:root {
    --primary-color: #007bff;
    --dark-color: #343a40;
    --light-color: #f8f9fa;
    --white-color: #ffffff;
    --text-color: #333333;
    --heading-color: #222222;
    --font-family: 'Montserrat', sans-serif;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2.5rem;
    --spacing-xl: 4rem;
    --border-radius: 5px;
    --transition-speed: 0.3s ease-in-out;
}

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

html { scroll-behavior: smooth; }
body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white-color);
}

h1, h2, h3 { color: var(--heading-color); margin-bottom: var(--spacing-sm); }
a { color: var(--primary-color); text-decoration: none; transition: color var(--transition-speed); }
a:hover { color: var(--dark-color); }
ul { list-style: none; }
img { max-width: 100%; height: auto; display: block; }

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

.section-padding { padding: var(--spacing-xl) 0; }
.section-title { text-align: center; font-size: 2.5rem; margin-bottom: var(--spacing-xl); position: relative; }
.section-title::after { content: ''; display: block; width: 60px; height: 4px; background-color: var(--primary-color); margin: var(--spacing-sm) auto 0; border-radius: var(--border-radius); }

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: background-color var(--transition-speed), transform var(--transition-speed);
    border: none;
}
.btn-primary { background-color: var(--primary-color); color: var(--white-color); }
.btn-primary:hover { background-color: var(--dark-color); transform: translateY(-2px); }

/* Header */
.main-header {
    background-color: var(--white-color);
    padding: var(--spacing-md) 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    width: 100%;
    z-index: 1000;
}
.main-header .container { display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 1.8rem; font-weight: 700; color: var(--heading-color); }

.main-nav .nav-list {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: var(--white-color);
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    padding: var(--spacing-sm) 0;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition-speed), opacity var(--transition-speed), visibility var(--transition-speed);
}
.main-nav.active .nav-list { display: flex; transform: translateY(0); opacity: 1; visibility: visible; }
.main-nav .nav-list li { text-align: center; margin: var(--spacing-xs) 0; }
.main-nav .nav-list a { display: block; padding: var(--spacing-xs) var(--spacing-md); font-weight: 600; color: var(--heading-color); }
.main-nav .nav-list a:hover { background-color: var(--light-color); color: var(--primary-color); }

.menu-toggle {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    width: 30px; height: 20px;
    background: transparent; border: none; cursor: pointer; padding: 0;
    position: relative; z-index: 1001;
}
.menu-toggle span { display: block; width: 100%; height: 2px; background-color: var(--heading-color); border-radius: 2px; transition: all var(--transition-speed); }
.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* Hero Section */
.hero-section {
    background-color: var(--dark-color);
    color: var(--white-color);
    padding: var(--spacing-xl) 0;
    min-height: 80vh;
    display: flex;
    align-items: center;
    text-align: center;
}
.hero-content h1 { font-size: 3rem; color: var(--white-color); }
.hero-content .tagline { font-size: 1.2rem; color: var(--light-color); margin-bottom: var(--spacing-lg); }
.hero-image img { border-radius: var(--border-radius); margin-top: var(--spacing-xl); box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2); }

/* About Section */
.about-content { display: flex; flex-direction: column; align-items: center; gap: var(--spacing-lg); text-align: center; }
.about-image img { border-radius: 50%; max-width: 250px; height: 250px; object-fit: cover; box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1); }

/* Services Section */
.bg-light { background-color: var(--light-color); }
.services-grid { display: grid; grid-template-columns: 1fr; gap: var(--spacing-lg); }
.service-card { background-color: var(--white-color); padding: var(--spacing-lg); border-radius: var(--border-radius); box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08); text-align: center; transition: transform var(--transition-speed), box-shadow var(--transition-speed); }
.service-card:hover { transform: translateY(-5px); box-shadow: 0 10px 20px rgba(0, 0, 0, 0.12); }
.service-card h3 { color: var(--primary-color); font-size: 1.5rem; }

/* Portfolio Section */
.portfolio-grid { display: grid; grid-template-columns: 1fr; gap: var(--spacing-lg); }
.portfolio-item { background-color: var(--white-color); border-radius: var(--border-radius); box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08); overflow: hidden; transition: transform var(--transition-speed), box-shadow var(--transition-speed); }
.portfolio-item:hover { transform: translateY(-5px); box-shadow: 0 10px 20px rgba(0, 0, 0, 0.12); }
.portfolio-item img { width: 100%; height: 250px; object-fit: cover; }
.portfolio-item .item-info { padding: var(--spacing-md); }

/* Contact Section */
.bg-dark { background-color: var(--dark-color); color: var(--white-color); }
.bg-dark .section-title { color: var(--white-color); }
.bg-dark .section-title::after { background-color: var(--accent-color); }
.contact-form { max-width: 600px; margin: 0 auto var(--spacing-xl); display: flex; flex-direction: column; gap: var(--spacing-md); }
.form-group label { display: block; margin-bottom: var(--spacing-xs); font-weight: 600; }
.form-group input, .form-group textarea { width: 100%; padding: var(--spacing-sm); border-radius: var(--border-radius); border: 1px solid #ccc; background-color: var(--white-color); color: var(--text-color); font-family: var(--font-family); font-size: 1rem; }
.contact-form .btn-primary { align-self: flex-start; }
.social-links { text-align: center; margin-top: var(--spacing-lg); }
.social-links a { display: inline-block; margin: 0 var(--spacing-sm); transition: transform var(--transition-speed); }
.social-links a:hover { transform: translateY(-3px); }

/* Footer */
.main-footer { background-color: var(--heading-color); color: var(--light-color); padding: var(--spacing-md) 0; text-align: center; font-size: 0.9rem; }

/* Responsive Design */
@media (min-width: 768px) {
    .main-nav .nav-list { display: flex; flex-direction: row; position: static; box-shadow: none; padding: 0; transform: none; opacity: 1; visibility: visible; }
    .main-nav .nav-list li { margin: 0 var(--spacing-sm); }
    .main-nav .nav-list a { padding: 0; background-color: transparent; }
    .menu-toggle { display: none; }
    .hero-section .container { flex-direction: row; justify-content: space-between; gap: var(--spacing-xl); text-align: left; }
    .hero-content h1 { font-size: 4.5rem; }
    .hero-content .tagline { font-size: 1.5rem; }
    .hero-image { flex: 1; text-align: right; }
    .hero-image img { margin-top: 0; }
    .about-content { flex-direction: row; text-align: left; }
    .about-text { flex: 2; }
    .about-image { flex: 1; text-align: center; }
    .services-grid { grid-template-columns: repeat(2, 1fr); }
    .portfolio-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
    .services-grid { grid-template-columns: repeat(4, 1fr); }
    .portfolio-grid { grid-template-columns: repeat(3, 1fr); }
}