/* ==========================================================================
   DESIGN SYSTEM & VARIABLES
   ========================================================================== */
:root {
    /* Fonts */
    --font-serif: 'Playfair Display', Georgia, serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    
    /* Transition Timings */
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --transition-slow: 0.6s var(--ease-out-expo);
    --transition-medium: 0.3s var(--ease-out-expo);
    --transition-fast: 0.15s ease;

    /* Spacing Scale */
    --space-xs: 0.5rem;   /* 8px */
    --space-sm: 1rem;     /* 16px */
    --space-md: 1.5rem;   /* 24px */
    --space-lg: 3rem;     /* 48px */
    --space-xl: 6rem;     /* 96px */
    --space-xxl: 10rem;   /* 160px */

    /* Max Widths */
    --container-max-width: 1200px;
}

/* Light Theme Tokens */
.light-theme {
    --bg-color: #fcfcfb;
    --text-primary: #121212;
    --text-secondary: #60605c;
    --text-muted: #9c9c98;
    
    --border-color: #e8e8e5;
    --border-color-hover: #121212;
    
    --card-bg: rgba(255, 255, 255, 0.4);
    --card-bg-hover: #ffffff;
    
    --accent-color: #3b5249; /* Verde desaturato */
    --accent-rgb: 59, 82, 73;
    
    --glow-opacity: 0.04;
    --glow-color: 210, 180, 140; /* Tonalità calda sabbia */
}

/* Dark Theme Tokens */
.dark-theme {
    --bg-color: #0b0b0b;
    --text-primary: #f5f5f3;
    --text-secondary: #a0a09a;
    --text-muted: #5a5a57;
    
    --border-color: #1a1a19;
    --border-color-hover: #f5f5f3;
    
    --card-bg: rgba(18, 18, 18, 0.4);
    --card-bg-hover: #141414;
    
    --accent-color: #8fa89b; /* Verde desaturato chiaro */
    --accent-rgb: 143, 168, 155;
    
    --glow-opacity: 0.15;
    --glow-color: 90, 120, 110;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-weight: 300;
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color var(--transition-slow), color var(--transition-slow);
    position: relative;
}

/* Decorative Background Glow */
.background-glow {
    position: fixed;
    top: -10%;
    right: -10%;
    width: 60vw;
    height: 60vw;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(var(--glow-color), 1) 0%, rgba(var(--bg-color), 0) 70%);
    opacity: var(--glow-opacity);
    z-index: -1;
    pointer-events: none;
    transition: opacity var(--transition-slow), background var(--transition-slow);
}

/* Typography Selection */
::selection {
    background-color: rgba(var(--accent-rgb), 0.15);
    color: var(--text-primary);
}

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */
.header {
    width: 100%;
    padding: var(--space-md) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: rgba(255, 255, 255, 0.01);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-bottom: 1px solid rgba(var(--accent-rgb), 0.03);
    transition: border-bottom var(--transition-medium);
}

.header-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--space-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.15rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    text-decoration: none;
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.8;
}

.logo-dot {
    color: var(--accent-color);
    transition: color var(--transition-slow);
}

/* Theme Toggle Button */
.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: grid;
    place-items: center;
    color: var(--text-primary);
    transition: border-color var(--transition-medium), background-color var(--transition-medium), transform var(--transition-medium);
}

.theme-toggle:hover {
    border-color: var(--border-color-hover);
    background-color: rgba(var(--accent-rgb), 0.05);
    transform: scale(1.05);
}

.theme-toggle svg {
    grid-area: 1 / 1;
    width: 18px;
    height: 18px;
    transition: opacity var(--transition-slow), transform var(--transition-slow);
}

/* Hide sun in light theme, show moon */
.light-theme .sun-icon {
    opacity: 0;
    transform: rotate(45deg);
}

.light-theme .moon-icon {
    opacity: 1;
    transform: rotate(0);
}

/* Hide moon in dark theme, show sun */
.dark-theme .sun-icon {
    opacity: 1;
    transform: rotate(0);
}

.dark-theme .moon-icon {
    opacity: 0;
    transform: rotate(-45deg);
}

/* ==========================================================================
   MAIN CONTENT
   ========================================================================== */
.main-content {
    flex-grow: 1;
    max-width: var(--container-max-width);
    width: 100%;
    margin: 0 auto;
    padding: var(--space-xl) var(--space-md) var(--space-xxl);
}

/* Hero Section */
.hero-section {
    max-width: 760px;
    margin-bottom: var(--space-xxl);
}

.hero-title {
    font-family: var(--font-serif);
    font-size: clamp(3rem, 7vw, 4.8rem);
    font-weight: 400;
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-md);
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp var(--transition-slow) forwards;
}

.italic-serif {
    font-style: italic;
    font-weight: 400;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.25rem);
    font-weight: 300;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 600px;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp var(--transition-slow) 0.15s forwards;
}

.hero-subtitle strong {
    font-weight: 500;
    color: var(--text-primary);
}

/* Grid Section */
.grid-section {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp var(--transition-slow) 0.3s forwards;
}

.section-title {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--text-muted);
    margin-bottom: var(--space-lg);
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    display: block;
    width: 30px;
    height: 1px;
    background-color: var(--accent-color);
    margin-top: 6px;
    transition: width var(--transition-slow);
}

.grid-section:hover .section-title::after {
    width: 50px;
}

/* Card Grid Container */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-md);
}

/* ==========================================================================
   CARDS & SKELETONS
   ========================================================================== */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: var(--space-lg) var(--space-md);
    border-radius: 4px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 320px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: 
        border-color var(--transition-medium), 
        background-color var(--transition-medium), 
        transform var(--transition-slow);
}

.card:hover {
    border-color: var(--border-color-hover);
    background-color: var(--card-bg-hover);
    transform: translateY(-4px);
}

/* Monogram Badge */
.card-monogram {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 24px;
    border-radius: 12px;
    margin-bottom: var(--space-lg);
    background-color: rgba(255, 255, 255, 0.02);
    transition: border-color var(--transition-medium), color var(--transition-medium);
}

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

/* Card Typography */
.card-title {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: 400;
    line-height: 1.2;
    margin-bottom: 0.35rem;
    color: var(--text-primary);
}

.card-subtitle {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--accent-color);
    margin-bottom: var(--space-sm);
    letter-spacing: -0.01em;
}

.card-description {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: var(--space-lg);
}

/* Tags Container */
.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: auto;
}

.tag-badge {
    font-size: 0.72rem;
    color: var(--text-secondary);
    background-color: rgba(var(--accent-rgb), 0.04);
    border: 1px solid var(--border-color);
    padding: 0.25rem 0.6rem;
    border-radius: 2px;
    font-weight: 400;
    transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.card:hover .tag-badge {
    border-color: rgba(var(--accent-rgb), 0.15);
    background-color: rgba(var(--accent-rgb), 0.08);
}

/* Skeleton Loading State */
.card-skeleton {
    min-height: 320px;
    background: linear-gradient(
        90deg, 
        rgba(var(--accent-rgb), 0.02) 25%, 
        rgba(var(--accent-rgb), 0.05) 50%, 
        rgba(var(--accent-rgb), 0.02) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite linear;
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.footer {
    width: 100%;
    border-top: 1px solid var(--border-color);
    padding: var(--space-lg) 0;
    margin-top: auto;
    font-size: 0.8rem;
    color: var(--text-muted);
    transition: border-top var(--transition-slow);
}

.footer-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--space-md);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-xs);
}

@media(min-width: 600px) {
    .footer-container {
        flex-direction: row;
        gap: 0;
    }
}

.tech-stack-indicator {
    font-weight: 400;
    font-size: 0.75rem;
    opacity: 0.7;
    position: relative;
    padding-left: 12px;
}

.tech-stack-indicator::before {
    content: '';
    display: inline-block;
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background-color: var(--accent-color);
}

/* ==========================================================================
   KEYFRAME ANIMATIONS
   ========================================================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================================================
   MEDIA QUERIES (RESPONSIVENESS)
   ========================================================================== */
@media (max-width: 768px) {
    :root {
        --space-xl: 4rem;
        --space-xxl: 6rem;
    }
    
    .main-content {
        padding-top: var(--space-lg);
    }
    
    .hero-section {
        margin-bottom: var(--space-xl);
    }
}