body{background-color:#f5f5f5;margin:0;font-family:Arial,sans-serif;transition:background-color 2s}header{color:#fff;text-align:center;background-color:navy;padding:20px}#appNav{background-color:#fff;border-bottom:2px solid #ddd;justify-content:center;gap:15px;padding:12px;display:flex}.nav-link{color:navy;cursor:pointer;background-color:#f5f5f5;border:1px solid #ccc;border-radius:6px;padding:8px 18px;font-weight:700;transition:all .3s}.nav-link:hover{color:#fff;background-color:#00f;border-color:#00f}.logout{color:red;border-color:red}.hidden{display:none!important}.main-card{background-color:#fff;border-radius:12px;width:85%;max-width:500px;margin:40px auto;padding:40px;transition:opacity 1s,transform 1s;box-shadow:0 4px 12px #d3d3d3}.exit-animation{opacity:0;pointer-events:none;transform:scale(.9)}h3{color:navy;text-align:center;margin-bottom:25px}.input-wrapper,#uploadForm input,#uploadForm select{margin-bottom:20px;display:block;position:relative}input[type=text],input[type=password],input[type=file],select{box-sizing:border-box;background-color:#f5f5f5;border:2px solid #f5f5f5;border-radius:8px;width:100%;padding:14px;font-size:16px}input:focus,select:focus{background-color:#fff;border-color:#00f;outline:none}.visibility-toggle{color:#00f;cursor:pointer;background:0 0;border:none;font-size:10px;font-weight:700;position:absolute;top:16px;right:15px}.action-button{color:#fff;cursor:pointer;background-color:#00f;border:none;border-radius:8px;width:100%;margin-top:10px;padding:15px;font-size:18px;font-weight:700}.greeting-text{text-align:center;color:navy;font-size:32px;font-weight:700;display:none;position:absolute;top:50%;left:50%;transform:translate(-50%,-50%)}.note-item{background-color:#f9f9f9;border-radius:6px;justify-content:space-between;align-items:center;margin-top:10px;padding:12px;display:flex}.delete-btn{color:#fff;cursor:pointer;background:red;border:none;border-radius:4px;padding:8px 12px}#coursesContainer div{border-left:4px solid navy;margin-top:20px;padding:10px}#coursesContainer a{color:#00f;margin:8px 0;text-decoration:none;display:block}.ai-floating-button{color:#fff;cursor:pointer;z-index:1000;background-color:navy;border:none;border-radius:6px;width:55px;height:55px;font-size:26px;position:fixed;bottom:25px;right:25px;box-shadow:0 4px 12px #d3d3d3}.ai-floating-button:hover{background-color:#00f}