:root {
    --primary: #0b0f1a;
    --secondary: #1e293b;
    --accent: #d946ef; /* Vivid Fuchsia */
    --accent-hover: #b82dd2;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --white: #ffffff;
    --glass: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --bg-overlay: rgba(11, 15, 26, 0.85);
    --hero-overlay: rgba(11, 15, 26, 0.85);
    --logo-yazilim: #ffffff;
    --hero-text-start: #ffffff;
    --transition: all 0.3s ease;
}

[data-theme="light"] {
    --primary: #f8fafc;
    --secondary: #e2e8f0;
    --accent: #8b5cf6; /* Vivid Purple */
    --accent-hover: #7c3aed;
    --text-main: #2e1065; /* Dark Purple Text */
    --text-muted: #5b21b6; /* Medium Dark Purple Text */
    --white: #ffffff;
    --glass: rgba(255, 255, 255, 0.6);
    --glass-border: rgba(0, 0, 0, 0.1);
    --bg-overlay: rgba(248, 250, 252, 0.85);
    --hero-overlay: rgba(248, 250, 252, 0.75);
    --logo-yazilim: #1e1b4b; /* Very dark rich purple for contrast */
    --hero-text-start: #3b0764; /* Visually readable dark purple */
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--primary);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

h1,
h2,
h3,
h4,
.logo {
    font-family: 'Outfit', sans-serif;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

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

ul {
    list-style: none;
}

/* Navbar */
.navbar {
    background: var(--bg-overlay);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    height: 80px;
    display: flex;
    align-items: center;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    border-bottom: 1px solid var(--glass-border);
    transition: background-color 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.logo .dnc {
    color: var(--accent);
}

.logo .yazilim {
    color: var(--logo-yazilim);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-muted);
    font-weight: 500;
}

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

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Theme Toggle Button */
.header-controls {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.theme-btn {
    background: var(--glass);
    border: 1px solid var(--glass-border);
    color: var(--text-main);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1.1rem;
}

.theme-btn:hover {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    transform: rotate(15deg) scale(1.1);
}

/* Hero Section */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(var(--hero-overlay), var(--hero-overlay)), url('../img/hero.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, var(--hero-text-start), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 700px;
    margin: 0 auto 2rem;
}

.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(56, 189, 248, 0.2);
}

/* Services Section */
.services {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.service-card {
    background: var(--glass);
    border: 1px solid var(--glass-border);
    padding: 3rem 2rem;
    border-radius: 20px;
    text-align: center;
    transition: var(--transition);
}

.service-card:hover {
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-10px);
}

.service-card i {
    font-size: 3rem;
    color: var(--accent);
    margin-bottom: 1.5rem;
}

.service-card h3 {
    margin-bottom: 1rem;
}

/* Footer */
.footer {
    background-color: var(--secondary);
    padding: 80px 0 40px;
    border-top: 1px solid var(--glass-border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: 4rem;
    margin-bottom: 4rem;
}

.footer-info h3 {
    margin-bottom: 1.5rem;
    color: var(--accent);
}

.footer-info p {
    color: var(--text-muted);
}

.footer-links h4,
.footer-contact h4 {
    margin-bottom: 1.5rem;
}

.footer-links ul li {
    margin-bottom: 0.8rem;
}

.footer-links ul li a {
    color: var(--text-muted);
}

.footer-links ul li a:hover {
    color: var(--accent);
}

.footer-contact p {
    margin-bottom: 0.8rem;
    color: var(--text-muted);
}

.footer-contact i {
    margin-right: 10px;
    color: var(--accent);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--glass-border);
    color: var(--text-muted);
}

/* Responsive */
@media (max-width: 992px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 80px;
        left: 0;
        width: 100%;
        background: var(--bg-overlay);
        padding: 2rem;
        gap: 1.5rem;
        border-bottom: 1px solid var(--glass-border);
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        display: flex;
        animation: slideDown 0.3s ease forwards;
    }

    @keyframes slideDown {
        from { opacity: 0; transform: translateY(-10px); }
        to { opacity: 1; transform: translateY(0); }
    }

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

    .hero h1 {
        font-size: 2.5rem;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}