body { font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; margin: 0; padding: 0; background-color: #fff; color: #555; }
header { background-color: #689F38; color: white; padding: 25px; text-align: center; border-bottom: 5px solid #558B2F; }
nav { background-color: #558B2F; overflow: hidden; }
nav a { display: inline-block; color: white; text-align: center; padding: 12px 20px; text-decoration: none; }
nav a:hover { background-color: #AED581; color: #33691E; }
.container { max-width: 1100px; margin: 25px auto; padding: 25px; background: #F1F8E9; border: 1px solid #DCEDC8; }
.activity { margin-bottom: 30px; padding: 15px; background: white; border-left: 5px solid #689F38; }
.activity img { max-width: 100%; height: auto; display: block; margin: 10px auto; }
footer { background-color: #558B2F; color: white; text-align: center; padding: 12px; }