:root {
    --primary-color: #3498db;
    --secondary-color: #2980b9;
    --danger-color: #e74c3c;
    --success-color: #2ecc71;
    --text-color: #333;
    --light-gray: #f5f5f5;
    --medium-gray: #ddd;
    --dark-gray: #888;
    --white: #fff;

}

* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
body{
    font: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(100deg, #667eea 0%, #764ba2 100%);
    color: var(--text-color);
    display:flex;
    justify-content: center;
    align-items: center;
    padding:20px;
}
.container{
    background-color: var(--white);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    max-width: 500px;
    border-radius: 15px;
    max-width: 500px;
    width: 100%;
    overflow: hidden;
}
h1{
    background-color: var(--primary-color);
    color:white;
    padding: 20px;
    text-align: center;
}
h1 span{
    margin-left: 20px;
}
.input-container{
    display:flex;
    padding:20px;
    box-shadow:0 2px 10px rgba(0, 0, 0, 0.05); 
}
.input-container input[type="text"]{
    flex-grow: 1;
    padding:12px 15px;
    border:2px solid var(--medium-gray);
    border-radius: 6px 0 0 6px;
    font-size: 1.2rem;
}
.input-container input[type="text"]:focus{
    outline:none;
    border-color:var(--primary-color);
}
.input-container button{
    padding: 12px 20px;
    background-color: var(--primary-color);
    color:white;
    border:none;
    border-radius: 0 6px 6px 0;
    cursor:pointer;
    transition: background-color 0.3s;
}
.filters{
    display:flex;
    justify-content: center;
    background-color: var(--light-grey);
    border-bottom: 1px solod var(--medium-gray);
    padding: 10px;
}
.trash{
    border: none;
}
.filter-btn{
    padding:8px 16px;
    color:var(--dark-gray);
    border:none;
    background: none;
    border-radius: 4px;
    margin-top: 0;
    margin-bottom: 0;
    margin-right: 5px;
    margin-left: 5px;
    cursor: pointer;
    font-weight: 500;
}
.filter-btn:hover{
    background-color: rgba(0,0,0,0.05);
}
.active:focus{
    background-color: var(--primary-color);
    color:white;
}
ul{
    border-bottom: 1px solid var(--medium-gray);
    border-top: 1px solid var(--medium-gray);
    height: 400px;
    list-style: none;
}
ul li{
    display: flex;
    justify-content:space-between;
    padding:15px 20px;
    border-bottom: 1px solid var(--medium-gray);
}
li:hover{
    background-color:var(--light-gray);
}
li input[type="checkbox"]{
    margin-right: 15px;
    width:20px;
    height: 20px;
    cursor:pointer;
    accent-color: var(--success-color);
}
li span{
    flex-grow: 1;
    word-break:break-word;
}
.completed{
    text-decoration: line-through;
    color:var(--dark-gray);
}
ul i{
    color:var(--danger-color);
    cursor: pointer;
    padding:5px;
    visibility: hidden;
}
li:hover i{
    visibility: visible;
}
.list-footer{
    display:flex;
    justify-content: space-between;
    padding:15px 20px;
    background-color: var(--light-gray);
    border-top:1px solid var(--medium-gray);
    color:var(--dark-gray);
    font-size: 0.9rem;
}
.list-footer button{
    border:none;
    background-color: none;
    cursor:pointer;
    font-size: 0.9rem;
    color:var(--dark-gray);
}
.list-footer button:hover{
    color:var(--danger-color);
    text-decoration: line-through;
}
.empty{
    font-style: italic;
}