body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #f4f9f4;
    color: #222;
}

header {
    background: #2e5d34;
    color: #fff;
    padding: 1em 0;
    text-align: center;
}

header img {
    max-width: 350px;
    display: block;
    margin: 0 auto 1em auto;
}

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

nav ul li {
    display: inline;
    margin: 0 1em;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    font-weight: bold;
}

.nav-buttons {
    display: flex;
    justify-content: center;
    gap: 1.5em;
    margin-bottom: 1.5em;
}

.nav-buttons a {
    background: #2a5298;
    color: #fff;
    padding: 0.6em 1.2em;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    letter-spacing: 1px;
    transition: background 0.2s;
}

.nav-buttons a:hover,
.nav-buttons a:focus {
    background: #ffd200;
    color: #2a5298;
    outline: none;
}

main {
    max-width: 800px;
    margin: 2em auto;
    padding: 1em;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

section {
    margin-bottom: 2em;
}

form {
    display: flex;
    flex-direction: column;
}

form label {
    margin-top: 1em;
}

form input, form textarea {
    padding: 0.5em;
    margin-top: 0.5em;
    border: 1px solid #ccc;
    border-radius: 4px;
}

form button {
    margin-top: 1em;
    padding: 0.7em;
    background: #2e5d34;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

footer {
    text-align: center;
    padding: 1em 0;
    background: #2e5d34;
    color: #fff;
    position: fixed;
    width: 100%;
    bottom: 0;
}

.tree-outline {
    width: 100%;
    overflow: hidden;
    line-height: 0;
    margin-bottom: 1em;
}