body {
            background-color: #1e3a5f;
            color: white;
            font-family: Arial, sans-serif;
        }
        .container {
            margin-top: 20px;
        }
        .center_div {
            margin: 0 auto;
            width: 80%;
            background-color: #2a4d69;
            padding: 20px;
            border-radius: 10px;
            box-shadow: 0px 0px 10px rgba(255, 255, 255, 0.2);
        }
        .submit-btn {
            width: 100%;
            height: 60px;
            font-weight: bold;
            background-color: #f39c12;
            color: white;
            font-size: 1.5rem;
            border: none;
            border-radius: 10px;
            transition: 0.3s;
        }
        .submit-btn:hover {
            background-color: #e67e22;
        }
        .navbar {
            background: linear-gradient(to right, #1e3a5f, #2a4d69);
            border-radius: 0;
            border: none;
        }
        .navbar-nav > li > a {
            color: white !important;
            font-weight: bold;
            font-size: 1.2rem;
            transition: all 0.3s ease-in-out;
        }
        .navbar-nav > li > a:hover {
            background: #f39c12 !important;
            color: white !important;
            border-radius: 5px;
        }
.footer {
    background-color: #1e3a5f; /* Màu nền xanh đậm theo logo */
    color: white;
    text-align: center;
    padding: 20px;
    font-size: 0.95rem;
    margin-top: 20px;
    border-top: 3px solid #f39c12; /* Đường line nhấn mạnh */
}

.footer p {
    margin: 8px 0;
}

.footer a {
    color: #f39c12;
    font-weight: bold;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease-in-out;
}

.footer a:hover {
    color: #e67e22;
    text-decoration: underline;
}

/* Mobile Optimization */
@media (max-width: 768px) {
    .footer {
        padding: 15px;
        font-size: 0.85rem;
    }

    .footer p {
        line-height: 1.6;
        padding: 0 10px;
    }

    .footer a {
        font-size: 1rem;
        padding: 5px 0;
    }
}


@media (max-width: 576px) {
    .center_div {
        width: 95%;
        padding: 15px;
    }

    .form-control {
        height: 45px;
        font-size: 1rem;
        border-radius: 8px;
    }

    .row .col-sm-6 {
        width: 100%;
        margin-bottom: 10px;
    }

    .submit-btn {
        height: 50px;
        font-size: 1.2rem;
        border-radius: 8px;
    }

    .navbar-toggle {
        border: none;
        background: #f39c12;
    }

    .navbar-toggle .icon-bar {
        background-color: white;
    }
}
body {
            background-color: #1e3a5f;
            color: white;
            font-family: Arial, sans-serif;
        }
        .container {
            margin-top: 20px;
        }
        .center_div {
            margin: 0 auto;
            width: 80%;
            background-color: #2a4d69;
            padding: 20px;
            border-radius: 10px;
            box-shadow: 0px 0px 10px rgba(255, 255, 255, 0.2);
        }
        .submit-btn {
            width: 100%;
            height: 60px;
            font-weight: bold;
            background-color: #f39c12;
            color: white;
            font-size: 1.5rem;
            border: none;
            border-radius: 10px;
            transition: 0.3s;
        }
        .submit-btn:hover {
            background-color: #e67e22;
        }
        .navbar {
            background: linear-gradient(to right, #1e3a5f, #2a4d69);
            border-radius: 0;
            border: none;
        }
        .navbar-nav > li > a {
            color: white !important;
            font-weight: bold;
            font-size: 1.2rem;
            transition: all 0.3s ease-in-out;
        }
        .navbar-nav > li > a:hover {
            background: #f39c12 !important;
            color: white !important;
            border-radius: 5px;
        }

        .footer {
            background-color: #1e3a5f;
            color: white;
            text-align: center;
            padding: 20px;
            font-size: 0.95rem;
            margin-top: 20px;
            border-top: 3px solid #f39c12;
        }

        .footer a {
            color: #f39c12;
            font-weight: bold;
            text-decoration: none;
            transition: all 0.3s ease-in-out;
        }

        .footer a:hover {
            color: #e67e22;
            text-decoration: underline;
        }

        /* Mobile Optimization */
        @media (max-width: 768px) {
            .footer {
                padding: 15px;
                font-size: 0.85rem;
            }
            .center_div {
                width: 95%;
                padding: 15px;
            }
            .submit-btn {
                height: 50px;
                font-size: 1.2rem;
                border-radius: 8px;
            }
            .navbar-toggle {
                border: none;
                background: #f39c12;
            }
            .navbar-toggle .icon-bar {
                background-color: white;
            }
            .guide-section {
                padding: 15px;
                font-size: 1rem;
                line-height: 1.6;
            }
            .guide-section h4 {
                font-size: 1.2rem;
                color: #f39c12;
                margin-top: 15px;
            }
            .guide-section ul {
                padding-left: 20px;
            }
            .guide-section ul li {
                margin-bottom: 8px;
            }
            .guide-section a {
                color: #f39c12;
                font-weight: bold;
            }
        }
.header-container {
    text-align: center;
    padding: 20px;
    position: relative;
    background: linear-gradient(to right, #1e3a5f, #2a4d69);
    border-bottom: 4px solid #f39c12;
    box-shadow: 0px 4px 10px rgba(255, 153, 0, 0.3);
    animation: fadeIn 1.2s ease-in-out;
}

.header-container img {
    width: 150px;
    border-radius: 50%;
    border: 3px solid #f39c12;
    box-shadow: 0 0 15px rgba(255, 153, 0, 0.5);
    transition: transform 0.3s ease-in-out, box-shadow 0.3s ease-in-out;
}

.header-container img:hover {
    transform: scale(1.1);
    box-shadow: 0 0 25px rgba(255, 153, 0, 0.7);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
.heading-title {
    font-size: 2.5rem;
    font-weight: bold;
    text-transform: uppercase;
    text-align: center;
    color: #f39c12;
    text-shadow: 3px 3px 5px rgba(255, 153, 0, 0.5);
    animation: glowingText 2s infinite alternate ease-in-out;
    margin-bottom: 20px;
}

@keyframes glowingText {
    0% {
        text-shadow: 3px 3px 5px rgba(255, 153, 0, 0.5);
        letter-spacing: 1px;
    }
    100% {
        text-shadow: 5px 5px 15px rgba(255, 153, 0, 0.9);
        letter-spacing: 3px;
    }
}

/* Responsive cho mobile */
@media (max-width: 768px) {
    .heading-title {
        font-size: 2rem;
        letter-spacing: 1px;
    }
}

@media (max-width: 576px) {
    .heading-title {
        font-size: 1.8rem;
    }
}
.navbar-brand {
    font-size: 1.8rem;
    font-weight: bold;
    text-transform: uppercase;
    color: #f39c12 !important;
    letter-spacing: 2px;
    transition: all 0.4s ease-in-out;
    position: relative;
    text-shadow: 2px 2px 10px rgba(243, 156, 18, 0.6);
}

.navbar-brand:hover {
    color: #fff !important;
    text-shadow: 0 0 15px rgba(255, 255, 255, 0.9), 0 0 30px rgba(243, 156, 18, 0.8);
    transform: scale(1.1);
}

.navbar-brand::after {
    content: "";
    position: absolute;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, #f39c12, #e67e22);
    bottom: -5px;
    left: 0;
    transform: scaleX(0);
    transition: transform 0.3s ease-in-out;
}

.navbar-brand:hover::after {
    transform: scaleX(1);
}

/* Hiệu ứng lan tỏa */
@keyframes glow {
    0% {
        text-shadow: 2px 2px 10px rgba(243, 156, 18, 0.6);
    }
    50% {
        text-shadow: 0 0 20px rgba(243, 156, 18, 0.9);
    }
    100% {
        text-shadow: 2px 2px 10px rgba(243, 156, 18, 0.6);
    }
}

.navbar-brand {
    animation: glow 2s infinite alternate ease-in-out;
}

input {
  touch-action: manipulation;
}