/*
CHANGE LOG
File: /var/www/memory_system/static/index.css
Document Type: CSS Stylesheet
Purpose: Styling for Memory System home page (index.html)
Main App: memory_app.py
Route: /
Context: Clean, professional home page with freemium features showcase
Dependencies: None
Version History:
2025-08-17 v1.0 - Extracted from inline styles with unique class names
*/

/* =================================
   INDEX PAGE VARIABLES
   ================================= */

:root {
    --index-primary: #6366f1;
    --index-primary-dark: #4f46e5;
    --index-secondary: #8b5cf6;
    --index-accent: #06b6d4;
    --index-success: #10b981;
    --index-background: #f8fafc;
    --index-surface: #ffffff;
    --index-text-primary: #1e293b;
    --index-text-secondary: #64748b;
    --index-text-muted: #94a3b8;
    --index-border: #e2e8f0;
    --index-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --index-shadow-lg: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --index-radius: 12px;
}

/* =================================
   INDEX PAGE BASE STYLES
   ================================= */

.index-page-body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--index-text-primary);
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.index-page-body *,
.index-page-body *::before,
.index-page-body *::after {
    box-sizing: border-box;
}

.index-main-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* =================================
   USER BAR STYLES
   ================================= */

.index-user-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 0.75rem 1rem;
    box-shadow: var(--index-shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    z-index: 100;
}

.index-user-info {
    color: var(--index-text-secondary);
    font-weight: 500;
}

.index-tier-badge {
    display: inline-block;
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    margin-left: 10px;
}

.index-tier-free {
    background: #17a2b8;
    color: white;
}

.index-tier-premium {
    background: linear-gradient(135deg, #ffd700, #ffed4e);
    color: #212529;
}

.index-logout-link {
    color: var(--index-primary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--index-radius);
    transition: all 0.2s;
}

.index-logout-link:hover {
    background: var(--index-primary);
    color: white;
    text-decoration: none;
}

/* =================================
   HEADER STYLES
   ================================= */

.index-header {
    text-align: center;
    margin-bottom: 3rem;
}

.index-logo {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    background: var(--index-surface);
    padding: 1.5rem 2.5rem;
    border-radius: var(--index-radius);
    box-shadow: var(--index-shadow);
    margin-bottom: 1.5rem;
    font-size: 2rem;
    font-weight: 700;
    color: var(--index-primary);
    text-decoration: none;
}

.index-brain-icon {
    font-size: 2.5rem;
    background: linear-gradient(135deg, var(--index-primary), var(--index-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.index-tagline {
    color: white;
    font-size: 1.125rem;
    font-weight: 500;
    text-shadow: 0 2px 4px rgb(0 0 0 / 0.3);
}

/* =================================
   CARDS GRID STYLES
   ================================= */

.index-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.index-card {
    background: var(--index-surface);
    border-radius: var(--index-radius);
    padding: 2.5rem;
    box-shadow: var(--index-shadow-lg);
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
    position: relative;
    overflow: hidden;
    text-align: center;
}

.index-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--index-primary), var(--index-secondary));
}

.index-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 25px 50px -12px rgb(0 0 0 / 0.25);
    text-decoration: none;
    color: inherit;
}

.index-card-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    display: block;
}

.index-card-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--index-text-primary);
}

.index-card-description {
    color: var(--index-text-secondary);
    line-height: 1.6;
    font-size: 1rem;
    margin-bottom: 1rem;
}

.index-card-badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    margin-top: 10px;
}

/* =================================
   CARD VARIANTS
   ================================= */

.index-card-primary .index-card-icon {
    background: linear-gradient(135deg, #10b981, #059669);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.index-card-secondary .index-card-icon {
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.index-card-premium .index-card-icon {
    background: linear-gradient(135deg, #ffd700, #ffed4e);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.index-card-free .index-card-icon {
    background: linear-gradient(135deg, #17a2b8, #138496);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.index-card-upgrade .index-card-icon {
    background: linear-gradient(135deg, #e74c3c, #c0392b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.index-card-upgrade {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.index-card-upgrade .index-card-title,
.index-card-upgrade .index-card-description {
    color: white;
}

.index-card-upgrade::before {
    background: linear-gradient(90deg, #ffd700, #ffed4e);
}

.index-badge-free {
    background: #17a2b8;
    color: white;
}

.index-badge-premium {
    background: linear-gradient(135deg, #ffd700, #ffed4e);
    color: #212529;
}

.index-badge-upgrade {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

/* =================================
   FEATURE SHOWCASE SECTION
   ================================= */

.index-features-section {
    background: var(--index-surface);
    border-radius: var(--index-radius);
    padding: 3rem;
    margin: 3rem 0;
    box-shadow: var(--index-shadow-lg);
    text-align: center;
}

.index-features-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--index-text-primary);
    margin-bottom: 1rem;
}

.index-features-subtitle {
    color: var(--index-text-secondary);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.index-features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.index-feature-item {
    text-align: center;
    padding: 1.5rem;
}

.index-feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.index-feature-name {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--index-text-primary);
    margin-bottom: 0.5rem;
}

.index-feature-desc {
    color: var(--index-text-secondary);
    font-size: 0.9rem;
    line-height: 1.4;
}

/* =================================
   ANIMATIONS
   ================================= */

@keyframes indexFadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.index-card {
    animation: indexFadeInUp 0.6s ease-out;
}

.index-card:nth-child(2) {
    animation-delay: 0.1s;
}

.index-card:nth-child(3) {
    animation-delay: 0.2s;
}

.index-card:nth-child(4) {
    animation-delay: 0.3s;
}

.index-card:nth-child(5) {
    animation-delay: 0.4s;
}

.index-card:nth-child(6) {
    animation-delay: 0.5s;
}

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

@media (max-width: 1024px) {
    .index-cards-grid {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        gap: 1.5rem;
    }
    
    .index-features-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
        gap: 1.5rem;
    }
}

@media (max-width: 768px) {
    .index-main-container {
        padding: 1rem;
        margin-top: 5rem;
    }
    
    .index-cards-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .index-card {
        padding: 2rem;
    }
    
    .index-logo {
        padding: 1rem 2rem;
        font-size: 1.5rem;
    }
    
    .index-brain-icon {
        font-size: 2rem;
    }
    
    .index-tagline {
        font-size: 1rem;
    }

    .index-user-bar {
        flex-direction: column;
        gap: 0.5rem;
        padding: 1rem;
    }
    
    .index-features-section {
        padding: 2rem 1.5rem;
    }
    
    .index-features-title {
        font-size: 1.6rem;
    }
    
    .index-features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

@media (max-width: 480px) {
    .index-main-container {
        padding: 0.5rem;
        margin-top: 6rem;
    }
    
    .index-card {
        padding: 1.5rem;
    }
    
    .index-card-icon {
        font-size: 3rem;
    }
    
    .index-card-title {
        font-size: 1.3rem;
    }
    
    .index-features-section {
        padding: 1.5rem 1rem;
    }
    
    .index-logo {
        padding: 0.75rem 1.5rem;
        font-size: 1.3rem;
        gap: 0.5rem;
    }
    
    .index-brain-icon {
        font-size: 1.8rem;
    }
}

/* Special Return Card (forest green) */
.index-card-return {
  background: #166534;         /* deep forest green */
  border: 2px solid #14532d;   /* slightly darker green border */
  color: #ffffff;              /* white text */
}

.index-card-return:hover {
  background: #14532d;
  transform: translateY(-3px);
  box-shadow: 0 6px 18px rgba(20, 83, 45, 0.4);
}

.index-card-return .index-card-title {
  color: #ffffff;
}

.index-card-return .index-card-description {
  color: rgba(255,255,255,0.85);
}