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

body {
    font-family: system-ui, sans-serif;
    line-height: 1.6;
    color: #333;
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

nav {
    display: flex;
    gap: 20px;
    padding: 20px 0;
    border-bottom: 1px solid #eee;
}

nav a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
}

.hero {
    text-align: center;
    padding: 80px 0;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.btn {
    display: inline-block;
    background: #333;
    color: #fff;
    padding: 10px 20px;
    text-decoration: none;
    border-radius: 5px;
    margin-top: 20px;
}

section {
    padding: 40px 0;
}

h2 {
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.project-card {
    border: 1px solid #eee;
    padding: 20px;
    border-radius: 8px;
}

.chat-container {
    max-width: 600px;
    margin: 0 auto;
}

#chat-box {
    border: 1px solid #eee;
    height: 400px;
    overflow-y: auto;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
}

.user-msg {
    background: #333;
    color: #fff;
    padding: 10px;
    border-radius: 8px;
    margin-bottom: 10px;
    text-align: right;
}

.ai-msg {
    background: #f0f0f0;
    padding: 10px;
    border-radius: 8px;
    margin-bottom: 10px;
}

.error {
    color: red;
    padding: 10px;
    margin-bottom: 10px;
}

#chat-form {
    display: flex;
    gap: 10px;
}

#chat-form input {
    flex: 1;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
}

#chat-form button {
    padding: 10px 20px;
    background: #333;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}