body {
    background: linear-gradient(135deg, #eef2ff, #f8fafc);

    font-family: Arial, sans-serif;

    padding: 40px 20px;

    margin: 0;
}

h1 {
    font-size: 40px;

    margin: 0;

    color: #1e293b;
}

section {
    margin: 40px 0;
}

form {
    display: flex;

    gap: 12px;

    align-items: center;
}

button {
    background-color: #2563eb;

    color: white;

    border: none;

    border-radius: 12px;

    padding: 12px 22px;

    margin: 10px;

    transition: all 0.25s ease;

    cursor: pointer;

    font-weight: bold;
}

input {

    flex: 1;

    border: 1px solid #cbd5e1;

    border-radius: 12px;

    padding: 12px 18px;

    margin: 0;

    outline: none;

    font-size: 16px;
}

.container {

    max-width: 750px;

    margin: 40px auto;

    background-color: white;

    padding: 40px;

    border-radius: 24px;

    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.08);

}

header {
    display: flex;

    align-items: center;

    gap: 20px;

    justify-content: flex-start;

    margin-bottom: 30px;
}

img {
    width: 50px;
}

progress {
    width: 100%;

    height: 30px;

    margin-top: 10px;
}

h2 {
    margin-bottom: 15px;

    color: #334155;
}

footer {
    text-align: center;

    margin-top: 40px;
}

footer p {
    margin-bottom: 10px;
}

ul {
    list-style: none;

    padding: 0;

    margin: 0;
}

li {
    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 15px;

    padding: 16px 20px;

    background: white;

    border: 1px solid #e2e8f0;

    border-radius: 16px;

    margin-bottom: 16px;

    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);

    transition: all 0.25s ease;
}

li span {
    flex: 1;

    font-size: 16px;

    color: #1e293b;

    word-break: break-word;
}

li input[type="checkbox"] {
    width: 18px;

    height: 18px;

    margin: 0;

    cursor: pointer;

    flex-shrink: 0;
}

li button {
    background: #ef4444;

    padding: 8px 14px;

    border-radius: 10px;

    font-size: 14px;

    margin: 0;
}

li button:hover {
    background: #dc2626;
}

button:hover {
    transform: translateY(-2px);

    background: #1d4ed8;
}

button:active {
    transform: translateY(0);
}

li:hover {
    transform: translateY(-4px);

    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.10);
}

.completed {
    text-decoration: line-through;

    opacity: 0.6;

    color: #64748b;
}

p {
    color: #64748b;

    line-height: 1.6;
}