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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background: #f5f5f5;
    color: #333;
}

/* Навигация */
header {
    background: #2c3e50;
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

nav a {
    color: #ecf0f1;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background 0.3s;
}

nav a:hover,
nav a.active {
    background: #34495e;
}

/* Основной контент */
main {
    max-width: 900px;
    margin: 2rem auto;
    padding: 2rem;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

h1 {
    color: #2c3e50;
    margin-bottom: 1rem;
    font-size: 2rem;
}

h2 {
    color: #34495e;
    margin: 1.5rem 0 0.75rem;
    font-size: 1.5rem;
}

h3 {
    color: #7f8c8d;
    margin: 1rem 0 0.5rem;
    font-size: 1.2rem;
}

p {
    margin-bottom: 1rem;
}

ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

li {
    margin-bottom: 0.5rem;
}

/* Форма */
form {
    background: #f9f9f9;
    padding: 1.5rem;
    border-radius: 6px;
    margin-top: 1rem;
}

label {
    font-weight: bold;
    display: block;
    margin-bottom: 0.3rem;
}

input[type="text"],
input[type="email"],
textarea {
    width: 100%;
    padding: 0.5rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

button {
    background: #2c3e50;
    color: #fff;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

button:hover {
    background: #34495e;
}

/* Подвал */
footer {
    text-align: center;
    padding: 2rem;
    background: #2c3e50;
    color: #ecf0f1;
    margin-top: 2rem;
}

/* Адаптивность */
@media (max-width: 600px) {
    nav {
        flex-direction: column;
        align-items: center;
        gap: 0.5rem;
    }

    main {
        margin: 1rem;
        padding: 1rem;
    }

    h1 {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 1.3rem;
    }
}