/**
 * Base Styles & Variables
 * Core styling and CSS custom properties
 */

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

/* CSS Variables */
:root {
    /* Colors */
    --primary: #0f172a;
    --primary-light: #1e293b;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --accent-light: #dbeafe;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-light: #64748b;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border: #e2e8f0;
    
    /* Shadows */
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    
    /* Transitions */
    --transition: all 0.2s ease;
    --transition-slow: all 0.3s ease;
}

/* Base Typography */
html {
    scroll-behavior: smooth;
}

/* Page Loading State */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Hide everything except loader during loading */
body.loading {
    overflow: hidden;
}

/* Keep navbar and page-header visible immediately to prevent flash */
body.loading .navbar,
body.loading .page-header,
body.loading .hero {
    visibility: visible !important;
    opacity: 1 !important;
}

/* Hide dynamic content during loading */
body.loading [data-dynamic],
body.loading #footer-placeholder {
    visibility: hidden;
    opacity: 0;
}

body:not(.loading) [data-dynamic],
body:not(.loading) #footer-placeholder {
    visibility: visible;
    opacity: 1;
    animation: fadeIn 0.3s ease;
}

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

/* Page Loader Overlay */
#page-loader {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

#page-loader.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.page-loader-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* Section */
.section {
    padding: var(--space-2xl) 0;
}

.section-alt {
    background: var(--bg-secondary);
    padding: var(--space-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--primary);
}

.section-header p {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* Loading State */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 200px;
}

.loading::after {
    content: '';
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--space-sm); }
.mt-2 { margin-top: var(--space-md); }
.mt-3 { margin-top: var(--space-lg); }
.mt-4 { margin-top: var(--space-xl); }

.mb-1 { margin-bottom: var(--space-sm); }
.mb-2 { margin-bottom: var(--space-md); }
.mb-3 { margin-bottom: var(--space-lg); }
.mb-4 { margin-bottom: var(--space-xl); }

.hidden { display: none !important; }

/* Background utilities */
.bg-secondary {
    background-color: var(--bg-secondary);
}

/* Text utilities */
.text-muted {
    color: var(--text-light);
    text-align: center;
    padding: 2rem;
}

/* ---------- Modern aesthetic layer (2026 refresh) ---------- */

/* Softer, more premium page background (still minimal) */
body {
    background:
        radial-gradient(1200px 700px at 15% -10%, rgba(59, 130, 246, 0.12), transparent 60%),
        radial-gradient(900px 600px at 90% 10%, rgba(16, 185, 129, 0.04), transparent 55%),
        radial-gradient(1000px 700px at 50% 110%, rgba(245, 158, 11, 0.06), transparent 60%),
        var(--bg-primary);
}

/* Subtle grain overlay (no external assets) */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    opacity: 0.045;
    mix-blend-mode: multiply;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='.42'/%3E%3C/svg%3E");
}

/* Slightly better type hierarchy */
h1, h2, h3 {
    letter-spacing: -0.02em;
}

.section-header h2 {
    letter-spacing: -0.03em;
}

/* Improve readability on large screens */
.section-header p,
.bio-text,
.hero-description {
    max-width: 68ch;
    margin-left: auto;
    margin-right: auto;
}

/* Accessible focus ring (nice + modern) */
:focus-visible {
    outline: 3px solid rgba(59, 130, 246, 0.55);
    outline-offset: 3px;
    border-radius: 10px;
}

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
        scroll-behavior: auto !important;
    }
}