/* ==========================================================================
   ExcelSuperGuru - Global Design System & Variables
   ========================================================================== */

:root {
    /* Font Stack */
    --font-primary: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, Roboto, sans-serif;

    /* Light Theme Tokens */
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f3f5;
    
    --text-primary: #1c1e21;
    --text-secondary: #495057;
    --text-muted: #6c757d;
    
    --excel-green: #107c41;
    --excel-green-hover: #0a5c2f;
    --excel-green-alpha: rgba(16, 124, 65, 0.1);
    
    --border-color: #dee2e6;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    --transition-smooth: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --max-width: 1280px;
}

body.dark-mode {
    /* Dark Theme Tokens */
    --bg-primary: #0f111a;
    --bg-secondary: #161925;
    --bg-tertiary: #1f2335;
    
    --text-primary: #f8f9fa;
    --text-secondary: #c1c7e0;
    --text-muted: #7a829e;
    
    --excel-green: #107c41;
    --excel-green-hover: #169e53;
    --excel-green-alpha: rgba(16, 124, 65, 0.25);
    
    --border-color: #2a2f45;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.4);
}

/* ==========================================================================
   CSS Reset
   ========================================================================== */

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

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    transition: background-color 0.25s ease, color 0.25s ease;
}

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

h1, h2, h3, h4, h5, h6 {
    
    font-weight: 600;
    line-height: 1.25;
    margin-bottom: 0.5rem;
}

h1 { font-size: 2.5rem; letter-spacing: -0.02em; }
h2 { font-size: 2rem; letter-spacing: -0.01em; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

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

a {
    color: var(--excel-green);
    text-decoration: none;
    transition: var(--transition-smooth);
}

a:hover {
    color: var(--excel-green-hover);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Utility Grid Systems */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 2rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }

.text-center { text-align: center; }
.section-padding { padding: 5rem 0; }



.neon-blue-text {
    color: hsl(243, 91%, 50%); /* Pure High-Vibrancy Neon Blue */
    font-weight: 700; /* Extra Bold taaki text alag se highlight ho */
    text-shadow: 0 0 8px rgba(0, 240, 255, 0.4); /* Subtle Neon Glow effect */
}