/* =====================================================
   SENSEI LMS SLIDESHOW MOCKUP - MAIN STYLES
   ===================================================== */

/* =====================================================
   CSS CUSTOM PROPERTIES & THEMING
   ===================================================== */
:root {
  /* Color Progression for 15 Slides */
  --slide-1: #1e3a8a;  /* Deep Blue - Hero */
  --slide-2: #0891b2;  /* Cyan - Chapter Overview */
  --slide-3: #059669;  /* Emerald - Concept Intro */
  --slide-4: #059669;  /* Emerald - Concept Deep Dive */
  --slide-5: #ca8a04;  /* Amber - Flashcard */
  --slide-6: #ea580c;  /* Orange - Real-world Application */
  --slide-7: #dc2626;  /* Red - Image Hotspots */
  --slide-8: #7c3aed;  /* Violet - Video */
  --slide-9: #9333ea;  /* Purple - Supporting Text */
  --slide-10: #be185d; /* Pink - Quiz */
  --slide-11: #374151; /* Gray - Task List */
  --slide-12: #1f2937; /* Dark Gray - Technical Details */
  --slide-13: #475569; /* Blue Gray - Case Study */
  --slide-14: #64748b; /* Slate - Summary */
  --slide-15: #0f172a; /* Dark Slate - Completion */

  /* Typography Scale */
  --font-size-hero: 3rem;        /* 48px */
  --font-size-h1: 2.5rem;        /* 40px */
  --font-size-h2: 2rem;          /* 32px */
  --font-size-h3: 1.5rem;        /* 24px */
  --font-size-h4: 1.25rem;       /* 20px */
  --font-size-body: 1.25rem;     /* 20px */
  --font-size-small: 1rem;       /* 16px */
  --font-size-ui: 0.875rem;      /* 14px */

  /* Font Weights */
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Spacing */
  --spacing-xs: 0.5rem;   /* 8px */
  --spacing-sm: 1rem;     /* 16px */
  --spacing-md: 1.5rem;   /* 24px */
  --spacing-lg: 2rem;     /* 32px */
  --spacing-xl: 3rem;     /* 48px */
  --spacing-2xl: 4rem;    /* 64px */

  /* Layout */
  --container-max-width: 1200px;
  --content-width: 60%;
  --image-width: 40%;

  /* Colors - UI */
  --color-text-primary: #ffffff;
  --color-text-secondary: rgba(255, 255, 255, 0.9);
  --color-text-muted: rgba(255, 255, 255, 0.7);
  --color-overlay: rgba(0, 0, 0, 0.3);
  --color-success: #10b981;
  --color-error: #ef4444;
  --color-warning: #f59e0b;

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 300ms ease-in-out;
  --transition-slow: 600ms ease-in-out;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-full: 9999px;
}

/* =====================================================
   RESET & BASE STYLES
   ===================================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-normal);
  line-height: 1.6;
  color: var(--color-text-primary);
  overflow: hidden;
  background: #000;
}

/* =====================================================
   TYPOGRAPHY
   ===================================================== */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

h1 {
  font-size: var(--font-size-h1);
}

h2 {
  font-size: var(--font-size-h2);
}

h3 {
  font-size: var(--font-size-h3);
}

h4 {
  font-size: var(--font-size-h4);
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
}

strong {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

ul, ol {
  margin-left: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
}

li {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
}

/* =====================================================
   LAYOUT - SLIDESHOW CONTAINER
   ===================================================== */
#slideshow-container {
  width: 100%;
  height: 100vh;
  position: relative;
  overflow: hidden;
}

.slide {
  width: 100%;
  height: 100vh;
  position: absolute;
  top: 0;
  left: 0;
  opacity: 1;
  transition: opacity var(--transition-normal), transform var(--transition-normal);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl) var(--spacing-lg);
  padding-bottom: 120px; /* Space for navigation */
}

.slide.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateX(50px);
}

.slide.exit-left {
  opacity: 0;
  transform: translateX(-50px);
}

/* Dynamic Slide Background Colors */
.slide[data-slide="1"] { background-color: var(--slide-1); }
.slide[data-slide="2"] { background-color: var(--slide-2); }
.slide[data-slide="3"] { background-color: var(--slide-3); }
.slide[data-slide="4"] { background-color: var(--slide-4); }
.slide[data-slide="5"] { background-color: var(--slide-5); }
.slide[data-slide="6"] { background-color: var(--slide-6); }
.slide[data-slide="7"] { background-color: var(--slide-7); }
.slide[data-slide="8"] { background-color: var(--slide-8); }
.slide[data-slide="9"] { background-color: var(--slide-9); }
.slide[data-slide="10"] { background-color: var(--slide-10); }
.slide[data-slide="11"] { background-color: var(--slide-11); }
.slide[data-slide="12"] { background-color: var(--slide-12); }
.slide[data-slide="13"] { background-color: var(--slide-13); }
.slide[data-slide="14"] { background-color: var(--slide-14); }
.slide[data-slide="15"] { background-color: var(--slide-15); }

/* =====================================================
   LAYOUT - SLIDE CONTENT
   ===================================================== */
.slide-content {
  max-width: var(--container-max-width);
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.content-area {
  flex: 1 1 var(--content-width);
  max-height: 80vh;
  overflow-y: auto;
  padding-right: var(--spacing-lg);
}

/* Custom Scrollbar */
.content-area::-webkit-scrollbar {
  width: 8px;
}

.content-area::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
}

.content-area::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-full);
}

.content-area::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.5);
}

.image-area {
  flex: 1 1 var(--image-width);
  display: flex;
  align-items: center;
  justify-content: center;
  max-height: 80vh;
}

.image-area img {
  max-width: 100%;
  max-height: 100%;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  object-fit: cover;
}

.image-area-small {
  flex: 0 1 30%;
}

.helper-text {
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
  text-align: center;
  font-style: italic;
}

/* =====================================================
   BUTTONS
   ===================================================== */
button {
  cursor: pointer;
  border: none;
  outline: none;
  font-family: inherit;
  transition: all var(--transition-fast);
}

.start-button,
.next-chapter-button {
  background: rgba(255, 255, 255, 0.2);
  color: var(--color-text-primary);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  border: 2px solid rgba(255, 255, 255, 0.3);
  margin-top: var(--spacing-lg);
}

.start-button:hover,
.next-chapter-button:hover {
  background: rgba(255, 255, 255, 0.3);
  border-color: rgba(255, 255, 255, 0.5);
  transform: scale(1.05);
}

.start-button:active,
.next-chapter-button:active {
  transform: scale(0.98);
}

/* =====================================================
   HERO SLIDE
   ===================================================== */
.hero-title {
  font-size: var(--font-size-hero);
  margin-bottom: var(--spacing-lg);
  animation: fadeInUp 0.8s ease-out;
}

.hero-description {
  font-size: var(--font-size-h4);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  animation: fadeInUp 1s ease-out 0.2s both;
}

/* =====================================================
   TEXT FOCUSED CONTENT
   ===================================================== */
.text-focus p {
  font-size: var(--font-size-body);
  line-height: 1.8;
}

.key-highlight {
  background: rgba(255, 255, 255, 0.15);
  padding: var(--spacing-md);
  border-left: 4px solid rgba(255, 255, 255, 0.5);
  border-radius: var(--radius-sm);
  margin-top: var(--spacing-lg);
}

/* =====================================================
   LISTS
   ===================================================== */
.objectives-list,
.summary-list {
  list-style: none;
  margin-left: 0;
}

.objectives-list li,
.summary-list li {
  padding-left: var(--spacing-lg);
  position: relative;
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-body);
}

.objectives-list li::before,
.summary-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-text-primary);
  font-weight: var(--font-weight-bold);
}

/* =====================================================
   NAVIGATION BAR
   ===================================================== */
.navigation-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(20px);
  padding: var(--spacing-md) var(--spacing-lg);
  z-index: 1000;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-controls {
  max-width: var(--container-max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-lg);
}

.nav-button {
  background: rgba(255, 255, 255, 0.1);
  color: var(--color-text-primary);
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-ui);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  border: 1px solid rgba(255, 255, 255, 0.2);
  min-width: 120px;
}

.nav-button:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.4);
}

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

.nav-icon {
  font-size: 1.2rem;
}

.nav-info {
  flex: 1;
  text-align: center;
}

.page-counter {
  color: var(--color-text-secondary);
  font-size: var(--font-size-ui);
  display: block;
  margin-bottom: var(--spacing-xs);
}

.current-page {
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  font-size: var(--font-size-small);
}

.progress-indicator {
  height: 4px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
  overflow: hidden;
  max-width: 400px;
  margin: 0 auto;
}

.progress-indicator .progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #60a5fa, #a78bfa);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

/* =====================================================
   UTILITY CLASSES
   ===================================================== */
.hidden {
  display: none !important;
}

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

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

/* =====================================================
   RESPONSIVE DESIGN
   ===================================================== */

/* Tablet */
@media (max-width: 1023px) {
  :root {
    --font-size-hero: 2.5rem;
    --font-size-h1: 2rem;
    --font-size-h2: 1.75rem;
    --font-size-body: 1.125rem;
  }

  .slide-content {
    flex-direction: column;
    gap: var(--spacing-lg);
  }

  .content-area,
  .image-area {
    flex: 1 1 100%;
    max-height: 50vh;
  }

  .image-area {
    max-height: 40vh;
  }
}

/* Mobile */
@media (max-width: 767px) {
  :root {
    --font-size-hero: 2rem;
    --font-size-h1: 1.75rem;
    --font-size-h2: 1.5rem;
    --font-size-h3: 1.25rem;
    --font-size-body: 1rem;
  }

  .slide {
    padding: var(--spacing-lg) var(--spacing-sm);
    padding-bottom: 100px;
  }

  .content-area {
    padding-right: 0;
  }

  .nav-button {
    min-width: 80px;
    padding: var(--spacing-xs) var(--spacing-sm);
  }

  .nav-text {
    display: none;
  }

  .nav-icon {
    font-size: 1.5rem;
  }

  .navigation-bar {
    padding: var(--spacing-sm);
  }
}