:root{--3sb-primary: #2563eb;--3sb-bg: #ffffff;--3sb-font: system-ui, sans-serif;--3sb-radius: 6px}*{box-sizing:border-box}body{font-family:var(--3sb-font);background:var(--3sb-bg);margin:0;padding:0}.field{display:flex;flex-direction:column;gap:4px;margin-bottom:16px}.field label{font-size:14px;font-weight:500}.field input,.field textarea,.field select{padding:8px 12px;border:1px solid #d1d5db;border-radius:var(--3sb-radius);font-size:14px;font-family:var(--3sb-font);width:100%}.field input:focus,.field textarea:focus,.field select:focus{outline:2px solid var(--3sb-primary);border-color:transparent}.field-error{color:#dc2626;font-size:12px}.field input[aria-invalid=true],.field textarea[aria-invalid=true]{border-color:#dc2626}.submit-btn{background:var(--3sb-primary);color:#fff;border:none;padding:10px 24px;border-radius:var(--3sb-radius);font-size:15px;cursor:pointer;width:100%}.submit-btn:disabled{opacity:.6;cursor:not-allowed}.amount-presets{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:8px}.preset-btn{border:1px solid var(--3sb-primary);background:#fff;color:var(--3sb-primary);padding:6px 16px;border-radius:var(--3sb-radius);cursor:pointer;font-size:14px}.preset-btn.active{background:var(--3sb-primary);color:#fff}.address-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}.address-grid .full-width{grid-column:1 / -1}