:root {
        --primary: #0b81c0;
        --dark: #222;
        --bg: #f4f4f4;
        --white: #ffffff;
    }
    body { font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; margin: 0; color: #343434; background: var(--bg); line-height: 1.6; }
    header { background: var(--white); padding: 1rem; border-bottom: 3px solid var(--primary); text-align: center; }
    .logo-container { max-width: 250px; margin: 0 auto; }
    nav { background: var(--dark); padding: 0.5rem; text-align: center; }
    nav a { color: var(--white); text-decoration: none; padding: 0 10px; font-size: 0.9rem; }
    .container { max-width: 800px; margin: 2rem auto; padding: 2rem; background: var(--white); border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }
    h2 { color: var(--primary); }
    .captcha-box { width: 300px; height: 90px; background: #ddd; margin: 1.5rem auto; display: flex; align-items: center; justify-content: center; font-weight: bold; border: 2px dashed #999; }
    input[type="text"] { width: 100%; padding: 10px; margin: 1rem 0; box-sizing: border-box; border: 1px solid #ccc; }
    input[type="submit"] { background: var(--primary); color: white; border: none; padding: 12px 24px; cursor: pointer; font-size: 1rem; }
    footer { text-align: center; padding: 2rem; font-size: 0.8rem; color: #777; }
    
    @media (min-width: 768px) {
        nav a { padding: 0 20px; }
    }