:root {
    --bg-color: #ffffff;
    --text-color: #333333;
    --primary-color: #0077ff;
    --secondary-color: #0055cc;
    --section-bg: #f9f9f9;
}

[data-theme="dark"] {
    --bg-color: #121212;
    --text-color: #f1f1f1;
    --primary-color: #bb86fc;
    --secondary-color: #3700b3;
    --section-bg: #1e1e1e;
}

body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    scroll-behavior: smooth;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 50px;
    background: var(--section-bg);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.logo {
    font-size: 24px;
    font-weight: bold;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
    margin: 0;
    padding: 0;
    align-items: center;
}

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

section {
    padding: 60px 50px;
    text-align: center;
}

section:nth-child(even) {
    background-color: var(--section-bg);
}

button, .btn {
    padding: 10px 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    border-radius: 5px;
    transition: background 0.3s;
}

button:hover, .btn:hover {
    background: var(--secondary-color);
}

.skills-container, .projects-container {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.skill {
    padding: 15px 30px;
    background: var(--primary-color);
    color: white;
    border-radius: 8px;
    font-weight: bold;
}

.project-card {
    background: var(--section-bg);
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 20px;
    width: 300px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.project-card img {
    max-width: 100%;
    border-radius: 4px;
}

form {
    display: flex;
    flex-direction: column;
    max-width: 400px;
    margin: 0 auto;
    gap: 15px;
}

form input, form textarea {
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

form textarea {
    height: 100px;
}

@media(max-width: 768px) {
    header {
        flex-direction: column;
        padding: 20px;
    }
    nav ul {
        flex-direction: column;
        gap: 10px;
        margin-top: 15px;
    }
    section {
        padding: 30px 20px;
    }
    h1 {
        font-size: 30px;
    }
}