:root{--nav:#14213d;--bg:#f4f7fb}.app-body{background:var(--bg);min-height:100vh}.sidebar{background:var(--nav);min-height:100vh;width:250px}.sidebar a{color:#cad3e2;text-decoration:none;padding:.65rem 1rem;border-radius:.5rem;display:block}.sidebar a:hover{background:#203354;color:#fff}.card{border:0;box-shadow:0 2px 12px #14213d12}.stat{font-size:2rem;font-weight:700}.chat-box{height:430px;overflow-y:auto;background:#f8fafc}.bubble{max-width:82%;padding:.8rem 1rem;border-radius:1rem;margin:.5rem}.bubble.user{margin-left:auto;background:#2563eb;color:#fff}.bubble.assistant{background:#fff;border:1px solid #e5e7eb}