:root {
    --primary-color: #2c3e50;
    --secondary-color: #5b9bd5;
    --accent-color: #f4a261;
    --text-color: #444;
    --light-bg: #faf8f5;
    --white: #ffffff;
    --shadow: 0 4px 12px rgba(0,0,0,0.08);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

/* Header & Navigation */
header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--white);
    text-decoration: none;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--white);
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #4a6fa5 0%, #7ba3d1 100%);
    color: var(--white);
    padding: 8rem 2rem;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.hero p {
    font-size: 1.4rem;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
}

/* Main Content */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.section {
    margin-bottom: 5rem;
}

.section h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 3rem;
    text-align: center;
    font-weight: 600;
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.project-card {
    background: var(--white);
    border-radius: 16px;
    padding: 2.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}

.project-card h3 {
    color: var(--primary-color);
    font-size: 1.6rem;
    margin-bottom: 1.2rem;
    font-weight: 600;
}

.project-card p {
    color: #666;
    margin-bottom: 2rem;
    line-height: 1.7;
}

.project-card .btn {
    display: inline-block;
    background-color: var(--secondary-color);
    color: var(--white);
    padding: 0.8rem 1.8rem;
    border-radius: 8px;
    text-decoration: none;
    transition: background-color 0.3s ease, transform 0.2s ease;
    font-weight: 500;
}

.project-card .btn:hover {
    background-color: var(--primary-color);
    transform: scale(1.05);
}

/* Content Page Styles */
.content-header {
    background-color: var(--light-bg);
    padding: 4rem 2rem;
    text-align: center;
}

.content-header h1 {
    font-size: 2.8rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

.content-section {
    background: var(--white);
    padding: 3rem;
    margin-bottom: 3rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.content-section h2 {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 1.5rem;
    text-align: left;
    font-weight: 600;
}

.content-section h3 {
    color: var(--secondary-color);
    font-size: 1.4rem;
    margin: 2rem 0 1rem 0;
    font-weight: 600;
}

.content-section ul {
    margin-left: 1.5rem;
    margin-bottom: 1.5rem;
}

.content-section li {
    margin-bottom: 0.8rem;
    line-height: 1.7;
}

.content-section p {
    line-height: 1.8;
    margin-bottom: 1.2rem;
}

.content-section .btn {
    display: inline-block;
    background-color: var(--secondary-color);
    color: var(--white);
    padding: 0.8rem 1.8rem;
    border-radius: 8px;
    text-decoration: none;
    transition: background-color 0.3s ease, transform 0.2s ease;
    font-weight: 500;
    margin-right: 1rem;
    margin-top: 0.5rem;
}

.content-section .btn:hover {
    background-color: var(--primary-color);
    transform: scale(1.05);
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--primary-color);
        flex-direction: column;
        padding: 1rem 0;
        gap: 0;
        display: none;
    }

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

    .nav-links li {
        padding: 0.5rem 2rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1.1rem;
    }

    .section h2 {
        font-size: 2rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }
}