:root {
    --green: #2e7d4f;
    --green-dark: #1f5c38;
    --bg: #f6f8f4;
    --card: #ffffff;
    --text: #1c2b20;
    --muted: #6b7a6f;
}
* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 24px 16px 64px;
}
.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    background: var(--green-dark);
    color: #fff;
}
.site-header .logo {
    color: #fff;
    font-weight: 700;
    text-decoration: none;
    font-size: 1.2rem;
}
.site-header nav a {
    color: #fff;
    text-decoration: none;
    margin-left: 18px;
    opacity: 0.9;
}
.site-header nav a:hover { opacity: 1; text-decoration: underline; }

.site-footer {
    text-align: center;
    padding: 24px;
    color: var(--muted);
    font-size: 0.9rem;
}

h1, h2 { color: var(--green-dark); }

.card {
    background: var(--card);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
}

.btn {
    display: inline-block;
    background: var(--green);
    color: #fff;
    border: none;
    padding: 10px 18px;
    border-radius: 8px;
    cursor: pointer;
    text-decoration: none;
    font-size: 1rem;
}
.btn:hover { background: var(--green-dark); }

.form-group { margin-bottom: 14px; }
.form-group label { display: block; margin-bottom: 4px; font-weight: 600; }
.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #d0d7d2;
    border-radius: 8px;
    font-size: 1rem;
}

.error { color: #b3261e; margin-bottom: 12px; }
.success { color: var(--green-dark); margin-bottom: 12px; }
.muted { color: var(--muted); font-size: 0.9rem; }

.tree-image {
    width: 100%;
    border-radius: 10px;
    margin-bottom: 10px;
    aspect-ratio: 1/1;
    object-fit: cover;
    background: #eef2ec;
}

.diary-entry {
    border-left: 3px solid var(--green);
    padding-left: 12px;
    margin-bottom: 14px;
}