/* Biến màu */
:root {
    --primary-color: #0A2342;
    --secondary-color: #FFD700;
    --text-color: #333;
    --light-text-color: #f0f0f0;
    --dark-bg: #1a1a1a;
    --light-bg: #ffffff;
}

/* Thiết lập chung */
body {
    font-family: 'Arial', sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    color: var(--text-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
}

a:hover {
    color: var(--secondary-color);
}

/* Header */
.site-header {
    background-color: var(--primary-color);
    color: var(--light-text-color);
    padding: 15px 0;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-header .logo {
    font-size: 2.2em;
    font-weight: bold;
    color: var(--secondary-color);
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 5px 10px;
    border: 2px solid var(--secondary-color);
    border-radius: 5px;
    transition: all 0.3s ease;
}

.site-header .logo:hover {
    background-color: var(--secondary-color);
    color: var(--primary-color);
}

.site-header .main-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}

.site-header .main-nav li {
    margin-left: 30px;
}

.site-header .main-nav a {
    color: var(--light-text-color);
    font-weight: bold;
    font-size: 1.1em;
    padding: 5px 0;
    position: relative;
}

.site-header .main-nav a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -5px;
    width: 0;
    height: 3px;
    background-color: var(--secondary-color);
    transition: width 0.3s ease-in-out;
}

.site-header .main-nav a:hover::after,
.site-header .main-nav a.active::after {
    width: 100%;
}

.hamburger-menu {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 30px;
    height: 25px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1000;
}

.hamburger-menu span {
    display: block;
    width: 100%;
    height: 3px;
    background: var(--secondary-color);
    border-radius: 3px;
    transition: all 0.3s ease-in-out;
}

.hamburger-menu.active span:nth-child(1) {
    transform: translateY(11px) rotate(45deg);
}

.hamburger-menu.active span:nth-child(2) {
    opacity: 0;
}

.hamburger-menu.active span:nth-child(3) {
    transform: translateY(-11px) rotate(-45deg);
}

/* Footer */
.site-footer {
    background-color: var(--dark-bg);
    color: var(--light-text-color);
    padding: 40px 0;
    font-size: 0.9em;
    position: relative;
}

.site-footer h3 {
    color: var(--secondary-color);
    margin-bottom: 20px;
    font-size: 1.3em;
}

.site-footer a {
    color: var(--light-text-color);
}

.site-footer a:hover {
    color: var(--secondary-color);
}

.site-footer .footer-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 30px;
}

.site-footer .footer-logo {
    font-size: 1.8em;
    font-weight: bold;
    color: var(--secondary-color);
    text-transform: uppercase;
    letter-spacing: 1px;
    display: block;
    margin-bottom: 15px;
}

.site-footer .company-info p {
    line-height: 1.6;
    margin-bottom: 10px;
}

.site-footer .quick-links ul,
.site-footer .footer-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.site-footer .quick-links li,
.site-footer .footer-nav li {
    margin-bottom: 10px;
}

.site-footer .newsletter input[type="email"] {
    width: calc(100% - 100px);
    padding: 10px;
    border: 1px solid var(--primary-color);
    border-radius: 5px 0 0 5px;
    background-color: #333;
    color: var(--light-text-color);
    box-sizing: border-box;
}

.site-footer .newsletter button {
    width: 90px;
    padding: 10px;
    background-color: var(--secondary-color);
    color: var(--primary-color);
    border: none;
    border-radius: 0 5px 5px 0;
    cursor: pointer;
    font-weight: bold;
    transition: background-color 0.3s ease;
}

.site-footer .newsletter button:hover {
    background-color: #e6c200;
}

.site-footer .footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

#scrollToTopBtn {
    display: none; /* Ẩn theo mặc định */
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 99;
    border: none;
    outline: none;
    background-color: var(--secondary-color);
    color: var(--primary-color);
    cursor: pointer;
    padding: 15px 20px;
    border-radius: 50%;
    font-size: 1.5em;
    line-height: 1;
    box-shadow: 0 2px 5px rgba(0,0,0,0.3);
    transition: background-color 0.3s ease;
}

#scrollToTopBtn:hover {
    background-color: #e6c200;
}

/* Responsive */
@media (max-width: 768px) {
    .site-header .main-nav {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px; /* Adjust based on header height */
        left: 0;
        width: 100%;
        background-color: var(--primary-color);
        box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
        z-index: 999;
    }

    .site-header .main-nav.active {
        display: flex;
    }

    .site-header .main-nav ul {
        flex-direction: column;
        text-align: center;
        padding: 20px 0;
    }

    .site-header .main-nav li {
        margin: 10px 0;
    }

    .site-header .main-nav a {
        display: block;
        padding: 10px 0;
        font-size: 1.2em;
    }

    .hamburger-menu {
        display: flex;
    }

    .site-footer .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .site-footer .newsletter input[type="email"] {
        width: calc(100% - 120px);
        border-radius: 5px;
        margin-bottom: 10px;
    }

    .site-footer .newsletter button {
        width: 100px;
        border-radius: 5px;
    }
    .site-footer .footer-nav ul {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
    }
    .site-footer .footer-nav li {
        margin: 0 10px 10px 10px;
    }
}