/* ===================================
   CSS Variables & Design Tokens
   =================================== */

:root {
    /* Colors - Light Mode */
    --background: hsl(210, 20%, 98%);
    --foreground: hsl(222, 47%, 11%);
    
    --card: hsl(0, 0%, 100%);
    --card-foreground: hsl(222, 47%, 11%);
    
    --popover: hsl(0, 0%, 100%);
    --popover-foreground: hsl(222, 47%, 11%);
    
    --primary: hsl(217, 91%, 60%);
    --primary-foreground: hsl(0, 0%, 100%);
    
    --secondary: hsl(160, 84%, 39%);
    --secondary-foreground: hsl(0, 0%, 100%);
    
    --muted: hsl(210, 20%, 96%);
    --muted-foreground: hsl(215, 16%, 47%);
    
    --accent: hsl(217, 91%, 95%);
    --accent-foreground: hsl(217, 91%, 40%);
    
    --destructive: hsl(0, 84%, 60%);
    --destructive-foreground: hsl(0, 0%, 100%);
    
    --border: hsl(214, 32%, 91%);
    --input: hsl(214, 32%, 91%);
    --ring: hsl(217, 91%, 60%);
    
    --radius: 0.75rem;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, hsl(217, 91%, 60%) 0%, hsl(217, 91%, 50%) 100%);
    --gradient-secondary: linear-gradient(135deg, hsl(160, 84%, 39%) 0%, hsl(160, 84%, 30%) 100%);
    --gradient-hero: linear-gradient(135deg, hsl(217, 91%, 60%) 0%, hsl(240, 91%, 65%) 50%, hsl(280, 91%, 60%) 100%);
    --gradient-subtle: linear-gradient(180deg, hsl(210, 20%, 98%) 0%, hsl(217, 91%, 98%) 100%);
    --gradient-card: linear-gradient(180deg, hsl(0, 0%, 100%) 0%, hsl(210, 20%, 99%) 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 hsl(222, 47%, 11%, 0.05);
    --shadow-md: 0 4px 6px -1px hsl(222, 47%, 11%, 0.1), 0 2px 4px -2px hsl(222, 47%, 11%, 0.1);
    --shadow-lg: 0 10px 15px -3px hsl(222, 47%, 11%, 0.1), 0 4px 6px -4px hsl(222, 47%, 11%, 0.1);
    --shadow-xl: 0 20px 25px -5px hsl(222, 47%, 11%, 0.1), 0 8px 10px -6px hsl(222, 47%, 11%, 0.1);
    --shadow-glow: 0 0 40px hsl(217, 91%, 60%, 0.3);
    --shadow-card: 0 4px 20px hsl(222, 47%, 11%, 0.08);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Typography */
    --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 200ms ease-in-out;
    --transition-slow: 300ms ease-in-out;
}

.dark {
    --background: hsl(222, 47%, 6%);
    --foreground: hsl(210, 40%, 98%);
    
    --card: hsl(222, 47%, 8%);
    --card-foreground: hsl(210, 40%, 98%);
    
    --popover: hsl(222, 47%, 8%);
    --popover-foreground: hsl(210, 40%, 98%);
    
    --primary: hsl(217, 91%, 60%);
    --primary-foreground: hsl(0, 0%, 100%);
    
    --secondary: hsl(160, 84%, 39%);
    --secondary-foreground: hsl(0, 0%, 100%);
    
    --muted: hsl(217, 33%, 17%);
    --muted-foreground: hsl(215, 20%, 65%);
    
    --accent: hsl(217, 33%, 17%);
    --accent-foreground: hsl(210, 40%, 98%);
    
    --destructive: hsl(0, 63%, 31%);
    --destructive-foreground: hsl(210, 40%, 98%);
    
    --border: hsl(217, 33%, 17%);
    --input: hsl(217, 33%, 17%);
    --ring: hsl(217, 91%, 60%);
    
    --gradient-primary: linear-gradient(135deg, hsl(217, 91%, 50%) 0%, hsl(217, 91%, 40%) 100%);
    --gradient-hero: linear-gradient(135deg, hsl(217, 91%, 50%) 0%, hsl(240, 91%, 55%) 50%, hsl(280, 91%, 50%) 100%);
    --gradient-subtle: linear-gradient(180deg, hsl(222, 47%, 6%) 0%, hsl(217, 47%, 8%) 100%);
    --gradient-card: linear-gradient(180deg, hsl(222, 47%, 8%) 0%, hsl(222, 47%, 10%) 100%);
    
    --shadow-glow: 0 0 40px hsl(217, 91%, 60%, 0.2);
    --shadow-card: 0 4px 20px hsl(0, 0%, 0%, 0.3);
}

/* ===================================
   Base Styles
   =================================== */

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background-color: var(--background);
    color: var(--foreground);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
}

/* ===================================
   Typography
   =================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

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

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-base);
}

a:hover {
    color: var(--accent-foreground);
}

/* ===================================
   Layout Utilities
   =================================== */

.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-wide {
    width: 100%;
    max-width: 1536px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-3xl) 0;
}

.section-sm {
    padding: var(--spacing-2xl) 0;
}

/* ===================================
   Grid System
   =================================== */

.grid {
    display: grid;
    gap: var(--spacing-lg);
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* ===================================
   Flexbox Utilities
   =================================== */

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

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

.justify-center {
    justify-content: center;
}

.justify-between {
    justify-content: space-between;
}

.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* ===================================
   Text Utilities
   =================================== */

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

.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-base { font-size: var(--font-size-base); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-2xl { font-size: var(--font-size-2xl); }
.text-3xl { font-size: var(--font-size-3xl); }
.text-4xl { font-size: var(--font-size-4xl); }
.text-5xl { font-size: var(--font-size-5xl); }

.font-light { font-weight: 300; }
.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }
.font-extrabold { font-weight: 800; }

.text-muted { color: var(--muted-foreground); }
.text-primary { color: var(--primary); }
.text-secondary { color: var(--secondary); }

/* ===================================
   Gradient Text
   =================================== */

.gradient-text {
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}

/* ===================================
   Animations
   =================================== */

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes pulse-soft {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

@keyframes slide-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes scale-in {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.animate-float {
    animation: float 6s ease-in-out infinite;
}

.animate-pulse-soft {
    animation: pulse-soft 3s ease-in-out infinite;
}

.animate-slide-up {
    animation: slide-up 0.5s ease-out forwards;
}

.animate-fade-in {
    animation: fade-in 0.5s ease-out forwards;
}

.animate-scale-in {
    animation: scale-in 0.3s ease-out forwards;
}

/* ===================================
   Loading Spinner
   =================================== */

.loading-spinner {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--muted);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

/* ===================================
   Custom Scrollbar
   =================================== */

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--muted);
}

::-webkit-scrollbar-thumb {
    background: var(--muted-foreground);
    border-radius: 4px;
    opacity: 0.3;
}

::-webkit-scrollbar-thumb:hover {
    opacity: 0.5;
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 1024px) {
    .grid-cols-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .grid-cols-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .container,
    .container-wide {
        padding: 0 var(--spacing-sm);
    }
    
    .section {
        padding: var(--spacing-2xl) 0;
    }
    
    .grid-cols-2,
    .grid-cols-3,
    .grid-cols-4 {
        grid-template-columns: 1fr;
    }
    
    h1 { font-size: var(--font-size-4xl); }
    h2 { font-size: var(--font-size-3xl); }
    h3 { font-size: var(--font-size-2xl); }
}

/* ===================================
   Utility Classes
   =================================== */

.hidden {
    display: none !important;
}

.visible {
    display: block !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.transition {
    transition: all var(--transition-base);
}

.cursor-pointer {
    cursor: pointer;
}