body {
    min-height: 100vh;
    margin: 0;
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;   /* horizontal center */
    align-items: center;       /* vertical center */
}

main {
    background: #3b82f6;
    border-radius: 20px;
    max-width: 500px;
    margin: 40px auto;
    padding: 24px 16px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.08);
}

.header-container {
    text-align: center;
    margin-bottom: 16px;
}

.main-title {
    font-size: 2rem;
    font-weight: bold;
    color: #ffffff;
    margin: 0;
}

form {
    background-color: #fff;
    padding: 16px;
    border-radius: 8px;
    display: flex;
    gap: 8px;
    align-items: flex-end;
    margin-bottom: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    flex: 1;
}
.form-inline {
    display: flex;
    gap: 8px;
    align-items: flex-end;
    margin-bottom: 16px;
    background: #fff;
    padding: 16px;
    border-radius: 8px;
}

.input-inline {
    margin-bottom: 0;
}

.input-inline[type="text"] {
    flex: 2;
    min-width: 0;
}

.input-inline[type="date"] {
    flex: 1;
    min-width: 0;
}

.btn-inline {
    padding: 8px 18px;
    font-size: 1.3rem;
    height: 40px;
    line-height: 1;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}
.label {
    font-size: 1rem;
    font-weight: 500;
    color: #374151;
    margin-bottom: 4px;
}

.input {
    padding: 6px 12px;
    border-radius: 8px;
    font-size: 1rem;
}

.input:focus {
    border-color: #3b82f6;
    box-shadow: 0 0 0 2px #bfdbfe;
}

.btn {
    padding: 6px 20px;
    border-radius: 8px;
    color: #fff;
    border: none;
    font-size: 1rem;
    cursor: pointer;
    margin-right: 8px;
    transition: background 0.2s, box-shadow 0.2s;
}

.btn:last-child {
    margin-right: 0;
}

.btn-green {
    background-color: #76f63b;
}

.btn-green:hover {
    background-color: #0fa047;
}
.btn-green.btn-inline {
    color: #111 !important;
    font-weight: bold;
}

.btn-gray {
    background-color: #6b7280;
    color: #fff;
}

.btn-gray:hover {
    background-color: #4b5563;
}

.btn-red {
    background-color: #ef4444;
    color: #fff;
}

.btn-red:hover {
    background-color: #b91c1c;
}
.btn-gray,
.btn-red {
    font-weight: bold;
}
.btn-yellow {
    background-color: #facc15;
    color: #333;
    font-weight: bold;
}
.btn-yellow:hover {
    background-color: #eab308;
}
.action-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
}

.section-title {
    font-size: 1.25rem;
    font-weight: bold;
    color: #3b82f6;
    margin: 0 0 16px 0;
}

#todo-list {
    height: 200px;
    overflow-y: auto;
    padding: 10px;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    background: #f9fafb;
}

#todo-list p {
    color: #6b7280;
    text-align: center;
    margin: 0;
}

li {
    border-bottom: 1px solid #e5e7eb;
    padding: 8px 0;
    list-style: none;
}

@media (max-width: 600px) {
    main {
        max-width: 98vw;
        padding: 16px 4vw;
    }
    form {
        flex-direction: column;
        gap: 0;
    }
    .form-group {
        width: 100%;
    }
    .btn {
        width: 100%;
        margin-top: 8px;
    }
}