body {
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        background: linear-gradient(135deg, #89f7fe, #66a6ff);
        display: flex;
        justify-content: center;
        align-items: center;
        height: 100vh;
        margin: 0;
    }

    .container {
        background: white;
        padding: 25px 30px;
        border-radius: 15px;
        box-shadow: 0 10px 25px rgba(0,0,0,0.15);
        width: 360px;
        transition: transform 0.2s ease;
    }
    .container:hover {
        transform: translateY(-5px);
    }

    h1 {
        text-align: center;
        color: #333;
        margin-bottom: 20px;
    }

    input {
        width: 70%;
        padding: 10px 12px;
        border: 1px solid #ccc;
        border-radius: 8px;
        font-size: 14px;
        outline: none;
        transition: border-color 0.2s ease;
    }
    input:focus {
        border-color: #4caf50;
    }

    button {
        padding: 10px 15px;
        border: none;
        border-radius: 8px;
        background-color: #4caf50;
        color: white;
        font-weight: bold;
        cursor: pointer;
        transition: background-color 0.2s ease;
    }
    button:hover {
        background-color: #45a049;
    }

    ul {
        list-style: none;
        padding: 0;
        margin-top: 20px;
    }

    li {
        padding: 10px 12px;
        margin-bottom: 8px;
        background-color: #f9f9f9;
        border-radius: 10px;
        cursor: pointer;
        transition: all 0.2s ease;
    }
    li:hover {
        background-color: #e0f7fa;
        transform: translateX(5px);
    }
    li.completed {
        text-decoration: line-through;
        color: #999;
        opacity: 0.7;
    }

    .progress-container {
        background-color: #eee;
        width: 100%;
        height: 14px;
        border-radius: 8px;
        margin-top: 15px;
        overflow: hidden;
    }
    #progressBar {
        height: 100%;
        width: 0%;
        background-color: #4caf50;
        border-radius: 8px;
        transition: width 0.4s ease;
    }