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

body {
    font-family: "Segoe UI", system-ui, sans-serif;
    background: linear-gradient(135deg, #eef2f7, #e5ebf1);
    min-height: 100vh;
}
.navbar {
    box-shadow: 0 4px 14px rgba(0,0,0,0.08);
}

.container {
    max-width: 900px;
}

.card {
    border-radius: 18px;
    border: none;
    background: #ffffff;
}

.card h3 {
    color: #1e293b;
}
.input-group input {
    border-radius: 12px 0 0 12px;
    padding: 12px;
}

.input-group button {
    border-radius: 0 12px 12px 0;
    padding: 12px 18px;
    font-weight: 600;
}

input:focus {
    box-shadow: 0 0 0 3px rgba(34,197,94,0.2);
}

.task-item {
    background: #f9fafb;
    border-radius: 14px;
    padding: 14px;
    margin-bottom: 12px;
    transition: all 0.3s ease;
}

.task-item:hover {
    background: #f1f5f9;
    transform: translateY(-2px);
}

.task-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.task-left {
    display: flex;
    align-items: center;
    gap: 14px;
    flex-grow: 1;
}

input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: #22c55e;
    cursor: pointer;
}

.edit-input {
    display: none;
    max-width: 260px;
    border-radius: 10px;
}
.completed-label {
    font-size: 12px;
    font-weight: 600;
    color: #16a34a;
    margin-left: 34px;
}

button {
    border-radius: 10px;
    font-weight: 500;
}

#errorMsg {
    font-weight: 600;
    font-size: 14px;
}

.row .card {
    padding: 22px;
    border-radius: 18px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

.row .card:hover {
    transform: translateY(-4px);
}

.card-number {
    font-size: 34px;
    font-weight: 700;
    margin-bottom: 6px;
}

.completed {
    text-decoration: line-through;
    color: gray;
}