;
  overflow-y: auto;
  box-shadow: 4px 0 16px rgba(0,0,0,0.04);
}

.content-area {
  flex: 1;
  padding: 2rem;
  overflow-y: auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.slide-premium {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: 1.25rem;
  padding: 2rem;
  max-width: 900px;
  width: 100%;
  min-height: 55vh;
  box-shadow: 0 8px 30px rgba(0,0,0,0.06);
  animation: popIn 0.45s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes popIn {
  from { opacity: 0; transform: scale(0.96) translateY(12px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.btn-primary {
  background-color: var(--color-teal);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius);
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.2s ease;
}

.btn-primary:active {
  transform: scale(0.95);
}

.card {
  background: white;
  border-radius: var(--border-radius);
  box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  padding: var(--spacing-base);
}