/* 
 * Potkasts Public CSS Core
 * Production-ready external stylesheet
 */

:root {
    /* Typography Scale */
    --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    /* Font Sizes */
    --font-size-xs: 0.75rem;      /* 12px */
    --font-size-sm: 0.875rem;     /* 14px */
    --font-size-base: 1rem;       /* 16px */
    --font-size-lg: 1.125rem;     /* 18px */
    --font-size-xl: 1.25rem;      /* 20px */
    
    /* Headings */
    --font-size-h1: 3rem;         /* 48px */
    --font-size-h2: 2.25rem;      /* 36px */
    --font-size-h3: 1.875rem;     /* 30px */
    --font-size-h4: 1.5rem;       /* 24px */
    --font-size-h5: 1.25rem;      /* 20px */
    --font-size-h6: 1.125rem;     /* 18px */
    
    /* Font Weights */
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-extrabold: 800;
    
    /* Line Heights */
    --line-height-tight: 1.2;
    --line-height-normal: 1.6;
    --line-height-relaxed: 1.8;
    
    /* Button System */
    --btn-border-radius: 12px;
    --btn-font-family: var(--font-family-base);
    --btn-font-weight: var(--font-weight-semibold);
    --btn-transition: all 0.3s ease;
    --btn-min-height: 44px;
    
    /* Button Sizes */
    --btn-padding-sm: 8px 16px;
    --btn-padding-base: 12px 24px;
    --btn-padding-lg: 16px 32px;
    --btn-font-size-sm: var(--font-size-sm);
    --btn-font-size-base: var(--font-size-base);
    --btn-font-size-lg: var(--font-size-lg);
    
    /* Shadows */
    --shadow-dropdown: 0 4px 20px rgba(0, 0, 0, 0.15);
    
    /* Brand Colors */
    --color-brand-primary: #7c3aed;
    --color-brand-secondary: #3b82f6;
    --color-brand-accent: #06b6d4;
    --color-brand-purple-light: #8b5cf6;
    --color-brand-blue-light: #60a5fa;
    --color-brand-cyan-light: #22d3ee;
    --color-brand-purple-lighter: #a855f7;
    --color-brand-purple-alpha: rgba(124, 58, 237, 0.1);
    --color-brand-purple-alpha-20: rgba(124, 58, 237, 0.2);
    --color-brand-purple-alpha-30: rgba(124, 58, 237, 0.3);
    --color-brand-purple-alpha-60: rgba(124, 58, 237, 0.6);
    
    /* Background System */
    --color-bg-primary: #0f0f23;
    --color-bg-secondary: #1a1a2e;
    --color-bg-tertiary: #1e1e32;
    --color-bg-quaternary: #2a2a40;
    --color-bg-accent: #16213e;
    --color-bg-glass: rgba(30, 30, 50, 0.8);
    --color-bg-overlay: rgba(0, 0, 0, 0.3);
    --color-bg-overlay-light: rgba(0, 0, 0, 0.2);
    
    /* Text System */
    --color-text-primary: #f8fafc;
    --color-text-secondary: #e4e4e7;
    --color-text-tertiary: #cbd5e1;
    --color-text-muted: #94a3b8;
    --color-text-subtle: #64748b;
    --color-text-disabled: #475569;
    --color-text-light: #e2e8f0;
    --color-text-white: #ffffff;
    
    /* State Colors */
    --color-success: #22c55e;
    --color-success-dark: #16a34a;
    --color-success-light: #4ade80;
    --color-warning: #f59e0b;
    --color-warning-dark: #d97706;
    --color-warning-light: #fbbf24;
    --color-danger: #ef4444;
    --color-danger-dark: #dc2626;
    --color-danger-light: #f87171;
    --color-info: #06b6d4;
    --color-info-dark: #0891b2;
    --color-info-light: #22d3ee;
    
    /* Interactive States */
    --color-hover-primary: var(--color-brand-purple-light);
    --color-hover-secondary: var(--color-brand-blue-light);
    --color-active-primary: var(--color-brand-primary);
    --color-focus-ring: rgba(124, 58, 237, 0.5);
    
    /* Border Colors */
    --color-border-primary: rgba(124, 58, 237, 0.2);
    --color-border-secondary: rgba(59, 130, 246, 0.2);
    --color-border-muted: rgba(148, 163, 184, 0.2);
    --color-border-subtle: rgba(100, 116, 139, 0.1);
    
    /* Shadow Colors */
    --color-shadow-primary: rgba(124, 58, 237, 0.3);
    --color-shadow-secondary: rgba(59, 130, 246, 0.3);
    --color-shadow-success: rgba(34, 197, 94, 0.3);
    --color-shadow-warning: rgba(245, 158, 11, 0.3);
    --color-shadow-danger: rgba(239, 68, 68, 0.3);
    --color-shadow-default: rgba(0, 0, 0, 0.3);
    --color-shadow-light: rgba(0, 0, 0, 0.1);
    
    /* Brand Gradients */
    --gradient-brand-primary: linear-gradient(135deg, var(--color-brand-primary) 0%, var(--color-brand-secondary) 100%);
    --gradient-brand-hover: linear-gradient(135deg, var(--color-brand-purple-light) 0%, var(--color-brand-blue-light) 100%);
    --gradient-bg-primary: linear-gradient(135deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 50%, var(--color-bg-accent) 100%);
    --gradient-bg-card: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-quaternary) 100%);
    --gradient-text-primary: linear-gradient(135deg, var(--color-text-white) 0%, var(--color-text-light) 100%);
    --gradient-success: linear-gradient(135deg, var(--color-success) 0%, var(--color-success-dark) 100%);
    --gradient-warning: linear-gradient(135deg, var(--color-warning) 0%, var(--color-warning-dark) 100%);
    --gradient-danger: linear-gradient(135deg, var(--color-danger) 0%, var(--color-danger-dark) 100%);
    
    /* Responsive Breakpoints */
    --breakpoint-sm: 480px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 1024px;
    --breakpoint-xl: 1200px;
    
    /* Button Colors */
    --btn-primary-bg: var(--gradient-brand-primary);
    --btn-primary-bg-hover: var(--gradient-brand-hover);
    --btn-primary-color: var(--color-text-white);
    --btn-primary-shadow: 0 10px 25px var(--color-shadow-primary);
    
    --btn-secondary-bg: var(--color-brand-purple-alpha);
    --btn-secondary-bg-hover: var(--color-brand-purple-alpha-20);
    --btn-secondary-border: 2px solid var(--color-brand-purple-alpha-30);
    --btn-secondary-border-hover: 2px solid var(--color-brand-purple-alpha-60);
    --btn-secondary-color: var(--color-brand-primary);
    --btn-secondary-color-hover: var(--color-brand-purple-light);
    
    --btn-success-bg: var(--gradient-success);
    --btn-success-bg-hover: linear-gradient(135deg, var(--color-success-light) 0%, var(--color-success) 100%);
    --btn-success-color: var(--color-text-white);
    --btn-success-shadow: 0 10px 25px var(--color-shadow-success);
    
    --btn-warning-bg: var(--gradient-warning);
    --btn-warning-bg-hover: linear-gradient(135deg, var(--color-warning-light) 0%, var(--color-warning) 100%);
    --btn-warning-color: var(--color-text-white);
    --btn-warning-shadow: 0 10px 25px var(--color-shadow-warning);
    
    --btn-danger-bg: var(--gradient-danger);
    --btn-danger-bg-hover: linear-gradient(135deg, var(--color-danger-light) 0%, var(--color-danger) 100%);
    --btn-danger-color: var(--color-text-white);
    --btn-danger-shadow: 0 10px 25px var(--color-shadow-danger);
    
    /* Button Transform Effects */
    --btn-transform-hover: translateY(-2px);
    --btn-transform-active: translateY(0px);
}

/* Mobile-first responsive typography */
@media (max-width: 768px) {
    :root {
        --font-size-h1: 2.25rem;      /* 36px on mobile */
        --font-size-h2: 1.875rem;     /* 30px on mobile */
        --font-size-h3: 1.5rem;       /* 24px on mobile */
        --font-size-h4: 1.25rem;      /* 20px on mobile */
        --font-size-h5: 1.125rem;     /* 18px on mobile */
        --font-size-h6: 1rem;         /* 16px on mobile */
    }
}

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

*:focus {
    outline: 2px solid var(--color-focus-ring);
    outline-offset: 2px;
}

/* Base typography */
body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    background: var(--gradient-bg-primary);
    color: var(--color-text-primary);
    line-height: var(--line-height-normal);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Accessibility improvements */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--color-brand-primary);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
    transition: top 0.3s ease;
}

.skip-link:focus {
    top: 6px;
}

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

/* Focus visible polyfill */
.focus-visible {
    outline: 2px solid var(--color-focus-ring);
    outline-offset: 2px;
}

/* Typography scale */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-bold);
    line-height: var(--line-height-tight);
    margin-bottom: 1rem;
}

h1 { font-size: var(--font-size-h1); }
h2 { font-size: var(--font-size-h2); }
h3 { font-size: var(--font-size-h3); }
h4 { font-size: var(--font-size-h4); }
h5 { font-size: var(--font-size-h5); }
h6 { font-size: var(--font-size-h6); }

p {
    margin-bottom: 1rem;
    color: var(--color-text-secondary);
}

/* Links */
a {
    color: var(--color-brand-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--color-brand-purple-light);
}

a:focus {
    outline: 2px solid var(--color-focus-ring);
    outline-offset: 2px;
}

/* Lists */
ul, ol {
    padding-left: 1.5rem;
    margin-bottom: 1rem;
}

li {
    margin-bottom: 0.5rem;
    color: var(--color-text-secondary);
}

/* Touch targets for mobile */
@media (max-width: 768px) {
    button, a, input, select, textarea {
        min-height: 44px;
        min-width: 44px;
    }
}