body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f9;
    color: #333;
    margin: 0;
    padding: 0;
    overflow-y: scroll;
}

header {
    width: 100%;
    background: linear-gradient(135deg, #88c057, #6ea04e);
    color: white;
    text-align: center;
    padding: 30px 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 32px;
    letter-spacing: 2px;
    font-variant: small-caps;
    margin: 0;
}

nav {
    display: flex;
    justify-content: center;
    background-color: #4a5568;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

nav ul {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
}

nav ul li {
    position: relative;
    padding: 15px 25px;
    transition: background-color 0.3s ease;
}

nav ul li:hover {
    background-color: #2d3748;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    display: block;
}

.dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #4a5568;
    min-width: 180px;
    display: none;
    flex-direction: column;
    border-radius: 0 0 8px 8px;
    overflow: hidden;
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
    z-index: 100
}

nav ul li:hover .dropdown {
    display: flex;
}

.dropdown a {
    padding: 12px 20px;
    color: white;
    transition: background-color 0.2s;
    z-index: 10
}

.dropdown a:hover {
    background-color: #2c3e50;
}

main section {
    background-color: white;
    border-radius: 16px;
    padding: 30px;
    margin: 40px auto;
    width: 60%;
    box-shadow: 0 4px 16px rgba(0,0,0,0.05);
    text-align: center;
 
}

.sectionnn {
    background-color: #fefefe;
    border: 2px solid #ccc;
    border-radius: 20px;
    padding: 25px;
    margin: 40px auto;
    width: 70%;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    z-index: -10;
}

.knopki {
    text-align: center;
    margin: 30px 0;
}

.knopki input[type="button"] {
    background-color: #3182ce;
    border: none;
    color: white;
    padding: 10px 20px;
    margin: 8px;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.knopki input[type="button"]:hover {
    background-color: #2b6cb0;
}

footer {
    text-align: center;
    padding: 20px;
    background-color: #edf2f7;
    font-size: 14px;
    color: #555;
    margin-top: 40px;
}

#message {
    font-family: 'Courier New', Courier, monospace;
    font-size: 26px;
    color: #e53e3e;
    text-align: center;
    padding: 40px 20px;
}

.koord {
    z-index: -10
}