/* ==============================================================================
   Core Design System & Tokens
   ============================================================================== */
:root {
    /* Color Palette (HSL for harmony) */
    --bg-dark: 222 24% 8%;         /* #090d16 */
    --bg-deep: 223 20% 5%;         /* #06080e */
    --accent-purple: 263 90% 64%;  /* #8b5cf6 */
    --accent-blue: 217 91% 60%;    /* #3b82f6 */
    --accent-cyan: 190 95% 50%;    /* #06b6d4 */
    
    --text-primary: 210 40% 98%;   /* #f8fafc */
    --text-muted: 215 15% 65%;     /* #94a3b8 */
    --text-dark: 215 15% 45%;      /* #64748b */
    
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.06);
    --glass-shadow: rgba(0, 0, 0, 0.4);
    --glow-glow: 0 0 20px rgba(139, 92, 246, 0.15);
    
    /* Font Stack */
    --font-sans: 'Outfit', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    
    /* Transitions */
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --transition-smooth: all 0.4s var(--ease-out-expo);
}

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

body {
    background-color: hsl(var(--bg-dark));
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(139, 92, 246, 0.1) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(59, 130, 246, 0.1) 0%, transparent 45%),
        radial-gradient(circle at 50% 50%, hsl(var(--bg-deep)) 0%, hsl(var(--bg-dark)) 100%);
    background-attachment: fixed;
    color: hsl(var(--text-primary));
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ==============================================================================
   Header & Navigation
   ============================================================================== */
#main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 72px;
    background-color: rgba(9, 13, 22, 0.7);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    border-bottom: 1px solid var(--glass-border);
    z-index: 1000;
    transition: var(--transition-smooth);
}

.header-container {
    max-width: 1200px;
    height: 100%;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img {
    height: 36px;
    width: 36px;
    object-fit: contain;
    border-radius: 8px;
    mix-blend-mode: screen;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: 2px;
    background: linear-gradient(135deg, hsl(var(--accent-purple)) 0%, hsl(var(--accent-cyan)) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-text span {
    font-weight: 300;
    color: hsl(var(--text-primary));
    -webkit-text-fill-color: hsl(var(--text-primary));
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: hsl(var(--text-muted));
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 600;
    transition: var(--transition-smooth);
    position: relative;
    padding: 4px 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, hsl(var(--accent-purple)), hsl(var(--accent-blue)));
    transition: var(--transition-smooth);
}

.nav-links a:hover,
.nav-links a.active {
    color: hsl(var(--text-primary));
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.btn-primary {
    background: linear-gradient(135deg, hsl(var(--accent-purple)) 0%, hsl(var(--accent-blue)) 100%);
    border: none;
    color: white;
    padding: 10px 24px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(139, 92, 246, 0.3);
    transition: var(--transition-smooth);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(139, 92, 246, 0.5);
}

/* ==============================================================================
   Main Content Layout
   ============================================================================== */
#main-content {
    margin-top: 72px;
    padding-bottom: 60px;
}

.hero-section {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 24px 30px;
    text-align: center;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    margin-bottom: 12px;
    background: linear-gradient(135deg, hsl(var(--text-primary)) 30%, hsl(var(--text-muted)) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    color: hsl(var(--text-muted));
    font-size: 1.1rem;
    font-weight: 300;
}

/* ==============================================================================
   Feed Section (Masonry Grid)
   ============================================================================== */
.feed-section {
    max-width: 1240px;
    margin: 0 auto;
    padding: 24px;
}

.feed-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 30px;
}

/* Elegant Glassmorphic Card */
.feed-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 30px var(--glass-shadow);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition: var(--transition-smooth);
    opacity: 0;
    transform: translateY(20px);
}

/* Slide in animation */
.feed-card.show {
    animation: fadeInUp 0.8s var(--ease-out-expo) forwards;
}

.feed-card:hover {
    transform: translateY(-8px);
    border-color: rgba(139, 92, 246, 0.3);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.6), var(--glow-glow);
}

/* Card Media Header */
.card-media-wrapper {
    width: 100%;
    position: relative;
    padding-top: 56.25%; /* 16:9 Aspect Ratio */
    background-color: hsl(var(--bg-deep));
    overflow: hidden;
}

.card-media-wrapper img, 
.card-media-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border: none;
    transition: transform 0.6s var(--ease-out-expo);
}

.feed-card:hover .card-media-wrapper img {
    transform: scale(1.05);
}

.card-tag {
    position: absolute;
    top: 16px;
    left: 16px;
    background: rgba(9, 13, 22, 0.6);
    backdrop-filter: blur(8px);
    border: 1px solid var(--glass-border);
    color: hsl(var(--accent-cyan));
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 4px 12px;
    border-radius: 12px;
    letter-spacing: 0.5px;
    z-index: 10;
}

/* Card Body */
.card-body {
    padding: 24px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: hsl(var(--text-primary));
    margin-bottom: 12px;
    line-height: 1.4;
    transition: color 0.3s;
}

.feed-card:hover .card-title {
    background: linear-gradient(90deg, hsl(var(--text-primary)) 0%, hsl(var(--accent-cyan)) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.card-excerpt {
    font-size: 0.92rem;
    color: hsl(var(--text-muted));
    line-height: 1.6;
    margin-bottom: 20px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Card Footer */
.card-footer {
    margin-top: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 16px;
    border-top: 1px solid var(--glass-border);
}

.card-meta-author {
    font-size: 0.8rem;
    color: hsl(var(--text-dark));
    font-weight: 600;
}

.card-meta-date {
    font-size: 0.8rem;
    color: hsl(var(--text-dark));
}

/* ==============================================================================
   Loading Indicator & Footer
   ============================================================================== */
.loading-trigger {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 0 20px;
    color: hsl(var(--text-muted));
    font-size: 0.9rem;
    gap: 16px;
}

.spinner {
    width: 32px;
    height: 32px;
    border: 3px solid rgba(139, 92, 246, 0.1);
    border-top-color: hsl(var(--accent-purple));
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

#main-footer {
    border-top: 1px solid var(--glass-border);
    background-color: hsl(var(--bg-deep));
    padding: 30px 24px;
    text-align: center;
    color: hsl(var(--text-dark));
    font-size: 0.85rem;
}

/* ==============================================================================
   Keyframes Animations
   ============================================================================== */
@keyframes spin {
    to { transform: rotate(360deg); }
}

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

/* Responsive adjustments */
@media (max-width: 768px) {
    .nav-links {
        display: none; /* Mobile navigation simplified */
    }
    .hero-title {
        font-size: 2rem;
    }
    .feed-grid {
        grid-template-columns: 1fr;
    }
}