:root {
    /* Color Palette - Light Mode */
    --bg-color: #fcfcfc;
    --bg-alt: #f3f4f6;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;
    --border-color: #e5e7eb;
    --card-bg: #ffffff;
    --nav-bg: rgba(252, 252, 252, 0.85);
    
    /* Typography */
    --font-main: 'Inter', sans-serif;
    
    /* Spacing & Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --container-width: 1000px;
}

body.dark {
    /* Color Palette - Dark Mode */
    --bg-color: #0f172a;
    --bg-alt: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --accent-color: #3b82f6;
    --accent-hover: #60a5fa;
    --border-color: #334155;
    --card-bg: #1e293b;
    --nav-bg: rgba(15, 23, 42, 0.85);
}

/* Global Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
}

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

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

ul {
    list-style: none;
}

/* Layout */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 100px 0;
}

.bg-alt {
    background-color: var(--bg-alt);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 3rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60px;
    height: 4px;
    background-color: var(--accent-color);
    border-radius: 2px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    color: #ffffff;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 2px solid var(--accent-color);
}

.btn-secondary:hover {
    background-color: rgba(59, 130, 246, 0.1);
    transform: translateY(-2px);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* Typography Utility */
.mt-4 {
    margin-top: 2rem;
}

/* Micro-Animations Class */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}