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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 500px;
}

.todo-app {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

h1 {
    color: #333;
    margin-bottom: 25px;
    text-align: center;
    font-size: 28px;
}

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

#todoInput {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 16px;
    outline: none;
    transition: border-color 0.3s;
}

#todoInput:focus {
    border-color: #667eea;
}

#addBtn {
    padding: 12px 24px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s, transform 0.2s;
}

#addBtn:hover {
    background: #5568d3;
    transform: translateY(-2px);
}

#addBtn:active {
    transform: translateY(0);
}

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

.todo-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    margin-bottom: 8px;
    background: #f5f5f5;
    border-radius: 10px;
    transition: background 0.3s;
}

.todo-item:hover {
    background: #eeeeee;
}

.todo-item.completed {
    opacity: 0.6;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
}

.todo-checkbox {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

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

.delete-btn {
    background: #ff6b6b;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 6px 12px;
    cursor: pointer;
    font-size: 14px;
    transition: background 0.3s;
}

.delete-btn:hover {
    background: #ff5252;
}

.footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 15px;
    border-top: 1px solid #e0e0e0;
}

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

#clearBtn {
    background: #ff6b6b;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 8px 16px;
    cursor: pointer;
    font-size: 14px;
    transition: background 0.3s;
}

#clearBtn:hover {
    background: #ff5252;
}

#todoList:empty::before {
    content: "No tasks yet. Add one above!";
    display: block;
    text-align: center;
    color: #999;
    padding: 20px;
    font-style: italic;
}