html {
    font-size: 14px;
}

@media (min-width: 768px) {
    html {
        font-size: 16px;
    }
}

html {
    position: relative;
    min-height: 100%;
}

body {
    margin-bottom: 60px;
}


* {
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}

body {
    background: #f8f6f7;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
}

.header {
    padding-top: 16px;
    margin-bottom: 24px;
}

    .header h1 {
        margin: 0;
        font-size: 32px;
        font-weight: 500;
    }

    .header p {
        font-size: 14px;
        color: #555;
    }

.survey-header {
    text-align: center;
    margin-bottom: 30px;
}

.company-logo {
    width: 200px !important;
    height: auto;
    margin-bottom: 16px;
}

.survey-header h1 {
    font-size: 1.8rem;
}

.form-group-top {
    margin-bottom: 18px;
    border: 1px solid #e0e0e0;
    border-radius: 14px;
    border-top: 14px solid #c62828;
    background: white;
    padding: 24px 32px;
    width: 100%;
    max-width: 650px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

.form-group {
    margin-bottom: 18px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    background: white;
    padding: 24px 32px;
    width: 100%;
    max-width: 650px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

    .form-group label {
        display: block;
        font-size: 16px;
        font-weight: 500;
        margin-bottom: 12px;
    }

.required::after {
    content: " *";
    color: red;
}

/* Likert Scale */
.likert-scale {
    text-align: center;
    display: flex;
}

.label-muc-do {
    width: 100px;
    font-size: 11px;
    margin: auto;
}



.likert-options {
    display: flex;
    justify-content: space-around;
    padding: 0 8px;
    flex: 1;
}

    .likert-options label {
        flex: 1;
    }

    .likert-options input[type="radio"] {
        appearance: none;
        width: 20px;
        height: 20px;
        border: 2px solid #555;
        border-radius: 50%;
        outline: none;
        transition: 0.2s;
        cursor: pointer;
    }

        .likert-options input[type="radio"]:checked {
            background-color: #c62828;
            border-color: #c62828;
        }

/* Text field */
.form-group input[type="text"] {
    width: 100%;
    border: none;
    border-bottom: 1px solid #ccc;
    padding: 8px 4px;
    font-size: 15px;
    outline: none;
    transition: border-color 0.3s;
}

    .form-group input[type="text"]:focus {
        border-color: #c62828;
    }

    .form-group input[type="text"]::placeholder {
        color: #aaa;
    }

.btn-modern {
    background: linear-gradient(135deg, #ec2929, #570506);
    color: white;
    padding: 8px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.3s ease;
    box-shadow: 0 4px 14px rgba(0,0,0,0.2);
}

    .btn-modern:hover {
        transform: translateY(-2px);
        box-shadow: 0 6px 20px rgba(0,0,0,0.3);
    }

.btn-link {
    background: none;
    border: none;
    padding: 0;
    color: #2575fc;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    position: relative;
    transition: color 0.2s ease;
}

    .btn-link::after {
        content: '';
        position: absolute;
        width: 0%;
        height: 2px;
        left: 0;
        bottom: -2px;
        background-color: #2575fc;
        transition: width 0.3s ease;
    }

    .btn-link:hover {
        color: #6a11cb;
    }

        .btn-link:hover::after {
            width: 100%;
        }


/* Nút hiện đại */
.btn-modern {
    background-color: #4CAF50;
    color: white;
    padding: 12px 24px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

    .btn-modern:hover:enabled {
        background-color: #45a049;
    }

    .btn-modern:disabled {
        background-color: #ccc;
        color: #666;
        cursor: not-allowed;
        opacity: 0.6;
    }

/* Link nút */
.btn-link {
    display: inline-block;
    margin-left: 10px;
    font-size: 16px;
    text-decoration: underline;
    background: none;
    border: none;
    color: #007BFF;
    cursor: pointer;
    padding: 8px 12px;
    transition: color 0.3s;
}

    .btn-link:hover {
        color: #0056b3;
    }

    /* Link bị vô hiệu hóa */
    .btn-link:disabled {
        pointer-events: none;
        color: #999;
        text-decoration: none;
        opacity: 0.6;
    }

.btn-end {
    display: flex;
    justify-content: space-between;
}

.active {
    border: 1px solid red;
}

.notification {
    width: 100%;
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    display: none;
    margin: 10px 0;
    color: #fff;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    animation: fadeInSlide 0.4s ease;
    transition: all 0.3s ease-in-out;
}

    .notification.success {
        background-color: #4CAF50;
        border-left: 6px solid #2e7d32;
    }

    .notification.error {
        background-color: #f44336;
        border-left: 6px solid #c62828;
    }

    .notification.warning {
        background-color: #ff9800;
        border-left: 6px solid #ef6c00;
    }

@keyframes fadeInSlide {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 600px) {
    body {
        padding: 12px !important;
        margin: 0px;
    }

    .likert-scale,
    .likert-options {
        flex-direction: column !important;
    }

        .likert-options > div {
            display: flex;
            justify-content: center;
        }

    .option-diem > p:first-child {
        margin: 19px;
    }
}