/* ==========================================================================
   Upclass Meet - Main CSS Variables & Base Styles
   ========================================================================== */

:root {
    /* Primary Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --primary-glow: rgba(99, 102, 241, 0.3);
    
    /* Accent Colors */
    --accent: #06b6d4;
    --accent-dark: #0891b2;
    
    /* Success/Error */
    --success: #10b981;
    --success-dark: #059669;
    --danger: #ef4444;
    --danger-dark: #dc2626;
    --warning: #f59e0b;
    
    /* Neutrals */
    --dark-900: #0f0f14;
    --dark-800: #18181f;
    --dark-700: #1f1f28;
    --dark-600: #2a2a36;
    --dark-500: #3a3a48;
    --dark-400: #52525b;
    --dark-300: #71717a;
    --dark-200: #a1a1aa;
    --dark-100: #d4d4d8;
    --white: #ffffff;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    --gradient-dark: linear-gradient(180deg, var(--dark-800) 0%, var(--dark-900) 100%);
    --gradient-glow: radial-gradient(circle at center, var(--primary-glow) 0%, transparent 70%);
    
    /* Typography */
    --font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px var(--primary-glow);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
}

/* Base Reset & Typography */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.6;
    color: var(--dark-100);
    background: var(--dark-900);
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    margin: 0;
    font-weight: 600;
    line-height: 1.2;
    color: var(--white);
}

p {
    margin: 0;
}

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

a:hover {
    color: var(--primary);
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    outline: none;
}

input {
    font-family: inherit;
    outline: none;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

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

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--dark-800);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb {
    background: var(--dark-500);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--dark-400);
}

/* Selection */
::selection {
    background: var(--primary);
    color: var(--white);
}

/* Focus Styles */
:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Loading Animation */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

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

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

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

/* Common Button Styles */
.btn-primary-custom {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--gradient-primary);
    color: var(--white);
    font-weight: 600;
    font-size: 1rem;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    text-decoration: none;
}

.btn-primary-custom:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
    color: var(--white);
}

.btn-secondary-custom {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--dark-600);
    color: var(--dark-100);
    font-weight: 600;
    font-size: 1rem;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    text-decoration: none;
    border: 1px solid var(--dark-500);
}

.btn-secondary-custom:hover {
    background: var(--dark-500);
    color: var(--white);
}