* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    padding: 2rem;
}

/* Container */
.container {
    max-width: 800px;
    margin: 0 auto;
    animation: fadeIn 0.5s ease-out;
}

/* Header */
h1 {
    text-align: center;
    color: #2d3748;
    margin-bottom: 2rem;
    font-size: 2.8rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
}

/* Input Section */
.input-section {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    position: relative;
}

input[type="text"] {
    flex: 1;
    padding: 1.2rem;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

input[type="text"]:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.3);
}

#btn {
    padding: 1.2rem 2.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

#btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.2);
}

/* Todo List */
.div-main {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

ol {
    list-style: none;
    padding: 0;
}

li {
    display: flex;
    align-items: center;
    padding: 1.2rem;
    margin: 0.8rem 0;
    background: #f8fafc;
    border-radius: 10px;
    animation: slideIn 0.3s ease-out;
    transition: all 0.3s ease;
    position: relative;
}

li:hover {
    transform: translateX(10px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.task-text {
    flex: 1;
    margin: 0 1rem;
}

.delete {
    background: #ff6b6b;
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    margin-left: 30rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.delete:hover {
    background: #ff5252;
    transform: scale(1.05);
}

/* Progress Bar */
.progress-container {
    margin-bottom: 2rem;
    background: #e2e8f0;
    border-radius: 10px;
    height: 15px;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
    transition: width 0.5s ease;
}

/* Filter Buttons */
.filter-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    justify-content: center;
}

.filter-btn {
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #e2e8f0;
    color: #2d3748;
}

.filter-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

/* Completed Tasks */
.completed {
    text-decoration: line-through;
    opacity: 0.7;
}

/* Checkbox */
.checkbox {
    width: 20px;
    height: 20px;
    border: 2px solid #667eea;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.checkbox.checked {
    background: #667eea;
    border-color: #667eea;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .input-section {
        flex-direction: column;
    }

    #btn {
        width: 100%;
    }

    h1 {
        font-size: 2rem;
    }

    li {
        padding: 1rem;
    }
}