.donate-box {
    max-width: 420px;
    margin: 20px auto;
    padding: 20px;
    border: 1px solid #ddd;
    border-radius: 12px;
    background: #fff;
    font-family: Arial, sans-serif;
}
.amount-buttons { display:flex; flex-wrap:wrap; gap:10px; }
.amount-btn { flex:1 1 calc(50% - 10px); padding:12px; text-align:center; background:#f5f5f5; border-radius:8px; cursor:pointer; border:2px solid transparent; transition:0.2s; }
.amount-btn.active { background:#007bff; color:#fff; border-color:#0056d2; }
.manual-input { margin-top:15px; }
.manual-input input { width:100%; padding:12px; border-radius:8px; border:1px solid #ccc; font-size:16px; }
.donate-btn { width:100%; margin-top:20px; padding:14px; background:#28a745; color:#fff; font-size:18px; border:none; border-radius:8px; cursor:pointer; transition:0.3s; }
.donate-btn:hover { background:#218838; }