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

body {
    background: linear-gradient(135deg, #667eea, #764ba2);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 550px;
    padding: 20px;
}

.todo-app {
    background: #ffffff;
    padding: 40px 30px;
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
    transition: all 0.3s ease-in-out;
}

.todo-app:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.todo-app h2 {
    color: #333;
    font-weight: 600;
    font-size: 24px;
    text-align: center;
    margin-bottom: 25px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
}

.todo-app h2 img {
    width: 35px;
    height: 35px;
}

.row {
    display: flex;
    align-items: center;
    gap: 10px;
    background: #f3f4f6;
    border-radius: 12px;
    padding: 8px 12px;
    margin-bottom: 20px;
    box-shadow: inset 0 2px 5px rgba(0,0,0,0.05);
    flex-wrap: wrap;
}

input {
    flex: 1;
    min-width: 0;
    border: none;
    outline: none;
    background: transparent;
    padding: 12px;
    font-size: 16px;
}

button {
    border: none;
    outline: none;
    padding: 12px 20px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    border-radius: 10px;
    transition: all 0.3s ease-in-out;
    flex-shrink: 0;
}

button:hover {
    opacity: 0.9;
    transform: scale(1.05);
}

ul {
    margin-top: 20px;
}

ul li {
    list-style: none;
    font-size: 16px;
    padding: 14px 50px 14px 45px;
    background: #fafafa;
    border-radius: 12px;
    margin-bottom: 12px;
    cursor: pointer;
    position: relative;
    transition: all 0.2s ease-in-out;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

ul li:hover {
    background: #f0f0f0;
}

ul li::before {
    content: '';
    position: absolute;
    height: 22px;
    width: 22px;
    border-radius: 6px;
    border: 2px solid #667eea;
    top: 50%;
    left: 12px;
    transform: translateY(-50%);
}

ul li.checked {
    color: #888;
    text-decoration: line-through;
    background: #e8eaf6;
}

ul li.checked::before {
    background: #667eea;
    border-color: #667eea;
}

ul li span {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    width: 30px;
    height: 30px;
    font-size: 18px;
    color: #888;
    line-height: 30px;
    text-align: center;
    border-radius: 50%;
    transition: all 0.2s ease-in-out;
}

ul li span:hover {
    background: #f3f4f6;
    color: #333;
}

/* Mobile responsive tweak */
@media (max-width: 480px) {
    .row {
        flex-direction: column;
        align-items: stretch;
    }

    button {
        width: 100%;
        margin-top: 8px;
    }
}

.watermark {
  position: fixed;
  bottom: 10px;
  right: 15px;
  font-size: 12px;
  font-style: italic;
  color: rgba(0, 0, 0, 0.4); /* light grey, unobtrusive */
  user-select: none; /* prevents text selection */
  pointer-events: none; /* makes it unclickable */
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}