/* Color Palette & Variables */
:root {
    --white: #ffffff;
    --off-white: #f8f9fa;
    --light-grey: #e9ecef;
    --medium-grey: #6c757d;
    --dark-grey: #343a40;
    --navy-blue: #0a192f;
    --navy-light: #112240;
    --accent: #1d3557; 
    --transition: all 0.3s ease-in-out;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--dark-grey);
    background-color: var(--white);
    line-height: 1.6;
}

.container {
    max-width: 100%;
    margin: 0 auto;
    padding: 0 20px;
}

.text-center {
    text-align: center;
}

/* Typography Utilities */
h1, h2, h3, h4 {
    color: var(--navy-blue);
    font-weight: 700;
    line-height: 1.2;
}

.navy-text {
    color: var(--navy-light);
}

.section-header {
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

/* Navigation */
.navbar {
    background-color: var(--white);
    border-bottom: 1px solid var(--light-grey);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    padding: 15px 0;
}

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

.logo {
    max-height: 50px;
    width: auto;
}

.nav-links {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: var(--medium-grey);
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
}

a {
    text-decoration: none;
}

.nav-links a:hover {
    color: var(--navy-blue);
}

.btn-nav {
    background-color: var(--navy-blue);
    color: var(--white) !important;
    padding: 10px 20px;
    border-radius: 4px;
}

.btn-nav:hover {
    background-color: var(--navy-light);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 15px 30px;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.btn-primary {
    background-color: var(--navy-blue);
    color: var(--white);
    border: 2px solid var(--navy-blue);
}

.btn-primary:hover {
    background-color: transparent;
    color: var(--navy-blue);
}

/* Hero Section */
.hero {
    padding: 10% 0 0;
    background: linear-gradient(to bottom, var(--off-white), var(--white));
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.1rem;
    color: var(--medium-grey);
    max-width: 800px;
    margin: 0 auto 40px;
}

/* About Us Section */
.about-section {
    padding: 80px 0;
    background-color: var(--white);
}

.intro-text {
    font-size: 1.1rem;
    max-width: 900px;
    margin: 0 auto;
    color: var(--medium-grey);
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 60px;
}

.value-card {
    background: var(--off-white);
    padding: 40px 30px;
    border-radius: 8px;
    border: 1px solid var(--light-grey);
    transition: var(--transition);
}

.value-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

.value-card h4 {
    margin-bottom: 15px;
    font-size: 1.2rem;
}

/* Split Pillars Section */
.split-pillars {
    display: grid;
    grid-template-columns: 1fr 1fr;
    border-top: 1px solid var(--light-grey);
}

.pillar {
    padding: 100px 10%;
}

.rd-pillar {
    background-color: var(--white);
}

.infra-pillar {
    background-color: var(--off-white);
    border-left: 1px solid var(--light-grey);
}

.pillar-badge {
    display: inline-block;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--medium-grey);
    border-bottom: 2px solid var(--navy-blue);
    margin-bottom: 20px;
    padding-bottom: 5px;
}

.pillar h3 {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.pillar-subtitle {
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 40px;
    font-size: 1.1rem;
}

.sub-sector {
    margin-bottom: 40px;
}

.sub-sector h4 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.sub-sector p {
    color: var(--medium-grey);
    margin-bottom: 15px;
}

.pillar-list {
    list-style: none;
}

.pillar-list li {
    margin-bottom: 15px;
    padding-left: 20px;
    position: relative;
    color: var(--dark-grey);
    font-size: 0.95rem;
}

.pillar-list li::before {
    content: "■";
    position: absolute;
    left: 0;
    color: var(--light-grey);
    font-size: 0.8rem;
    top: 4px;
}

/* Portfolio Section */
.portfolio-section {
    padding: 10% 0;
    background-color: var(--white);
    border-top: 1px solid var(--light-grey);
}

.portfolio-filters {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
}

.filter-btn {
    background: transparent;
    border: 2px solid var(--light-grey);
    padding: 10px 20px;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 600;
    color: var(--medium-grey);
    transition: var(--transition);
}

.filter-btn.active, .filter-btn:hover {
    background: var(--navy-blue);
    color: var(--white);
    border-color: var(--navy-blue);
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: 30px;
    justify-content: center;
}

.portfolio-card {
    background: var(--off-white);
    padding: 40px 30px;
    border-radius: 8px;
    border: 1px solid var(--light-grey);
}

.card-tags {
    font-size: 0.8rem;
    color: var(--accent);
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 15px;
}

.portfolio-card h4 {
    font-size: 1.3rem;
    margin-bottom: 15px;
}

.portfolio-card p {
    color: var(--medium-grey);
    font-size: 0.95rem;
}

/* Contact Section */
.contact-section {
    padding: 100px 0;
    background-color: var(--off-white);
    border-top: 1px solid var(--light-grey);
}

.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.contact-details {
    margin-top: 30px;
    color: var(--medium-grey);
}

.contact-details p {
    margin-bottom: 10px;
}

.contact-form {
    background: var(--white);
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 0.9rem;
}

.form-group input, 
.form-group select, 
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--light-grey);
    border-radius: 4px;
    font-family: inherit;
    font-size: 1rem;
    color: var(--dark-grey);
    background-color: var(--off-white);
}

.form-group input:focus, 
.form-group select:focus, 
.form-group textarea:focus {
    outline: none;
    border-color: var(--navy-blue);
    background-color: var(--white);
}

/* Footer */
.footer {
    background-color: var(--navy-blue);
    color: var(--light-grey);
    padding: 60px 0;
    text-align: center;
}

.footer-logo {
    max-height: 40px;
    margin-bottom: 20px;
    filter: brightness(0) invert(1);
    opacity: 0.8;
}

.footer p {
    font-size: 0.9rem;
    color: var(--medium-grey);
}

/* Responsive Design */
@media (max-width: 900px) {
    .values-grid, .portfolio-grid, .contact-container, .split-pillars {
        grid-template-columns: 1fr;
    }
    
    .infra-pillar {
        border-left: none;
        border-top: 1px solid var(--light-grey);
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .nav-links {
        display: none;
    }
}