:root {
    /* Color Palette */
    --color-primary: #003366;    /* Deep Blue */
    --color-secondary: #007BFF;  /* Vibrant Blue */
    --color-dark: #222222;       /* Dark Grey */
    --color-light: #F8F9FA;      /* Light Grey Background */
    --color-white: #FFFFFF;
    --color-text: #333333;
    --color-text-light: #666666;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--color-text);
    background-color: var(--color-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

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

ul {
    list-style: none;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.75rem; }

p {
    margin-bottom: var(--spacing-sm);
}

/* Container */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 4px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all var(--transition-medium);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
}

.btn-primary {
    background-color: var(--color-secondary);
    color: var(--color-white);
}

.btn-primary:hover {
    background-color: #0056b3;
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--color-white);
    color: var(--color-white);
}

.btn-outline:hover {
    background-color: var(--color-white);
    color: var(--color-primary);
}

/* Header */
header {
    background-color: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-sm) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    color: var(--color-white);
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
}

.nav-links a {
    color: rgba(255,255,255,0.8);
    font-weight: 500;
    position: relative;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--color-white);
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--color-secondary);
    transition: width var(--transition-medium);
}

.nav-links a:hover::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--color-white);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Footer */
footer {
    background-color: var(--color-dark);
    color: rgba(255,255,255,0.7);
    padding: var(--spacing-lg) 0 var(--spacing-md);
    margin-top: auto;
}

footer h4 {
    color: var(--color-white);
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a:hover {
    color: var(--color-secondary);
}

.copyright {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--color-primary);
        flex-direction: column;
        padding: var(--spacing-md);
        gap: var(--spacing-sm);
        text-align: center;
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: block;
    }
}