/* CSS Variables - Modern AI SaaS Theme */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #f1f3f5;
  --text-primary: #1a1a1a;
  --text-secondary: #495057;
  --text-muted: #868e96;
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --accent-light: #eef2ff;
  --danger: #ef4444;
  --danger-hover: #dc2626;
  --border: #e9ecef;
  --shadow: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.1);
  --radius: 12px;
  --radius-sm: 8px;
}

/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-narrow {
  max-width: 680px;
}

/* Header */
.header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 18px;
}

.logo-icon {
  font-size: 24px;
}

.logo-text {
  color: var(--text-primary);
}

.nav {
  display: flex;
  gap: 24px;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  padding: 8px 0;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* Main Content */
.main {
  min-height: calc(100vh - 70px);
}

.page {
  display: none;
  padding: 60px 0;
}

.page.active {
  display: block;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 80px 0;
  max-width: 800px;
  margin: 0 auto;
}

.hero-title {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.hero-subtitle {
  font-size: clamp(18px, 2vw, 22px);
  color: var(--text-secondary);
  margin-bottom: 40px;
  line-height: 1.5;
}

/* Features */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
  margin-top: 60px;
}

.feature-card {
  background: var(--bg-secondary);
  padding: 32px;
  border-radius: var(--radius);
  text-align: center;
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: var(--border);
}

.btn-danger {
  background: var(--danger);
  color: white;
}

.btn-danger:hover {
  background: var(--danger-hover);
}

.btn-lg {
  padding: 16px 32px;
  font-size: 18px;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 14px;
}

.btn-block {
  width: 100%;
}

/* Forms */
.form-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
}

.form-title {
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 32px;
  color: var(--text-primary);
  text-align: center;
}

.form-group {
  margin-bottom: 24px;
}

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.form-group textarea {
  width: 100%;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-family: inherit;
  resize: vertical;
  transition: border-color 0.2s;
}

.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

/* Radio Groups */
.radio-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
}

.radio-card {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 14px 20px;
  background: var(--bg-secondary);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

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

.radio-card input[type="radio"] {
  display: none;
}

.radio-card:has(input:checked) {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--accent);
}

/* Slide Selector */
.slide-selector {
  display: flex;
  gap: 12px;
}

.slide-option {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: var(--bg-secondary);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 600;
  font-size: 18px;
}

.slide-option:hover {
  border-color: var(--accent);
}

.slide-option input[type="radio"] {
  display: none;
}

.slide-option:has(input:checked) {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--accent);
}

/* Editor Layout */
.editor-container {
  display: grid;
  grid-template-columns: 280px 1fr 300px;
  gap: 24px;
  height: calc(100vh - 130px);
  min-height: 600px;
}

.editor-sidebar,
.editor-settings {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.sidebar-header,
.settings-header {
  padding: 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sidebar-header h3,
.settings-header h3 {
  font-size: 16px;
  font-weight: 600;
}

.slide-thumbnails {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
}

.thumbnail {
  background: var(--bg-primary);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px;
  margin-bottom: 12px;
  cursor: pointer;
  transition: all 0.2s;
}

.thumbnail:hover {
  border-color: var(--accent);
}

.thumbnail.active {
  border-color: var(--accent);
  background: var(--accent-light);
}

.thumbnail-number {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.thumbnail-title {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Slide Preview */
.editor-main {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.slide-preview-container {
  flex: 1;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  overflow: auto;
}

.slide-preview {
  background: white;
  width: 100%;
  max-width: 900px;
  aspect-ratio: 16/9;
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  padding: 60px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.slide-content {
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.slide-content h2 {
  font-size: 36px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
  line-height: 1.2;
}

.slide-content ul {
  list-style: none;
}

.slide-content li {
  font-size: 20px;
  color: var(--text-secondary);
  padding: 12px 0;
  padding-left: 28px;
  position: relative;
  line-height: 1.5;
}

.slide-content li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 24px;
  line-height: 1.4;
}

.editor-controls {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 24px;
  padding: 16px;
}

.slide-counter {
  font-weight: 600;
  color: var(--text-secondary);
  min-width: 80px;
  text-align: center;
}

/* Settings Panel */
.settings-content {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 8px 0;
}

/* Loading Overlay */
.loading-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(255,255,255,0.95);
  z-index: 1000;
  align-items: center;
  justify-content: center;
}

.loading-overlay.active {
  display: flex;
}

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

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto 20px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-content p {
  font-size: 18px;
  color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 1024px) {
  .editor-container {
    grid-template-columns: 1fr;
    height: auto;
  }

  .editor-sidebar,
  .editor-settings {
    display: none;
  }

  .slide-preview-container {
    min-height: 400px;
  }
}

@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: 16px;
  }

  .nav {
    gap: 16px;
  }

  .hero {
    padding: 40px 0;
  }

  .features {
    grid-template-columns: 1fr;
  }

  .form-card {
    padding: 24px;
  }

  .radio-group {
    grid-template-columns: 1fr;
  }
}