* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    min-height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 25%, #f093fb 50%, #4facfe 75%, #00f2fe 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

@keyframes gradientShift {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

.container {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
}

.todo-app {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 30px;
    animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 2.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.input-section {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

#taskInput {
    flex: 1;
    padding: 15px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 16px;
    transition: all 0.3s ease;
    outline: none;
}

#taskInput:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.add-btn {
    padding: 15px 30px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.add-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.add-btn:active {
    transform: translateY(0);
}

.filter-section {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    justify-content: center;
}

.filter-btn {
    padding: 8px 20px;
    background: #f0f0f0;
    border: none;
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #666;
}

.filter-btn:hover {
    background: #e0e0e0;
}

.filter-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.task-list {
    list-style: none;
    max-height: 400px;
    overflow-y: auto;
    margin-bottom: 20px;
}

.task-list::-webkit-scrollbar {
    width: 8px;
}

.task-list::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

.task-list::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
}

.task-item {
    background: white;
    padding: 15px 20px;
    margin-bottom: 10px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateX(-10px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.task-item:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    border-color: #667eea;
}

.task-item.completed {
    opacity: 0.6;
    background: #f5f5f5;
}

.task-checkbox {
    width: 22px;
    height: 22px;
    cursor: pointer;
    accent-color: #667eea;
}

.task-text {
    flex: 1;
    font-size: 16px;
    color: #333;
    word-break: break-word;
}

.task-item.completed .task-text {
    text-decoration: line-through;
    color: #999;
}

.delete-btn {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a6f 100%);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 8px 15px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(255, 107, 107, 0.3);
}

.delete-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 15px rgba(255, 107, 107, 0.5);
}

.footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 20px;
    border-top: 2px solid #e0e0e0;
}

#taskCount {
    color: #666;
    font-size: 14px;
}

.clear-btn {
    background: linear-gradient(135deg, #ffa726 0%, #fb8c00 100%);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 8px 20px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(255, 167, 38, 0.3);
}

.clear-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(255, 167, 38, 0.5);
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: #999;
    font-size: 18px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .todo-app {
        padding: 20px;
    }

    h1 {
        font-size: 2rem;
    }

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

    .add-btn {
        width: 100%;
    }

    .filter-section {
        flex-wrap: wrap;
    }

    .footer {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .task-item {
        padding: 12px 15px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.5rem;
    }

    #taskInput {
        padding: 12px 15px;
        font-size: 14px;
    }

    .add-btn {
        padding: 12px 20px;
        font-size: 14px;
    }

    .task-text {
        font-size: 14px;
    }
}